Measurement of pulmonary transit time and estimation of pulmonary blood volume after exercise using contrast echocardiography

BACKGROUND

Pulmonary transit time (PTT) and pulmonary blood volume (PBV) derived from non-invasive imaging correlate with pulmonary artery wedge pressure. The response of PBV to exercise may be useful in the evaluation of cardiopulmonary disease but whether PBV can be obtained reliably following exercise is unknown. We therefore aimed to assess the technical feasibility of measuring PTT and PBV after exercise using contrast echocardiography.

METHODS

In healthy volunteers, PTT was calculated from time-intensity curves generated as contrast traversed the cardiac chambers before and immediately after participants performed sub-maximal exercise on the Standard Bruce Protocol. From the product of PTT and heart rate (HR) during contrast passage through the pulmonary circulation, PBV relative to systemic stroke volume (rPBV) was calculated.

RESULTS

The cohort consisted of 14 individuals (age: 46 ± 8 years; 2 female) without cardiopulmonary disease. Exercise time was 8 ¾ ± 1 ¾ minutes and participants reached 85 ± 9% of age-predicted maximal HR, which corresponded to a near-doubling of resting HR at the time of post-exercise contrast injection. Data sufficient to derive PTT and rPBV were obtained for all participants. With exercise, the change in PBV from baseline ranged from 56 to 138% of systemic stroke volume, consistent with rPBV and absolute PBV values obtained in prior studies.

CONCLUSIONS

Acquisition of PTT and rPBV using contrast echocardiography after exercise is achievable and the results are physiologically plausible. As the next step towards clinical implementation, validation of this technique against hemodynamic exercise studies appears reasonable.

Determinants of exercise capacity in patients with heart failure without left ventricular hypertrophy

BACKGROUND

Determinants of exercise intolerance in a phenotype of heart failure with preserved ejection fraction (HFpEF) with normal left ventricular (LV) structure have not been fully elucidated.

METHODS

Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 44 HFpEF patients without LV hypertrophy. Exercise capacity was determined by peak oxygen consumption (peak VO₂). Doppler-derived cardiac output (CO), transmitral E velocity, systolic (LV-s') and early diastolic mitral annular velocities (e'), systolic pulmonary artery (PA) pressure (SPAP), tricuspid annular plane systolic excursion (TAPSE), and peak systolic right ventricular (RV) free wall velocity (RV-s') were measured at rest and exercise. E/e' and TAPSE/SPAP were used as an LV filling pressure parameter and RV-PA coupling, respectively.

RESULTS

During exercise, CO, LV-s', RV-s', e', and SPAP were significantly increased (p < 0.05 for all), whereas E/e' remained unchanged and TAPSE/SPAP was significantly reduced (p < 0.001). SPAP was higher and TAPSE/SPAP was lower at peak exercise in patients showing lower-half peak VO₂. In univariable analyses, LV-s' (R = 0.35, p = 0.022), SPAP (R = -0.40, p = 0.008), RV-s' (R = 0.47, p = 0.002), and TAPSE/SPAP (R = 0.42, p = 0.005) were significantly correlated with peak VO₂. In multivariable analyses, not only SPAP, but also TAPSE/SPAP independently determined peak VO₂ even after the adjustment for clinically relevant parameters.

CONCLUSIONS

In HFpEF patients without LV hypertrophy, altered RV-PA coupling by exercise could be associated with exercise intolerance, which might not be caused by elevated LV filling pressure.

Absence of cardiac damage induced by long-term intensive endurance exercise training: A cardiac magnetic resonance and exercise echocardiography analysis in masters athletes

•

Endurance long-term high level of training induces significant cardiac remodelling involving all cardiac chambers, also known as ‘athletes-heart”.

•

Both left and right ventricular longitudinal strain increases significantly at exercise.

•

Cardiac extracellular volume is normal in master athletes and there is no evidence of cardiac fibrosis induced by long term endurance training in master athletes.

•

There is no evidence of cardiac damage induced by intensive endurance training in healthy asymptomatic master athletes.

Objectives

It is under debate whether the long-term practice of intensive endurance exercise induces chronic cardiac damage such as myocardial fibrosis and ventricle contractile dysfunction. Multimodality analysis was performed to evaluate myocardial damage induced by long term intensive endurance training in master athletes.

Methods

Thirty-three asymptomatic endurance master athletes (47 ± 6 year-old, 9,6 ± 1,7 h training/week for 26 ± 6 years), were compared to 18 sedentary controls (49 ± 7 year-old). They underwent a CMR protocol including 4 chambers morphological and late gadolinium-enhancement (LGE) analysis, left (LV) and right ventricular (RV) T1 mapping and calculation of cardiac extracellular volume (ECV). A maximal exercise echocardiography with left and right ventricular longitudinal global strain (LGS) analysis was performed. Cardiac biomarkers of fibrosis (high sensitive cardiac Troponin T, N-Terminal pro brain natriuretic peptide, N-terminal propeptide of procollagen type I and N-terminal propeptide of procollagen type III) were analysed.

Results

Athletes had larger left and right atrial volume, LV and RV end diastolic volume and increased LV and RV mass compared to controls. LGE was not found in athletes. Native T1 values of LV and RV were not significantly different in athletes compared with controls. ECV was normal in both groups (21,5%± 1,6% [18.3 – 23%] in athletes, 22%± 2,2% [18.5 – 27%] in controls). LV and RV peak exercise LGS values were higher in athletes. Cardiac biomarkers levels were normal.

Conclusion

Despite significant physiological cardiac remodelling, consistent with previous descriptions of athlete's heart, there was no evidence of myocardial fibrosis or exercise left or right ventricular dysfunction or cardiac fibrosis in endurance athletes. Our results are not supporting the hypothesis of deleterious cardiac effects induced by long term and intensive endurance exercise training.

Associations between cardiorespiratory fitness, sex and long term mortality amongst adults undergoing exercise treadmill testing

BACKGROUND

Cardiorespiratory fitness (CRF) varies with sex and is an independent predictor of mortality. We sought to investigate sex differences in the exercise protocol selected, CRF levels, and their relationships with long term all-cause mortality.

METHODS

In a 25-year stress testing registry spanning from 1991 to 2014, consecutive all-comer patients who underwent exercise stress testing at Cleveland Clinic were categorized by sex, stress protocol and imaging modality. All tests were conducted by one or more of stress test technicians, sonographers and nuclear medicine technologists, and interpreted by cardiologists. The primary outcome all-cause mortality was analyzed in using multivariable Cox regression.

RESULTS

In 120,705 patients, the mean age was 53.3 ± 12.5 years, and 41% were female. Females were more commonly referred for non-Bruce exercise protocols (modified Bruce, Cornell 0, 5 and 10, Naughton and modified Naughton) with odds ratio of 2.62; 95% confidence interval (95%CI) (2.54-2.70) after adjusting for age and comorbidities. When also adjusting for the protocol chosen, females achieved lower CRF with beta -1.40, 95% CI (-1.43, -1.37). There were 8426 (6.9%) deaths during a mean follow-up of 8.7 years. Both female sex and CRF were independently associated with lower all-cause mortality with hazards ratio (95%CI) of 0.44 (0.41-0.46) and 0.41 (0.39-0.42) respectively, after adjusting for age, co-morbidities and protocol chosen.

CONCLUSIONS

Women were more likely referred for less demanding exercise protocols, more imaging protocols and achieved lower CRF than men. Despite this, female sex was associated with significantly lower long term mortality for equivalent CRF level in adjusted analyses.

Prognostic Value of Peak Exercise Systolic Pulmonary Arterial Pressure in Asymptomatic Primary Mitral Valve Regurgitation

BACKGROUND

The contribution of exercise echocardiography in primary asymptomatic mitral regurgitation (MR) remains debated. The aim of this study was to gain evidence regarding its usefulness in this setting and to investigate the prognostic value of peak exercise systolic pulmonary artery pressure (SPAP).

METHODS

One hundred seventy-seven patients (mean age, 56 ± 13 years; 69% men) with moderate to severe (grade 3+) or severe (grade 4+) degenerative MR and preserved left ventricular ejection fraction, in sinus rhythm, referred for clinically indicated exercise echocardiography were identified. The end point, MR-related events, was a composite of all-cause death or occurrence of symptoms, heart failure, atrial fibrillation, left ventricular ejection fraction < 60%, left ventricular end-systolic diameter ≥ 45 mm, or resting SPAP > 50 mm Hg.

RESULTS

At rest, effective regurgitant orifice area was 48 ± 16 mm², regurgitant volume 74 ± 26 mL, and SPAP 32 ± 7 mm Hg, and MR was severe in 138 patients (78%). Peak exercise SPAP was 55 ± 10 mm Hg. Positive results on exercise testing motivated surgery in 26 patients, 11 underwent prophylactic surgery, 10 were lost to follow-up, and 130 were included in the outcome analysis. During a follow-up period of 19 ± 7 months, 31 MR-related events (24%) were reported. Peak exercise SPAP was predictive of outcomes in univariate analysis (P = .01) and after adjustment for age, gender, MR severity, and resting SPAP (P < .05). Peak exercise SPAP ≥ 50 mm Hg was associated with worse event-free survival (hazard ratio, 5.24; 95% CI, 1.77-15.53; P = .003), but not the threshold of ≥60 mm Hg proposed in previous guidelines (hazard ratio, 1.70; 95% CI, 0.71-4.03; P = .24).

CONCLUSIONS

The present findings support the use of exercise echocardiography for risk stratification in patients with asymptomatic primary MR and suggest a lower peak exercise SPAP threshold (50 mm Hg) than previously recommended to define the timing of intervention. Prospective studies are needed to confirm these findings.

A multicentric quality-control study of exercise Doppler echocardiography of the right heart and the pulmonary circulation. The RIGHT Heart International NETwork (RIGHT-NET)

Purpose

This study was a quality-control study of resting and exercise Doppler echocardiography (EDE) variables measured by 19 echocardiography laboratories with proven experience participating in the RIGHT Heart International NETwork.

Methods

All participating investigators reported the requested variables from ten randomly selected exercise stress tests. Intraclass correlation coefficients (ICC) were calculated to evaluate the inter-observer agreement with the core laboratory. Inter-observer variability of resting and peak exercise tricuspid regurgitation velocity (TRV), right ventricular outflow tract acceleration time (RVOT Act), tricuspid annular plane systolic excursion (TAPSE), tissue Doppler tricuspid lateral annular systolic velocity (S’), right ventricular fractional area change (RV FAC), left ventricular outflow tract velocity time integral (LVOT VTI), mitral inflow pulsed wave Doppler velocity (E), diastolic mitral annular velocity by TDI (e’) and left ventricular ejection fraction (LVEF) were measured.

Results

The accuracy of 19 investigators for all variables ranged from 99.7 to 100%. ICC was > 0.90 for all observers. Inter-observer variability for resting and exercise variables was for TRV = 3.8 to 2.4%, E = 5.7 to 8.3%, e’ = 6 to 6.5%, RVOT Act = 9.7 to 12, LVOT VTI = 7.4 to 9.6%, S’ = 2.9 to 2.9% and TAPSE = 5.3 to 8%. Moderate inter-observer variability was found for resting and peak exercise RV FAC (15 to 16%). LVEF revealed lower resting and peak exercise variability of 7.6 and 9%.

Conclusions

When performed in expert centers EDE is a reproducible tool for the assessment of the right heart and the pulmonary circulation.

Value of a comprehensive exercise echocardiography assessment for patients with hypertrophic cardiomyopathy

BACKGROUND

Exercise echocardiography (ExE) may assess left ventricular (LV) systolic and diastolic function, LV outflow tract (LVOT) obstruction, and mitral regurgitation (MR). We aimed to evaluate the prognostic value of these assessments during exercise in patients with hypertrophic cardiomyopathy (HCM).

METHODS

LV systolic function, LV-derived filling pressures, LVOT gradients, and MR were prospectively evaluated during treadmill ExE in 285 patients with HCM and preserved LV ejection fraction (EF) (≥50%). Recordings were obtained at rest and peak exercise for LV systolic function and at rest and post-exercise for LVOT gradients, MR, and ratio of early LV inflow velocity to early tissue Doppler annulus velocity (E/e´).

RESULTS

Thirty-seven patients (13%) had LVOT obstruction at rest, and 76 (27%) developed exercise-induced LVOT obstruction. New wall motion abnormalities were detected in 38 patients (13%). E/e´>14 was observed in 129 patients at rest (45%) and in 134 at post-exercise (47%). Corresponding figures for significant MR (moderate or severe) were 21 (7%) and 17 (6%). During follow-up (3.9 ± 2.5 years), 27 patients had a hard event, 39 a combined event (hard plus new atrial fibrillation or syncope), and 58 a combined event or intervention. Exercise electrocardiographic testing, exercise LVEF, and the combination of positive ExE and increased E/e´ with exercise predicted outcome. The worst event rate corresponded to patients with raised E/e' values at post-exercise and positive ExE (annualized hard event-rate of 5.9%).

CONCLUSIONS

A comprehensive assessment during ExE is feasible for patients with HCM and preserved LV systolic function, and provides significant incremental prognostic information.

The Prognostic Value of Exercise Echocardiography After Percutaneous Coronary Intervention

BACKGROUND

Exercise echocardiography (EE) is a valuable noninvasive method for diagnostic and prognostic assessment of ischemic cardiac disease. The prognostic value of a negative EE test is well known overall, but its role in patients who undergo percutaneous coronary intervention remains poorly validated. The aim of this study was to ascertain the prognostic value of treadmill EE and to determine predictors of cardiac events in this population, with an emphasis on nonpositive (negative or inconclusive) test results.

METHODS

A retrospective single-center study was performed. It included 516 patients (83% man; mean age, 62 ± 9 years) previously subjected to percutaneous coronary intervention who underwent treadmill EE between 2008 and 2017. Demographic, clinical, echocardiographic, and angiographic data were collected. The occurrence of cardiac events (cardiac death, acute coronary syndrome, or coronary revascularization) during follow-up was investigated. A multivariate Cox regression analysis was used to evaluate predictors of cardiac events. The Kaplan-Meier method was used to evaluate event-free survival rates.

RESULTS

The results of EE were negative for myocardial ischemia in 245 patients (47.5%), inconclusive in 144 (27.9%), and positive in 127 (24.6%). During a mean follow-up period of 40 ± 34 months, cardiac events occurred in 152 patients (29.5%). The positive and negative predictive values of EE were 81.6% and 85.3%, respectively. The sensitivity of the exercise test was 73.9%, with specificity of 90.1%. Predictors of cardiac events were typical angina (hazard ratio [HR], 1.95; 95% CI, 1.16-3.27; P = .011), a positive ischemic response detected by electrocardiographic monitoring during EE (HR, 2.01; 95% CI, 1.21-3.34; P = .007), and the test result (inconclusive result: HR, 1.06; 95% CI, 0.51-2.19; P = .878; positive result: HR, 4.35; 95% CI, 2.42-7.80; P < .001). Patients with inconclusive (log-rank P = .038) and positive (log-rank P < .001) results had significantly more cardiac events during follow-up than those with negative EE test results. Focusing on those patients with nonpositive results, cardiac event-free survival rates at 1, 3, and 5 years were 96.6 ± 0.9%, 88.3 ± 1.9%, and 79.5 ± 2.6%, respectively. In this subpopulation, an inconclusive test result (HR, 1.67; 95% CI, 1.03-2.70; P = .039), more extensive coronary artery disease (two vessels: HR, 1.37; 95% CI, 0.75-2.30; P = .304; three vessels: HR, 2.59; 95% CI, 1.38-4.87; P = .003), and arterial hypertension (HR, 2.07; 95% CI, 1.10-3.91; P = .025) were significantly associated with the occurrence of cardiac events.

CONCLUSION

Patients with known coronary disease with negative results on EE are at low risk for hard events. Patients with inconclusive results are at higher risk for cardiac events than those with negative results. The detection of patients with low-risk results on EE should decrease the number of unnecessary repeat invasive coronary angiographic examinations.

Exercise echocardiography demonstrates potential myocardial damage in patients with repaired tetralogy of Fallot using layer-specific strain analysis

INTRODUCTION

Exercise stress echocardiography and layer-specific strains are emerging as important tools for cardiac assessment. This study was aimed to evaluate layer-specific strains and torsion parameters during exercise in order to investigate the characteristics of cardiac dysfunction in patients with repaired tetralogy of Fallot and to detect subclinical left ventricular dysfunction.

MATERIALS AND METHODS

Thirteen patients with repaired tetralogy of Fallot (median age, 17.3 [interquartile range, 14.5-22.9] years; 6 males) and 13 controls (median age, 28.5 [interquartile range, 27.6-31.6] years; 13 males) underwent echocardiography at rest and during supine exercise. Layer-specific longitudinal strain and circumferential strain of three myocardial layers (endocardium, midmyocardium, and epicardium), torsion, and untwisting rate were measured using two-dimensional speckle-tracking echocardiography.

RESULTS

Peak endocardial papillary circumferential strain (-21.1 ± 2.6% vs. -25.8 ± 3.8%, p = 0.007), midmyocardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.001), epicardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.021), and torsion (8.9 ± 6.0 vs. 14.9 ± 4.8 degree, p = 0.021) were significantly lower in the repaired tetralogy of Fallot group than in the control group during exercise, though no significant difference was found between patients and controls at rest.

CONCLUSIONS

Analysis of layer-specific strains and torsion parameters during exercise could detect subclinical left ventricular dysfunction in patients with repaired tetralogy of Fallot, which might reflect potential myocardial damage, at a stage where these parameters have normal values at rest. This finding provides new insight into the mechanisms of cardiac dysfunction in patients with repaired tetralogy of Fallot.

Subclinical impairment of dynamic left ventricular systolic and diastolic function in patients with obstructive sleep apnea and preserved left ventricular ejection fraction

Background

Hypoxia affects myocardial oxygen supply resulting in subclinical cardiac dysfunction in obstructive sleep apnea (OSA) patients, with cardiovascular complications being associated with increased oxidative burst (OB). The aims of our study were to assess left ventricular (LV) dynamic myocardial deformation and diastolic reserve at rest and upon exercise, along with OB determination in this patients subset.

Methods

Conventional echocardiography, Doppler myocardial imaging and LV 2D speckle tracking echocardiography were performed in 55 OSA patients with preserved LV ejection fraction (EF) and 35 age and sex-comparable healthy controls. Peripheral OB levels were evaluated by flow cytometry.

Results

Despite comparable LVEF, LV global longitudinal strain (GLS) was significantly reduced in OSA at rest (− 13.4 ± 3.8 vs − 18.4 ± 3.3 in controls, P <  0.001) and at peak exercise (− 15.8 ± 2.6 vs − 23.4 ± 4.3, P <  0.001). Systolic pulmonary artery pressure (sPAP) and E/E′ ratios increase during effort were higher in OSA than in controls (ΔsPAP 44.3% ± 6.4 vs 32.3% ± 5.5, P <  0.0001, and ΔE/E’ 87.5% ± 3.5 vs 25.4% ± 3.3, P <  0.0001, respectively). The best correlate of E/E′ at peak stress was peak exertion capacity (r = − 0.50, P <  0.001). OB was also increased in OSA patients (P = 0.001) but, unlike OSA severity, was not associated with LV diastolic dysfunction.

Conclusions

Evaluation of diastolic function and myocardial deformation during exercise is feasible through stress echocardiography. OSA patients with preserved LVEF show subclinical LV systolic dysfunction, impaired LV systolic and diastolic reserve, reduced exercise tolerance, and increased peripheral levels of OB. Therapy aimed at increasing LV diastolic function reserve might improve the quality of life and exercise tolerability in OSA patients.

How to diagnose heart failure with preserved ejection fraction: the HFA-PEFF diagnostic algorithm: a consensus recommendation from the Heart Failure Association (HFA) of the European Society of Cardiology (ESC)

Making a firm diagnosis of chronic heart failure with preserved ejection fraction (HFpEF) remains a challenge. We recommend a new stepwise diagnostic process, the 'HFA-PEFF diagnostic algorithm'. Step 1 (P=Pre-test assessment) is typically performed in the ambulatory setting and includes assessment for heart failure symptoms and signs, typical clinical demographics (obesity, hypertension, diabetes mellitus, elderly, atrial fibrillation), and diagnostic laboratory tests, electrocardiogram, and echocardiography. In the absence of overt non-cardiac causes of breathlessness, HFpEF can be suspected if there is a normal left ventricular (LV) ejection fraction, no significant heart valve disease or cardiac ischaemia, and at least one typical risk factor. Elevated natriuretic peptides support, but normal levels do not exclude a diagnosis of HFpEF. The second step (E: Echocardiography and Natriuretic Peptide Score) requires comprehensive echocardiography and is typically performed by a cardiologist. Measures include mitral annular early diastolic velocity (e'), LV filling pressure estimated using E/e', left atrial volume index, LV mass index, LV relative wall thickness, tricuspid regurgitation velocity, LV global longitudinal systolic strain, and serum natriuretic peptide levels. Major (2 points) and Minor (1 point) criteria were defined from these measures. A score ≥5 points implies definite HFpEF; ≤1 point makes HFpEF unlikely. An intermediate score (2-4 points) implies diagnostic uncertainty, in which case Step 3 (F₁ : Functional testing) is recommended with echocardiographic or invasive haemodynamic exercise stress tests. Step 4 (F₂ : Final aetiology) is recommended to establish a possible specific cause of HFpEF or alternative explanations. Further research is needed for a better classification of HFpEF.

Pulmonary Artery Systolic Pressure Response to Exercise in Patients with Rheumatic Mitral Stenosis: Determinants and Prognostic Value

BACKGROUND

Pulmonary hypertension in response to exercise is a marker of the hemodynamic severity of mitral stenosis (MS). However, the factors related to elevated pulmonary pressure with exercise are not well defined. The aim of this study was to assess the parameters associated with the pulmonary pressure response to exercise in patients with pure rheumatic MS. An additional aim was to determine the impact of exercise-induced pulmonary hypertension on clinical outcome.

METHODS

One hundred thirty patients with MS (94% women; mean age, 45 ± 11 years) underwent exercise echocardiography. A range of echocardiographic parameters were obtained at rest and at peak exercise. Symptom-limited graded ramp bicycle exercise was performed in the supine position. The primary end point was mitral valve intervention, either percutaneous or surgical.

RESULTS

In the overall population, systolic pulmonary artery pressure (SPAP) increased from 38.3 ± 13.4 mm Hg at rest to 65.8 ± 20.7 mm Hg during exercise. Increases in mean mitral gradient, right ventricular function, left atrial volume, and net atrioventricular compliance were independently associated with SPAP at peak exercise, after adjusting for changes in heart rate. During the follow-up period (median, 17 months; range, 1-45 months), 46 adverse clinical events were observed. By multivariate Cox proportional-hazards analysis adjusted for age and sex, SPAP achieved at peak exercise was an important predictor of adverse outcome (adjusted hazard ratio, 1.025; 95% CI, 1.010-1.040; P = .001). New York Heart Association functional class (adjusted hazard ratio, 2.459; 95% CI, 1.509-4.006; P < .001) and the interaction between valve area and net atrioventricular compliance (P = .001) were also significant predictors of adverse events. Time-dependent areas under the receiver operating characteristic curve for the model with SPAP during exercise were better than for the model with SPAP at rest, with a significant improvement from 3 years onward.

CONCLUSIONS

In patients with MS, the pulmonary artery pressure response to exercise is determined by a combination of factors, including transmitral mean gradient at exercise, net atrioventricular compliance, left atrial volume, and right ventricular function. Pulmonary artery pressure at peak exercise is a predictor of clinical outcomes and adds incremental prognostic value beyond that provided by standard resting measurements, including valve area.

Left Ventricular Pressure-Strain-Derived Myocardial Work at Rest and during Exercise in Patients with Cardiac Amyloidosis

BACKGROUND

Left ventricular pressure-strain-derived myocardial work index (LVMWI) is a novel, noninvasive method for left ventricular (LV) function evaluation in relation to LV pressure dynamics. LV global longitudinal strain (LVGLS) has proven benefit for diagnosis and risk stratification in patients with cardiac amyloidosis (CA), but LVGLS does not adjust for loading conditions. The aim of the present study was to characterize LVMWI at rest and during exercise in patients with CA.

METHODS

A total of 155 subjects were retrospectively included. These subjects comprised 100 patients with CA and 55 healthy control subjects. All patients had previously undergone comprehensive two-dimensional echocardiographic examinations at rest. Furthermore, a subgroup 27 patients with CA and 41 control subjects was examined using semisupine exercise stress echocardiography.

RESULTS

Patients with CA had significantly lower LVGLS, LVMWI, and LV myocardial work efficiency (LVMWE) than control subjects (P < .0001 for all). The reduction in LV myocardial performance was more pronounced in the basal segments, which led to significant alterations in the average apical-to-basal segmental ratios between patients with CA and control subjects (LVGLS, 2.6 [1.9 to 4.1] vs 1.3 [1.2 to 1.5]; LVMWI, 2.6 [1.7 to 3.8] vs 1.3 [1.1 to 1.5]; LVMWE, 1.1 [1.0 to 1.3] vs 1.0 [1.0 to 1.1]; P < .0001 for all). The average increase in LVMWI from rest to peak exercise was 1,974 mm Hg% (95% CI, 1,699 to 2,250 mm Hg%; P < .0001) in control subjects and 496 mm Hg% (95% CI, 156 to 835 mm Hg%; P < .01) in patients with CA. The absolute numeric LVGLS increase was 5.6% (95% CI, 3.9% to 7.3%; P < .0001) in control subjects and only 1.2% (95% CI, -0.9% to 3.3%; P = .26) in patients with CA (between groups, P < .0001) from rest to peak exercise. The LVMWI increase in patients with CA was mediated by improvement in the apical segments (P < .0001), whereas there was no significant LVMWI alterations in the midventricular or basal segments. LVMWE remained stable during exercise in control subjects (Δ -0.6%; 95% CI, -2.5% to 1.2%; P = .50) but decreased significantly in patients with CA (Δ -2.5%; 95% CI, -4.8% to -0.2%; P < .05).

CONCLUSIONS

Patients with CA have significantly reduced magnitude of LVMWI compared with healthy control subjects. With exercise, the differences are even more pronounced. Even though LVMWI increased with exercise, LVMWE decreased, suggesting inefficient myocardial energy exploitation in patients with CA.

Reduced Exercise Capacity in Diabetes Mellitus Is Not Associated with Impaired Deformation or Twist

BACKGROUND

Exercise capacity is frequently reduced in people with diabetes mellitus (DM) and may be due to subclinical cardiac dysfunction. Speckle-tracking echocardiography is now widely available; however, the clinical utility and significance of left ventricular (LV) strain and twist parameters remain uncertain. We hypothesized that LV strain and twist would be reduced in DM subjects during exercise.

METHODS

Adults with type 1 or type 2 DM and age- and sex-matched controls performed cardiopulmonary exercise testing (VO₂ peak) and supine bicycle exercise echocardiography. Detailed echocardiographic assessment of biventricular function was performed at baseline and repeated during incremental exercise to maximal intensity.

RESULTS

Of the 60 participants completing the study protocol, 51 (34 DM, 17 controls; mean age, 42 ± 13 years; 69% male; DM duration, 16 ± 10 years) had sufficient image quality to assess LV deformation and twist mechanics at rest. Of these, 38 (25 DM, 13 controls) were able to be assessed immediately after exercise. Baseline LV systolic and diastolic function using standard echocardiography measurements were similar between groups. Resting LV global longitudinal strain, twist, twist rate and untwist rate, and the corresponding peak exercise and reserve measures did not differ significantly. As compared with the control subjects, exercise capacity was reduced in the DM cohort (VO₂ peak 33 ± 10 vs 41 ± 12 mL/minute/kg; P = .02); however, no correlation was observed between VO₂ peak and LV twist reserve (R = 0.28, P = .09), LV twist rate reserve (R = 0.14, P = .39), or LV untwist rate reserve (R = 0.24, P = .14).

CONCLUSIONS

Despite reduced VO₂ peak, LV twist mechanics at rest and after maximal intensity exercise did not differ significantly in a cohort of asymptomatic DM subjects with normal resting LV systolic and diastolic function compared with age- and sex-matched controls. This would suggest that exercise capacity can be reduced in the absence of subclinical cardiac dysfunction and that noncardiac factors should be considered as alternative explanations.

Should the septum be included in the assessment of right ventricular longitudinal strain? An ultrasound two-dimensional speckle-tracking stress study

Right ventricular longitudinal strain (RVLS) by 2D speckle-tracking echocardiography (2D-STE) is a useful parameter for assessing systolic function. However, the exact method to perform it is not well defined as some authors evaluate only free wall (FW) segments while others include all six RV segments. To compare the assessment of RVLS at rest and during exercise by these two approaches. Echocardiography was performed on 80 healthy subjects at rest and during exercise. The analysis consisted of standard and 2D-STE assessment of RV global and segmental strain tracing only RVFW and also tracing all six RV segments. At rest, RVLS could be assessed in 78 (feasibility 97.5%) subjects by both methods. However, during exercise, RVLS by RVFW method was feasible in 67 (83.8%) as compared to 74 (92.5%) by RV6S approach. Both at rest and during exercise, RVLS values by the two methods showed excellent correlation (r =  > 0.90). However, RVLS values assessed by RV6S were lower (absolute values) than those by RVFW approach (RV6S vs. RVFW; rest: - 27.0 ± 3.9 vs. - 9.5 ± 3.9, p < 0.001 and exercise: - 30.7 ± 5.2 vs. - 33.3 ± 5.1, p < 0.001). Furthermore, basal strain was higher and apical strain lower (absolute values) by RV6S approach. At rest, reproducibility for RVLS was excellent and similar for the two methods. However, during exercise, reproducibility for RVFW method was poorer, especially at the apex. The two currently described methods for RVLS assessment by 2D-STE demonstrated excellent agreement. However, the RV6S approach seemed to be more feasible and reproducible, particularly during exercise. Moreover, global and segmental strain values are different with both methods and should not be interchanged.

The Association Between Longitudinal Strain at Rest and Stress and Outcome in Asymptomatic Patients With Moderate and Severe Aortic Stenosis

BACKGROUND

Calcific aortic stenosis (AS) is a progressive disease, and once moderate AS is present, the likelihood of symptom onset within 5 years is significant. The aim of this study was to determine the incremental value of global longitudinal strain (GLS) and basal longitudinal strain (BLS) at rest and during exercise on outcomes among asymptomatic patients' with moderate and severe AS.

METHODS

Seventy-five patients with isolated, asymptomatic AS and preserved left ventricular function were retrospectively enrolled and underwent symptom-limited exercise echocardiography. Clinical and echocardiographic data, including GLS and BLS at rest and during exercise, were assessed. Occurrence of AS-related cardiovascular events was recorded.

RESULTS

The mean age was 71 ± 10 years, and 63% were men. The mean aortic valve gradient was 30 ± 11 mm Hg, and the mean aortic valve area was 0.98 ± 0.21 cm². Resting GLS and BLS were -16.5 ± 4% and -16.9 ± 3.6%, respectively. Exercise stress test results were positive in 27 patients (36%). Mean exercise GLS was -17.8 ± 3.5%, and mean exercise BLS was -17.9 ± 4%. During mean follow-up of 34.5 ± 3.5 months, cardiovascular events were observed in 45 patients. In multivariate analysis, aortic valve mean gradient (HR, 1.073; 95% CI, 1.032-1.115; P < .001) and peak exercise BLS (HR, 1.177; 95% CI, 1.07-1.295; P = .001) were associated with cardiac events during follow-up.

CONCLUSIONS

Reduced exercise BLS is associated with future cardiovascular events in patients' with asymptomatic AS, independently of clinical factors and conventional echocardiographic parameters. Detection of postexercise myocardial dysfunction in patients with asymptomatic AS with preserved left ventricular function can aid in risk assessment of these patients.

Decreased biventricular mechanics and functional reserve in nonobstructive hypertrophic cardiomyopathy patients: implications for exercise capacity

The present study investigated the changes of biventricular mechanics at rest and during exercise and examined the association between exercise capacity and biventricular mechanics and functional reserve in nonobstructive hypertrophic cardiomyopathy (NHCM) patients. A total of 50 NHCM patients and 25 controls were consecutively recruited for this study. Using echocardiography and two-dimensional speckle-tracking imaging, an experienced echocardiographer determined the following indices: RV free wall longitudinal strain (RVFWLS), LV global longitudinal strain (LVGLS), strain rate (SR), and functional reserve of strain values. We also investigated the relationships between biventricular mechanics and exercise capacity using metabolic equivalents (METs). NHCM patients had lower RVFWLS, LVGLS, systolic SR, early diastolic SR, and systolic and diastolic reserve during exercise compared to controls. An association of biventricular mechanics (LVGLS, RVFWLS) with exercise capacity at rest and during exercise was established. Multivariable logistic regression revealed that RVFWLS and LVE/e' during exercise (RVFWLS-exe, E/e'-exe) were independent predictors of exercise intolerance. Receiver operating characteristic curve analysis indicated that LVE/e'-exe had a higher area under the curve for predicting exercise intolerance in NHCM patients. In hierarchical analysis, RVFWLS-exe provided an incremental predictive value of exercise intolerance over LVGLS during exercise (LVGLS-exe) and LVE/e'-exe. LVE/e'-exe also changed incrementally compared to LVGLS-exe and RVFWLS-exe. NHCM patients have decreased biventricular mechanics at rest and during exercise and impaired biventricular functional reserve, and biventricular mechanics are associated with functional capacity. We propose that simultaneous evaluation of biventricular function should provide incremental predictive value for exercise intolerance.

Diastolic stress test echocardiography in patients with suspected heart failure with preserved ejection fraction: a pilot study

AIMS

The purpose of this pilot study was to assess the potential usefulness of diastolic stress test (DST) echocardiography in patients with suspected heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

Patients with suspected HFpEF (left ventricular ejection fraction ≥ 50%, exertional dyspnoea, septal E/e' at rest 9-14, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at rest < 220 pg/mL; n = 13) and a control group constituted from asymptomatic patients with arterial hypertension (n = 19) and healthy subjects (n = 18) were included. All patients were analysed by two-dimensional and Doppler echocardiography at rest and during exercise (DST) and underwent cardiopulmonary exercise testing and NT-proBNP analysis during exercise. HFpEF during exercise was defined as exertional dyspnoea and peak VO₂  ≤ 20.0 mL/min/kg. In patients with suspected HFpEF at rest, 84.6% of these patients developed HFpEF during exercise, whereas in the group of asymptomatic patients with hypertension and healthy subjects, the rate of developed HFpEF during exercise was 0%. Regarding the diagnostic performance of DST to detect HFpEF during exercise, an E/e' ratio >15 during exercise was the most accurate parameter to detect HFpEF (accuracy 86%), albeit a low sensitivity (45.5%). Nonetheless, combining E/e' with tricuspid regurgitation (TR) velocity > 2.8 m/s during exercise provided a significant increase in the sensitivity to detect patients with HFpEF during exercise (sensitivity 72.7%, specificity 79.5%, and accuracy 78%). Consistent with these findings, an increase of E/e' was significantly linked to worse peak VO₂ , and the combination of an increase of both E/e' and TR velocity was associated with elevated NT-proBNP values during exercise.

CONCLUSIONS

The findings of this pilot study suggest that DST using E/e' ratio and TR velocity could be of potential usefulness to diagnose HFpEF during exercise in patients with suspected HFpEF at rest.

Late right ventricular performance after mitral valve repair assessed by exercise echocardiography

Objectives

The aim of the study was to evaluate the right ventricular (RV) performance during exercise in patients who underwent mitral valve repair for chronic mitral valve insufficiency relative to healthy individuals and to assess exercise capacity using a semisupine ergometer.

Methods

We studied 56 patients who underwent mitral valve repair for degenerative posterior mitral leaflet prolapse between 2005 and 2014 and a control group of 13 healthy individuals. Clinical data were collected prospectively, and echocardiographic measurements of RV function were obtained at rest and at peak exercise.

Results

One-third of the study patients had RV systolic dysfunction as indicated by tricuspid annular plane excursion (TAPSE) at rest. Resting TAPSE was lower in the study group (16.7 ± 3.3 mm) than in the control group (24.4 ± 4.3 mm), p < 0.001. TAPSE increased in both groups during exercise and exercise was shown to have a significant main effect on TAPSE F(1, 52) = 80, p < 0.001. TAPSE increased more in the control group and an interaction was detected between the participant groups (study group vs. control group) and exercise, F(1, 52) = 24, p < 0.001. In the study group, Poor postoperative RV function was associated with preoperative left ventricular dilatation but was not correlated with impaired maximum exercise capacity.

Conclusions

Despite the excellent clinical outcome during rest and exercise after mitral valve repair, our results suggest patients that have undergone mitral valve repair due to posterior leaflet prolapse have significantly reduced RV function at rest and during exercise compared to healthy controls at long-term follow-up, as measured by TAPSE.

Exercise capacity in diabetes mellitus is predicted by activity status and cardiac size rather than cardiac function: a case control study

Background

The reasons for reduced exercise capacity in diabetes mellitus (DM) remains incompletely understood, although diastolic dysfunction and diabetic cardiomyopathy are often favored explanations. However, there is a paucity of literature detailing cardiac function and reserve during incremental exercise to evaluate its significance and contribution. We sought to determine associations between comprehensive measures of cardiac function during exercise and maximal oxygen consumption (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}O_{2}$$\end{document}V˙O2peak), with the hypothesis that the reduction in exercise capacity and cardiac function would be associated with co-morbidities and sedentary behavior rather than diabetes itself.

Methods

This case–control study involved 60 subjects [20 with type 1 DM (T1DM), 20 T2DM, and 10 healthy controls age/sex-matched to each diabetes subtype] performing cardiopulmonary exercise testing and bicycle ergometer echocardiography studies. Measures of biventricular function were assessed during incremental exercise to maximal intensity.

Results

T2DM subjects were middle-aged (52 ± 11 years) with a mean T2DM diagnosis of 12 ± 7 years and modest glycemic control (HbA_1c 57 ± 12 mmol/mol). T1DM participants were younger (35 ± 8 years), with a 19 ± 10 year history of T1DM and suboptimal glycemic control (HbA_1c 65 ± 16 mmol/mol). Participants with T2DM were heavier than their controls (body mass index 29.3 ± 3.4 kg/m² vs. 24.7 ± 2.9, P = 0.001), performed less exercise (10 ± 12 vs. 28 ± 30 MET hours/week, P = 0.031) and had lower exercise capacity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}O_{2}$$\end{document}V˙O2peak = 26 ± 6 vs. 38 ± 8 ml/min/kg, P < 0.0001). These differences were not associated with biventricular systolic or left ventricular (LV) diastolic dysfunction at rest or during exercise. There was no difference in weight, exercise participation or \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}O_{2}$$\end{document}V˙O2peak in T1DM subjects as compared to their controls. After accounting for age, sex and body surface area in a multivariate analysis, significant positive predictors of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}O_{2}$$\end{document}V˙O2peak were cardiac size (LV end-diastolic volume, LVEDV) and estimated MET-hours, while T2DM was a negative predictor. These combined factors accounted for 80% of the variance in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}O_{2}$$\end{document}V˙O2peak (P < 0.0001).

Conclusions

Exercise capacity is reduced in T2DM subjects relative to matched controls, whereas exercise capacity is preserved in T1DM. There was no evidence of sub-clinical cardiac dysfunction but, rather, there was an association between impaired exercise capacity, small LV volumes and sedentary behavior.

Rest and Stress Longitudinal Systolic Left Ventricular Mechanics in Hypertrophic Cardiomyopathy: Implications for Prognostication

BACKGROUND

Exercise intolerance is the most common symptom in hypertrophic cardiomyopathy (HCM). We examined whether inability to augment myocardial mechanics during exercise would influence functional performance and clinical outcomes in HCM.

METHODS

Ninety-five HCM patients (32 nonobstructive, 32 labile-obstructive, 31 obstructive) and 26 controls of similar age and gender distribution were recruited prospectively. They underwent rest and treadmill stress strain echocardiography, and 61 of them underwent magnetic resonance imaging. Mechanical reserve (MRES) was defined as percent change in systolic strain rate (SR) immediately postexercise.

RESULTS

Global strain and SR were significantly lower in HCM patients at rest (strain: nonobstructive, -15.6 ± 3.0; labile-obstructive, -15.9 ± 3.0; obstructive, -13.8 ± 2.9; control, -17.7% ± 2.1%, P < .001; SR: nonobstructive, -0.92 ± 0.20; labile-obstructive, -0.94 ± 0.17; obstructive, -0.85 ± 0.18; control, -1.04 ± 0.14 s^-1, P = .002); and immediately postexercise (strain: nonobstructive, -15.6 ± 3.0; labile-obstructive, -17.6 ± 3.6; obstructive, -15.6 ± 3.6; control, -19.2 ± 3.1%; P = .001; SR: nonobstructive, -1.41 ± 0.37; labile-obstructive, -1.64 ± 0.38; obstructive, -1.32 ± 0.29; control, -1.82 ± 0.29 s^-1, P < .001). MRES was lower in nonobstructive and obstructive compared with labile-obstructive and controls (51% ± 29%, 54% ± 31%, 78% ± 38%, 77% ± 30%, P = .001, respectively). Postexercise SR and MRES were associated with exercise capacity (r = 0.47 and 0.42, P < .001 both, respectively). When adjusted for age, gender, body mass index, E/e', and resting peak instantaneous systolic gradient, postexercise SR best predicted exercise capacity (r = 0.74, P = .003). Postexercise SR was correlated with extent of late gadolinium enhancement (r = 0.34, P = .03). By Cox regression, exercise SR and MRES predicted ventricular tachycardia/ventricular fibrillation (VT/VF) even after adjustment for age, gender, family history of sudden cardiac death, septum ≥ 3 cm and abnormal blood pressure response (P = .04 and P = .046, respectively).

CONCLUSIONS

Nonobstructive and obstructive patients have reduced MRES compared with labile-obstructive and controls. Postexercise SR correlates with LGE and exercise capacity. Exercise SR and MRES predict VT/VF.

Influence of Cardiovascular Risk in the Prediction and Timing of Cardiac Events After Exercise Echocardiogram Testing Without Ischemia

INTRODUCTION AND OBJECTIVES

There have been no analyses of the influence of cardiovascular risk as a predictor of events in patients with exercise echocardiography (EE) without ischemia. Our objective was to determine the predictors of cardiac events, paying special attention to cardiovascular risk.

METHODS

This study included 1640 patients with EE without ischemia. Of these, there were 1206 with no previously known coronary artery disease (CAD), whose risk of a fatal cardiovascular disease event was estimated according to the European SCORE (Systematic COronary Risk Evaluation) risk assessment system, and 434 with known CAD. The primary endpoint was cardiac event-free survival (EFS) (cardiac death, nonfatal acute coronary syndrome, and coronary revascularization).

RESULTS

After a median follow-up of 35 [23-54] months, no differences were found in cardiac EFS between patients with a SCORE ≥ 10 or diabetes and patients with previous CAD (89.8% vs 87.1%). In the first year, cardiac EFS was high in all groups (99.4% if SCORE < 5; 100% if 5-9; 98% if ≥ 10 or diabetes and 97% in patients with CAD). In the third year, cardiac EFS was similar in the group with SCORE ≥ 10 or diabetes (94.5%) and patients with CAD (91.1%, P = NS). In these patients, the annualized event rate was 2.8% and 2.55%, respectively, and was significantly higher than in groups with SCORE < 5 (0.6%) and SCORE 5-9 (0.12%). The most frequent events were non-ST-segment elevation acute coronary syndrome and late revascularization. Predictors of cardiac events were previous CAD, SCORE ≥ 10 or diabetes mellitus, creatinine clearance, left ventricular ejection fraction, and chest pain during EE.

CONCLUSIONS

Initial outcome after an EE without ischemia is favorable but is subsequently modulated by cardiovascular risk.

Left ventricular torsion and circumferential strain responses to exercise in patients with ischemic coronary artery disease

LV torsion during exercise in patients with coronary artery disease (CAD) is not well known. Circumferential strain (CS) and left ventricular (LV) torsion (Tor) have not been evaluated during ischemia in these patients. We aimed to assess the effect of ischemia during exercise echocardiography (ExE) on CS and Tor. We studied a group of 73 patients with true positive ExE results (Ischemic group: ischemia plus an abnormal coronary angiogram) and a matched control group of 66 patients with negative ExE and either normal coronary angiography or low post-test probability of CAD. Basal rotation (Rot) and apical rotation and basal and apical CS were studied by speckle tracking at rest and exercise. Apical CS and apical and basal Rot values were similar between groups at rest, except basal CS which was already worse in the ischemic group. At exercise, all rotational and CS parameters were impaired in the ischemic in comparison with the control group (basal CS: -18 ± 5 vs. -25 ± 7 %, p < 0.001; apical CS: -31 ± 11 vs. - 43 ± 9 %, p < 0.001; time to basal CS: 52 ± 6 vs. 48 ± 7 %, p = 0.001; time to apical CS: 55 ± 7 vs. 49 ± 6 %, p < 0.001; basal rotation: -0.7 ± 6.5° vs. -6.2 ± 8.5°, p < 0.001; LV twist 13.0 ± 10.4° vs.19.7 ± 11.5°, p < 0.001; LV-Tor 1.9 ± 1.6°/cm vs. 2.8 ± 1.7˚/cm, p = 0.001) with the exception of apical rotation which was similar (12.3 ± 7.4° vs. 13.4 ± 7.7°, p = NS). Basal and apical CS and basal rotation impair during exercise-induced ischemia. LV-Tor decreases with ischemia due to worsening of basal rotation, whereas apical rotation does not impair, suggesting the existence of an apical compensatory mechanism.

Outcome by Exercise Echocardiography in Patients with Low Pretest Probability of Coronary Artery Disease

BACKGROUND

Recommendations for testing in patients with low pretest probability of coronary artery disease differ in guidelines from no testing at all to different tests. The aim of this study was to assess the value of exercise echocardiography (ExE) to define outcome in this population.

METHODS

A retrospective analysis was conducted of 1,436 patients with low pretest probability of coronary artery disease (<15%) who underwent initial ExE. Overall mortality, major adverse cardiac events (MACEs), defined as cardiac death or nonfatal myocardial infarction, and revascularization during follow-up, were assessed. Ischemia (development of new wall motion abnormalities with exercise) and fixed wall motion abnormalities were measured.

RESULTS

The mean age was 50 ± 12 years. Resting wall motion abnormalities were seen in 13 patients (0.9%) and ischemia in 108 (7.5%). During follow-up, 38 patients died, 10 of cardiac death (annualized death rate, 0.39%); 20 patients had MACEs (annualized MACE rate, 0.21%); and 48 patients (29 with ischemia) underwent revascularization (annualized revascularization rate, 0.51%). The number and percentage of MACEs in the abnormal and normal ExE groups were similar (two [1.7%] vs 18 [1.4%], P = .70), as was the annualized MACE rate (0.31% vs 0.21%, P = .50). Peak left ventricular ejection fraction exhibited a nonsignificant trend for predicting MACEs (P = .11). The number of studies needed to detect an abnormal finding was 12.6 and to detect a patient with extensive ischemia was 26.1.

CONCLUSIONS

ExE offers limited prognostic information in patients with low pretest probability of coronary artery disease. The small number of abnormal findings on ExE and low event rates and the large number of studies needed to detect an abnormal finding limit further the value of imaging in this population.

Assessment of Speckle-Tracking Echocardiography-Derived Global Deformation Parameters During Supine Exercise in Children

Exercise echocardiography is an underutilized tool in pediatrics with current applications including detecting segmental wall abnormalities, assessing the utility of global ventricular function, and measuring pulmonary hemodynamics. No prior study has applied speckle-tracking echocardiography (STE) during exercise echocardiography in children. The aim of this study was to determine the feasibility of measuring speckle-tracking-derived peak systolic velocities, global longitudinal and circumferential strain, and global strain rates at various phases of exercise. Ninety-seven healthy children underwent cardiopulmonary exercise testing using supine cycle ergometry. The exercise stress test consisted of baseline pulmonary function testing, monitoring of blood pressure and heart rate responses, electrocardiographic recordings, and oxygen saturations while subjects pedaled against a ramp protocol based on body weight. Echocardiographic measurements and specifically speckle-tracking analysis were performed during exercise at baseline, at a heart rate of 160 beats per minute and at 10 min after exercise. Peak systolic velocity, peak systolic strain, and peak systolic strain rate at these three phases were compared in the subjects in which all measurements were accurately obtained. We were able to complete peak velocity, strain, and strain rate measurements in all three exercise phases for 36 out of the 97 subjects tested. There was no significant difference between the feasibility of measuring circumferential versus longitudinal strain (p = 0.25, B-corrected = 0.75). In the 36 subjects studied, the magnitude of circumferential strain values decreased from -18.3 ± 4.8 to -13.7 ± 4.0 % from baseline to HR 160 (p < 0.0001, B-corrected < 0.0001), before returning to -19.6 ± 4.4 % at recovery (p = 0.19 when compared to baseline). Longitudinal strain did not vary significantly from baseline to HR 160 (from -17.7 ± 4.4 to -16.6 ± 4.4 %, p = 0.16); likewise the average recovery strain was no different from those values (-18.4 ± 3.6 %; p = 0.34). Peak circumferential and longitudinal strain rates increased from baseline to HR 160, but neither decreased to baseline levels after 10 min of recovery, which correlated with heart rate variations with exercise. We studied the effects of frame rate on deformation measurements and we observed no difference between measurements taken at lower (<60 frames per second, fps) and higher (≥60 fps) frame rates. This study shows that it is technically difficult to retrospectively measure peak velocities, strain, and strain rate in exercising pediatric subjects with STE. The majority of subjects that were excluded from the study had inadequate echocardiographic images when tachycardic from increased respiratory effort and body movements near peak exercise. Improvements in technique and higher image frame rates could make application of STE to pediatric cardiopulmonary testing more successful in the future.

Noninvasive Stress Testing for Coronary Artery Disease

Stress testing remains the cornerstone for noninvasive assessment of patients with possible or known coronary artery disease (CAD). The most important application of stress testing is risk stratification. Most patients who present for evaluation of stable CAD are categorized as low risk by stress testing. These low-risk patients have favorable clinical outcomes and generally do not require coronary angiography. Standard exercise treadmill testing is the initial procedure of choice in patients with a normal or near-normal resting electrocardiogram who are capable of adequate exercise. Stress imaging is recommended for patients with prior revascularization, uninterpretable electrocardiograms, or inability to adequately exercise.

Prediction of new onset of resting pulmonary arterial hypertension in systemic sclerosis

BACKGROUND

Early detection of pulmonary arterial hypertension (PH) is crucial in systemic scleroderma. However, predictors of new onset of resting PH during follow-up (FUPH) have been poorly explored.

AIM

To determine whether nailfold videocapillaroscopy (NVC) grade and exercise echocardiographic variables are predictors of FUPH.

METHODS

We prospectively enrolled 40 patients with systemic sclerosis (age 54±13 years; 68% women). All patients underwent graded semisupine exercise echocardiography and NVC. Baseline resting PH and FUPH were defined as systolic pulmonary arterial pressure (sPAP)>35 mmHg, and exercise-induced PH (EIPH) as exercise sPAP>50 mmHg.

RESULTS

Seventeen patients developed EIPH (43%). During follow-up (FU) (25±15 months), 11 patients without baseline PH developed FUPH (28%), all from the EIPH group. Patients with FUPH were significantly older (60±14 vs 50±12 years; P=0.04), had higher resting and exercise sPAP (30±4 vs 22±5 and 60±12 vs 40±11 mmHg, respectively; P<0.0001) and a higher exercise E/e' ratio (9.4±0.7 vs 5.8±0.4; P=0.0003) and presented more frequently NVC grade>2 (90% vs 35%; P=0.0009). After adjustment for age, resting sPAP, exercise sPAP and NVC grade>2 were associated with maximal resting sPAP during follow-up and FUPH (P<0.05). Patients with both EIPH and NVC grade>2 had a very high incidence of FUPH (82%), and both variables remained strongly associated with FUPH after adjustment for age (hazard ratio 11.6, 95% confidence interval 2.4-55.3; P=0.002).

CONCLUSION

Exercise echocardiography and NVC can identify a subgroup of patients with systemic sclerosis who are at risk of developing FUPH.

Exercise echocardiography for structural heart disease

Since the introduction of transcatheter structural heart intervention, the term "structural heart disease" has been widely used in the field of cardiology. Structural heart disease refers to congenital heart disease, valvular heart disease, and cardiomyopathy. In structural heart disease, valvular heart disease is frequently identified in the elderly. Of note, the number of patients who suffer from aortic stenosis (AS) and mitral regurgitation (MR) is increasing in developed countries because of the aging of the populations. Transcatheter aortic valve replacement and percutaneous mitral valve repair has been widely used for AS and MR, individually. Echocardiography is the gold standard modality for initial diagnosis and subsequent evaluation of AS and MR, although the difficulties in assessing patients with these diseases still remain. Here, we review the clinical usefulness and prognostic impact of exercise echocardiography on structural heart disease, particularly on AS and MR.

Exercise left ventricular ejection fraction predicts events in right bundle branch block

OBJECTIVE

Interpretation of the electrocardiogram (ECG) during exercise is not easy in patients with right bundle branch block (RBBB). Also, the value of exercise echocardiography (ExE) for predicting outcome in them has not been addressed. We sought to assess its prognostic value in patients with RBBB and known/suspected coronary disease.

DESIGN

Retrospective analysis of data on 703 patients with RBBB who were submitted to a clinically-indicated ExE. The end points were overall mortality and combined myocardial infarction and cardiovascular mortality.

RESULTS

During follow-up (4.1 ± 4.5 years) there were 130 deaths and 108 combined events. Independent predictors of combined events were history of coronary artery disease (hazard ratio [HR] = 2.37, 95% Confidence Interval [CI] = 1.24-4.52, p = 0.009) resting wall motion score index (HR = 2.14, 95% CI = 1.12-4.10, p = 0.02), metabolic equivalents (HR = 0.89, 95% CI = 0.93-0.97, p = 0.007), Δ in double product with exercise (HR = 0.96, 95% CI = 0.92-1.00, p = 0.036) and Δ in left ventricular ejection fraction (LVEF) with exercise (HR = 0.97, 95% CI = 0.94-0.99, p = 0.01). Neither positive clinical nor ECG exercise testing was predictive. Combined event rates were 3.3% in patients with ΔLVEF > 5%, 4.7% in those with ΔLVEF between 1-5% and 8.2% in those with no increase (Δ < 1%).

CONCLUSIONS

A decrease in LVEF during exercise is predictive of serious events in patients with RBBB.

Incremental value of exercise echocardiography over exercise electrocardiography in a chest pain unit

BACKGROUND

Limited data are available on the added value of exercise echocardiography (ExEcho) over exercise electrocardiography (ExECG) in patients with suspected acute coronary syndromes (ACS) referred to a chest pain unit. We aimed to assess the incremental value of ExEcho over ExECG in this setting.

METHODS

ExECG and ExEcho were performed in parallel in 1052 patients with suspected ACS, nondiagnostic but interpretable electrocardiograms, and negative serial troponin results. The primary outcome was a composite of coronary death, nonfatal myocardial infarction or unstable angina with angiographic documentation of significant coronary artery disease within 6 months.

RESULTS

The primary outcome occurred in 2/614 patients (0.3%) with both negative ExECG and ExEcho, 3/60 (5%) with positive ExECG and negative ExEcho, 73/135 (54.1%) with negative ExECG and positive ExEcho, 106/136 (77.9%) with both positive ExECG and ExEcho, and 8/107 (7.5%) with inconclusive results. The addition of ExEcho data to a model based on clinical and ExECG data significantly increased the c statistic from 0.898 to 0.968 (change +0.070, 95% confidence interval 0.052-0.092), with a continuous net reclassification improvement of 1.56 and an integrated discrimination improvement of 22% (p<0.001). Decision curve analysis showed that a strategy of referral to coronary angiography based on ExEcho was associated with the highest net benefit and with the largest reduction in unnecessary coronary angiographies.

CONCLUSION

ExEcho provides significant incremental prognostic information and higher net clinical benefit than a strategy based on ExECG in patients referred to a chest pain unit for suspected ACS and negative troponin levels.

Noninvasive stress testing for coronary artery disease

Stress testing remains the cornerstone for noninvasive assessment of patients with possible or known coronary artery disease (CAD). The most important application of stress testing is risk stratification. Most patients who present for evaluation of stable CAD are categorized as low risk by stress testing. These low-risk patients have favorable clinical outcomes and generally do not require coronary angiography. Standard exercise treadmill testing is the initial procedure of choice in patients with a normal or near-normal resting electrocardiogram who are capable of adequate exercise. Stress imaging is recommended for patients with prior revascularization, uninterpretable electrocardiograms, or inability to adequately exercise.

Prognostic value of exercise-induced left ventricular systolic dysfunction in hypertensive patients without coronary artery disease

INTRODUCTION AND OBJECTIVES

We sought to assess the prognostic value of exercise-induced left ventricular systolic dysfunction in hypertensive patients with normal resting echocardiography and absence of coronary artery disease.

METHODS

From our database of patients referred for treadmill exercise echocardiography, we identified 93 hypertensive patients with preserved resting left ventricular ejection fraction (≥ 50%), no evidence of structural heart disease, and absence of coronary artery disease on angiography. Overall, 39 patients developed exercise-induced left ventricular systolic dysfunction (defined as a decrease in left ventricular ejection fraction below 50% at peak exercise) and 54 exhibited a normal left ventricular ejection fraction response to exercise. The mean follow-up was 6.1 (3.7) years. End points were all-cause mortality, cardiac death, heart failure, and the composite event of cardiac death or heart failure.

RESULTS

Patients who developed exercise-induced left ventricular systolic dysfunction were at higher risk of death from any cause (hazard ratio=3.4; 95% confidence interval, 1.1-10.3), cardiac death (hazard ratio=5.6; 95%CI, 1.1-29.4), heart failure (hazard ratio=8.9; 95% confidence interval, 1.8-44.2), and the composite end point (hazard ratio=5.7; 95% confidence interval, 1.7-19.0). In the multivariate analysis, exercise-induced left ventricular systolic dysfunction remained an independent predictor of both heart failure (hazard ratio=6.9; 95% CI, 1.3-37.4) and the composite event of cardiac death or heart failure (hazard ratio=4.5; 95% confidence interval, 1.2-16.0).

CONCLUSIONS

In hypertensive patients with preserved resting left ventricular ejection fraction and absence of coronary artery disease, exercise-induced left ventricular systolic dysfunction is a strong predictor of cardiac events and may represent early hypertensive heart disease.

Abnormal left ventricular contractile response to exercise in the absence of obstructive coronary artery disease is associated with resting left ventricular long-axis dysfunction

BACKGROUND

The etiology of reduced left ventricular (LV) ejection fraction after exercise, without obstructive coronary artery disease or other established causes, is unclear. The aims of this study were to determine whether patients undergoing treadmill stress echocardiography with this abnormal LV contractile response to exercise (LVCRE) without established causes have resting LV long-axis dysfunction or microvascular dysfunction and to determine associations with this abnormal LVCRE.

METHODS

Of 5,275 consecutive patients undergoing treadmill stress echocardiography, 1,134 underwent cardiac computed tomography angiography or invasive angiography. Having excluded patients with obstructive coronary artery disease, hypertensive response, submaximal heart rate response, resting LV ejection fraction < 50%, and valvular disease, 110 with "abnormal LVCRE" and 212 with "normal LVCRE" were analyzed. Resting mitral annular velocities were measured to assess LV long-axis function. Myocardial blush grade and corrected Thrombolysis In Myocardial Infarction frame count were determined angiographically to assess microvascular function.

RESULTS

Comparing normal LVCRE with abnormal LVCRE, age (mean, 59.7 ± 11.1 vs 61.4 ± 10.0 years), hypertension (53% vs 55%), diabetes (16% vs 20%), and body mass index (mean, 29.1 ± 5.4 vs 29.5 ± 6.4 kg/m(2)) were similar (P > .05). Abnormal LVCRE had reduced resting LV long-axis function with lower septal (mean, 6.1 ± 1.9 vs 7.7 ± 2.2 cm/sec) and lateral (mean, 8.1 ± 2.9 vs 10.4 ± 3.0 cm/sec) e' velocities (P < .001) and larger resting left atrial volumes (mean, 37.3 ± 10.1 vs 31.1 ± 7.2 mL/m(2), P < .001). On multivariate analysis, female gender (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.15-1.99; P < .001), exaggerated chronotropic response (OR, 1.49; 95% CI, 1.09-2.05; P < .001), resting left atrial volume (OR, 2.38; 95% CI, 1.63-3.47; P < .001), and resting lateral e' velocity (OR, 1.70; 95% CI, 1.22-2.49; P = .003) were associated with abnormal LVCRE, but not myocardial blush grade or corrected Thrombolysis In Myocardial Infarction frame count.

CONCLUSIONS

An abnormal LVCRE in the absence of established causes is associated with resting LV long-axis dysfunction and is usually seen in women.

Exercise echocardiography and multidetector computed tomography for the evaluation of acute chest pain

INTRODUCTION AND OBJECTIVES

Up to 4% of patients with acute chest pain, normal electrocardiogram, and negative troponins present major adverse cardiac events as a result of undiagnosed acute coronary syndrome. Our aim was to compare the diagnostic performance of multidetector computed tomography and exercise echocardiography in patients with a low-to-intermediate probability of coronary artery disease.

METHODS

We prospectively included 69 patients with acute chest pain, normal electrocardiogram, and negative troponins who underwent coronary tomography angiography and exercise echocardiography. Patients with coronary stenosis ≥ 50% or Agatston calcium score ≥ 400 on coronary tomography angiography or positive exercise echocardiography, or with inconclusive results, were admitted to rule out acute coronary syndrome.

RESULTS

An acute coronary syndrome was confirmed in 17 patients (24.6%). This was lower than the suspected 42% based on coronary tomography angiography (P<.05) and not significantly different than the suspected 29% based on the results of exercise echocardiography (P=.56). Exercise echocardiography was normal in up to 37% of patients with pathological findings on coronary tomography angiography. The latter technique provided a higher sensitivity (100% vs 82.3%; P=.21) but lower specificity (76.9% vs 88.4%; P=.12) than exercise echocardiography for the diagnosis of acute coronary syndrome, although without reaching statistical significance. Increasing the stenosis cutoff point to 70% increased the specificity of coronary tomography angiography to 88.4%, while maintaining high sensitivity.

CONCLUSIONS

Coronary tomography angiography offers a valid alternative to exercise echocardiography for the diagnosis of acute coronary syndrome among patients with low-to-intermediate probability of coronary artery disease. A combination of both techniques could improve the diagnosis of acute coronary syndrome.

Exercise echocardiography in asymptomatic patients with severe aortic stenosis and preserved left ventricular ejection fraction

The management of asymptomatic patients with severe aortic stenosis (AS) remains controversial. Recent series reported that early aortic valve replacement might be associated with improved clinical outcomes. However, the risk-benefit ratio should be carefully evaluated and early surgery only be proposed to a subset of asymptomatic patients considered at higher risk. Exercise echocardiography can help unmask symptomatic patients combined with assessment of the hemodynamic consequences of AS. Recent studies have demonstrated that exercise echocardiography can provide incremental prognostic value to identify patients who may benefit most from early surgery. In "truly" asymptomatic patients, an increase in mean aortic gradient ≥ 18-20 mmHg, a limited left ventricular contractile reserve or a pulmonary hypertension during exercise are predictive parameters of adverse cardiac events. Exercise echocardiography is low-cost, safe and available in many referral centers, and does not expose patients to radiation. The purpose of this article is to describe the role of exercise testing and echocardiography in the management of asymptomatic patients with severe AS and preserved left ventricular ejection fraction.

Altered transmural contractility in postmenopausal women affected by cardiac syndrome X

BACKGROUND

Cardiac syndrome X (CSX) is characterized by typical angina and abnormal exercise test results, with normal coronary arteries. Cardiovascular magnetic resonance imaging has shown subendocardial hypoperfusion in patients with CSX after adenosine. The aim of this study was to investigate the contribution of separate myocardial layers to global function under stress in women with CSX.

METHODS

Twenty-two postmenopausal women with CSX were studied and compared with 20 healthy women matched for age and body mass index. All subjects underwent clinical evaluations and exercise echocardiography. Left ventricular systolic and diastolic parameters were evaluated at rest and at peak exercise. Layer-specific global longitudinal strain (GLS) and strain rate (SR) were assessed from the endocardium, midmyocardium, and epicardium using two-dimensional speckle-tracking echocardiography.

RESULTS

All subjects showed normal contractile function at rest and at peak exercise. Significant increases in GLS and SR in all myocardial layers were observed at peak exercise in the control group, whereas patients with CSX showed significantly lower increases in endocardial GLS and SR compared with the control group (endocardial ΔSR, 0.17 ± 0.19 vs 0.33 ± 0.13 [P < .01]; endocardial ΔGLS, 1.33 ± 2.93 vs 6.64 ± 2.62 [P < .001]). Moreover, significantly impaired diastolic function (ΔE', 1.1 ± 3.3 vs 4.0 ± 2.03) was observed in patients with CSX.

CONCLUSIONS

The results of this study show subendocardial impairment of contractile function during exercise in patients with CSX, confirming the existence of reduced myocardial perfusion reserve in patients with CSX and suggesting layer-targeted exercise echocardiography as a sensitive diagnostic tool in the assessment of suspected CSX.

Strain analysis during exercise in patients with left ventricular hypertrophy: impact of etiology

BACKGROUND

Hypertrophic cardiomyopathy (HCM) and aortic stenosis (AS) may influence left ventricular (LV) systolic function, despite preservation of LV ejection fraction. The aim of this study was to determine the relative importance of cardiac afterload and myocardial hypertrophy in the potential dysfunction of myocardial deformation, at rest and during standardized exercise.

METHODS

Patients with moderate to severe (≤ 1.5 cm(2)) asymptomatic AS and patients with HCM in sinus rhythm were prospectively studied using resting and exercise echocardiography during submaximal exercise. Myocardial deformations were assessed using two-dimensional strain. Exclusion criteria were altered LV ejection fraction (<50%), coronary artery disease, intra-LV obstruction > 30 mm Hg at rest, diastolic LV thickness ≥ 30 mm, and New York Heart Association class > II. Thus, 50 patients (25 with AS, 25 with HCM) were selected and matched for age, sex, rest and exercise blood pressure, degree of LV hypertrophy (defined by maximal wall thickness), and LV ejection fraction.

RESULTS

Mean resting global longitudinal strain (GLS) was -14.9 ± 4.7% in patients with AS and -16.1 ± 3.9% in those with HCM (P = .30). During exercise (mean heart rate, 110 ± 10 beats/min), mean GLS was -13.9 ± 4.2% in patients with AS and -18.1 ± 5.4% in those with HCM (P = .004). GLS decreased in patients with AS but increased in those with HCM (ΔGLS, 0.9 ± 3.1% and -1.9 ± 3.2%, respectively, P = .003). The same results were observed for global circumferential strain. Mean resting global circumferential strain was -16.4 ± 5.8% in patients with AS and -17.9 ± 4.5% in those with HCM (P = .36). During exercise, mean global circumferential strain was -13.8 ± 4.1% in patients with AS and -18.6 ± 5.3% in those with HCM (P = .011). Afterload was higher, particularly during exercise, in patients with AS than in those with HCM.

CONCLUSIONS

Longitudinal and circumferential LV deformation during exercise was lower in patients with AS compared with those with HCM, despite similar resting characteristics. The greater afterload observed in patients with AS led to reduced contractile reserve.

Noninvasive prediction of the exercise-induced elevation in left ventricular filling pressure in post-heart transplant patients with normal left ventricular ejection fraction

OBJECTIVES

At present, there are conflicting data on the ability of echocardiographic parameters to predict the exercise-induced elevation of left ventricular (LV) filling pressure. The purpose of the present study was to validate the ratio of early diastolic transmitral (E) to mitral annular velocity (e') obtained at peak exercise in its capacity to determine the exercise-induced elevation of pulmonary capillary wedge pressure (PCWP) and to reveal new noninvasive parameters with such capacity.

METHODS

Sixty-one patients who had undergone heart transplantation with normal LV ejection fraction underwent simultaneous exercise echocardiography and right heart catheterization.

RESULTS

In 50 patients with a normal PCWP at rest, exercise E/e' ≥8.5 predicted exercise PCWP ≥25 mmHg with a sensitivity of 64.3% and a specificity of 84.2% (area under the curve [AUC]=0.74). A comparable or slightly better prediction was achieved by exercise E/peak systolic mitral annular velocity (s') ≥11.0 (sensitivity 79.3%; specificity 57.9%; AUC=0.75) and exercise E/LV systolic longitudinal strain rate ≤-105 cm (sensitivity 78.9%; specificity 78.6%; AUC=0.87). Combined, exercise E/s' and exercise E/e' resulted in a trend toward a slightly more precise prediction (sensitivity 53.6%; specificity 89.5%; AUC=0.78) than did either variable alone.

CONCLUSIONS

Exercise E/e', used as a sole parameter, is not sufficiently precise to predict the exercise-induced elevation of PCWP. Exercise E/s', E/LV systolic longitudinal strain rate or combinations of these parameters may represent further promising possibilities for predicting exercise PCWP elevation.

Impaired left ventricular systolic function reserve limits cardiac output and exercise capacity in HFpEF patients due to systemic hypertension

OBJECTIVES

Heart failure (HF) patients with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) due to systemic hypertension (SHT) are known to have limited exercise tolerance. Despite having normal EF at rest, we hypothesize that these patients have abnormal systolic function reserve limiting their exercise capacity.

METHODS

Seventeen patients with SHT (mean age 68 ± 9 years) but no valve disease and 14 healthy individuals (mean age of 65 ± 10 years) underwent resting and peak exercise echocardiography using conventional, tissue Doppler and speckle tracking techniques. The differences between resting and peak exercise values were also analyzed (Δ). Exercise capacity was determined as the workload divided by body surface area.

RESULTS

Resting values for left atrial (LA) volume/BSA (r=-0.66, p<0.001) and global longitudinal strain rate (GLSR) in early (e) and late (a) diastole (r=0.47 and 0.46, p<0.05 for both) correlated with exercise capacity. LVEF increased during exercise in normals (mean Δ EF=10 ± 8%) but failed to do so in patients (mean Δ EF=0.6 ± 9%, p<0.001 between groups). LV GLSR during systole (s) also failed to increase with exercise in patients, to the same extent as it did in normals (0.2 ± 0.2 vs. 0.6 ± 0.3 1/s, p<0.001). The difference between rest and exercise (Δ) in LV lateral wall systolic velocity from tissue Doppler (s') (0.71, p<0.001), Δ in cardiac output (r=0.60, p<0.001) and Δ GLSRs (r=0.48, p<0.05) all correlated with exercise capacity independent of changes in heart rate.

CONCLUSION

HFpEF patients with hypertensive LV disease have significantly limited exercise capacity which is related to left atrial enlargement as well as compromised LV systolic function at the time of the symptoms. The limited myocardial systolic function reserve seems to be underlying important explanation for their limited exercise capacity.

Early diastolic function during exertion influences exercise intolerance in patients with hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) patients with preserved left ventricular ejection fraction (LVEF) often develop dyspnea and exercise intolerance. Diastolic dysfunction may contribute to exercise intolerance in these patients. This study aimed to clarify our hypothesis as to whether diastolic function rather than systolic function would be associated with exercise intolerance in HCM using two-dimensional (2D) speckle tracking echocardiography during exercise.

METHODS

Thirty-three HCM patients (mean age 59.3 ± 15.7 years) underwent 2D speckle tracking echocardiography at rest and during submaximal semi-supine bicycle exercise. Global longitudinal strain (LS), LS rate during systole (LSRs), early diastole (LSRe), and late diastole (LSRa) were measured. The symptom-limited cardiopulmonary exercise testing was performed using a cycle ergometer for measuring the peak oxygen consumption (peak [Formula: see text]).

RESULTS

In the multivariate linear regression analysis, peak [Formula: see text] did not associate with strain or strain rate at rest. However, peak [Formula: see text] correlated with LS (β = -0.403, p = 0.007), LSRe (β = 6.041, p = 0.001), and LSRa (β = 5.117, p = 0.021) during exercise after adjustment for age, gender, and heart rate. The first quartile peak [Formula: see text] (14.2 mL/min/kg) was assessed to predict exercise intolerance. The C-statistic of delta LSRe was 0.74, which was relatively greater than that of delta LS (0.70) and delta LSRa (0.58), indicating that early diastolic function rather than systolic and late diastolic function affects exercise intolerance.

CONCLUSIONS

LSRe during exercise is closely associated with the peak [Formula: see text]. Early diastolic function during exercise is an important determinant of exercise capacity in patients with HCM.

Exercise echocardiography

Exercise echocardiography has been used for 30 years. It is now considered a consolidated technique for the diagnosis and risk stratification of patients with known or suspected coronary artery disease (CAD). Of the stress echocardiography techniques, it represents the first choice for patients who are able to exercise. Given that the cost-effectiveness and safety of stress echocardiography are higher than those of other imaging techniques, its use is likely to be expanded further. Recent research has also proposed this technique for the evaluation of cardiac pathology beyond CAD. Although the role of new technology is promising, the assessment of cardiac function relies on good quality black and white harmonic images.