Left ventricular diastolic functional reserve during exercise in patients with impaired myocardial relaxation at rest

Due Diligence of a Diastolic Index as a Prognostic Factor in Heart Failure with Preserved Ejection Fraction

Of the existing non-invasive diastolic indices, none consider arterial load. This article reveals points of caution for determining the diastolic prognostic index using a novel index of vascular resistance-integrated diastolic function in old, real-world patients with heart failure with preserved ejection fraction (HFpEF) in Japan. This index represents the ratio of left ventricular diastolic elastance (Ed) to arterial elastance (Ea), where Ed/Ea = (E/e')/(0.9 × systolic blood pressure), showing a relative ratio of left atrial filling pressure to left ventricular end-systolic pressure. The role of hemodynamic prognostic factors related to diastolic function, such as Ed/Ea, may differ according to the clinical endpoint, follow-up duration, and sex. In HFpEF patients with heterogenous cardiac structure and function, an assessment using a serial echocardiographic diastolic index in clinical care can provide an accurate prognosis.

Time-sensitive prognostic performance of an afterload-integrated diastolic index in heart failure with preserved ejection fraction: a prospective multicentre observational study

OBJECTIVES

The prognostic significance of an afterload-integrated diastolic index, the ratio of diastolic elastance (Ed) to arterial elastance (Ea) (Ed/Ea=[E/e']/[0.9×systolic blood pressure]), is valid for 1 year after discharge in older patients with heart failure with preserved ejection fraction (HFpEF). We aimed to clarify the association with changes in Ed/Ea from enrolment to 1 year and prognosis thereafter in patients with HFpEF.

SETTING

A prospective, multicentre observational registry of collaborating hospitals in Osaka, Japan.

PARTICIPANTS

We enrolled 659 patients with HFpEF hospitalised for acute decompensated heart failure (men/women: 296/363). Blood tests and transthoracic echocardiography were performed before discharge and at 1 year after.

PRIMARY OUTCOME MEASURES

All-cause mortality and/or re-admission for heart failure were evaluated after discharge.

RESULTS

High Ed/Ea assessed before discharge was a significant prognostic factor during the first, but not the second, year after discharge in all-cause mortality or all-cause mortality and/or re-admission for heart failure. When re-analysis was performed using the value of Ed/Ea at 1 year after discharge, high Ed/Ea was significant for the prognosis during the second year for both end points (p=0.012 and p=0.033, respectively). The poorest mortality during 1‒2 years after enrolment was observed in those who showed a worsening Ed/Ea during the first year associated with larger left ventricular mass index and reduced left ventricular ejection fraction. In all-cause mortality and/or re-admission for heart failure, the event rate during 1‒2 years was highest in those with persistently high Ed/Ea even after 1 year.

CONCLUSIONS

Time-sensitive prognostic performance of Ed/Ea, an afterload-integrated diastolic index, was observed in older patients with HFpEF.

TRIAL REGISTRATION NUMBER

UMIN000021831.

Stress Testing in Heart Failure with Preserved Ejection Fraction

Exertional dyspnea is the most common symptom in patients with heart failure with preserved ejection fraction; however, it is not specific to this disease. Stress testing provides crucial information about the diagnosis and prognosis of heart failure with preserved ejection before it reaches the advanced stage. Among various stress tests, noninvasive supine bicycle diastolic stress echocardiography has provided the most evidence for diagnosing and predicting the prognosis of heart failure with preserved ejection fraction. In current practice guidelines, a noninvasive or invasive diastolic stress test is recommended when a diagnosis is unclear in resting echocardiography.

[The role of diastolic transthoracic stress echocardiography with incremental workload in the evaluation of heart failure with preserved ejection fraction: indications, methodology, interpretation. Expert consensus developed under the auspices of the National Medical Research Center of Cardiology, Society of Experts in Heart Failure (SEHF), and Russian Association of Experts in Ultrasound Diagnosis in Medicine (REUDM)]

Diagnosis of heart failure with preserved ejection fraction (HFpEF) is associated with certain difficulties since many patients with HFpEF have a slight left ventricular diastolic dysfunction and normal filling pressure at rest. Diagnosis of HFpEF is improved by using diastolic transthoracic stress-echocardiography with dosed exercise (or diastolic stress test), which allows detection of increased filling pressure during the exercise. The present expert consensus explains the requirement for using the diastolic stress test in diagnosing HFpEF from clinical and pathophysiological standpoints; defines indications for the test with a description of its methodological aspects; and addresses issues of using the test in special patient groups.

Heart Failure with Preserved Ejection Fraction: the Major Unmet Need in Cardiology

Heart failure with preserved ejection fraction (HFpEF) has recently been recognized as the single greatest unmet need in cardiovascular medicine. As the population ages and the comorbidity increases, the prevalence of HFpEF increases considerably. Even though there have been large numbers of studies on pathophysiology, diagnosis, and treatment of HFpEF for latest years, there are no current pharmacologic interventions that can reduce mortality. HFpEF is currently understood as a heterogeneous syndrome originated from the interplay of cardiac and extracardiac abnormalities recognized by systemic inflammation, endothelial and coronary microvascular dysfunction, cardiomyocyte dysfunction and skeletal muscle dysfunction. The difficult “jigsaw puzzle” called HFpEF has been filled with some pieces, but it is still not enough to meet clinical needs. Here, we review recent evidences and unsolved problems about HFpEF to improve our understanding of HFpEF. Finally, we hope to accelerate to completion of the problematic “jigsaw puzzle”.

Determinants of Cardiorespiratory Fitness Following Thoracic Radiotherapy in Lung or Breast Cancer Survivors

We measured peak oxygen consumption (VO₂) in previous recipients of thoracic radiotherapy and assessed the determinants of cardiorespiratory fitness with an emphasis on cardiac and pulmonary function. Cancer survivors who have received thoracic radiotherapy with incidental cardiac involvement often experience impaired cardiorespiratory fitness, as measured by reduced peak VO₂, a marker of impaired cardiovascular reserve. We enrolled 25 subjects 1.8 (0.1 to 8.2) years following completion of thoracic radiotherapy with significant heart exposure (at least 10% of heart volume receiving at least 5 Gray). All subjects underwent cardiopulmonary exercise testing, Doppler echocardiography, and circulating biomarkers assessment. The cohort included 16 Caucasians (64%), 15 women (60%) with a median age of 63 (59 to 66) years. The peak VO₂ was 16.8 (13.5 to 21.9) ml·kg^-1·min^-1 or moderately reduced at 62% (50% to 93%) of predicted. The mean cardiac radiation dose was 5.4 (3.7 to 14.7) Gray, and it significantly correlated inversely with peak VO₂ (R = -0.445, p = 0.02). Multivariate regression analysis revealed the diastolic functional reserve index and the N-terminal pro-brain natriuretic peptide (NTproBNP) serum levels were independent predictors of peak VO₂ (ß = +0.813, p <0.01 and ß = -0.414, p = 0.04, respectively). In conclusion, patients who had received thoracic radiation display a dose-dependent relation between the cardiac radiation dose received and the impairment in peak VO₂, the reduction in diastolic functional reserve index, and elevation of NTproBNP.

Ventricular Stiffness and Ventricular-Arterial Coupling in Heart Failure: What Is It, How to Assess, and Why?

The heart and blood vessels are constantly interfering with each other in a closed system. For a few decades, the concept of ventricular-arterial coupling has been considered as a key pathogenesis of heart failure especially in heart failure with preserved ejection fraction.

Left and Right Ventricular Systolic and Diastolic Functional Reserves Are Impaired in Anthracycline-Treated Long-Term Survivors of Childhood Cancers

BACKGROUND

The aim of this study was to test the hypothesis that left ventricular (LV) and right ventricular (RV) functional reserves are altered in anthracycline-treated long-term survivors of childhood cancers.

METHODS

One hundred three survivors (55% men) aged 25.0 ± 5.8 years at 15.2 ± 5.8 years after chemotherapy and 61 healthy control subjects (52% men) were studied. Tissue Doppler-derived mitral and tricuspid systolic (s) and early diastolic (e) velocities and LV myocardial acceleration during isovolumic contraction (IVA) were determined at rest and during bicycle exercise. The slope of the LV force-frequency relationship was derived from changes in IVA with heart rate during exercise (ΔIVA/Δ[heart rate]). LV and RV functional reserves were further assessed by the systolic functional reserve index (Δs × [1 - 1/s at baseline]) and diastolic functional reserve index (Δe × [1 - 1/e at baseline]).

RESULTS

At baseline, mitral annular tissue Doppler indices were similar between survivors and control subjects (P > .05 for all), while tricuspid s and e velocities were significantly lower in survivors (P < .05 for both). The force-frequency relationship slope (P < .001), LV systolic functional reserve index (P < .001), and RV systolic functional reserve index (P = .001) were significantly lower in survivors than control subjects. For diastolic functional reserve, LV but not RV diastolic functional reserve index was significantly lower in survivors (P < .001). Multivariate analysis revealed survivor status (β = -0.39, P < .001) and baseline LV IVA (β = 0.15, P < .044) as significant determinants of the LV force-frequency relationship.

CONCLUSIONS

LV and RV functional reserves during exercise are impaired in anthracycline-treated long-term survivors of childhood cancer.

Diastolic stress echocardiography: from basic principles to clinical applications

Heart failure with preserved ejection fraction (HFpEF) looms as a major public heart challenge with increasing prevalence due to an ageing population. Diagnosis can be challenging due to non-specific symptomatology, low natriuretic peptide levels and equivocal diastology on resting echocardiography. Diastolic stress echocardiography represents a non-invasive option to refining the diagnosis in this subset of patients. Diastolic responses to exercise are most commonly measured with a non-invasive measure of left ventricular filling pressures (LVFP) estimated by the ratio of the early mitral inflow wave to early diastolic tissue velocity (E/e' ratio). This is measured pre- and post-exercise , and is highly feasible. An elevation of exercise E/e' >15 is classified as an abnormal response as per current guidelines. An alternative measure of exercise-related diastolic performance, the Diastolic Functional Reserve Index has also been proposed, but has not been as well studied as exercise E/e'. A number of studies have validated exercise E/e' as a measure of LVFP against invasively measured LVFP using simultaneous echocardiography-catheterisation studies. The independent prognostic value of exercise E/e' has also been well delineated in a number of studies. While diastolic stress echocardiography can be considered for all patients with suspected HFpEF, it is of particular value in patients with normal or equivocal diastolic indices on resting echocardiography.

Wave intensity as a useful modality for assessing ventilation-perfusion imbalance in subclinical patients with hypertension

Wave intensity (WI) is a novel noninvasive index of circulatory dynamics that reflects ventriculo-arterial coupling. It is calculated as the product of the first derivative of blood pressure and that of flow velocity measured by carotid echocardiography. This study aimed to clarify the clinical implications of WI and its relation with carbon dioxide production (VE/VCO₂ slope). Twenty-one healthy volunteers (control group) and 21 patients with hypertension (HT group) underwent cardiopulmonary exercise testing (CPX) and exercise stress echocardiography. WI was assessed in the right carotid artery using an ultrasound system. The first peak of WI (W₁) during the early ejection phase was measured at baseline and mitral annular velocity was assessed by tissue Doppler imaging. Ventilatory kinetics during exercise was assessed using the relation of minute ventilation to VE/VCO₂ slope. VE/VCO₂ slope, W₁, and E/E' were greater in the HT group than in the control group. PeakVO₂ and VO₂ at the anaerobic threshold were lower in the HT group than in the control group. VE/VCO₂ slope was significantly correlated with W₁ (r = 0.58, p < 0.01) and E/E' (r = 0.44, p < 0.01). Stepwise multivariate analysis revealed that W₁ was an independent determinant of VE/VCO₂ slope (β = 0.43, p < 0.01). In conclusion, W₁ might be able to predict the severity of heart failure without the need for CPX. Moreover, WI may be a useful modality in assessing heart failure pathophysiology based on ventriculo-arterial coupling.

Relationship of biomarkers of extracellular matrix with myocardial function in Type 2 diabetes mellitus

AIM

The study evaluated the relationship of extracellular matrix and renin angiotensin system with myocardial dysfunction in Type 2 diabetes mellitus.

METHODS

All patients underwent resting and exercise echocardiography, including conventional parameters, E/E' ratio, global longitudinal strain and diastolic function reserve index. Plasma matrix metalloproteinase-1, TIMP-1, amino-terminal propeptide of type I and type III procollagen and renin angiotensin system activity were measured.

RESULTS

As patients with diastolic dysfunction had a higher plasma level of TIMP-1 and propeptide of type III procollagen than those with no diastolic dysfunction. After multivariate adjustment, TIMP-1 associated with E/E' (both at rest and stress) and diastolic function reserve index.

CONCLUSION

TIMP-1 is independently associated with myocardial diastolic dysfunction in patients with Type 2 diabetes mellitus.

Diastolic stress echocardiography

Evaluation of diastolic dysfunction and diagnosis of heart failure with preserved ejection fraction (HFpEF) by echocardiography are routinely performed at rest. However, many patients with modest HFpEF develop symptoms such as dyspnea only during exercise. Therefore, echocardiographic analysis at rest could be insufficient to identify these patients. Recent studies have demonstrated the utility of diastolic stress echocardiography to evaluate diastolic dysfunction during exercise. This review attempts to summarize and discuss current studies in diastolic stress echocardiography.

Two Distinct Responses of Left Ventricular End-Diastolic Pressure to Leg-Raise Exercise in Euvolemic Patients with Exertional Dyspnea

Background and Objectives

Few studies have invasively assessed diastolic functional reserve and serial changes in left ventricular hemodynamics in euvolemic patients with exertional dyspnea. In this study, sequential changes in left ventricular end-diastolic pressure (LVEDP) to leg-raise exercise were measured invasively in patients with early heart failure with preserved ejection fraction (HFpEF) to determine the association between these serial changes and echocardiographic results or clinical features.

Subjects and Methods

During their hospital stay, 181 patients with early HFpEF underwent left cardiac catheterization, coronary angiography, and transthoracic echocardiography (TTE). Leg-raise exercise was performed in two stages: during cardiac catheterization and again during TTE.

Results

Compared with the initial values, all the invasively measured LVEDP values increased significantly during the leg-raise exercise, whereas the septal e/e' ratio remained unchanged. Active leg-raise led to increased LVEDP, which caused dyspnea. The severity of symptoms correlated with the level and extent of changes in LVEDP. At the end of active leg-raise, LVEDP decreased in 40 patients (22.1%), who were younger and had significantly lower e/e' ratios. On multivariate analysis to predict the response of LVEDP to active leg-raise, age and the septal e/e' ratio remained significant predictors.

Conclusion

Despite having similar LVEDP values at rest, patients may respond to exercise with different LVEDP levels and clinical manifestations, depending on their diastolic capacity. The leg-raise exercise in early HFpEF can elucidate individual diastolic profiles, and the LVEDP response to the leg-raise test may serve as a useful criterion in stratifying patients with early HFpEF with respect to functional reserve.

Gender Differences in Ventricular-vascular Coupling Following Exercise

OBJECTIVE

To study the differences of cardiovascular system between men and women in response to exercise stress.

METHODS

Forty healthy youth were tested according to Bruce protocol of exercise stress. They were detected by ultrasonography during the rest, peak exercise, and recovery stages, respectively. The left ventricular diastolic elastance (Ed), effective arterial elastance (Ea), left ventricular end-systolic elatance (Ees), ventricular-vascular coupling index (VVI), and total stiffness index (TSI) were measured and calculated according to the formulas. The results of all stages were compared according to genders.

RESULTS

All stages, the Ed, TSI, and VVI of women were higher than those of men, but the Ees was lower than that of men (all P<0.05); there was no significant difference in Ea between men and women. The Ed, Ees, Ea, and TSI were closely related with left ventricular oxygen consumption and heart function, and women showed more closely. Before and after exercise, the changes were different in Ed, Ees, Ea, TSI, and VVI (all P<0.05), and VVI changed least.

CONCLUSIONS

Before and after exercise, the ventricular stiffness matched well with arterial stiffness and maintained within a narrow range. For women, the tolerance of exercise was lower than that of men.

Altered myocardial response in patients with diabetic retinopathy: an exercise echocardiography study

Background

Type 2 diabetes mellitus (T2DM) complicated by retinopathy is associated with altered left ventricular (LV) structure and resting myocardial dysfunction unlike T2DM without retinopathy. The myocardial response to stress has not been compared in patients with and without diabetic retinopathy. The aim of this retrospective study was to determine the relationship between retinopathy and myocardial function in patients with T2DM at rest and during exercise echocardiography.

Methods

134 patients with T2DM and no evidence of underlying coronary artery disease were recruited. All patients underwent retinal photography to screen for diabetic retinopathy, and resting and exercise echocardiography. Resting echocardiography was analyzed by conventional echocardiographic parameters and speckle tracking derived global longitudinal strain (GLS). Exercise echocardiography parameters included diastolic function reserve index (DFRI) and stress GLS.

Results

The mean age of participants was 60 years and 49 % were male. Diabetic retinopathy was identified in 43 patients (32 %). Resting echocardiography revealed that those with diabetic retinopathy had a higher prevalence of impaired diastolic function, higher E/E′ ratio (LV filling pressures) and impaired resting GLS compared with those without. Exercise echocardiography revealed that those with diabetic retinopathy also had more impaired DFRI and stress GLS. Multivariable analysis showed that the presence of diabetic retinopathy was independently associated with high resting E/E′, diastolic dysfunction grade, impaired resting GLS, low DFRI and impaired stress GLS.

Conclusions

In conclusion, the presence of diabetic retinopathy was independently associated with impaired resting myocardial function (diastolic and systolic function) and myocardial function during stress (evaluated by DFRI and stress GLS).

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-015-0281-5) contains supplementary material, which is available to authorized users.

Left ventricular diastolic reserve in patients with type 2 diabetes mellitus

AIMS

Diastolic reserve is the ability of left ventricular filling pressures to remain normal with exercise. Impaired diastolic reserve may be an early sign of diabetic cardiomyopathy. We aimed to determine whether diastolic reserve differs in type 2 diabetes (DM) compared with non-DM, and to identify clinical, anthropological, metabolic and resting echocardiographic correlates of impaired diastolic reserve in patients with DM.

METHODS AND RESULTS

237 patients (aged 53±11 years, 133 DM, ejection fraction 68±9%) underwent rest and exercise echocardiography. Mitral E and septal e' were measured at rest, immediately post, and 10 min into recovery. Analysis of covariance (ANCOVA) and binary regression with continuous outcomes were used to model e' and E/e' changes with exercise to identify impaired diastolic reserve defined as post-exercise E/e' ≥15. After adjusting for baseline differences, patients with DM immediately post-exercise had a lower septal e', a lower Δe' (1.2 vs 2.3 cm/s, p=0.006) and a higher Δ septal E/e' (1.7 vs 0.08, p<0.001) than patients without DM. In patients with normal resting E/e' of ≤8 (n=130), DM had a significantly higher post-exercise septal E/e' and a higher Δseptal E/e' (2.63 vs 0.50, p<0.001). E/e' in patients with DM remained significantly elevated up to 10 min post-exercise. Hypertension, longer duration of insulin therapy, poorer glycaemic control, worse renal function, larger left atrial volume and lower septal e' were independent correlates of impaired diastolic reserve in patients with DM.

CONCLUSIONS

Patients with DM have impaired diastolic reserve manifest as a blunted e' response with exercise, persisting into recovery. Clinical, anthropometric, metabolic and echocardiographic correlates of impaired diastolic reserve in patients with DM were identified. An impaired LV diastolic reserve may be the underlying pathophysiological mechanism in patients with DM with unexplained exertional dyspnoea and may allow earlier detection of DM cardiomyopathy.

A systematic review of diastolic stress tests in heart failure with preserved ejection fraction, with proposals from the EU-FP7 MEDIA study group

AIMS

Cardiac function should be assessed during stress in patients with suspected heart failure with preserved ejection fraction (HFPEF), but it is unclear how to define impaired diastolic reserve.

METHODS AND RESULTS

We conducted a systematic review to identify which pathophysiological changes serve as appropriate targets for diagnostic imaging. We identified 38 studies of 1111 patients with HFPEF (mean age 65 years), 744 control patients without HFPEF, and 458 healthy subjects. Qualifying EF was >45-55%; diastolic dysfunction at rest was a required criterion in 45% of studies. The initial workload during bicycle exercise (25 studies) varied from 12.5 to 30 W (mean 23.1 ± 4.6), with increments of 10-25 W (mean 19.9 ± 6) and stage duration 1-5 min (mean 2.5 ± 1); targets were submaximal (n = 8) or maximal (n = 17). Other protocols used treadmill exercise, handgrip, dobutamine, lower body negative pressure, nitroprusside, fluid challenge, leg raising, or atrial pacing. Reproducibility of echocardiographic variables during stress and validation against independent reference criteria were assessed in few studies. Change in E/e' was the most frequent measurement, but there is insufficient evidence to establish this or other tests for routine use when evaluating patients with HFPEF.

CONCLUSIONS

To meet the clinical requirements of performing stress testing in elderly subjects, we propose a ramped exercise protocol on a semi-supine bicycle, starting at 15 W, with increments of 5 W/min to a submaximal target (heart rate 100-110 b.p.m., or symptoms). Measurements during submaximal and recovery stages should include changes from baseline in LV long-axis function and indirect echocardiographic indices of LV diastolic pressure.

Kinetics of left ventricular rotation during exercise and its relation to exercise tolerance in atrial fibrillation: assessment by two-dimensional speckle tracking echocardiography

BACKGROUND

Left ventricular (LV) rotation plays an important role in cardiac function both at rest and during exercise in sinus rhythm. The kinetics of rotation during exercise and the relation between exercise tolerance and rotation-related parameters in patients with atrial fibrillation (AF) are unknown.

METHODS

Twenty-nine patients (age 62 ± 13 years, 6 females) with AF and preserved LV ejection fraction (LVEF) were studied using two-dimensional speckle tracking echocardiography at rest and during exercise with a supine bicycle ergometer (20 W, 10 min). We measured the systolic rotation (Rot) and the peak rotation rate in systole and early diastole (eRotR) at the apical and basal levels of the LV. All patients underwent cardiopulmonary exercise testing to obtain their percent achieved of the predicted peak oxygen consumption (% peak VO2) value.

RESULTS

During exercise, apical Rot-related indices were significantly increased only in the preserved % peak VO2 group. In contrast, E/e' was significantly elevated only in the reduced % peak VO2 group. Multivariable stepwise regression analysis showed that apical ΔRot was independently associated with % peak VO2 (β = 0.72; p < 0.01). Apical ΔeRotR, which could not be selected as an independent predictor of % peak VO2, had a good linear correlation with apical ΔRot (r = 0.81, p < 0.01).

CONCLUSIONS

The augmentation of apical rotation in response to exercise may coincide with an increase of the apical derotation rate, and apical rotation reserve may reflect exercise tolerance in patients with AF and preserved LVEF.

Causes of exercise intolerance in heart failure with preserved ejection fraction: searching for consensus

Exercise intolerance is one of the cardinal symptoms of heart failure with preserved ejection fraction (HFpEF). We review its mechanistic basis using evidence from exercise studies. One barrier to a consensus understanding of the pathophysiology is heterogeneity of the patient population. Therefore, we pay special attention to varying study definitions of the disease and their possible impact on the causal factors that are implicated. We then discuss the role of exercise testing and its potential to subtype HFpEF in to more homogeneous mechanism-based subclasses.

Left Ventricular Diastolic Function Is Associated With Symptom Status in Severe Aortic Valve Stenosis

Background—

In aortic valve stenosis (AS), the occurrence of heart failure symptoms does not always correlate with severity of valve stenosis and left ventricular (LV) function. Therefore, we tested the hypothesis that symptomatic patients with AS have impaired diastolic, longitudinal systolic function, and left atrial dilatation compared with asymptomatic patients.

Methods and Results—

In a retrospective descriptive study, we compared clinical characteristics and echocardiographic parameters in 99 symptomatic and 139 asymptomatic patients with severe AS and LV ejection fraction ≥50%. Independent predictors of symptomatic state were identified using logistic regression analysis. Symptomatic patients were younger (72±10 versus 76±12 years of age; P =0.002), presented less often with atrial fibrillation (13% versus 24%; P =0.05) and chronic obstructive pulmonary disease (2% versus 19%; P <0.001), and had a lower prevalence of hypertension (73% versus 40%; P <0.001). Despite similar AS severity, symptomatic patients had higher LV mass index (120±39 versus 95±25 g/m 2 ; P <0.0001), increased relative wall thickness (0.61±0.15 versus 0.50±0.11; P <0.0001), shorter mitral deceleration time (199±58 versus 268±62 ms; P <0.0001), and increased left atrial volume index (49±18 versus 42±15 mL/m 2 ; P =0.02). When adjusting for age, history of hypertension, atrial fibrillation, and chronic obstructive pulmonary disease in a multivariable logistic regression analysis, LV mass index, relative wall thickness, left atrial volume index, and deceleration time were still associated with the presence of symptoms.

Conclusions—

The present study demonstrates that symptomatic status in severe AS is associated with impaired diastolic function, LV hypertrophy, concentric remodeling, and left atrial dilatation when corrected for indices of AS severity.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00294775.

The relationship between ventricular-vascular uncoupling during exercise and impaired left ventricular longitudinal functional reserve in hypertensive patients

Uncoupling between heart and vessel may be accompanied by left ventricular (LV) dysfunction during exercise. We investigated the association between ventricular-vascular uncoupling during exercise and impaired LV longitudinal functional reserve in hypertensive subjects. Supine bicycle exercise echocardiography (25-watt, 3-minute increments) was performed in 216 hypertensive patients (106 male; mean age, 58 ± 9 years). Arterial elastance (Ea), end-systolic ventricular elastance (Ees), and ventricular-vascular interaction (VVI) index (Ea/Ees) were calculated at rest and at each stage of exercise. The patients were divided into three groups according to the tertile value of VVI ratio. The VVI ratio was defined as the ratio of VVI index at 50 W exercise over VVI index at rest; normal VVI response (n = 72); borderline VVI response (n = 72); and abnormal VVI response (n = 72). There were no significant differences in conventional echo parameters, mitral inflow velocities, mitral annular early diastolic (E') velocity, and mitral annular systolic velocity (S') at rest among the three groups. However, E' velocities and S' velocities at 25 W and 50 W were significantly lower in patients with abnormal VVI response compared with those in the other groups (P = .010 at 25 W, P = .008 at 50 W in E' velocity; P = .022 at 25 W, P = .043 at 50 W in S' velocity). Longitudinal diastolic functional reserve index from rest to 50 W was significantly lower in patients with abnormal VVI response compared with the other groups. Ventricular-vascular uncoupling during exercise was related to impaired LV longitudinal functional reserve in hypertensive patients.

Cardiac response to exercise in normal-weight and obese, Hispanic men and women: implications for exercise prescription

AIM

The effects of obesity on cardiac function during incremental exercise to peak oxygen consumption (VO(2peak)) have not been previously described. The purpose of this study was to compare submaximal and maximal cardiac function during exercise in normal-weight and obese adults.

METHODS

Normal-weight (n = 20; means ± SE: age = 21.9 ± 0.5 years; BMI = 21.8 ± 0.4 kg m(-2)) and obese (n = 15; means ± SE: age = 25.1 ± 5.2 years; BMI = 34.1 ± 01.0 kg m(-2)) participants were assessed for body composition, VO(2peak) and cardiac variables (thoracic bioimpedance analysis) at rest and at heart rates (HR) of 110, 130, 150 and 170 beats min(-1) and maximal HR during incremental cycling exercise to exhaustion. Differences between groups were assessed with mixed-model ancova with repeated measures. Cardiac variables were statistically indexed for body surface area and resting HR. VO(2) and arteriovenous oxygen difference (a-vO(2)) were statistically indexed for fat-free mass and resting HR.

RESULTS

Significant main effects for group indicated obese participants had higher cardiac output (Q) index and stroke volume (SV) index but lower ejection fraction (EF) and a-vO(2) index during incremental exercise to exhaustion compared with their normal-weight peers, despite similar submaximal and maximal VO(2) and absolute power outputs (P < 0.05).

CONCLUSIONS

Our findings suggest that although Q index and SV index were higher in obese, young adults, EF and a-vO(2) index were significantly lower when compared to matched, normal-weight adults.

The pathophysiology of heart failure with preserved ejection fraction: from molecular mechanisms to exercise haemodynamics

The pathophysiology of HfpEF is complex. In this review we discuss the molecular aspects of HfpEF as well as the profoundly disturbed haemodynamics with particular focus on exercise haemodynamic abnormalities.

The concept of ventricular reserve in heart failure and pulmonary hypertension: an old metric that brings us one step closer in our quest for prediction

PURPOSE OF REVIEW

Ventricular reserve is emerging a strong predictor of outcome in heart failure and cardiovascular disease. Ventricular reserve is the term used to describe the extent of increase or change in ventricular function that occurs during exercise or pharmacological stress (typically with dobutamine).

RECENT FINDINGS

The interest in ventricular reserve lies in its ability to assess viability in coronary artery disease, to predict clinical outcome and response to therapy in patients with heart failure and to screen patients for early cardiovascular disease.

SUMMARY

In this paper, we will review the emerging role of ventricular reserve in heart failure and pulmonary hypertension. We will also explore the mechanisms involved in the pathophysiology of impaired ventricular reserve and discuss future directions of research in the field.

Diastolic relaxation and compliance reserve during dynamic exercise in heart failure with preserved ejection fraction

BACKGROUND

Recent studies have examined haemodynamic changes with stressors such as isometric handgrip and rapid atrial pacing in heart failure with preserved ejection fraction (HFpEF), but little is known regarding left ventricular (LV) pressure-volume responses during dynamic exercise.

OBJECTIVE

To assess LV haemodynamic responses to dynamic exercise in patients with HFpEF.

METHODS

Twenty subjects with normal ejection fraction (EF) and exertional dyspnoea underwent invasive haemodynamic assessment during dynamic exercise to evaluate suspected HFpEF.

RESULTS

LV end-diastolic pressure was elevated at rest (>15 mm Hg, n=18) and with exercise (≥20 mm Hg, n=20) in all subjects, consistent with HFpEF. Heart rate (HR), blood pressure, arterial elastance and cardiac output increased with exercise (all p<0.001). Minimal and mean LV diastolic pressures increased by 43-56% with exercise (both p<0.0001), despite a trend towards a reduction in LV end-diastolic volume (p=0.08). Diastolic filling time was abbreviated with increases in HR and the proportion of diastole that elapsed prior to estimated complete relaxation increased (p<0.0001), suggesting inadequate relaxation reserve relative to the shortening of diastole. LV diastolic chamber elastance acutely increased 50% during exercise (p=0.0003). Exercise increases in LV filling pressures correlated with changes in diastolic relaxation rates, chamber stiffness and arterial afterload but were not related to alterations in preload volume, HR or cardiac output.

CONCLUSION

In patients with newly diagnosed HFpEF, LV filling pressures increase during dynamic exercise in association with inadequate enhancement of relaxation and acute increases in LV chamber stiffness. Therapies that enhance diastolic reserve function may improve symptoms of exertional intolerance in patients with hypertensive heart disease and early HFpEF.

Usefulness of at rest and exercise hemodynamics to detect subclinical myocardial disease in type 2 diabetes mellitus

Patients with type 2 diabetes mellitus (T2DM) might have subclinical myocardial dysfunction identified at rest or unmasked during exercise. We examined the correlates of the myocardial exercise response in patients with T2DM. Myocardial dysfunction was sought during at rest and exercise echocardiography in 167 healthy patients with T2DM (97 men, 55 ± 10 years). Myocardial ischemia was excluded using stress echocardiography. Standard echocardiography and color tissue Doppler imaging measures (early diastolic tissue velocity [Em], strain, and strain rate) were acquired at baseline and peak stress. The calibrated integrated backscatter was calculated from the at rest parasternal long-axis view. The longitudinal diastolic functional reserve index after exercise was defined as ΔEm [1 - (1/Em(base))]. The clinical, anthropometric, and metabolic data were collected at rest and stress. Subclinical myocardial dysfunction at baseline (n = 24) was independently associated with weight (odds ratio [OR] 1.02, p = 0.04) and hemoglobin A1c (OR 1.36, p = 0.03). This group displayed an impaired exercise response that was independently associated with a reduced exercise capacity (OR 0.84, p = 0.034) and longitudinal diastolic functional reserve index (OR 0.69, p = 0.001). Inducible myocardial dysfunction (stress Em <-9.9 cm/s) was identified after exercise in 70 of the remaining 143 subjects. This finding was associated with calibrated integrated backscatter (OR 1.08, p = 0.04) and lower peak heart rate (OR 0.97, p = 0.002) but not metabolic control. The intensity of the metabolic derangement in patients with T2DM was associated with subclinical at rest myocardial dysfunction, but not with the myocardial exercise response. In conclusion, the association of an abnormal stress response with nonmetabolic factors, including backscatter and blunted peak heart rate, suggests potential roles for myocardial fibrosis and cardiac autonomic neuropathy in patients with nonischemic diabetic heart disease.

Use of bicycle exercise echocardiography for unexplained exertional dyspnea

Unexplained exertional dyspnea is a common and perplexing clinical problem. Myocardial ischemia and left ventricular systolic dysfunction are important cardiac causes, but are often not detected in these patients. Recently, exercise-induced left ventricular diastolic dysfunction and exercised-induced pulmonary hypertension have emerged as common alternative mechanisms. While conventional exercise treadmill echocardiography effectively diagnoses left ventricular systolic dysfunction and myocardial ischemia, it has limited ability to detect exercise-induced diastolic dysfunction or pulmonary hypertension. The latest advances in exercise echocardiography, including utilization of tissue Doppler imaging and harmonic imaging, make noninvasive evaluation of both conventional and alternative cardiac causes of exertional dyspnea possible. These advancements, when coupled with newly designed supine exercise platforms for bicycle exercise echocardiography (BE), facilitate the detection of exercise-induced diastolic dysfunction and pulmonary hypertension. Moreover, BE using supine ergometry additionally permits the dynamic evaluation of valvular function and interatrial shunting and detection of pulmonary arteriovenous fistula, uncommon but important causes of unexplained exertional dyspnea. Therefore, we propose that because of its superior diagnostic capabilities, BE should be included as part of a comprehensive cardiac evaluation of patients with unexplained exertional dyspnea.