Clinical evaluation of left ventricular diastolic performance

Normal fetal echocardiography ratios - a multicenter cross-sectional retrospective study

OBJECTIVES

Normal fetal echocardiography ratios reflect blood flow balance and developmental patterns, providing a basis for more accurate diagnosis and prediction of congenital heart disease in fetuses. Despite its significance, standardized studies with ample samples are lacking. We aim to establish reference ranges for fetal cardiac structural parameters and hemodynamics using extensive multicenter data, including 11 ratios, and to clarify how these ratios change with gestational age.

METHODS

This is a multicenter cross-sectional retrospective study. 23,313 normal fetal echocardiographic examinations were enrolled from three medical centers. Analysis included 11 fetal cardiac-related ratios, such as right/left heart diameter ratio, mitral and tricuspid valve E/A-wave velocity ratio. To determine the reference ranges for various ratios across different gestational ages, a nonparametric quantile regression model, which does not presuppose normality, was utilized. The study investigated how the ratios change with gestational age by examining nonparametric regression plots and their first and second derivatives.

RESULTS

We established normal percentile reference ranges for 11 ratios at each gestational day. Analysis of ratio changes across gestation reveals several key patterns: The right heart system consistently dominates, with the right heart/left heart internal diameter ratio accelerating from 21.7 weeks of gestation; throughout fetal development, the E/A ratio of the mitral and tricuspid valves initially remains below one but increases progressively with gestational age, both reaching their maximum growth rates at week 25.7.

CONCLUSIONS

This study provides new references for routine obstetric screening, may enhance the understanding of the growth and developmental patterns of normal fetal hearts.

Hemodynamic Assessment via Echocardiography During Propofol Anesthetic Induction in Healthy Dogs

Introduction: Propofol is an intravenous anesthetic administered as a bolus or continuous infusion during anesthetic induction and maintenance. Its pharmacokinetic characteristics include hepatic and extrahepatic metabolism with a rapid onset of action and short duration, which provides a smooth anesthetic induction without excitatory effects. Objective: To evaluate whether the isolated use of propofol in anesthetic induction in dogs changes the hemodynamic variables assessed via echocardiography. Study Design: Prospective clinical study. Animals: Twelve healthy dogs. Methods: The dogs were induced with propofol (dose/effect) at 3 mg/kg/minute, and echocardiographic evaluations were performed immediately before anesthetic induction (MB) and immediately after its interruption (MI), at the end of the supply of the anesthetic agent. Results: A significant reduction was observed between the values of the following hemodynamic variables: Ejection Fraction (EF%), which varied from 70% to 65% (p=0.011) between moments, and the Doppler Ejection Index (DEI), which ranged from 27.1 mL/beat/m2 to 22.4 mL/beat/m2 (p=0.044). The heart rate (HR) and the other studied hemodynamic variables showed no significant differences between the evaluated moments. Conclusion and Clinical Relevance: Propofol was a safe anesthetic-inducing agent, maintaining stable hemodynamic indices during anesthetic induction at the used rate.

Improved Interpretation of Pulmonary Artery Wedge Pressures through Left Atrial Volumetry-A Cardiac Magnetic Resonance Imaging Study

BACKGROUND

The pulmonary artery wedge pressure (PAWP) is regarded as a reliable indicator of left ventricular end-diastolic pressure (LVEDP), but this association is weaker in patients with left-sided heart disease (LHD). We compared morphological differences in cardiac magnetic resonance imaging (CMR) in patients with heart failure (HF) and a reduced left ventricular ejection fraction (LVEF), with or without elevation of PAWP or LVEDP.

METHODS

We retrospectively identified 121 patients with LVEF < 50% who had undergone right heart catheterization (RHC) and CMR. LVEDP data were available for 75 patients.

RESULTS

The mean age of the study sample was 63 ± 14 years, the mean LVEF was 32 ± 10%, and 72% were men. About 53% of the patients had an elevated PAWP (>15 mmHg). In multivariable logistic regression analysis, NT-proBNP, left atrial ejection fraction (LAEF), and LV end-systolic volume index independently predicted an elevated PAWP. Of the 75 patients with available LVEDP data, 79% had an elevated LVEDP, and 70% had concomitant PAWP elevation. By contrast, all but one patient with elevated PAWP and half of the patients with normal PAWP had concomitant LVEDP elevation. The Bland-Altman plot revealed a systematic bias of +5.0 mmHg between LVEDP and PAWP. Notably, LAEF was the only CMR variable that differed significantly between patients with elevated LVEDP and a PAWP ≤ or >15 mmHg.

CONCLUSIONS

In patients with LVEF < 50%, a normal PAWP did not reliably exclude LHD, and an elevated LVEDP was more frequent than an elevated PAWP. LAEF was the most relevant determinant of an increased PAWP, suggesting that a preserved LAEF in LHD may protect against backward failure into the lungs and the subsequent increase in pulmonary pressure.

Catheter ablation of atrial arrhythmias in cardiac amyloidosis: Impact on heart failure and mortality

BACKGROUND

Atrial arrhythmias (AA) commonly affect patients with cardiac amyloidosis (CA) and are a contributing risk factor for the development of heart failure (HF). This study sought to investigate the long-term efficacy and impact of catheter ablation on HF progression in patients with CA and AA.

METHODS

Thirty-one patients with CA and AA undergoing catheter ablation were retrospectively included (transthyretin-ATTR CA 61% and light chain-AL CA 39%). AA subtypes included atrial fibrillation (AFib) in 22 (paroxysmal in 10 and persistent in 12), atrial flutter (AFl) in 17 and atrial tachycardia (AT) in 11 patients. Long-term AA recurrence rates were evaluated along with the impact of sinus rhythm (SR) maintenance on HF and mortality.

RESULTS

AA recurrence was observed in 14 patients (45%) at a median of 3.5 months (AFib n = 8, AT n = 6, AFl = 0). Post-cardioversion, medical therapy or catheter ablation, 10 patients (32%) remained in permanent AA. Over a median follow-up of 19 months, all-cause mortality was 39% (n = 12): 3 with end-stage HF, 5 due to late complications of CA, 1 sudden cardiac death, 1 stroke, 1 COVID 19 (and one unknown). With maintenance of SR following catheter ablation, significant reductions in serum creatinine and natriuretic peptide levels were observed with improvements in NYHA class. Two patients required hospitalization for HF in the SR maintenance cohort compared to 5 patients in the AA recurrence cohort (p = 0.1). All 3 patients with deaths secondary to HF had AA recurrence compared to 11 out of the 28 patients whom were long-term survivors or deaths not related to HF (p = 0.04). All-cause mortality was not associated with AA recurrence.

CONCLUSION

This study demonstrates moderate long-term efficacy of SR maintenance with catheter ablation for AA in patients with CA. Improvements in clinical and biological status with positive trends in HF mortality are observed if SR can be maintained.

Myofilament dysfunction in diastolic heart failure

Diastolic heart failure (DHF), in which impaired ventricular filling leads to typical heart failure symptoms, represents over 50% of all heart failure cases and is linked with risk factors, including metabolic syndrome, hypertension, diabetes, and aging. A substantial proportion of patients with this disorder maintain normal left ventricular systolic function, as assessed by ejection fraction. Despite the high prevalence of DHF, no effective therapeutic agents are available to treat this condition, partially because the molecular mechanisms of diastolic dysfunction remain poorly understood. As such, by focusing on the underlying molecular and cellular processes contributing to DHF can yield new insights that can represent an exciting new avenue and propose a novel therapeutic approach for DHF treatment. This review discusses new developments from basic and clinical/translational research to highlight current knowledge gaps, help define molecular determinants of diastolic dysfunction, and clarify new targets for treatment.

First-pass perfusion cardiovascular magnetic resonance parameters as surrogate markers for left ventricular diastolic dysfunction: a validation against cardiac catheterization

OBJECTIVES

The non-invasive assessment of left ventricular (LV) diastolic dysfunction remains a challenge. The role of first-pass perfusion cardiac magnetic resonance (CMR) parameters in quantitative hemodynamic analyses has been reported. We therefore aimed to validate the diagnostic ability and accuracy of such parameters against cardiac catheterization for LV diastolic dysfunction in patients with left heart disease (LHD).

METHODS

We retrospectively enrolled 77 LHD patients who underwent CMR imaging and cardiac catheterization. LV diastolic dysfunction was defined as pulmonary capillary wedge pressure (PCWP) or LV end-diastolic pressure (LVEDP) > 12 mmHg on catheterization. On first-pass perfusion CMR imaging, pulmonary transit time (PTT) was measured as the time for blood to pass from the left ventricle to the right ventricle (RV) through the pulmonary vasculature. Pulmonary transit beat (PTB) was the number of cardiac cycles within the interval, and pulmonary blood volume indexed to body surface area (PBVi) was the product of PTB and RV stroke volume index (RVSVi).

RESULTS

Of the 77 LHD patients, 53 (68.83%) were found to have LV diastolic dysfunction, and showed significantly higher PTTc, PTB, and PBVi (p < 0.05) compared with those without. In multivariate analyses, only PTTc and PTB were identified as independent predictors of LV diastolic dysfunction (p < 0.05). With an optimal cutoff of 11.9 s, PTTc yielded the best diagnostic performance for LV diastolic dysfunction (area under the curve = 0.83, p < 0.001).

CONCLUSIONS

PTTc may represent a non-invasive quantitative surrogate marker for the detection and assessment of diastolic dysfunction in LHD patients.

KEY POINTS

• PTTc yielded the best diagnostic accuracy for diastolic dysfunction, with an optimal cutoff of 11.9 s, and a specificity of 100%. • PTTc and PTB were found to be independent predictors of LV diastolic dysfunction across different multivariate models with high reproducibility. • PTTc is a promising non-invasive surrogate marker for the detection and assessment of diastolic dysfunction in LHD patients.

Clinical Outcomes of Autologous Stem Cell-Patch Implantation for Patients With Heart Failure With Nonischemic Dilated Cardiomyopathy

Background

Clinical effectiveness of autologous skeletal cell‐patch implantation for nonischemic dilated cardiomyopathy has not been clearly elucidated in clinical settings. This clinical study aimed to determine the feasibility, safety, therapeutic efficacy, and the predictor of responders of this treatment in patients with nonischemic dilated cardiomyopathy.

Methods and Results

Twenty‐four nonischemic dilated cardiomyopathy patients with left ventricular ejection fraction <35% on optimal medical therapy were enrolled. Autologous cell patches were implanted over the surface of the left ventricle through left minithoracotomy without procedure‐related complications and lethal arrhythmia. We identified 13 responders and 11 nonresponders using the combined indicator of a major cardiac adverse event and incidence of heart failure event. In the responders, symptoms, exercise capacity, and cardiac performance were improved postoperatively (New York Heart Association class II 7 [54%] and III 6 [46%] to New York Heart Association class II 12 [92%] and I 1 [8%], P<0.05, 6‐minute walk test; 471 m [370–541 m] to 525 m [425–555 m], P<0.05, left ventricular stroke work index; 31.1 g·m²·beat [22.7–35.5 g·m²·beat] to 32.8 g·m²·beat [28–38.5 g·m²·beat], P=0.21). However, such improvement was not observed in the nonresponders. In responders, the actuarial survival rate was 90.9±8.7% at 5 years, which was superior to the estimated survival rate of 70.9±5.4% using the Seattle Heart Failure Model. However, they were similar in nonresponders (47.7±21.6% and 56.3±8.1%, respectively). Multivariate regression model with B‐type natriuretic peptide, pulmonary capillary wedge pressure, and expression of histone H3K4me3 (H3 lysine 4 trimethylation) strongly predicted the responder of this treatment (B‐type natriuretic peptide: odds ratio [OR], 0.96; pulmonary capillary wedge pressure: ​OR, 0.58; H3K4me3: OR, 1.35, receiver operating characteristic–area under the curve, 0.96, P<0.001).

Conclusions

This clinical trial demonstrated that autologous skeletal stem cell–patch implantation might promise functional recovery and good clinical outcome in selected patients with nonischemic dilated cardiomyopathy, in addition to safety and feasibility.

Registration

URL: http://www.umin.ac.jp/english/. Unique identifiers: UMIN000003273, UMIN0000012906 and UMIN000015892.

Modulation of left ventricular diastolic filling during exercise in persons with cervical motor incomplete spinal cord injury

PURPOSE

To characterize left ventricular diastolic function during an exertional challenge in adults with incomplete cervical spinal cord Injury (icSCI).

METHODS

In this cross-sectional study, a two-group convenience sample was used to compare left ventricular LV diastolic performance during a 5-10 W·min-1 incremental arm ergometer exercise protocol, using bioimpedance cardiography. Subjects were eight males with cervical incomplete spinal cord injury (icSCI; C5-C7: age 39 ± 14 years) versus eight able-bodied males (CON: age 38 ± 13 years). Left ventricular (LV) diastolic indices included end-diastolic volume (EDV) and early diastolic filling ratio (EDFR). LV ejection time (LVET), inotropic index (dZ/dT2) and stroke volume (SV) were compared between the groups at peak exercise, and maximum workload for the icSCI group (isomax).

RESULTS

EDV (at peak exercise:131.4 ± 7.3 vs 188.78 ± 9.4, p < 0.001; at isomax: 131.4 ± 7.3 vs 169 ± 23, p = 0.0009) and EDFR (at peak exercise 73 ± 14% vs 119 ± 11%, p = 0.006; at isomax 94 ± 10; p = 0.009) were significantly reduced in icSCI compared to CON, respectively. Significant differences in LVET (icSCI: 273 ± 48 vs CON: 305 ± 68; p = 0.1) and dZ/dT2 (icSCI: 0.64 ± 0.11 vs CON: 0.85 ± 0.31; p = 0.1) were not observed at isomax, despite a significant decrease in SV in the subjects with icSCI (77.1 ± 6.05 mL vs 105.8 ± 9.2 mL, p < 0.00) CONCLUSION: Left ventricular filling was impaired in the subjects with icSCI as evidenced at both peak exercise and isomax. It is likely that restrictions on the skeletal muscle pump mechanized the impairment but increased left ventricular wall stiffness could not be excluded as a mediator.

Increased atrial contraction contribution to left ventricular filling during early septic shock

PURPOSE

To assess the atrial systolic function and the contribution of atrial contraction to left ventricular (LV) filling in septic shock patients as compared with healthy volunteers.

METHODS

Twenty-seven septic patients evaluated during first 48 h of ICU admission and compared with 27 healthy volunteers. Left atrial (LA) contraction contribution to LV filling was calculated as the active emptying atrial volume/LV end-diastolic volume. Atrial systolic function was evaluated with the atrial kinetic force [LAKE = 0.5 × blood density × LVV_active × (peak A velocity)²] and atrial ejection force [LASF = 0.5 × blood density × mitral annulus area × (peak A velocity)²].

RESULTS

LV ejection fraction was lower in septic patients than in control group: 51 ± 14%vs 60 ± 6% (p < 0.01). Contribution of LA contraction to LV preload was greater in septic patients than in normal subjects (26.7 ± 11.3% vs 15.9 ± 5.9%, p < 0.001), even if adjusted for age (0.49 ± 0.19 vs 0.35 ± 0.13, p = 0.004). LAKE and LASF were also significantly larger in septic patients than in normal subjects (21.8 ± 9.1 vs 7.3 ± 3 kdynes·cm, p < 0.001; 16.1 ± 11.7 vs 9.8 ± 4.3 kdynes, p = 0.048, respectively), and remained unchanged during the next 48 h.

CONCLUSION

In septic shock patients, LA systolic function increased and greatly contributed to support LV filling. These results highlight the role of preserving atrial contraction on the hemodynamic resuscitation in early septic shock.

Left Ventricular Relaxation Half-Time as a Predictor of Cardiac Events in Idiopathic Dilated Cardiomyopathy and Hypertrophic Cardiomyopathy With Left Ventricular Systolic and/or Diastolic Dysfunction

PURPOSE

Diastolic dysfunction preceding systolic dysfunction is considered an important interaction in cardiomyopathy with poor prognosis. The aim of this study was to compare left ventricular (LV) isovolumic relaxation with the other parameters as a potential prognostic marker for patients with idiopathic dilated cardiomyopathy (IDC) and hypertrophic cardiomyopathy (HC).

METHODS

A total of 145 patients with IDC and 116 with HC were evaluated for hemodynamic parameters; LV pressure was directly measured by a micromanometer catheter, and relaxation half-time (T_1/2) was used to determine LV isovolumic relaxation. The median follow-up period was 4.7 years.

RESULTS

The mean ages of the patients with IDC and HC were 52.0 ± 12.0 and 57.1 ± 12.4 years, respectively. Each patient group was further divided into 2 groups based on the median value of T_1/2: (1) <41.0 ms (D-L group) and ≥41.0 ms (D-H group) (2) <38.5 ms (H-L group) and ≥38.5 ms (H-H group). Kaplan-Meier analysis showed a significantly higher probability of cardiac events in the D-H group than in the D-L group (p = 0.001) and in the H-H group than in the H-L group (p = 0.028). Further, Cox proportional hazard regression analysis revealed that T_1/2 was an independent predictor of cardiac events for patients with IDC (hazard ratio 1.109; p = 0.007) and HC (hazard ratio 1.062; p = 0.041). In conclusion, regardless of the type of cardiomyopathy, T_1/2 as a measure of LV isovolumic relaxation function was found to be associated with the occurrence of cardiac events.

Improved diastolic function in type 2 diabetes after a six month liraglutide treatment

AIMS

To investigate whether liraglutide improves diastolic function in type 2 diabetes.

METHODS

Thirty-seven patients with type 2 diabetes who began liraglutide therapy between June 2013 and May 2014 were enrolled in this observational, prospective study. 26 patients received liraglutide therapy for at least 6months. The remaining 11 patients withdrew from liraglutide therapy during the first month, were started on other hypoglycaemic therapies and formed the control group. Anthropometric, metabolic and echocardiographic parameters including pulsed wave tissue Doppler imaging were evaluated at baseline and at 6months.

RESULTS

In the liraglutide group the early diastolic mitral annulus velocity on the lateral (e-lat) and medial (e-med) sides of the mitral annulus increased from 9.2±3.4 to 11.6±4.7cm/s (p<0.001) and from 6.9±1.7 to 8.4±2.6cm/s (p<0.003), respectively. The ratio of early-to-late velocities on the lateral and medial sides of the mitral annulus increased from 0.7±0.3 to 0.9±0.4 (p<0.001) and from 0.5±0.1 to 0.6±0.1 (p<0.02), respectively. The ratio of early diastolic mitral inflow velocity to early diastolic myocardial relaxation velocity decreased from 10.7±4.3 to 8.5±2.5 (p<0.005). No improvements in diastolic function was detected in the control group. Glucose control improved similarly in both groups: HA1bc -1.5% (-17mmol/mol) vs -1.3% (-14mmol/mol), p=0.67.

CONCLUSIONS

In patients with type 2 diabetes, 6months liraglutide treatment was associated with a significant improvement in diastolic function.

Congestive heart failure with normal ejection fraction

Clinicians must remain undaunted when history, physical examination, and chest radiography suggest congestive heart failure but left ventricular systolic function is normal. Many of these patients have diastolic dysfunction, and standard therapy for left ventricular systolic dysfunction is often ineffectual or detrimental. Noninvasive testing is subject to many pitfalls but may confirm a clinical suspicion and provide indications to treat or to proceed with invasive testing. In the absence of clinical signs and symptoms of congestive failure, however, abnormal diastolic indexes should not be interpreted as diagnostic of diastolic dysfunction and are not an indication to treat.

Improvement of left ventricular filling by ivabradine during chronic hypertension: involvement of contraction-relaxation coupling

Chronic hypertension is associated with left ventricular (LV) hypertrophy and LV diastolic dysfunction with impaired isovolumic relaxation and abnormal LV filling. Increased heart rate (HR) worsens these alterations. We investigated whether the I f channel blocker ivabradine exerts beneficial effects on LV filling dynamic. In this setting, we also evaluated the relationship between LV filling and isovolumic contraction as a consequence of contraction-relaxation coupling. Therefore, hypertension was induced by a continuous infusion of angiotensin II during 28 days in 10 chronically instrumented pigs. LV function was investigated after stopping angiotensin II infusion to offset the changes in loading conditions. In the normal heart, LV relaxation filling, LV early filling, LV peak early filling rate were positively correlated to HR. In contrast, these parameters were significantly reduced at day 28 vs. day 0 (18, 42, and 26 %, respectively) despite the increase in HR (108 ± 6 beats/min vs. 73 ± 2 beats/min, respectively). These abnormalities were corrected by acute administration of ivabradine (1 mg/kg, iv). Ivabradine still exerted these effects when HR was controlled at 150 beats/min by atrial pacing. Interestingly, LV relaxation filling, LV early filling and LV peak early filling were strongly correlated with both isovolumic contraction and relaxation. In conclusion, ivabradine improves LV filling during chronic hypertension. The mechanism involves LV contraction-relaxation coupling through normalization of isovolumic contraction and relaxation as well as HR-independent mechanisms.

The Short-Term Effects of Ketogenic Diet on Cardiac Ventricular Functions in Epileptic Children

OBJECTIVE

Our primary aim was to determine the short-term effects of a ketogenic diet on cardiac ventricular function in patients with refractory epilepsy.

METHODS

Thirty-eight drug-resistant epileptic patients who were treated with a ketogenic diet were enrolled in this prospective study. Echocardiography was performed on all patients before beginning the ketogenic diet and after the sixth month of therapy. Two-dimensional, M-mode, color flow, spectral Doppler, and pulsed-wave tissue Doppler imaging measurements were performed on all patients.

RESULTS

The median age of the 32 patients was 45.5 months, and 22 (57.8%) of them were male. Body weight, height, and body mass index increased significantly at the sixth month of therapy when compared with baseline values (P < 0.05). Baseline variables assessed by conventional M-mode echocardiography showed no significant difference at month 6 (P > 0.05). Doppler flow indices of mitral annulus and tricuspid annulus velocity of patients at baseline and month 6 showed no significant differences (P > 0.05). Tricuspid annular E/A ratio was lower at month 6 (P < 0.05). Although mitral annulus tissue Doppler imaging studies showed no significant difference (P > 0.05), there was a decrease in Ea velocity and Ea/Aa ratio gathered from tricuspid annulus at month 6 compared with baseline (P < 0.05).

CONCLUSION

A 6-month duration ketogenic diet does not impair left ventricular functions in children with refractory epilepsy; however, it may be associated with a right ventricular diastolic dysfunction.

Intermediate Diastolic Velocity as a Parameter of Cardiac Dysfunction in Growth-Restricted Fetuses

OBJECTIVE

To evaluate the intermediate intracardiac diastolic velocities in fetuses with growth restriction.

METHODS

Doppler waveforms of the two atrioventricular valves were obtained. Peak velocities of the E (early) and A (atrial) components, and the lowest intermediate velocity (IDV) between them, were measured in 400 normally grown and in 100 growth-restricted fetuses. The prevalence of abnormal IDV, E/IDV, and A/IDV ratios in fetuses presenting with perinatal death or acidemia at birth (pH ≤7.1) was estimated.

RESULTS

IDV was significantly lower and E/IDV ratios significantly higher in the two ventricles of growth-restricted fetuses with reduced diastolic velocities in the umbilical artery (p < 0.05). In 13 fetuses presenting with perinatal death or acidemia at birth, 11 (85%) had either an E/IDV or A/IDV ratio >95th percentile, whereas 5 (38%) showed absent or reversed atrial velocities in the ductus venosus (DV-ARAV; p < 0.04). Fetuses without DV-ARAV but with elevated E/IDV ratios in either ventricle were nearly 7-fold more likely to have perinatal demise or acidemia at birth (OR 6.9, 95% CI 1.4-34) than those with E/IDV ratios <95th percentile.

CONCLUSION

The E/IDV and A/IDV ratios in the two cardiac ventricles might provide information about the risk of perinatal demise or acidemia in growth-restricted fetuses.

Effect of exercise, heat stress and dehydration on myocardial performance

BACKGROUND

Myocardial dysfunction is a well-documented outcome of extended periods of high cardiac output. Whether similar effects occur during firefighting, an occupation characterized by repeated periods of work compounded by dehydration and heat stress, is uncertain.

AIMS

To investigate the independent and combined effects of moderate heat stress and dehydration on indicators of myocardial performance following intermittent, submaximal treadmill exercise while wearing personal protective equipment (PPE).

METHODS

Twelve aerobically fit young men (age 21.5±2.6 years; maximal oxygen uptake [VO2max] 60.3±4.4ml kg(-1) min(-1)) performed intermittent treadmill walking exercise consisting of three 20min bouts at an intensity of ~40% VO2max separated by two periods of rest in four different conditions in random order: (i) no heat stress-euhydrated, (ii) heat stress-euhydrated (heat stress created by wearing PPE, (iii) no heat stress-dehydrated and (iv) heat stress-dehydrated. We measured core temperature by a telemetric gastrointestinal pill. We determined cardiac variables by standard echocardiographic techniques immediately before and ~30min after exercise.

RESULTS

We recorded no significant changes in markers of systolic (ejection fraction, shortening fraction, tissue Doppler-S) or diastolic (mitral peak E velocity, tissue Doppler-E' and E/E') function following exercise in any of the four conditions.

CONCLUSIONS

In this model of exercise designed to mimic the work, heat stress and dehydration associated with firefighting activities, we observed no negative effects on myocardial inotropic or lusitropic function.

Effect of exercise training on diastolic function in metabolic syndrome

It has been reported that metabolic syndrome (MetS) impairs left ventricular (LV) diastolic function. The objective of this study was to determine whether exercise training can improve LV diastolic function in individuals with MetS. Twenty-eight individuals with MetS (9 males, aged 60 ± 5 years) underwent a 1-year combined endurance and resistance exercise training program; maximal aerobic capacity (V̇O2max), blood pressure, blood markers, and LV diastolic function were measured at weeks 0, 12, 24, and 52 throughout the training. Pulsed wave Doppler echocardiography across the mitral valve was used to assess peak early flow velocity (E) and peak atrial flow velocity (A) to determine the E/A ratio. Individuals with MetS had a reversed E/A ratio, suggesting impaired LV relaxation, the first stage of LV diastolic dysfunction. Exercise training reduced systolic blood pressure (SBP) (129 ± 14 to 120 ± 12 mm Hg; p < 0.01) and increased V̇O2max (29.2 ± 6.3 to 33.4 ± 6.5 mL·kg−1·min−1; p < 0.01) and high-density lipoprotein cholesterol (1.04 ± 0.21 to 1.12 ± 0.25 mmol·L−1; p = 0.02), but did not improve LV diastolic function. Individuals with an E/A ratio <1 at the start of training had a tendency toward an increased E/A ratio (p = 0.12) accompanied by significant decreases in SBP and increases in V̇O2max with exercise training. Combined resistance and aerobic exercise training improved cardiometabolic health but did not improve the impaired LV diastolic function of individuals with MetS.

Left atrial volume index over late diastolic mitral annulus velocity (LAVi/A') is a useful echo index to identify advanced diastolic dysfunction and predict clinical outcomes

BACKGROUND

Combined interpretation of late diastolic mitral annulus velocity (A') with left atrial volume index (LAVi) may have additional benefits in the assessment of diastolic dysfunction.

HYPOTHESIS

The LAVi/A' ratio may be useful in the identifying advanced diastolic dysfunction (ADD) and predicting clinical outcomes in patients with dyspnea.

METHODS

We enrolled 395 consecutive patients hospitalized with dyspnea (New York Heart Association class II-IV) and performed transthoracic Doppler echocardiography and B-type natriuretic peptide (BNP) measurement. LAVi/A' values were evaluated in terms of diagnosing ADD and predicting clinical outcome.

RESULTS

On the receiver operation characteristic curve analysis for the determination of ADD, the area under the curves of LAVi/A' in the entire population was comparable to those of BNP (0.94 vs 0.93, P = 0.845) and mitral E/E' (0.94 vs 0.93, P = 0.614) and higher than that of LAVi (0.94 vs 0.87; P = 0.014). A LAVi/A' of 4.0 was the best cut-off value to identify ADD. During a median follow-up of 31.9 months (range, 0.3 to 45.7 months), the group with LAVi/A' ≥4.0 had a higher incidence of primary composite outcomes (cardiac death and/or rehospitalization for heart failure) than the group with LAVi/A'<4.0 (25.0% vs 3.3%, P < 0.001). LAVi/A' ≥4.0 was an independent predictor of clinical outcomes (odds ratio, 3.245; 95% confidence interval, 1.386-7.598; P = 0.007).

CONCLUSIONS

As a new echo index, LAVi/A' is a useful parameter to identify ADD and predict clinical outcomes in patients with dyspnea.

Transthoracic bioimpedance and brain natriuretic peptide levels accurately indicate additional diastolic dysfunction in patients with chronic advanced systolic heart failure

AIMS

Diastolic dysfunction in patients with heart failure has prognostic relevance, possibly because of its relationship with worsening haemodynamic status. In the quest for simpler indexes of haemodynamic status in patients, brain natriuretic peptide (BNP) levels have been proposed as a surrogate of diastolic function. To date, the value of combining BNP levels with non-invasive haemodynamic monitoring by transthoracic electric bioimpedance (TEB) for the prediction of diastolic function has not been evaluated.

METHODS AND RESULTS

We compared left ventricular diastolic function measured by tissue Doppler imaging (TDI) with TEB results and BNP levels in 120 patients with chronic advanced systolic heart failure on optimal treatment (70 +/- 9 years, NYHA 2.4 +/- 0.8, ejection fraction 31 +/- 5%). Of the TEB variables measured, we only considered thoracic fluid content (TFC). To describe diastolic function, we used the TDI of the velocity of displacement of the mitral annulus (E') and the ratio E/E'. In all patients, E/E' was significantly related to TFC and to BNP levels (P < 0.001). Moreover, the combination of BNP > or = 350 pg/mL and TFC > or = 35/kOmega identified patients with diastolic dysfunction (defined as E/E' > or = 15) with high sensitivity and specificity (95 and 94%, respectively).

CONCLUSION

The combination of transthoracic bioimpedance monitoring and BNP measurement accurately indicated the presence of diastolic dysfunction in most patients. These user-friendly and operator-independent tools may be useful as a screening assessment for diastolic dysfunction, and consequently abnormal central haemodynamic status, either in ambulatory patients or when an adequate echocardiographic evaluation is not readily available.

Multi-modality imaging of diastolic function

Non-invasive evaluation of diastolic function continues to play a critical role in furthering our understanding of diastole, improving the diagnosis of diastolic dysfunction, evaluating left ventricular filling pressures, and providing important prognostic information for patients with heart failure. Echocardiography, cardiovascular magnetic resonance, and nuclear cardiology each provide important tools for evaluating diastolic performance. This review will focus on the techniques from multiple cardiovascular imaging modalities which have been used for the clinical assessment of diastolic function.

Evaluation of left ventricular diastolic function from the pattern of left ventricular filling

The pattern of left ventricular (LV) filling can be determined by Doppler echocardiography. Normally most LV filling occurs early in diastole, with some additional filling occurring during atrial systole, late in diastole. In the absence of mitral stenosis, three patterns of LV filling indicate progressively greater diastolic dysfunction: (1) Reduced early diastolic filling with a compensatory increase in importance of atrial filling, termed a pattern of "impaired relaxation;" (2) "pseudo-normalization" with most filling early in diastole but with rapid deceleration of mitral flow; and (3) "restricted filling" with almost all filling of the LV occurring very early in diastole in association with very rapid deceleration of mitral flow. A large, prolonged atrial regurgitant flow in the pulmonary veins also indicates impaired diastolic performance. The time for early filling deceleration is predominantly determined by LV stiffness: the shorter the deceleration time, the stiffer the LV. Patients with short deceleration time have a poor prognosis.

Left ventricular longitudinal relaxation velocity: a sensitive index of diastolic function

OBJECTIVE

The aim of the present study was to evaluate maximal longitudinal relaxation velocity of the left ventricle as an index of diastolic function.

DESIGN

Sixty-four consecutive patients with known or suspected heart failure, referred to echocardiography, were investigated by M-mode recordings and pulsed tissue Doppler recordings of the maximal early diastolic velocity of the mitral annulus. The classification as true positive or true negative cases was done using age-related reference values of mitral inflow and pulmonary vein flow.

RESULTS

A rather high sensitivity of 89% was found for M-mode recordings and a slightly lower sensitivity of 81% for pulsed tissue Doppler recordings. A moderate high specificity was found: 81% for M-mode recordings and 78% for tissue Doppler recordings. The velocities recorded by pulsed tissue Doppler were about 30% higher than velocities recorded by M-mode.

CONCLUSION

Maximal relaxation velocity in the long axis of the left ventricle, recorded by either M-mode or tissue Doppler, can be used for assessment of diastolic function but reference values cannot be used interchangeably.

Heart failure with normal left ventricular ejection fraction: what is the evidence?

Heart failure with a normal ejection fraction (HFNEF) is a common clinical problem with many unsolved questions regarding pathophysiology, diagnosis, and therapy. Although the term diastolic heart failure has been abandoned, diastolic left ventricular (LV) dysfunction together with combined systolic ventricular and arterial stiffening are considered to be the main pathophysiologic mechanisms in HFNEF. Current guidelines define HFNEF by symptoms or signs of heart failure in the presence of LV ejection fraction of more than 50%, but with additional evidence of LV diastolic dysfunction. Definite diagnosis of HFNEF requires exclusion of valvular heart disease, constrictive pericarditis, and several noncardiac diseases. Echocardiographic assessment of the tissue Doppler-derived filling index E/E', which is the ratio of the peak early mitral valve flow velocity to the peak early diastolic mitral annular velocity, should improve the noninvasive estimation of filling pressures in suspected HFNEF. Elevated plasma levels of natriuretic peptides may confirm HFNEF if tissue Doppler echocardiography is inconclusive. Treatment of HFNEF is symptom oriented and mainly based on pathophysiologic assumptions such as heart rate reduction, blood pressure control, and maintenance of sinus rhythm. In contrast to heart failure with reduced ejection fraction, large-scale randomized controlled drug trials for HFNEF are scarce and could not demonstrate mortality reduction so far.

Plasma big-endothelin levels, cardiac autonomic neuropathy, and cardiac functions in patients with insulin-dependent diabetes mellitus

BACKGROUND

The alteration of endothelin (ET) levels in diabetic patients with cardiac autonomic neuropathy (CAN) has not been studied extensively and its correlation with cardiac function parameters has not been discussed.

HYPOTHESIS

The aim of the present study was to discuss the correlation between the degree of cardiac autonomic neuropathy, plasma big-ET levels, and cardiac functions in diabetic patients who were clinically free of cardiovascular disease.

METHODS

Twenty subjects (32.1 +/- 7.8 years, 11 men, 9 women) with insulin-dependent diabetes mellitus (IDDM) were studied to evaluate the relationship between circulating big-endothelin (big-ET1) levels, CAN, and cardiac functions. The severity of CAN was scored according to Ewing's criteria. Cardiac functions were assessed using Doppler echocardiography.

RESULTS

Left ventricular systolic function in the patient group was within normal limits and comparable with the values of the control group (n = 10). The mean E/A values of diabetics with CAN (1.15 +/- 0.33, p = 0.004) and without CAN (1.34 +/- 0.17) were significantly lower than those of controls (1.57 +/- 0.27). Diabetics with CAN had significantly higher big-ET1 values (81.1 +/- 94 pg/ml) compared with others (12.4 +/- 5.9 and 21.1 +/- 17.7 pg/ml, p = 0.04). Circulating big-ET1 levels showed a significant correlation with E/A values in the control group (p = 0.01, r = -0.7) and with peak A values (p = 0.003, r = 0.64) in diabetics. The CAN score correlated negatively with E/A values (p = 0.01, r = 0.54).

CONCLUSIONS

High big-ET levels might have an important role in the pathogenesis or consequences of diastolic dysfunction in diabetics with CAN. Their role in cardiac autonomic neuropathy and diastolic dysfunction should be investigated further.

The assessment of diastolic function in patients with rheumatoid arthritis

Introduction. Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune chronic disease. In comparison with the overall population, mortality and morbidity of RA patients are increased due to cardiovascular diseases. There is increasing evidence that autoimmunity mechanisms are included in pathogenesis of cardiovascular diseases. Isolated disorder of diastolic function can, even with normal heart contractility, lead to heart failure. The aim of this study was to assess diastolic function in RA patients and determine factors causing diastolic dysfunction. Material and methods. The study included 88 patients with RA treated at Rheumatology Department, Clinical Hospital Centre, Zemun. All the patients were thoroughly examined (clinical findings, laboratory and echocardiographic examination). All parameters of diastolic function (mitral and pulmonary flow) were measured. Results. In RA patients 98,9% had diastolic function disorder. This parameter had been changed prior to clinical signs of heart failure and decrease of ejection fraction. Indicators of diastolic function, velocities E, A and their ratio VE/VA, as well as velocities S, D and their ratio VS/VD were lower in patients with positive rheumatoid factor. The patients' age (p<0.01), duration of the disease (p<0.05), high level of cholesterol (p<0.05), triglycerides (p<0.05) and arterial hypertension (p<0.05) were significant factors considerably affecting diastolic function. Conclusion. These findings suggest subclinical myocardial disorder in a great number of RA patients. Apart from early and aggressive treatment of the chronic inflammatory process, it is also necessary to prevent further heart complications by timely recognition and treatment of 'standard' risk factors for cardiovascular diseases.

Diastolic dysfunction in exercise and its role for exercise capacity

Diastolic dysfunction is frequent in elderly subjects and in patients with left ventricular hypertrophy, vascular disease and diabetes mellitus. Patients with diastolic dysfunction demonstrate a reduced exercise capacity and might suffer from congestive heart failure (CHF). Presence of symptoms of CHF in the setting of a normal systolic function is referred to as heart failure with normal ejection fraction (HFNEF) or, if evidence of an impaired diastolic function is observed, as diastolic heart failure (DHF). Reduced exercise capacity in diastolic dysfunction results from a number of pathophysiological alterations such as slowed myocardial relaxation, reduced myocardial distensibility, elevated filling pressures, and reduced ventricular suction forces. These alterations limit the increase of ventricular diastolic filling and cardiac output during exercise and lead to pulmonary congestion. In healthy subjects, exercise training can enhance diastolic function and exercise capacity and prevent deterioration of diastolic function in the course of aging. In patients with diastolic dysfunction, exercise capacity can be enhanced by exercise training and pharmacological treatment, whereas improvement of diastolic function can only be observed in few patients.

Diastolic dysfunction: a link between hypertension and heart failure

Diastolic heart failure is characterized by the symptoms and signs of heart failure, a preserved ejection fraction and abnormal left ventricular (LV) diastolic function caused by a decreased LV compliance and relaxation. The signs and symptoms of diastolic heart failure are indistinguishable from those of heart failure related to systolic dysfunction; therefore, the diagnosis of diastolic heart failure is often one of exclusion. The majority of patients with heart failure and preserved ejection fraction have a history of hypertension. Hypertension induces a compensatory thickening of the ventricular wall in an attempt to normalize wall stress, which results in LV concentric hypertrophy, which in turn decreases LV compliance and LV diastolic filling. There is an abnormal accumulation of fibrillar collagen accompanying the hypertension-induced LV hypertrophy, which is also associated with decreased compliance and LV diastolic dysfunction. There are no specific guidelines for treating diastolic heart failure, but pharmacological treatment should be directed at normalizing blood pressure, promoting regression of LV hypertrophy, preventing tachycardia and treating symptoms of congestion. Preventive strategies directed toward an early and aggressive blood pressure control are likely to offer the greatest promise for reducing the incidence of diastolic heart failure.

E/E' ratio is more sensitive than E/A ratio for detection of left ventricular diastolic dysfunction in systemic lupus erythematosus

Abstract

To investigate whether the ratio of mitral peak velocity of early filling (E) to early diastolic mitral annular velocity (E') (E/E' ratio) can detect left ventricular diastolic dysfunction more sensitively than the ratio of E to mitral peak velocity of late filling (A) (E/A ratio) in systemic lupus erythematosus (SLE). A total of 137 patients with SLE were investigated and compared with 110 age-matched and sex-matched controls retrospectively. Two-dimensional echocardiography and M-mode echocardiography including conventional and tissue Doppler imaging were performed. There were no differences in the left ventricle ejection fractions and the mean E/A ratio between the two groups. However, the mean E/E' ratio of patients was higher than that of the controls (10.4 ± 4.0 vs 7.7 ± 2.1, P < 0.01). Significantly higher left ventricle ejection fractions and lower E/E' ratio were found in patients with systemic lupus erythematosus receiving angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker than those not receiving ( P < 0.05). Our study showed that the E/E' ratio is more sensitive than the E/A ratio for detection of the left ventricle diastolic dysfunction. Furthermore, patients who had received angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker treatment showed significantly better preservation of both systolic and diastolic function of left ventricle in comparison with those who had not received.

The kinematic filling efficiency index of the left ventricle: contrasting normal vs. diabetic physiology

An index of filling efficiency incorporating stiffness and relaxation (S&R) parameters has not been derived or validated, although numerous studies have focused on the effects of altered relaxation or stiffness on early rapid filling and diastolic function. Previous studies show that S&R parameters can be obtained from early rapid filling (Doppler E-wave) via kinematic modeling. E-wave contours are governed by harmonic oscillatory motion modeled via the parameterized diastolic filling (PDF) formalism. The previously validated model determines three (unique) oscillator parameters from each E-wave having established physiological analogues: x(o) (load), c (relaxation/viscoelasticity) and k (chamber stiffness). We define the dimensionless, filling-volume-based kinematic filling efficiency index (KFEI) as the ratio of the velocity-time integral (VTI) of the actual clinical E-wave contour fit via PDF to the VTI of the PDF model-predicted ideal E-wave contour having the same x(o) and k, but with no resistance to filling (c = 0). To validate the new index, Doppler E-waves from 36 patients with normal ventricular function, 17 diabetic and 19 well-matched non-diabetic controls, were analyzed. E-wave parameters x(o), c and k and KFEI were computed for each patient and compared. In concordance with prior human and animal studies in which c differentiated between normal and diabetic hearts, KFEI differentiated (p < 0.001) between nondiabetics (55.8% +/- 3.3%) and diabetics (49.1% +/- 3.3%). Thus, the new index introduces and validates the concept of filling efficiency, and, using diabetes as a working example, provides quantitative and mechanistic insight into how S&R affect ventricular filling efficiency.

How to diagnose diastolic heart failure: a consensus statement on the diagnosis of heart failure with normal left ventricular ejection fraction by the Heart Failure and Echocardiography Associations of the European Society of Cardiology

Diastolic heart failure (DHF) currently accounts for more than 50% of all heart failure patients. DHF is also referred to as heart failure with normal left ventricular (LV) ejection fraction (HFNEF) to indicate that HFNEF could be a precursor of heart failure with reduced LVEF. Because of improved cardiac imaging and because of widespread clinical use of plasma levels of natriuretic peptides, diagnostic criteria for HFNEF needed to be updated. The diagnosis of HFNEF requires the following conditions to be satisfied: (i) signs or symptoms of heart failure; (ii) normal or mildly abnormal systolic LV function; (iii) evidence of diastolic LV dysfunction. Normal or mildly abnormal systolic LV function implies both an LVEF > 50% and an LV end-diastolic volume index (LVEDVI) <97 mL/m(2). Diagnostic evidence of diastolic LV dysfunction can be obtained invasively (LV end-diastolic pressure >16 mmHg or mean pulmonary capillary wedge pressure >12 mmHg) or non-invasively by tissue Doppler (TD) (E/E' > 15). If TD yields an E/E' ratio suggestive of diastolic LV dysfunction (15 > E/E' > 8), additional non-invasive investigations are required for diagnostic evidence of diastolic LV dysfunction. These can consist of blood flow Doppler of mitral valve or pulmonary veins, echo measures of LV mass index or left atrial volume index, electrocardiographic evidence of atrial fibrillation, or plasma levels of natriuretic peptides. If plasma levels of natriuretic peptides are elevated, diagnostic evidence of diastolic LV dysfunction also requires additional non-invasive investigations such as TD, blood flow Doppler of mitral valve or pulmonary veins, echo measures of LV mass index or left atrial volume index, or electrocardiographic evidence of atrial fibrillation. A similar strategy with focus on a high negative predictive value of successive investigations is proposed for the exclusion of HFNEF in patients with breathlessness and no signs of congestion. The updated strategies for the diagnosis and exclusion of HFNEF are useful not only for individual patient management but also for patient recruitment in future clinical trials exploring therapies for HFNEF.

The Influence of Percutaneous Closure of Patent Ductus Arteriosus on Left Ventricular Size and Function

OBJECTIVES

We aimed to evaluate the effect of percutaneous closure of patent ductus arteriosus (PDA) on left ventricular (LV) hemodynamics.

BACKGROUND

Today, most PDAs are closed percutaneously. Little is known, however, about hemodynamic changes after the procedure.

METHODS

Of 37 children (ages 0.6 to 10.6 years) taken to the catheterization laboratory for percutaneous PDA closure, the PDA was closed in 33. Left ventricular diastolic and systolic dimensions, volumes, and function were examined by two-dimensional (2D) and three-dimensional (3D) echocardiography and serum concentrations of natriuretic peptides measured before PDA closure, on the following day, and 6 months thereafter. Control subjects comprised 36 healthy children of comparable ages.

RESULTS

At baseline, LV diastolic diameter measured >+2 SD in 5 of 33 patients. In 3D echocardiography, a median LV diastolic volume measured 54.0 ml/m2 in the control subjects and 58.4 ml/m2 (p < 0.05) in the PDA group before closure and 57.2 ml/m2 (p = NS) 6 months after closure. A median N-terminal brain natriuretic peptide (pro-BNP) concentration measured 72 ng/l in the control group and 141 ng/l in the PDA group before closure (p = 0.001) and 78.5 ng/l (p = NS) 6 months after closure. Patients differed from control subjects in indices of LV systolic and diastolic function at baseline. By the end of follow-up, all these differences had disappeared. Even in the subgroup of patients with normal-sized LV at baseline, the LV diastolic volume decreased significantly during follow-up.

CONCLUSIONS

Changes in LV volume and function caused by PDA disappear by 6 months after percutaneous closure. Even the children with normal-sized LV benefit from the procedure.

Consequences of increasing heart rate on deceleration time, the velocity-time integral, and E/A

The ascendancy of diastolic heart failure to "epidemic" proportions has increased the use of and reliance on Doppler echocardiography as a source for diagnosis and as the preferred method for determining indexes of diastolic function (DF). Current indexes are primarily derived from shape-based features of Doppler E and A waves, such as their amplitudes, slopes, durations, and areas. Load dependence and pathologic correlates of these indexes have been considered, but DF indexes are not routinely corrected for heart rate (HR). To determine the dependence of selected Doppler-derived indexes of DF on HR, transmitral Doppler flow velocities and electrocardiograms were simultaneously recorded during supine bicycle exercise in 21 young, healthy volunteers. Standard E- and A-wave shape-based indexes (acceleration time, deceleration time [DT], peak E, peak A) were measured using triangle approximation. Velocity-time integrals (VTIs) were calculated by trapezoidal and triangular approximations. A-wave peak velocity (A) was measured conventionally, relative to baseline, and also using 2 alternative methods: A*, measured relative to the E@A velocity, and Ac, relative to the E-wave deceleration value at peak A-wave velocity. E/A was calculated conventionally and by using A* and Ac. The results showed that DF indexes derived from individual E waves are essentially HR independent. DT showed a mere 20% decrease for a 100% increase in HR. A triangular approximation for the E-wave VTI and the corrected E/Ac were found to be nearly HR independent. In conclusion, on the basis of the established continuity of cardiac output as a function of increasing HR and the observed data, Doppler-derived indexes of DF (DT, VTIs, E/Ac) can be treated as essentially HR independent only if the VTI and A-wave peak are corrected for HR as described.

Systolic and diastolic functions in elderly patients with and without heart failure

BACKGROUND

A considerable number of patients with heart failure (HF) have a normal left ventricular ejection fraction (LVEF). In these subjects, HF has usually been related to diastolic heart failure (DHF), still a frequently overlooked clinical entity.

METHODS

This study reports the clinical, instrumental, and conventional echocardiographic evaluation of 159 consecutive, hospitalized elderly patients, 87 admitted with HF and 72 admitted for other reasons without overt HF.

RESULTS

All of the 87 HF patients had signs of diastolic dysfunction (DDYS), yet 44.8% of them had a normal LVEF. Forty-four of the 72 patients admitted without overt HF (61.1%) had mild DDYS and 14 (19.5%) also had a reduced LVEF. There was a clear relationship between LVEF reduction and the severity of DDYS.

CONCLUSIONS

HF is often a combination of diastolic and systolic function abnormalities. DHF may be difficult to detect in HF subjects with normal LVEF because their DDYS is often mild. However, there are signs of DDYS in all HF patients that increase in severity as LVEF decreases. DDYS could be considered a marker for all forms of HF, especially in elderly patients.