Hemodynamic determinants of the mitral annulus diastolic velocities by tissue Doppler

Diastolic Stress Echocardiography in Patients With Hypertrophy Cardiomyopathy: Association With Exercise Capacity

Diastolic dysfunction plays a major role in precipitating congestive heart failure in patients with hypertrophic cardiomyopathy (HCM). In many such patients, symptoms are unmasked only during exercise because left ventricular (LV) filling pressure is normal at rest but increase with exercise. We sought to establish whether abnormal postexercise diastolic parameters are associated with reduced exercise capacity in patients with HCM. We examined 590 patients with asymptomatic/minimally symptomatic HCM (age 54 ± 14 years, 57% men, body mass index 30 ± 6 kg/m2, 84% on β blockers) with HCM by 2-dimensional and Doppler echocardiography at rest and after maximal treadmill exercise echocardiography (TSE). A complete echocardiogram (including LV ejection fraction, LV thickness, LV outflow tract [LVOT] gradient, degree of mitral regurgitation) was recorded. Diastolic parameters (septal and lateral [e'] velocities of the mitral annulus, peak early [E] and late [A] mitral inflow velocity, E/A ratio, E/e', right ventricular systolic pressure [RVSP], and left atrial volume index) were recorded at rest and after TSE. Exercise functional capacity was recorded and divided into <85% or >85% of age-gender predicted metabolic equivalents (AGP-METs). After maximal exercise, 32% patients had at least moderate mitral regurgitation, mean LVOT gradient was 61 ± 59 mm Hg, E/A ratio was 1.2 ± 1.0, average E/e' ratio 12.9 ± 1.0, and peak RVSP was 36 ± 15 mm Hg. Only 42% of patients achieved >85% of AGP-METs; the mean METs was 7 ± 3. On multivariable logistic regression analysis, higher body mass index (odds ratio [OR] 1.05), β-blocker use (OR 2.58), higher left atrial volume index (OR 1.02), higher peak stress LVOT gradient (LVOTG) (OR 1.06), peak stress E/e' (OR 1.04), and higher RVSP (OR 1.03) were independently associated with <85% AGP-METs achieved (all p <0.05). In conclusion, in patients with asymptomatic/minimally symptomatic HCM who underwent TSE, there is a significant and independent association between abnormal diastolic response to exercise and reduced exercise capacity in HCM. Incorporating diastolic parameters during stress echocardiography could provide incremental diagnostic utility in deciphering the exact etiology of dyspnea in such patients.

Effect of Sevoflurane Anesthesia on Diastolic Function: A Prospective Observational Study

BACKGROUND

The effect of sevoflurane on left ventricular diastolic function is not well understood. We hypothesized that parameters of diastolic function may improve under sevoflurane anesthesia in patients with preexisting diastolic dysfunction compared to patients with normal diastolic function.

METHODS

This observational study included 60 patients undergoing breast surgery or laparoscopic cholecystectomy. Patients were assigned to diastolic dysfunction (n = 34) or normal (n = 26) groups of septal e' < 8 or ≥ 8.0 cm/s on the first thoracic echocardiography (TTE) performed before anesthesia. During anesthesia, sevoflurane was maintained at 1 to 2 minimum alveolar concentration (MAC) to maintain the bispectral index at 40 to 50. At the end of surgery, the second TTE was performed under 0.8 to 1 MAC of sevoflurane with the patient breathing spontaneously without ventilator support. Primary end point was the percentage change (Δ) of e' on 2 TTEs (Δe'). Secondary end points were ΔE/e', Δleft atrial volume index (ΔLAVI), and Δtricuspid regurgitation maximum velocity (ΔTR Vmax). These percentage changes (Δ) were compared between diastolic dysfunction and normal groups.

RESULTS

e' (Δe': 30 [6, 64] vs 0 [-18, 11]%; P < .001), mitral inflow E wave velocity (E), mitral inflow E/A ratio (E/A), and mitral E velocity deceleration time (DT) improved significantly in diastolic dysfunction group compared to normal group. LAVI decreased in diastolic dysfunction group but did not reach statistical significance between the 2 groups (ΔLAVI:-15 [-31, -3] vs -4 [-20, 10]%, P = .091). ΔE/e' was not different between the 2 groups (11 [-16, 26] vs 12 [-9, 22]%, P = .853) (all: median [interquartile range, IQR]). TR was minimal in both groups.

CONCLUSIONS

In this study, echocardiographic parameters of diastolic function, including septal e', E, E/A, and DT, improved with sevoflurane anesthesia in patients with preexisting diastolic dysfunction, but remained unchanged in patients with normal diastolic function.

Increased preload and echocardiographic assessment of diastolic function

AIMS

Echocardiographic diastolic parameters are used to diagnose and monitor increased left ventricular filling pressure (LVFP) and we hypothesized that increased loading conditions cause increased E/e'. Our aim was to assess the effect of preload augmentation on diastolic parameters among both healthy subjects and subjects with known cardiac disease.

METHODS AND RESULTS

We included 129 subjects merged from two cohorts; one dialysis cohort (n = 47) and one infusion cohort (n = 82). Echocardiography was performed immediately before and after hemodialysis (HD) or saline infusion, under low and high loading conditions. Elevated LVFP was defined as septal E/e' ≥ 15 and/or lateral E/e' ≥ 13 at high-loading conditions. The population was divided according to elevated LVFP (n = 31) and normal LVFP (n = 98). The load difference for the population was 972 ± 460 mL, with no differences in load difference between elevated and normal LVFP (p NS). The subjects with elevated LVFP were older (63 ± 11 vs. 46 ± 16 years, p < .001), and had lower LV ejection fraction (50 ± 14 vs. 59 ± 8.1%, p < .01). After augmented preload, EDV increased in the normal LVFP group (p < .01) but remained unchanged in the elevated LVFP group (p NS). Both E and e' increased among the subjects with normal LVFP, whereas E/e' remained unchanged (∆E/e' +.1 [-.5-1.2]), p NS). Among the subjects with elevated, LVFP we observed increased E but not e', resulting in significantly increased E/e' (∆ average E/e' +2.4 [0-4.0], p < .01).

CONCLUSION

Augmented preload does not seem to affect E/e' among subjects with normal LVFP, whereas E/e' seems to increase significantly among subjects with elevated LVFP.

Current and Clinically Relevant Echocardiographic Parameters to Analyze Left Atrial Function

The evaluation of the left atrial (LA) size using the LA volume index (LAVI) is clinically relevant due to its prognostic significance in various conditions. Nonetheless, adding a LA function assessment to the LAVI provides further clinical and prognostic information in different cardiovascular (CV) diseases. The assessment of LA function by echocardiography primarily includes volumetric measurements (LA ejection fraction [LAEF]), tissue Doppler imaging (TDI) (mitral annular late diastolic velocity [a']), and speckle-tracking methods, such as LA longitudinal reservoir strain (LA strain). This review analyzes and discusses the current medical evidence and potential clinical usefulness of these different methods to analyze LA function.

Echocardiographic Strain Abnormalities Precede Left Ventricular Hypertrophy Development in Hypertrophic Cardiomyopathy Mutation Carriers

Hypertrophic cardiomyopathy (HCM) is a genetic disease characterized by unexplained left ventricular hypertrophy (LVH), diastolic dysfunction, and increased sudden-death risk. Early detection of the phenotypic expression of the disease in genetic carriers without LVH (Gen+/Phen-) is crucial for emerging therapies. This clinical study aims to identify echocardiographic predictors of phenotypic development in Gen+/Phen-. Sixteen Gen+/Phen- (one subject with troponin T, six with myosin heavy chain-7, and nine with myosin-binding protein C3 mutations), represented the study population. At first and last visit we performed comprehensive 2D speckle-tracking strain echocardiography. During a follow-up of 8 ± 5 years, five carriers developed LVH (LVH+). At baseline, these patients were older than those who did not develop LVH (LVH-) (30 ± 8 vs. 15 ± 8 years, p = 0.005). LVH+ had reduced peak global strain rate during the isovolumic relaxation period (SRIVR) (0.28 ± 0.05 vs. 0.40 ± 0.11 1/s, p = 0.048) and lower global longitudinal strain (GLS) (-19.8 ± 0.4 vs. -22.3 ± 1.1%; p < 0.0001) than LVH- at baseline. SRIVR and GLS were not correlated with age (overall, p > 0.08). This is the first HCM study investigating subjects before they manifest clinically significant or relevant disease burden or symptomatology, comparing at baseline HCM Gen+/Phen- subjects who will develop LVH with those who will not. Furthermore, we identified highly sensitive, easily obtainable, age- and load-independent echocardiographic predictors of phenotype development in HCM gene carriers who may undergo early preventive treatment.

Assessment of left atrial function provides incremental value: the left atrial volumetric/mechanical coupling index in patients with chronic kidney disease

Background

Heart failure is a common cause of adverse cardiovascular outcomes in patients with chronic kidney disease (CKD). Left atrial (LA) characteristics are thought to be involved in the development of heart failure. However, LA assessment is complex. Though a variety of parameters have been defined, there is no single parameter that best defines LA function. Pilot data indicate that left atrial volumetric/mechanical coupling index (LACI) may be useful, but data with CKD are lacking.

Aim

The objective of this study was to define LACI in a cohort of patients with CKD and to assess its value in evaluating LA function and predicting heart failure.

Methods

A cohort of patients with CKD was enrolled at our hospital between 2021 and 2023. Follow-up was performed for heart failure. LACI is a volumetric to mechanical coupling index, calculated as the ratio of the LA volume index to the tissue-Doppler myocardial velocity at atrial contraction. Spearman's rank correlation or Pearson's correlation was used to calculate the correlation between LACI and echocardiographic/hemodynamic variables. Receiver operating characteristic curve (ROC) analysis was utilised to derive the area under the curve (AUC) for LACI, LVGLS, LASr, LASct and LASI for the detection of heart failure. Kaplan-Meier survival curves were employed to compare clinical outcomes based on LACI thresholds. A multivariable logistic regression analysis was employed to assess the relationship between risk factors and elevated LACI. Cox proportional hazards regression was used to identify risk factors for heart failure.

Results

LACI showed a positive correlation with NT-proBNP, CK-MB, LAVI, E/e' and LASI (r = 0.504, 0.536, 0.856, 0.541 and 0.509, p < 0.001); and a negative correlation with LASr (r = -0.509, p < 0.001). On the ROC analysis for the determination of heart failure, the AUC of LACI was comparable to those of LVGLS (0.588 vs. 509, p = 0.464), LASr (0.588 vs. 0.448, p = 0.132), LASct (0.588 vs. 0.566, p = 0.971) and LASI (0.588 vs. 0.570, p = 0.874). The cardiovascular risk factors increased by LACI were age, BMI, diabetes, triglycerides, LA size, LASr, LASI, E/A, E/e' and EF (p < 0.05). During a median follow-up of 16 months (range, 6-28 months), the event-free survival curves demonstrated a higher risk of heart failure in the group with LACI > 5.0 (log-rank test: P < 0.001). LACI > 5.0 was an independent predictor of heart failure [OR: 0.121, 95% CI (0.020-0.740), p = 0.022].

Conclusion

LACI may prove to be a valuable tool for assessing LA function in patients with CKD, and could be integrated into the routine assessment of LA for the purpose of prognostic assessment and clinical decision-making in patients with CKD.

The assessment of left ventricular diastolic function: guidance and recommendations from the British Society of Echocardiography

Impairment of left ventricular (LV) diastolic function is common amongst those with left heart disease and is associated with significant morbidity. Given that, in simple terms, the ventricle can only eject the volume with which it fills and that approximately one half of hospitalisations for heart failure (HF) are in those with normal/'preserved' left ventricular ejection fraction (HFpEF) (Bianco et al. in JACC Cardiovasc Imaging. 13:258-271, 2020. 10.1016/j.jcmg.2018.12.035), where abnormalities of ventricular filling are the cause of symptoms, it is clear that the assessment of left ventricular diastolic function (LVDF) is crucial for understanding global cardiac function and for identifying the wider effects of disease processes. Invasive methods of measuring LV relaxation and filling pressures are considered the gold-standard for investigating diastolic function. However, the high temporal resolution of trans-thoracic echocardiography (TTE) with widely validated and reproducible measures available at the patient's bedside and without the need for invasive procedures involving ionising radiation have established echocardiography as the primary imaging modality. The comprehensive assessment of LVDF is therefore a fundamental element of the standard TTE (Robinson et al. in Echo Res Pract7:G59-G93, 2020. 10.1530/ERP-20-0026). However, the echocardiographic assessment of diastolic function is complex. In the broadest and most basic terms, ventricular diastole comprises an early filling phase when blood is drawn, by suction, into the ventricle as it rapidly recoils and lengthens following the preceding systolic contraction and shortening. This is followed in late diastole by distension of the compliant LV when atrial contraction actively contributes to ventricular filling. When LVDF is normal, ventricular filling is achieved at low pressure both at rest and during exertion. However, this basic description merely summarises the complex physiology that enables the diastolic process and defines it according to the mechanical method by which the ventricles fill, overlooking the myocardial function, properties of chamber compliance and pressure differentials that determine the capacity for LV filling. Unlike ventricular systolic function where single parameters are utilised to define myocardial performance (LV ejection fraction (LVEF) and Global Longitudinal Strain (GLS)), the assessment of diastolic function relies on the interpretation of multiple myocardial and blood-flow velocity parameters, along with left atrial (LA) size and function, in order to diagnose the presence and degree of impairment. The echocardiographic assessment of diastolic function is therefore multifaceted and complex, requiring an algorithmic approach that incorporates parameters of myocardial relaxation/recoil, chamber compliance and function under variable loading conditions and the intra-cavity pressures under which these processes occur. This guideline outlines a structured approach to the assessment of diastolic function and includes recommendations for the assessment of LV relaxation and filling pressures. Non-routine echocardiographic measures are described alongside guidance for application in specific circumstances. Provocative methods for revealing increased filling pressure on exertion are described and novel and emerging modalities considered. For rapid access to the core recommendations of the diastolic guideline, a quick-reference guide (additional file 1) accompanies the main guideline document. This describes in very brief detail the diastolic investigation in each patient group and includes all algorithms and core reference tables.

Modifiers of the Association between E/e' Ratio and Survival among Patients with No Apparent Structural or Functional Cardiac Abnormality

BACKGROUND

The ratio between early mitral flow wave to early diastolic mitral annulus velocity (E/e' ratio) varies according to age and sex and is associated with mortality in heart failure. We sought to describe the association between E/e' and mortality in patients with no apparent structural or functional cardiac abnormality and explore possible modifiers of this association.

METHODS

A retrospective study of 104,315 patients who underwent echocardiographic evaluation during 2009-2021 in the largest tertiary center in Israel. Patients with cancer, ventricular dysfunction, significant valvular or structural heart disease, or evidence of pulmonary hypertension were excluded.

RESULTS

The final analysis included 32,836 patients with a median age of 56 (43-66) years, and 13,547 (41%) were female. The median E/e' was 8.3 (6.8-10.3), and 9,306 (28%) had an E/e' >10. During a median follow-up of 5.7 (3.3-8.5) years, 2,396 (7.3%) individuals died. E/e' >10 was associated with mortality (adjusted hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.07-1.27, p<0.001). The mortality risk associated with E/e' >10 was significantly higher in those aged ≤70 (HR 1.26, 95% CI 1.12-1.42, p<0.001), males (HR 1.34, 95% CI 1.19-1.49, p<0.001), a normal left ventricular mass (HR 1.13, 95% CI 1.02-1.24, p = 0.017), and pulmonary artery pressure <30 mmHg (HR 1.18, 95% CI 1.06-1.30, p = 0.003).

CONCLUSION

An elevated E/e' is associated with mortality, specifically in younger individuals, males, and those with a normal left ventricular mass and lower pulmonary artery pressure. This suggests that an elevated E/e' might be a marker of subclinical risk in these subgroups. Further studies are needed to identify whether an elevated E/e' is useful in shared decision-making regarding the management of cardiovascular risk factors.

The value of a dynamic echocardiographic approach to diastolic dysfunction in intensive care medicine

Diastolic dysfunction is an underestimated feature in the context of the critically ill setting and perioperative medicine. Advances in echocardiography, its noninvasive, safe and easy use, have allowed Doppler echocardiography to become a cornerstone for diagnosing diastolic dysfunction in clinical practice. The diagnosis of diastolic dysfunction and increased filling pressures is nevertheless complex. Using an echocardiographic assessment and the routine application of preload stress maneuvers during echocardiographic examination can help identify early stages of diastolic dysfunction leading to better management of patients at risk of acute heart decompensation in the perioperative period or during ICU stay.

Dobutamine effects on systolic and diastolic left ventricular long-axis excursion and timing - significance for the interpretation of s' and e'

BACKGROUND

Dobutamine effects on the relationships of the peak velocity of left ventricular (LV) long-axis systolic motion (s') with systolic excursion (SExc), systolic duration (SDur) and heart rate, of LV long-axis early diastolic excursion (EDExc) with SExc, and of the peak velocity of LV long-axis early diastolic motion (e') with EDExc, early diastolic duration (EDDur) and isovolumic relaxation time (IVRT') are unknown.

METHODS

Two groups of adult subjects, one young and healthy (n = 10), and one with impaired LV long-axis function (n = 10), were studied, with the aim of identifying consistent findings for the two groups and for the septal and lateral walls. Dobutamine was infused at doses of 5 and 10 µg/kg/min. The relationships between tissue Doppler imaging (TDI) variables acquired before and during dobutamine infusion were analysed using mixed effect multivariate regression modelling.

RESULTS

In both groups, heart rate increased and SDur decreased during dobutamine infusion, and there were independent inverse correlations of SDur with heart rate and dobutamine dose. In contrast, there was no change in EDDur during dobutamine infusion, and no consistent changes in IVRT' independent of heart rate. s' was positively correlated with SExc and inversely correlated with SDur, and there were positive correlations between EDExc and SExc and between e' and EDExc.

CONCLUSION

Dobutamine increases s' due to effects on both systolic excursion and duration and it increases e' due to the associated increases in systolic and early diastolic excursion. A lack of effect on diastolic times does not support the presence of a lusitropic effect of dobutamine.

Left atrial strain assessment using cardiac computed tomography in patients with hypertrophic cardiomyopathy

PURPOSE

To evaluate left atrial (LA) function in patients with hypertrophic cardiomyopathy (HCM) by LA strain assessment using cardiac computed tomography (CT-derived LA strain).

MATERIALS AND METHODS

This was a retrospective study of 34 patients with HCM and 31 non-HCM patients who underwent cardiac computed tomography (CT) using retrospective electrocardiogram-gated mode. CT images were reconstructed every 5% (0-95%) of the RR intervals. CT-derived LA strain (reservoir [LASr], conduit [LASc], and booster pump strain [LASp]) were semi-automatically analyzed using a dedicated workstation. We also measured the left atrial volume index (LAVI) and left ventricular longitudinal strain (LVLS) for the left atrial and ventricular functional parameters to assess the relationship with CT-derived LA strain.

RESULTS

CT-derived LA strain significantly correlated with LAVI: r = - 0.69, p < 0.001 for LASr; r = - 0.70, p < 0.001 for LASp; and r = - 0.35, p = 0.004 for LASc. CT-derived LA strain also significantly correlated with LVLS: r = - 0.62, p < 0.001 for LASr; r = - 0.67, p < 0.001 for LASc; and r = - 0.42, p = 0.013 for LASp. CT-derived LA strain in patients with HCM was significantly lower than that in non-HCM patients: LASr (20.8 ± 7.6 vs. 31.7 ± 6.1%, p < 0.001); LASc (7.9 ± 3.4 vs. 14.2 ± 5.3%, p < 0.001); and LASp (12.8 ± 5.7 vs. 17.6 ± 4.3%, p < 0.001). Additionally, CT-derived LA strain showed high reproducibility; inter-observer correlation coefficients were 0.94, 0.90, and 0.89 for LASr, LASc, and LASp, respectively.

CONCLUSION

CT-derived LA strain is feasible for quantitative assessment of left atrial function in patients with HCM.

Left Ventricular Filling Pressure in Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by obstruction of major pulmonary arteries with organized thrombi. Clinical risk factors for pulmonary hypertension due to left heart disease including metabolic syndrome, left-sided valvular heart disease, and ischemic heart disease are common in CTEPH patients.

OBJECTIVES

The authors sought to investigate prevalence and prognostic implications of elevated left ventricular filling pressures (LVFP) in CTEPH.

METHODS

A total of 593 consecutive CTEPH patients undergoing a first diagnostic right and left heart catheterization were included in this study. Mean pulmonary arterial wedge pressure (mPAWP) and left ventricular end-diastolic pressure (LVEDP) were utilized for assessment of LVFP. Two cutoffs were applied to identify patients with elevated LVFP: 1) for the primary analysis mPAWP and/or LVEDP >15 mm Hg, as recommended by the current pulmonary hypertension guidelines; and 2) for the secondary analysis mPAWP and/or LVEDP >11 mm Hg, representing the upper limit of normal. Clinical and echocardiographic features, and long-term mortality were assessed.

RESULTS

LVFP was >15 mm Hg in 63 (10.6%) and >11 mm Hg in 222 patients (37.4%). Univariable logistic regression analysis identified age, systemic hypertension, diabetes, atrial fibrillation, calcific aortic valve stenosis, mitral regurgitation, and left atrial volume as significant predictors of elevated LVFP. Atrial fibrillation, calcific aortic valve stenosis, mitral regurgitation, and left atrial volume remained independent determinants of LVFP in adjusted analysis. At follow-up, higher LVFPs were measured in patients who had meanwhile undergone pulmonary endarterectomy (P = 0.002). LVFP >15 mm Hg (P = 0.021) and >11 mm Hg (P = 0.006) were both associated with worse long-term survival.

CONCLUSIONS

Elevated LVFP is common, appears to be due to comorbid left heart disease, and predicts prognosis in CTEPH.

Cardiovascular safety pharmacology of ivermectin assessed using the isoflurane-anesthetized beagle dogs: ICH S7B follow-up study

Antiparasitic ivermectin has been reported to induce cardiovascular adverse events, including orthostatic hypotension, tachycardia and cardiopulmonary arrest, of which the underlying pathophysiology remains unknown. Since its drug repurposing as an antiviral agent is underway at higher doses than those for antiparasitic, we evaluated the cardiovascular safety pharmacology of ivermectin using isoflurane-anesthetized beagle dogs (n=4). Ivermectin in doses of 0.1 followed by 1 mg/kg was intravenously infused over 10 min with an interval of 20 min, attaining peak plasma concentrations of 0.94 ± 0.04 and 8.82 ± 1.25 μg/mL, which were 29-31 and 276-288 times higher than those observed after its antiparasitic oral dose of 12 mg/body, respectively. The latter peak concentration was > 2 times greater than those inhibiting proliferation of dengue virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and hepatitis B virus in vitro. Ivermectin decreased heart rate without altering mean blood pressure, suggesting that ivermectin does not cause hypotension or tachycardia directly. Ivermectin hardly altered atrioventricular nodal or intraventricular conduction, indicating a lack of inhibitory action on Ca2+ or Na+ channel in vivo. Ivermectin prolonged QT interval/QTcV in a dose-related manner and tended to slow the repolarization speed in a reverse frequency-dependent manner, supporting previously described its IKr inhibition, which would explain Tpeak-Tend prolongation and heart-rate reduction in this study. Meanwhile, ivermectin did not significantly prolong J-Tpeakc or terminal repolarization period, indicating torsadogenic potential of ivermectin leading to the onset of cardiopulmonary arrest would be small. Thus, ivermectin has a broad range of cardiovascular safety profiles, which will help facilitate its drug repurposing.

Left Ventricular Diastolic Response to Isometric Handgrip Exercise in Physically Active and Sedentary Individuals

Aims: This study aims to investigate the diastolic left ventricular (LV) response to isometric handgrip exercise among healthy middle-aged men with high physical activity levels, versus matched sedentary individuals. Methods: Two groups of 10 men aged 41−51 years were studied. Men in the first group had high weekly self-reported physical activity levels (>3000 METs × min/week). In comparison, men in the second group reported low physical activity levels (<300 METs × min/week). An isometric handgrip exercise (IHE) stress echocardiography test was performed in all of them. Results: Both groups showed a similar and statistically significant increase in heart rate, systolic, diastolic, and mean arterial pressure following IHE. The group of active men under study did not show a statistically significant change in the ratio of early diastolic mitral valve inflow velocity to early diastolic lateral wall tissue velocity (E/e’ ratio) in response to IHE. Conversely, the inactive participants’ E/e’ ratio was higher at peak activity in the isometric handgrip exercise. Conclusions: Apparently, healthy middle-aged men with high levels of physical activity seem to have an improved lusitropic cardiac function compared to men with low levels of physical activity, as observed by the different diastolic LV responses induced by isometric handgrip exercise.

The a' velocity by tissue-Doppler echocardiography correlates to invasive mean left atrial pressure in patients with normal ejection fraction

OBJECTIVES

To evaluate the correlation of a' velocity by tissue-Doppler measurements with invasively measured mean left atrial pressure in patients with normal ejection fraction.

DESIGN

In this retrospective study, we evaluated the septal a', lateral a' and average a' velocity by tissue-Doppler echocardiography, in 125 in-hospital patients, 1-12 h before an elective pulmonary vein isolation due to intermittent atrial fibrillation, and compared to invasively measured mean left atrial pressure (LAP) during the invasive procedure. The patients, aged 35-81 years, had to be in sinus rhythm at both examinations, no atrial fibrillation during two procedures, no or mild valve disease and normal ejection fraction (>50%).

RESULTS

Invasively measured mean LAP correlated well to septal a' (r = -0.435), lateral a' (r = -0.473) and average a' velocity (r = -0.491). Normal mean LAP (≤12 mmHg) was found in 95 patients and elevated mean LAP (>12 mmHg) in 30 patients. The patients with elevated mean LAP had a lower septal a' velocity (6.5 ± 2.7 vs 8.6 ± 2.3 cm/s; p < .01), lateral a' velocity (5.9 ± 2.3 vs 8.6 ± 2.1 cm/s; p < .01) and average a' velocity (6.2 ± 2.4 vs 8.8 ± 2.1 cm/s; p < .01) compared to patients with normal mean LAP. Septal a', lateral a' and average a' velocity were good predictors of elevated mean LAP with AUC of 0.78, 0.83 and 0.82. Average a' velocity with cut-off < 7.25 cm/s had a sensitivity of 83% and a specificity of 77% to predict elevated mean LAP.

CONCLUSION

The a' velocity is a good indicator of mean LAP and might be considered in the evaluation of left ventricle filling pressure in patients with normal ejection fraction.

The impact of cardiac loading on a novel metric of left ventricular diastolic function in healthy middle-aged adults: Systolic-diastolic coupling

AIMS

Left ventricular (LV) restoring forces are primed by ventricular deformation during systole and contribute to cardiac relaxation and early diastolic suction. Systolic-diastolic coupling, the relationship between systolic contraction and diastolic recoil, is a novel marker of restoring forces, but the effect of left atrial pressure (LAP) is unknown. We tested preliminary methods of systolic-diastolic coupling comparing mitral annular velocities versus excursion distances and hypothesized a recoil/contraction distance ratio would remain unaffected across varying LAP, providing a surrogate for quantifying LV restoring forces.

METHODS AND RESULTS

Healthy subjects (n = 61, age 52 ± 5 years) underwent manipulation of LAP with lower body negative pressure (LBNP) and rapid normal saline (NS) infusion. Pulmonary capillary wedge pressure (PCWP; pulmonary artery catheter) and tissue Doppler imaging of the mitral annulus were measured. Two models of systolic-diastolic coupling--early diastolic excursion (EDexc )/systolic contraction (Sexc ) distances and e'/systolic (s') velocities were compared. Velocity (e'/s') coupling ratios varied significantly (mean e'/s', slope = 0.022, p < 0.001) in relationship with PCWP (5-20 mmHg). Excursion (EDexc /Sexc ) coupling ratio did not vary in relationship with PCWP (EDexc /Sexc : slope = -0.001, p = 0.19).

CONCLUSIONS

Systolic-diastolic coupling using mitral annular distance ratios to standardize early diastolic recoil to systolic contraction was not significantly impacted by LAP, in contrast to coupling ratios using velocities. The pressure invariance of annular distance coupling ratios suggests this metric quantifies the efficiency of LV restoring forces by isolating systolic contributions to early diastolic restoring forces independent from changes in LAP.

Prognostic Value of Diastolic Dysfunction Derived From D-SPECT in Coronary Artery Disease Patients With Normal Ejection Fraction

Diastolic dysfunction (DD) with normal systolic function has been elucidated to be associated with heart failure and worse prognosis. The recently introduced single photon emission computed tomography (SPECT) with dedicated cardiac cadmium-zinc-telluride (CZT) cameras (D-SPECT) is a novel method to quantitate left ventricular functional parameters. We aimed to evaluate the prognostic value of DD derived from D-SPECT in coronary artery disease (CAD) patients with normal ejection fraction. All CAD patients who underwent D-SPECT and invasive coronary angiography within 3 months were considered. DD was defined as peak filling rate (PFR) <2.1 end diastolic volume (EDV, ml)/s according to the D-SPECT results. Patients were divided into three groups: group 1 (n = 226)-normal PFR; group 2 (n = 67)-ischemia-related DD (abnormal stress PFR and normal rest PFR); and group 3 (n = 106)-rest DD (abnormal rest PFR). The primary clinical endpoint of the present study was a composite of heart failure events (HFE). A total of 399 consecutive CAD patients with normal systolic function undergoing stress D-SPECT were analyzed. The incidence rates of HFE among the three groups were 4.0, 7.5, and 11.3%, respectively. Cox regression analysis showed that the multivariate predictors of HFE were rest PFR, diabetes mellitus, obesity, and old age. DD derived from D-SPECT in CAD patients with normal ejection fraction is predictive of HFE.

Clinical Significance of Late Diastolic Tissue Doppler Velocity at 24 Hours or 14 Days After Onset of ST-Elevation Acute Myocardial Infarction

Background: The significance of late diastolic velocity (a') obtained by tissue Doppler imaging (TDI), which reveals atrial function, in ST-elevation myocardial infarction (STEMI) remains unclear. This study evaluated the association of TDI parameters determined either immediately or 2 weeks after percutaneous coronary intervention (PCI) with long-term outcomes. Methods and Results: In all, 740 patients with first-time STEMI underwent immediate PCI (i.e., within 12 h of onset). Echocardiography was performed in 307 patients 2 weeks after onset (Group A; mean age 64 years, 249 males), in 277 patients immediately after PCI (Group B; mean age 65 years, 229 males), and in 156 patients twice (i.e., immediately and 2 weeks after PCI; Group C; mean age 65 years, 135 males). Patients were followed-up for up to 10 years (mean 81 months). The primary endpoints were cardiac death or heart failure hospitalization. Major adverse cardiovascular events (MACE) occurred in 143 patients (19%) during the follow-up period. Both univariate and multivariate Cox hazard analyses were used to determine predictors of MACE. At 24 h and 2 weeks after STEMI onset, a' and E/e' were the strongest predictors of MACE, respectively. Conclusions: TDI parameters have different implications depending on the timing of echocardiography after a first-time STEMI. Based on the results of this study, atrial dysfunction measured by TDI 24 h after STEMI onset may indicate a poor prognosis.

Current clinical applications of spectral tissue Doppler echocardiography (E/e' ratio) as a noninvasive surrogate for left ventricular diastolic pressures in the diagnosis of heart failure with preserved ejection fraction. Revisited 15 years later

It is currently well established that more than half of heart failure patients have preserved ejection fraction. The diagnosis of heart failure with preserved ejection fraction is complex in clinical practice despite ESC recommendations issued in 2019. In this context, the demonstration of increased left ventricular filling pressures at rest or during exercise allows a definite diagnosis of heart failure with preserved ejection fraction in patients with signs and/or symptoms compatible with the diagnosis and a preserved ejection fraction. The spectral tissue Doppler-derived E/e' ratio by transthoracic Doppler echocardiography has been validated in the noninvasive assessment of left ventricular diastolic pressures at rest and during exercise. Several studies report the validity of E/e' in the diagnosis of heart failure with preserved ejection fraction in patients with both isolated exertional and acute dyspnea, as well as in risk stratification. In light of the current literature, E/e' deserves to be included on every transthoracic Doppler echocardiography report in patients with suspected heart failure with preserved ejection fraction. This updated review provides an overview of the diagnostic relevance of E/e' in patients in its two modes of clinical presentation, isolated exertional dyspnea and the decompensated congestive form.

Cardiac performance in patients hospitalized with COVID-19: a 6 month follow-up study

Aims

Myocardial injury is frequently observed in patients hospitalized with coronavirus disease 2019 (COVID‐19) pneumonia. Different cardiac abnormalities have been reported during the acute COVID‐19 phase, ranging from infra‐clinic elevations of myocardial necrosis biomarkers to acute cardiac dysfunction and myocarditis. There is limited information on late cardiac sequelae in patients who have recovered from acute COVID‐19 illness. We aimed to document the presence and quantify the extent of myocardial functional alterations in patients hospitalized 6 months earlier for COVID‐19 infection.

Methods and results

We conducted a prospective echocardiographic evaluation of 48 patients (mean age 58 ± 13 years, 69% male) hospitalized 6 ± 1 month earlier for a laboratory‐confirmed and symptomatic COVID‐19. Thirty‐two (66.6%) had pre‐existing cardiovascular risks factors (systemic hypertension, diabetes, or dyslipidaemia), and three patients (6.2%) had a known prior myocardial infarction. Sixteen patients (33.3%) experienced myocardial injury during the index COVID‐19 hospitalization as identified by a rise in cardiac troponin levels. Six months later, 60.4% of patients still reported clinical symptoms including exercise dyspnoea for 56%. Echocardiographic measurements under resting conditions were not different between patients with versus without myocardial injury during the acute COVID‐19 phase. In contrast, low‐level exercise (25W for 3 min) induced a significant increase in the average E/e′ ratio (10.1 ± 4.3 vs. 7.3 ± 11.5, P = 0.01) and the systolic pulmonary artery pressure (33.4 ± 7.8 vs. 25.6 ± 5.3 mmHg, P = 0.02) in patients with myocardial injury during the acute COVID‐19 phase. Sensitivity analyses showed that these alterations of left ventricular diastolic markers were observed regardless of whether of cardiovascular risk factors or established cardiac diseases indicating SARS‐CoV‐2 infection as a primary cause.

Conclusions

Six months after the acute COVID‐19 phase, significant cardiac diastolic abnormalities are observed in patients who experienced myocardial injury but not in patients without cardiac involvement.

In vivo characterization of anti-atrial fibrillatory potential and pharmacological safety profile of INa,L plus IKr inhibitor ranolazine using the halothane-anesthetized dogs

To characterize in vivo anti-atrial fibrillatory potential and pharmacological safety profile of ranolazine having I_Na,L plus I_Kr inhibitory actions in comparison with those of clinically available anti-atrial fibrillatory drugs; namely, dronedarone, amiodarone, bepridil and dl-sotalol in our previous studies, ranolazine dihydrochloride in sub-therapeutic (0.3 mg/kg) and supra-therapeutic (3 mg/kg) doses was intravenously infused over 10 min to the halothane-anesthetized dogs (n = 5). The low dose increased the heart rate, cardiac output and atrioventricular conduction velocity possibly via vasodilator action-induced, reflex-mediated increase of adrenergic tone. Meanwhile, the high dose decreased the heart rate, ventricular contraction, cardiac output and mean blood pressure, indicating that drug-induced direct actions may exceed the reflex-mediated compensation. In addition, it prolonged the atrial and ventricular effective refractory periods, of which potency and selectivity for the former were less great compared with those of the clinically-available drugs. Moreover, it did not alter the ventricular early repolarization period in vivo, but prolonged the late repolarization with minimal risk for re-entrant arrhythmias. These in vivo findings of ranolazine suggest that I_Na,L suppression may attenuate I_Kr inhibition-associated prolongation of early repolarization in the presence of reflex-mediated increase of adrenergic tone. Thus, ranolazine alone may be less promising as an anti-atrial fibrillatory drug, but its potential risk for inducing torsade de pointes will be small. These information can be used as a guide to predict the utility and adverse effects of anti-atrial fibrillatory drugs having multi-channel modulatory action.

Evolution of cardiac geometry and function in women with severe preeclampsia from immediately post-delivery to 1 year postpartum

Preeclampsia is associated with left ventricular (LV) geometrical and functional changes, which could be related to cardiovascular risk later in life. The purpose of our study was to evaluate evolution of LV dimensions and function in severe preeclamptic women from immediately post-delivery to 1 year postpartum. Twenty-five women with severe preeclampsia and 15 healthy term controls underwent standard and speckle-tracking echocardiography 1 day after delivery and 1 year postpartum. On day 1 post-delivery preeclamptic women were exposed to higher preload (p = 0.003) and afterload (p < 0.001) compared to controls. Parameter of longitudinal LV systolic function s' was significantly lower in preeclamptic compared to control group (p = 0.017) 1 day post-delivery. Additionally, diastolic function parameters were significantly more impaired in preeclamptic compared to control group (lower e' (p = 0.02) and higher E/e' ratio (p = 0.003) in preeclamptic group). Larger LV mass (p = 0.03) and a trend of higher proportion of altered cardiac geometry (p = 0.061) were observed in preeclampsia 1 day post-delivery. One year after delivery both groups had comparable geometric and functional parameters with similar afterload and preload (p > 0.05, for all). In preeclamptic group systolic and diastolic functional parameters improved significantly during follow-up (p < 0.05), while no such evolution was noted in controls (> 0.05). In women with severe preeclampsia subtle cardiac functional impairment immediately post-delivery completely resolved 1 year postpartum. Observed cardiac alterations suggest intrinsic myocardial dysfunction in preeclampsia, which became unmasked or exacerbated by higher load imposed on the LV immediately post-delivery that disappeared in mid-term follow-up.

Relationship between paced QRS duration and myocardial relaxation of the left ventricle in patients with chronic right ventricular apical pacing

BACKGROUND

Right ventricular (RV) apical pacing is associated with systolic dysfunction and heart failure. Paced QRS duration has been suggested as a predictor of heart failure and left ventricular (LV) systolic dysfunction. However, the effect of paced QRS duration on LV diastolic function is not well known.

OBJECTIVE

This study was designed to evaluate the relationship between paced QRS duration and LV diastolic function.

METHODS

This retrospective study included 88 patients who had chronic RV apical pacing. Myocardial relaxation was assessed with tissue Doppler imaging. Patients with severe valvular dysfunction or significant structural heart disease were excluded. Paced QRS duration was measured with standard 12‑lead ECG at follow-up.

RESULTS

Median age of the patients was 65.9 years (interquartile ranges (IQR), 56.5, 72.7) with 64.8% of female patients. Median duration of RV pacing was 8.6 years (IQR, 5.3, 11.1). Major indication of RV pacing was complete atrioventricular block (89.8%), and dual chamber pacemakers were predominantly implanted (89.8%). Mean of paced QRS duration was 160.5 ± 18.2 msec. Median LV ejection fraction (EF) was 63% (IQR, 55.5, 67.5), and negatively correlated with paced QRS duration (R = -0.478, p < 0.001). LV end diastolic dimension was positively correlated with paced QRS duration (R = 0.531, p < 0.001). Mean E' velocity at the septal mitral annulus was 5.2 ± 1.5 and negatively related to paced QRS duration (R = -0.521, p < 0.001). After adjusting covariables, paced QRS duration was independently related to E' velocity (beta = -0.038, p = 0.005). Paced QRS duration was also associated with worsening functional capacity or elevated LV filling pressure in patients with preserved EF (odd ratio = 1.10; 95% confidence interval, 1.02-1.20, p = 0.015).

CONCLUSION

Paced QRS duration was associated with LV relaxation which might be another possible mechanism of worsening heart failure in patients with long paced QRS duration.

Update of clinical echocardiographic assessment of heart failure with preserved ejection fraction

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction (HFpEF) has an increasing global prevalence. Diastolic dysfunction is the predominant cause of symptoms, most commonly, exertional dyspnea. Although prevalent, the syndrome is challenging to identify due to the comorbid conditions that can present similarly. This paper will review established, guideline recommended, echocardiographic variables, and pathophysiology.

RECENT FINDINGS

Echocardiography is the primary diagnostic modality. The latest advances in strain analysis, algorithmic use of multiple parameters, and deeper understanding of exercise hemodynamics have improved our classification of those with HFpEF.

SUMMARY

There remains a paucity of therapies with mortality benefit in this subgroup. Thus, improving diagnostic efficacy is important as it can clarify epidemiologic, phenotypic, and pathologic features of HFpEF.

Hemodynamic determinants of left atrial strain in patients with hypertrophic cardiomyopathy: A combined echocardiography and CMR study

Background

Left atrial (LA) strain is associated with symptomatic status and atrial fibrillation in patients with hypertrophic cardiomyopathy (HCM). However, hemodynamic determinants of LA reservoir (LARS), conduit, and pump strains have not been examined and data are needed on the relation of LA strain with exercise tolerance in HCM.

Methods

Fifty HCM patients with echocardiographic and CMR imaging within 30 days were included. Left ventricular (LV) volumes, mass, EF, scar extent, extracellular volume fraction (ECV), and LA maximum volume were measured by CMR. Echo studies were analyzed for mitral inflow, pulmonary vein flow, mitral annulus tissue Doppler velocities, LV global longitudinal strain, and LA strain. Twenty six patients able and willing to exercise underwent cardiopulmonary stress testing for peak oxygen consumption (MVO2), and V_E/V_CO2 slope. Patients were followed for clinical events.

Findings

LARS was significantly associated with indices of LA systolic function, LV GLS, and LV filling pressures (P<0.05). Conduit strain was significantly associated with mitral annulus early diastolic velocity and ECV, whereas LA pump strain was determined by LA systolic function and indices of LV end diastolic pressure (all P<0.05). LARS and conduit strain were significantly higher in patients who achieved ≥80% of MVO₂. LARS, conduit, and pump strains were significantly associated with atrial fibrillation (P<0.05).

Conclusions

LV structure, systolic and diastolic function, and LA systolic function determine the 3 components of LA strain. LA strain is associated with exercise tolerance and clinical events in patients with HCM.

[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.

Left Atrial Volumetric/Mechanical Coupling Index: A Novel Predictor of Outcome in Heart Failure With Reduced Ejection Fraction

BACKGROUND

Left atrial assessment is complex, particularly in heart failure with reduced ejection fraction due to interactions with functional mitral regurgitation (FMR). Pilot data suggest that left atrial volumetric/mechanical coupling index (LACI) may be useful, but large outcome data are lacking.

METHODS

We enrolled a comprehensively characterized cohort of patients in sinus rhythm with heart failure with reduced ejection fraction diagnosis at Mayo Clinic from 2007 to 2011. Routinely measured left atrial volume index and tissue-doppler-imaging a' allowed LACI calculation as (left atrial volume index)/(tissue-doppler-imaging a'). Survival was the outcome measured.

RESULTS

The cohort's 4196 patients (69 [58-77] years, ejection fraction 40 [31-45]%) had mild FMR in 1505 and moderate-severe FMR in 1068. LACI was overall 5.06 (3.50-8.10) and increased with each FMR grade (3.86 [2.94-5.29] without FMR, 5.38 [3.80-8.02] with mild, 5.45 [1.49-8.07] with moderate/severe FMR; P<0.0001). At diagnosis, higher LACI was independently determined by more severe FMR and by higher left ventricular mass index, lower ejection fraction, higher E/e', and lower glomerular filtration rate (all P<0.0001). During follow-up 1588 (38%) patients died. In spline modeling, excess mortality appeared around LACI=6 and steeply increased thereafter (5-year survival 72±1% with LACI<6 and 49±2% with LACI ≥6, P<0.0001). Multivariable comprehensive adjustment showed LACI strong association with excess mortality (adjusted hazard ratio, 1.41 [1.23-1.61], P<0.0001 for LACI ≥6). Independent link to mortality persistent across FMR grades (adjusted hazard ratio, 1.45 [1.13-1.86], P=0.004 without FMR, 1.42 [1.16-1.77], P=0.0008 with mild FMR, and 1.38 [1.01-1.66], P=0.04 with moderate/severe FMR) without interaction (P=0.3). LACI independent impact on outcome was incremental to that of left atrial volume index, tissue-doppler-imaging a', or any other characteristic including the Meta-Analysis Global Group in Chronic-score (least significant P=0.02).

CONCLUSIONS

In this large cohort, left atrial volumetric/mechanical coupling measured by LACI in routine practice integrates the influence of several morphological/hemodynamic determinants but displays progressive deterioration with increasing FMR severity in heart failure with reduced ejection fraction. About outcome, higher LACI is strongly, independently, and incrementally associated with excess mortality, irrespective of FMR grade and in all subsets. Hence, LACI is a novel and critical measure in heart failure with reduced ejection fraction, quantifiable in routine practice, which should be integrated in prognostication and decision-making.

Effects of pimobendan on left atrial transport function in cats

BACKGROUND

Arterial thromboembolism is a sequela of hypertrophic cardiomyopathy (HCM) in cats related to left atrial (LA) enlargement and dysfunction.

HYPOTHESIS

Pimobendan improves LA transport function in cats.

ANIMALS

Twenty-two client-owned cats with HCM and 11 healthy cats.

METHODS

Prospective, double-blind, randomized, placebo-controlled clinical cohort study. Cats were randomized to receive either pimobendan (0.25 mg/kg PO q12h) or placebo for 4 to 7 days. Nineteen echocardiographic variables of LA size and function were evaluated. Statistical comparisons included t tests, analysis of variance, and multivariable analyses.

RESULTS

Peak velocity of left auricular appendage flow (LAapp peak; mean ± SD, 0.85 ± 0.20 vs 0.71 ± 0.22 m/s; P = .01), maximum LA volume (P = .03), LA total emptying volume (P = .03), peak velocity of late diastolic transmitral flow (A peak velocity; 0.77 ± 0.12 vs 0.62 ± 0.17 m/s; P = .05), and A velocity time integral (A VTI; 3.05 ± 0.69 vs 3.37 ± 0.49; P = .05) were increased after pimobendan. Mean change after pimobendan was larger in cats with HCM compared to healthy cats for LA fractional shortening (2.1% vs -2.1%; P = .05), A VTI (0.58 vs 0.01 cm; P = .01), LAapp peak (0.20 vs 0.02 m/s; P = .02), LA kinetic energy (3.51 vs -0.10 kdynes-cm; P = .05), and LA ejection force (1.93 vs -0.07 kdynes; P = .01) in the multivariable model. The stronger effect of pimobendan in cats with HCM was independent of LA size.

CONCLUSIONS AND CLINICAL IMPORTANCE

We identified positive, albeit minor, effects of pimobendan on LA function in cats with HCM. Whether or not treatment with pimobendan decreases the risk of cardiogenic embolism deserves further study.

Discrepancies in Assessing Diastolic Function in Pre-Clinical Heart Failure Using Different Algorithms-A Primary Care Study

Background: Current guidelines on diastolic function (DF) by the American Society of Echocardiography and the European Association of Cardiovascular Imaging (ASE/EACVI) have been disputed and two alternative algorithms have been proposed by Johansen et al. and Oh et al. We sought (a) to assess the concordance of ASE/EACVI guidelines on DF using these proposed alternative approaches and (b) to evaluate the prevalence of indeterminate diastolic dysfunction (DD) by each method, exploring means for reducing their number. Methods: We retrospectively analyzed the echocardiographic reports of 1158 outpatients including subjects at risk of heart failure without (n = 644) or with (n = 241) structural heart disease, and 273 healthy individuals. Concordance was calculated using the k coefficient and overall proportion of DD reclassification rate. The effectiveness of pulmonary vein flow (PVF), Valsalva maneuver, and left atrial volume index/late diastolic a’-ratio (LAVi/a’) over indeterminate grading was assessed. Results: The DD reclassification rate was 30.1% (k = 0.35) for ASE/EACVI and OH, 36.5% (k = 0.27) for ASE/EACVI and JOHANSEN and 31.1% (k = 0.37) for OH and JOHANSEN (p < 0.0001 for all comparisons). DF could not be graded only by ASE/EACVI and OH in 9% and 11% patients, respectively. The majority of patients could be reclassified using PVF or Valsalva maneuver or LAVi/a’, with the latter being the single most effective parameter. Conclusion: Inconsistencies between updated guidelines and independent approaches to assess and grade DF impede their interchangeable clinical use. The inconclusive diagnoses can be reconciled by conventional echocardiography in most patients, and LAVi/a’ emerges as a simple and effective approach to this aim.

Cardiohemodynamic and Arrhythmogenic Effects of the Anti-Atrial Fibrillatory Compound Vanoxerine in Halothane-Anesthetized Dogs

While vanoxerine (GBR-12909) is a synaptosomal dopamine uptake inhibitor, it also suppresses I_Kr, I_Na and I_Ca,L in vitro. Based on these profiles on ionic currents, vanoxerine has been developed as a candidate compound for treating atrial fibrillation. To investigate electropharmacological profiles, vanoxerine dihydrochloride was intravenously administered at 0.03 and 0.3 mg/kg to halothane-anesthetized dogs (n = 4), possibly providing subtherapeutic and therapeutic concentrations, respectively. The low dose increased the heart rate and cardiac output, whereas it prolonged the ventricular refractoriness. The high dose decreased the heart rate but increased the total peripheral vascular resistance, whereas it delayed the ventricular repolarization and increased the atrial refractoriness in addition to further enhancing the ventricular refractoriness. The extent of increase in the refractoriness in the atrium was 0.8 times of that in the ventricle. The high dose also prolonged the early and late repolarization periods of the ventricle as well as the terminal repolarization period. Meanwhile, no significant change was detected in the mean blood pressure, ventricular contraction, preload to the left ventricle, or the intra-atrial, intra-ventricular or atrioventricular conductions. The high dose can be considered to inhibit I_Kr, but it may not suppress I_Na or I_Ca in the in situ heart, partly explaining its poor atrial selectivity for increasing refractoriness. The prolongation of early repolarization period may reflect enhancement of net inward current, providing potential risk for intracellular Ca²⁺ overload. Thus, vanoxerine may provide both trigger and substrate toward torsade de pointes, which would make the drug less promising as an anti-atrial fibrillatory drug.

Mechanistic validation of the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging Guidelines for the assessment of diastolic dysfunction in heart failure with reduced ejection fraction

Background

The American Society for Echocardiography/European Association of Cardiovascular Imaging (ASE/EACVI) 2016 guidelines for assessment of diastolic dysfunction (DD) are based primarily on the effects of diastolic dysfunction on left ventricular filling hemodynamics. However, these measures do not provide quantifiable mechanistic information about diastolic function. The Parameterized Diastolic Filling (PDF) formalism is a validated theoretical framework that describes DD in terms of the physical properties of left ventricular filling.

Aims

We hypothesized that PDF analysis can provide mechanistic insight into the mechanical properties governing higher grade DD.

Methods

Patients referred for echocardiography showing reduced left ventricular ejection fraction (< 45%) were prospectively classified into DD grade according to 2016 ASE/EACVI guidelines. Serial E-waves acquired during free breathing using pulsed wave Doppler of transmitral blood flow were analyzed using the PDF formalism.

Results

Higher DD grade (grade 2 or 3, n = 20 vs grade 1, n = 30) was associated with increased chamber stiffness (261 ± 71 vs 169 ± 61 g/s², p < 0.001), increased filling energy (2.0 ± 0.9 vs 1.0 ± 0.5 mJ, p < 0.001) and greater peak forces resisting filling (median [interquartile range], 18 [15–24] vs 11 [8–14] mN, p < 0.001). DD grade was unrelated to chamber viscoelasticity (21 ± 4 vs 20 ± 6 g/s, p = 0.32). Stiffness was inversely correlated with ejection fraction (r = − 0.39, p = 0.005).

Conclusions

Higher grade DD was associated with changes in the mechanical properties that determine the physics of poorer left ventricular filling. These findings provide mechanistic insight into, and independent validation of the appropriateness of the 2016 guidelines for assessment of DD.

Heart failure with preserved ejection fraction: insights into diagnosis and pathophysiology

Heart failure with preserved ejection fraction (HFpEF) accounts for at least half the cases of heart failure, currently diagnosed. There are several cardiac and non-cardiac manifestations of the syndrome. Structure and function abnormalities can include all four cardiac chambers. The left ventricle has abnormal systolic and diastolic functions which can be examined by invasive and non-invasive measurements. In addition, the left atrium enlarges with abnormal left atrial function, pulmonary hypertension occurs, and the right ventricle can develop hypertrophy, enlargement, and systolic dysfunction. There are a paucity of data on calcium handling in HFpEF patients. Growing literature supports the presence of abnormalities in titin and its phosphorylation, and increased interstitial fibrosis contributing to increased chamber stiffness. A systemic inflammatory state causing reduced myocardial cyclic guanosine monophosphate along with defects in the unfolded protein response have been recently reported. Diagnosis relies on signs and symptoms of heart failure, preserved ejection fraction, and detection of diastolic function abnormalities based on echocardiographic findings and abnormally elevated natriuretic peptide levels or invasive measurements of wedge pressure at rest or with exercise. There are currently two diagnostic algorithms: H2FPEF, and HFA-PEFF with limited data comparing their performance head to head in the same patient population. Despite the growing understanding of the syndrome's pathophysiology, there have been little success in developing specific treatment for patients with HFpEF.

Left ventricular diastolic function in mitral stenosis

The assessment of left ventricular (LV) function in the setting of mitral stenosis (MS) has been critically examined for decades. Accurate assessment of aberrations in diastolic function is important as these subjects often present with signs and symptoms of heart failure and pulmonary congestion that cannot be solely explained by the severity of mechanical obstruction. Echocardiographic evaluation of diastolic dysfunction includes an evaluation of reduced LV compliance, diminished restoring forces, and enhanced stiffness, which are challenging in the setting of MS owing to altered hemodynamic loading. Conventional echocardiographic and Doppler measures offer limited information. Novel assessments employing speckle tracking echocardiography are relatively less studied. A more comprehensive assessment including clinical evaluation, identification of concomitant disorders, and comorbidities is particularly warranted in older subjects with degenerative MS to suspect diastolic dysfunction and arrive at optimal medical therapy or intervention. This review provides an overview of etiological, pathophysiological, echocardiographic, and invasive assessment of diastolic dysfunction in the setting of MS, with specific focus on strengths and limitations of available echocardiographic and Doppler techniques.

Presence and prognostic value of ventricular diastolic function in arrhythmogenic right ventricular cardiomyopathy

INTRODUCTION

Limited data exist regarding the presence and importance of diastolic parameters in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). We sought to evaluate RV diastolic parameters and echo-based diastolic predictors of major adverse cardiovascular events (MACE).

METHOD

48 patients with a definitive diagnosis of ARVC were included and followed for 6-18 months. A comprehensive standard two-dimensional (2D) transthoracic echocardiography (TTE) with precise evaluation of systolic and diastolic indices of both ventricles was done. RV isovolumetric relaxation time (IVRT), RV myocardial performance index (MPI), and right atrial (RA) volume were evaluated.

RESULTS

48 patients (mean age = 38.5 ± 14 years; 79.2% male) were enrolled. 27.3% had grade I, 68.2% had grade II, and 4.5% had grade III RV diastolic dysfunction. In 12-month follow-up, 12 patients (25%, with mean RV3DEF = 24.8 ± 9%) experienced MACE and required hospitalization: ventricular tachyarrhythmia in 7 patients (14.6%), RV clot in 2 subjects (4.2%), and right-sided failure in 3 cases (6.3%). In logistic regression analysis, tissue Doppler velocity of tricuspid annulus (e' TV) (P = .02, OR = 0.581, CI = 0.368-0.917), peak E mitral valve (P = .043, OR = 0.95, CI = 0.913-0.999), tissue Doppler velocity of septal e' (P = .052, OR = 0.733, CI = 0.536-1.003), and MPI (P = .009, OR = 95, CI = 3.083-2942) were powerful predictors of MACE.

CONCLUSION

In our study, RV diastolic function parameters including e' TV and e' MV, RA volume and area, and RV MPI were powerful predictors of MACE and may be considered during the baseline and follow-up of the ARVC patients.

Left ventricular overloading identified by critical care echocardiography is key in weaning-induced pulmonary edema

Purpose

To assess the role of left ventricular overload and cumulated fluid balance in the development weaning-induced pulmonary edema (WIPO).

Methods

Ventilated patients in sinus rhythm with COPD and/or heart failure (ejection fraction ≤ 40%) were studied. Echocardiography was performed immediately before and during a 30-min spontaneous breathing trial (SBT) using a T-tube. Patients who failed were treated according to echocardiography results before undergoing a second SBT.

Results

Twelve of 59 patients failed SBT, all of them developing WIPO. Patients who succeeded SBT had lower body weight (− 2.5 kg [− 4.8; − 1] vs. + 0.75 kg [− 2.95;  + 5.57]: p = 0.02) and cumulative fluid balance (− 2326 ml [− 3715;  + 863] vs. + 143 ml [− 2654; + 4434]: p = 0.007) than those who developed WIPO. SBT-induced central hemodynamic changes were more pronounced in patients who developed WIPO, with higher E wave velocity (122 cm/s [92; 159] vs. 93 cm/s [74; 109]: p = 0.017) and E/A ratio (2.1 [1.2; 3.6] vs. 0.9 [0.8; 1.4]: p = 0.001), and shorter E wave deceleration time (85 ms [72; 125] vs. 147 ms [103; 175]: p = 0.004). After echocardiography-guided treatment, all patients who failed the first SBT were successfully extubated. Fluid balance was then negative (− 2224 ml [− 7056; + 100] vs. + 146 ml [− 2654; + 4434]: p = 0.005). Left ventricular filling pressures were lower (E/E′: 7.3 [5; 10.4] vs. 8.9 [5.9; 13.1]: p = 0.028); SBT-induced increase in E wave velocity (+ 10.6% [− 2.7/ + 18] vs. + 25.6% [+ 12.7/ + 49]: p = 0.037) and of mitral regurgitation area were significantly smaller.

Conclusion

In high-risk patients, WIPO appears related to overloaded left ventricle associated with excessive fluid balance. SBT-induced central hemodynamic changes monitored by CCE help in guiding therapy for successful weaning.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06061-y) contains supplementary material, which is available to authorized users.

Electropharmacological Characterization of Aciclovir in the Halothane-Anesthetized Dogs: A Proposal of Evaluation Method for Cardiovascular Safety Pharmacology of Anti-virus Drugs

Given limited information regarding the pathophysiology underlying aciclovir-associated, clinically observed cardiovascular adverse events including chest pain, tachycardia, bradycardia, palpitation, arrhythmia, hypertension and hypotension, we investigated its electropharmacological effects using the halothane-anesthetized beagle dogs. Aciclovir in doses of 2 and 20 mg/kg was sequentially infused over 10 min with an interval of 20 min (n = 4), which would achieve sub-therapeutic to supra-therapeutic levels of plasma concentrations. Aciclovir decreased the total peripheral vascular resistance along with the blood pressure in a dose-related manner, which increased the heart rate, ventricular contraction and atrioventricular nodal conduction speed probably via a reflex-mediated increase of sympathetic tone. No significant change was detected in the intra-atrial or intra-ventricular conduction, indicating that aciclovir may not inhibit atrial or ventricular I_Na. Aciclovir prolonged the repolarization period in a dose-related as well as in a reverse frequency-dependent manners, indicating that aciclovir may inhibit I_Kr, which was supported by the T_peak - T_end prolongation. Aciclovir transiently prolonged the J - T_peakc possibly through a reflex-mediated increase of sympathetic tone, indicating an increase of net inward current in the early repolarization phase. Thus, aciclovir may directly inhibit I_Kr, and also have the potential to indirectly induce Ca²⁺ overload leading to early afterdepolarization. These in vivo electropharmacological profile of aciclovir would partly explain the onset mechanism of clinical adverse events.

How the Deuteration of Dronedarone Can Modify Its Cardiovascular Profile: In Vivo Characterization of Electropharmacological Effects of Poyendarone, a Deuterated Analogue of Dronedarone

Since deuterium replacement has a potential to modulate pharmacodynamics, pharmacokinetics and toxicity, we developed deuterated dronedarone; poyendarone, and assessed its cardiovascular effects. Poyendarone hydrochloride in doses of 0.3 and 3 mg/kg over 30 s was intravenously administered to the halothane-anesthetized dogs (n = 4), which provided peak plasma concentrations of 108 ± 10 and 1120 ± 285 ng/mL, respectively. The 0.3 mg/kg shortened the ventricular repolarization period. The 3 mg/kg transiently increased the heart rate at 5 min but decreased at 45 min, and elevated the total peripheral vascular resistance and left ventricular preload, whereas it reduced the mean blood pressure at 5 min, left ventricular contractility and cardiac output. The transient tachycardic action is considered to be induced by the hypotension-induced, reflex-mediated increase of sympathetic tone. The 3 mg/kg delayed both intra-atrial and intra-ventricular conductions, indicating Na⁺ channel inhibitory action. Moreover, the 3 mg/kg transiently shortened the ventricular repolarization period at 5 min. No significant change was detected in the late repolarization by poyendarone, indicating it might not hardly significantly alter rapidly activating delayed-rectifier K⁺ current (I_Kr). Poyendarone prolonged the atrial effective refractory period greater than the ventricular parameter. When compared with dronedarone, poyendarone showed similar pharmacokinetics of dronedarone, but reduced β-adrenoceptor blocking activity as well as the cardio-suppressive effect. Poyendarone failed to inhibit I_Kr and showed higher atrial selectivity in prolonging the effective refractory period of atrium versus ventricle. Thus, the deuteration may be an effective way to improve the cardiovascular profile of dronedarone. Poyendarone is a promising anti-atrial fibrillatory drug candidate.

The Prognostic Value of the Diastolic Stress Test in Patients Undergoing Treadmill Stress Echocardiography

BACKGROUND

Exercise stress echocardiography (SE) is well validated for the evaluation of myocardial ischemia. Diastolic stress testing (DST) is recommended in the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging Guidelines for unexplained dyspnea. This study's aim was to prognostically evaluate the DST prospectively in a large stress testing population.

METHODS

Patients underwent SE with mitral E/e' measured before and after maximal treadmill exertion to estimate diastolic function. Patients were divided into four groups: group 1 (n = 201)-ischemic; group 2 (n = 1,563)-negative DST (E/e'_pre < 12, E/e'_post < 12); group 3 (n = 68)-positive DST (E/e'_pre < 12, E/e'_post ≥ 12); group 4 (n = 314)-high baseline E/e' (E/e'_pre ≥ 12).

RESULTS

Consecutive patients (n = 2,201, 770 [35%] female; 58 ± 12 years) were followed after SE for 27,964 patient-months. Time to first heart failure event (composite of heart failure admission, worsening New York Heart Association class, worsening ejection fraction, or cardiovascular death) was analyzed and adjusted using Cox proportional hazards regression. Ischemic patients hazard ratio (HR) was 28, 95% CI, 17-44, P < .0005, for subsequent heart failure compared with negative DST patients. Nonischemic, positive DSTs were highly predictive (HR = 4.2; 95% CI, 1.6-11.0; P = .001); while high E/e'_pre was not predictive (HR = 1.3; 95% CI, 0.7-2.4; P = .49) of future heart failure events.

CONCLUSIONS

DST differentiates heart failure prognosis in patients with induced diastolic dysfunction. Ischemia predictably portends the worst heart failure outcomes, and nonischemic, positive diastolic stress tests predicted more events compared with negative tests. These prognostic data support and add to the recommendations of the 2016 guidelines.

Indexing peak rapid filling velocity to both relaxation and filling volume to estimate left ventricular filling pressures

AIMS

The peak transmitral velocity/peak mitral annular velocity (E/e') ratio has been used as a left ventricular (LV) filling pressure (LVFP) correlate. However, the E/e' and its changes with haemodynamic alterations have not always correlated with changes in LVFP's. We hypothesized that indexing E/e' to a measure of LV filling volume may enhance the correlation with LVFP and LVFP changes.

METHODS AND RESULTS

We summarized previously obtained haemodynamic and Doppler echo data in 137 dogs with coronary microsphere embolization induced-chronic LV dysfunction prior to and following haemodynamic induced alterations in LVFP's. E/e' values were obtained as E*tau where tau is the inverse logarithmic LV pressure decay. E*tau was indexed to LV filling volume by dividing by the diastolic time velocity integral (DVI) and correlated with LV mean diastolic pressure (LVmDP). Similarly, the relationship of E/e' and E/e'/DVI to LV pre A wave pressure was evaluated in 84 patients by invasive haemodynamics and Doppler echo. Combining data from all interventions, LVmDP correlated with E*tau (r = 0.408) but more strongly with E*tau/DVI (r = 0.667, z = 3.03, P = 0.0008). The change in LVmDP correlated with the change in E*tau/DVI (r = 0.742) more strongly than E*Tau (r = 0.187, Z = 4.01, P < 0.0001). In the patient cohort, E/e' was modestly correlated with LV pre A wave pressure (r = 0.301) but more strongly correlated with E/e'/DVI (r = 0.636, z = 2.36, P = 0.0161).

CONCLUSION

Indexing E to both LV relaxation and filling volume results in a more robust relation with LVFP's and with LVFP changes.