Acceleration Time To Ejection Time Research Articles

Associations of right ventricular pulsatile load and cardiac power output to clinical outcomes in heart failure: Difference from systemic circulation

BackgroundAlthough left ventricular (LV) cardiac power output (CPO) is a powerful prognostic indicator in heart failure (HF), the significance of right ventricular (RV) CPO is unknown. In contrast, RV pulsatile load is a key prognostic marker in HF. We investigated the impact of RV-CPO and pulsatile load on cardiac outcome and the prognostic performance of the combined systemic and pulmonary circulation parameters in HF. MethodsRight heart catheterization and echocardiography were performed in 231 HF patients (62 ± 16 years, LV ejection fraction 42 ± 18 %). Invasive and noninvasive CPOs were calculated from mean systemic or pulmonary arterial pressure and cardiac output. LV-CPO was then normalized to LV mass (LV-P/M). Pulmonary arterial capacitance and the ratio of acceleration time to ejection time (AcT/ET) of RV outflow were used as parameters of RV pulsatile load. The primary endpoints, defined as a composite of cardiac death, HF hospitalization, ventricular arrythmia, and LVAD implantation after the examination, were recorded. ResultsNoninvasive CPOs were moderately correlated with invasive ones (LV: ρ = 0.787, RV: ρ = 0.568, and p < 0.001 for both). During a median follow-up period of 441 days, 57 cardiovascular events occurred. Lower LV-P/M and higher RV pulsatile load were associated with cardiovascular events; however, RV-CPO was not associated with the outcome. Echocardiographic LV-P/M and AcT/ET showed significant incremental prognostic value over the clinical parameters. ConclusionsRV pulsatile load assessed by AcT/ET may be a predictor of clinical events in HF patients. The combination of echocardiographic LV-P/M and AcT/ET could be a novel noninvasive prognostic indicator in HF patients.

Abstract 10027: Pulsatile Load, Rather Than Cardiac Power Output, for the Right Ventricle Determines the Prognosis in Heart Failure Patients

Background: Although cardiac power output (CPO), a parameter of cardiac performance, for the left ventricle (LV) is reported to be a powerful prognostic indicator in heart failure (HF), significance of the right ventricular (RV) CPO in HF has not been elucidated. On the other hand, RV pulsatile load stands for one of the prognostic markers in HF. We thus investigated the relationship of the RV CPO and pulsatile load to the outcome in HF. Methods: Right heart catheterization and echocardiography were performed in 231 HF patients (62±16 years, LV ejection fraction 42±18%). Invasive and noninvasive CPOs were calculated from mean systemic or pulmonary arterial pressures and cardiac output for the LV and RV. LV CPO was then corrected by LV mass (LV CPO/M). Pulmonary artery compliance (PAC) and the ratio of acceleration time to ejection time (AcT/ET) of the RV outflow velocity were used as parameters of RV pulsatile load. Cardiac death, HF hospitalization, ventricular arrhythmia and LVAD implantation after the examination were recorded. Results: Noninvasive CPOs were moderately correlated with invasive ones (LV: R=0.73, RV: R=0.58, P &lt;0.001 for both). During a median follow-up period of 441 days, cardiac events occurred in 57 patients. Using the cut-off of median values, lower LV CPO/M was associated with higher event rates, however, RV CPO did not discriminate the risk of future cardiac events. In contrast, higher RV pulsatile load was associated with higher event rates regardless of the level of LV CPO/M ( Figure ). In multivariable Cox proportional hazard analyses, echocardiographic LV CPO/M and AcT/ET both determined cardiac events independently of age, NYHA classification, LV ejection fraction and plasma brain natriuretic peptide levels. Conclusion: Pulsatile load, rather than CPO, for the RV was associated with cardiac events in HF. Furthermore, combination of echocardiographic LV CPO/M and AcT/ET could become a novel noninvasive prognostic indicator in HF patients.

Clinical significance of the ratio of acceleration time to ejection time in severe aortic stenosis

The ratio of acceleration time to ejection time (AT/ET) is a simple and reproducible echocardiographic parameter that integrates AS severity and its consequences on the LV. The prognostic impact of AT/ET on outcome in patients with SAS and no or mild symptoms has not been investigated. This study sought to determine the prognostic impact of AT/ET on mortality in patients with severe aortic stenosis (SAS), preserved left ventricular ejection fraction (LVEF) and no or only mild symptoms. Three hundred and fifty-three patients [median age 79 (71–85), 46% women] with high gradient [mean pressure gradient ≥ 40 mmHg and/or aortic peak jet velocity (Vmax)≥4 m/s] SAS, LVEF ≥ 50% and no or only mild AS symptoms were studied. Patients were retrospectively stratified by AT/ET ≤ or > 0.35. Survival analyses were carried out to study the impact of AT/ET on all-cause mortality. During a median follow-up of 39 (23–62) months, 70 patients died. AT/ET > 0.35 was associated with a considerable increased mortality risk after adjustment for established prognostic factors in SAS when the entire follow up (medical and/or surgical management) was considered [adjusted HR 2.54 (95%CI,1 .47–4.37); P < 0.001] but also under medical management [adjusted HR 3.29 (95%CI, 1.70–6.39); P < 0.001]. In addition, AT/ET > 0.35 improved the predictive performance of multivariable models including established risk factors in SAS as indicated by better global model fit, reclassification, and discrimination. After propensity score matching ( n = 236), increased risk of mortality persisted for patients with AT/ET > 0.35 compared with those with AT/ET ≤ 0.35 [adjusted HR 2.67 (95% CI, 1.45–4.92); P = 0.002] ( Fig. 1 ). AT/ET > 0.35 is a strong predictor of outcome in patients with SAS and no or only mild symptoms and identifies a subgroup of patients at higher risk of death who may derive benefit from earlier aortic valve replacement.

Correlates of the ratio of acceleration time to ejection time in patients with aortic stenosis: An echocardiographic and computed tomography study

An increased acceleration time to ejection time (AT/ET) ratio is associated with increased mortality in patients with aortic stenosis (AS). To identify the factors associated with an increased AT/ET ratio. The relationships between the AT/ET ratio and clinical and Doppler echocardiographic variables of interest in the setting of AS were analysed retrospectively in 1107 patients with AS and preserved left ventricular (LV) ejection fraction (LVEF). The computed tomography aortic valve calcium (CT-AVC) score was studied in a subgroup of 342 patients. In the univariate analysis, the AT/ET ratio was found to correlate with peak aortic jet velocity (r=0.57; P<0.0001), mean pressure gradient (r=0.60; P<0.0001), aortic valve area (r=-0.50; P<0.0001) and CT-AVC score (r=0.24; P<0.0001). The AT/ET ratio had good accuracy in predicting a peak aortic jet velocity≥4m/s, a mean pressure gradient≥40mmHg and an aortic valve area≤1.0cm2, with an optimal cut-off value of 0.34. Multivariable linear regression analysis showed that presence of AS-related symptoms, decreased LV stroke volume index, LVEF, absence of diabetes mellitus, systolic blood pressure, increased LV mass index, relative wall thickness and peak aortic jet velocity were independently associated with an increased AT/ET ratio (all P<0.05). In the subgroup of patients who underwent CT-AVC scoring, the CT-AVC score was independently associated with an increased AT/ET ratio (P<0.05). The AT/ET ratio is related to echocardiographic and CT-AVC indices of AS severity. However, multiple intricate factors beyond the haemodynamic and anatomical severity of AS influence the AT/ET ratio, including LV geometry, function and systolic blood pressure. These findings should be considered when assessing the AT/ET ratio in patients with AS and preserved LVEF.

Impact of ejection dynamics parameters on outcome in patients with aortic stenosis

We sought to evaluate and compare both the prognostic value of acceleration time (AT) and the ratio of AT to ejection time (AT/ET) in aortic stenosis (AS). Ejection dynamics parameters are useful in assessing prosthetic valve obstruction but very limited data are available in the setting of native AS. AT and AT/ET were measured in a prospective cohort of patients with aortic stenosis (AVA < 1.3 cm 2 ). The relationships between AT/ET, AT, overall and cardiovascular mortality during follow-up were studied. Four hundred and fifty-six patients with AS (mean AVA 0.85 ± 0.24 cm 2 ) were included. After adjustment on variables of prognostic importance and on AVR as a time-dependent covariate, patients in the highest tertile of both AT/ET (> 0.36) and AT (> 112 ms) were at high risk of overall mortality (HR 2.57 [1.68–3.94] and HR 2.06 [1.33–3.18] respectively) and of cardiovascular mortality (HR 3.33[1.78–6.21] and HR 2.36[1.30–4.30] respectively), compared to patients in the lowest tertiles of AT/ET and AT, while the survival was similar for the other tertiles (all P values = NS). Compared to patients with an AT/ET≤ 0.36, an increased risk of overall and cardiovascular mortality was observed in patients with AT/ET > 0.36 (adjusted HR 2.55 [1.79–3.62] and adjusted HR 3.40 [2.05–5.64] respectively). Compared to patients with an AT≤ 112 ms, an increased risk of overall and cardiovascular mortality was observed in patients with AT > 112 ms (adjusted HR 1.75 [1.21–2.53] and adjusted HR 2.23[1.34–3.71] respectively). However, AT/ET showed better predictive performance than AT in terms of both overall and cardiovascular mortality with improved global model fit, reclassification, and better discrimination. Ejection dynamics parameters in AS, particularly AT/ET, are strongly associated with an excess risk of death during follow-up. AT/ET should be considered in the multi-parametric echocardiographic prognostic assessment of AS in clinical practice.

Invasive assessment of coronary flow reserve impairment in severe aortic stenosis and ecochadiographic correlations

Objectives and backgroundPatients with aortic stenosis (AS) may have impaired coronary flow reserve (CFR) despite angiographically normal coronary arteries. This is the first report of invasive thermodilution-derived CFR and IMR in patients with AS and their associations with echocardiographic parameters for AS assessment. MethodsThirty-six consecutive severe AS patients and ten patients without AS underwent prospectively cardiac catheterization and coronary physiological parameters were determined in the left anterior descending (LAD). Mean transit time (Tmn), a surrogate of absolute coronary flow, was obtained from the coronary thermodilution curve. ResultsIn AS patients we found a high LAD flow at rest (Tmn rest 0.55±0.3 vs 0.99±0.4, p=0.01) and a low flow at hyperemia (Tmnhyp 0.44±0.2 vs 27.7±0.1, p=0.02) and consequently a severe CFR impairment (1.4±0.4 vs 3.8±1.4, p<0.001) compared with controls. An elevated index of microvascular resistance (IMR) (32.7±16 vs 17.8±6.5, p=0.01) and a low baseline microvascular coronary resistance (48.1±29 vs 84±34, p=0.02) were also found.In AS patients there were significant correlations between CFR and left ventricular mass index (r=−0.32; p=0.02), and the ratio of acceleration time to ejection time (AT/ET) (r=−0.4; p=0.01) a non-flow dependent echocardiographic parameter for AS assessment. Multiple linear stepwise regression analysis showed that AT/ET (β=−0.441, p=0.019) was the only independently variable associated with CFR ConclusionsIn severe AS, invasive CFR shows a progressive decrease with AS severity and a good correlation with echocardiographic parameters of AS, especially with flow-independent ones.

Ratio of Acceleration Time to Ejection Time for Assessing Aortic Stenosis Severity

Inconsistencies in the grading of aortic valve stenosis are frequent (24-38%). Guidelines highlight the waveform shape when discrepancies are present. Our aim was to evaluate the severity of aortic stenosis by the ratio of acceleration time to ejection time (AT/ET). Between January 2011 and January 2013, patients with at least moderate aortic stenosis (valve area < 1.5 cm(2) ) evaluated in our echocardiography laboratory were enrolled. Clinical data were recorded including symptoms attributable to aortic stenosis. Quantitative echocardiographic Doppler parameters as ejection dynamics (ejection time and acceleration time) and conventional parameters, and usual laboratory test including natriuretic peptides (NT-proBNP) were analyzed. One hundred eight patients with aortic valve stenosis were recruited (mean age 77 ± 7 years; 57% women). Comorbidity of the patients was frequent: 85% hypertension, 59% diabetes, 31% chronic renal failure, 26% smokers, mean body mass index 30.0 ± 6.6 kg/m(2) . Ninety-six patients (90%) were symptomatic at the index visit. Using a cutoff of 0.35, AT/ET had a sensitivity of 77% and a specificity of 100% to discriminate symptomatic patients. Serum value of NT-proBNP was higher in patients with AT/ET > 0.35 (9885 ± 3111 vs. 2600 ± 1175, P < 0.001). This ratio showed a good correlation with indexed left ventricle mass (r = 0.60, P < 0.001), DVI (r = -0.56, P < 0.001), and AVA (r = -0.49, P < 0.001). Ejection dynamics through aortic valve, particularly AT/ET ratio, is a useful tool for assessing aortic stenosis severity, with a good correlation with flow-independent parameters in aortic stenosis.

THU0056 A Small Chemical Compound Identified as an ACE2 Activator Prevented Pulmonary Arterial Hypertension Induced by Monocrotaline

BackgroundPulmonary arterial hypertension (PAH) is a lethal clinical symptom characterized by progressive increase in pulmonary arterial pressure and causes right ventricular hypertrophy (RVH) with RV failure. Complications of PAH are...

PREVENTIVE EFFECT OF TADALAFIL ON MONOCROTALINE-INDUCED PULMONARY HYPERTENSION: STUDY OF SEXUAL DIFFERENCE: PP.13.490

Background and Purpose: We already studied that monocrotaline (MCT) easily induced pulmpnary hypertension (PH) in male rats and estrogen could have a powerful preventive effect on development of PH. But the effect of tadalafil, phosphodiesterase 5 (PDE5) inhibitor, on PH is not clear in the model without estrogen. Methods: We used 4-week-old male and ovariectomized female SD rats to induce pulmonary hypertension by 5-time subcutaneous injection of 10 mg/kg/day MCT within 2 weeks. After 5 times administration of MCT, we evaluated heart function by echocardiography. The right and left ventricular end-diastolic area (RVEDA and LVEDA) were measured from left ventricular short axis view and maximal velocity of tricuspid regurgitant flow were measured. We calculated the ratio of RVEDA to LVEDA and peak pressure gradient between right ventricle and atrium. We also observed pulmonary artery flow: the ratio of acceleration time to ejection time (AT/ET) and maximal flow velocity (Vmax), by using a pulse wave Doppler. After orally administration of tadalafil (9.5 mg/kg/day) or vehicle for 6 times every other day, we evaluated heart function again. After verification of survival rate at 8-week-old, we measured the weight of RV, LV and the lung. Result: The survival rate of males at 8-week-old with vehicle and ovariectomized females and males with tadalafil was 33.3 %, 85.7% and 58.3%, respectively (Figure). The heart functions in the tadalafil group at 8 weeks were much better than those in the vehicle group, moreover those in ovariectomized females were better than those in males (Table). Conclusion: Tadalafil could be effective in preventing deterioration of MCT induced PH in rats. There might be a sexual difference in the effect of tadalafil on PH except for estrogen.

Association between intrapulmonary arterial Doppler parameters and degree of lung growth as measured by lung‐to‐head ratio in fetuses with congenital diaphragmatic hernia

To describe the association between the intrapulmonary circulation and the degree of lung growth in fetuses with congenital diaphragmatic hernia (CDH). Thirty-six fetuses with isolated left CDH at 22-29 weeks of gestation were studied. Four groups were defined according to lung-to-head ratio (LHR), expressed as the ratio of observed to expected LHR for gestational age (O/E LHR). Pulsatility index (PI), peak systolic velocity (PSV), peak early-diastolic reversed flow (PEDRF), end-diastolic velocity (EDV), acceleration time (AT), time averaged velocity (TAV) and the ratio AT to ejection time (AT/ET) were measured in all fetuses in the proximal arterial branch of both lungs. For analysis, Doppler values were converted to Z-scores. It was possible to record all Doppler parameters from the contralateral lung of all CDH fetuses, and from the ipsilateral lung in 28 (77.7%). PEDRF significantly increased in relation to the decrease in O/E LHR in both lungs (contralateral: r = - 0.65, P = 0.01; ipsilateral: r = - 0.43, P = 0.02). PI increased significantly with the reduction in O/E LHR but only on the side contralateral to the hernia (r = - 0.55, P = 0.02). In the ipsilateral pulmonary artery, PI values showed a significant overall increase but no differences were observed among the O/E LHR groups. PSV, EDV and TAV were reduced in both lungs with respect to normal values, but no association was found with the O/E LHR. No changes in AT or AT/ET were observed in either lung. PEDRF is quick and easy to calculate, and showed the strongest and most consistent correlation with O/E LHR. The association between PEDRF and LHR might be an additional parameter that could help to establish prognosis in fetuses with CDH.

Progressive development of pulmonary hypertension leading to right ventricular hypertrophy assessed by echocardiography in rats.

The present study aimed to evaluate the development of pulmonary hypertension by serial echocardiography, including measurements of pulmonary artery (PA) flow velocities, and correlate echocardiographic indices with pathological findings in rats administered monocrotaline (MCT). MCT (60 mg/kg body weight) or physiologic saline was administered to a total of 9 male Wistar rats at the age of 4 weeks (MCT group: n = 4, control group: n = 5, respectively). Echocardiography was performed serially until the age of 8 weeks. The ratio of right ventricular (RV) outflow tract dimensions to aortic dimensions increased progressively in the MCT group and became significantly greater than that of the control group after the age of 6 weeks. Peak PA velocity (Peak V) in the MCT group was significantly less than that of the control group at the ages of 7 and 8 weeks. The ratio of acceleration time to ejection time (AT/ET) in PA flow waveforms declined progressively and was significantly less than that of the control group after the age of 6 weeks. The ratio of RV weight to body weight (RVW/BW) in the MCT group was significantly greater than that of the control group. Both AT/ET ratio and Peak V were significantly inversely correlated with RVW/BW ratio. Furthermore, these echocardiographic findings were also significantly inversely correlated with the mean cross-sectional RV myocyte area. In conclusion, the progressive development of pulmonary hypertension leading to RV hypertrophy can be evaluated appropriately by echocardiography including PA flow Doppler indices in rats.

Echocardiographic insights into the mechanisms of relief of left ventricular outflow tract obstruction after nonsurgical septal reduction therapy in patients with hypertrophic obstructive cardiomyopathy

OBJECTIVESWe sought to evaluate the mechanisms by which nonsurgical septal reduction therapy (NSRT) reduces left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM) both acutely and on a long-term basis.BACKGROUNDNSRT reduces LVOT obstruction in patients with HOCM and leads to symptomatic improvement. The mechanisms involved, however, are not well studied.METHODSAn initial group of 30 HOCM patients (age 46 ± 17, 16 women) who underwent NSRT had echocardiographic studies performed at baseline and six months after the procedure. Measurements included LVOT diameter, end-diastolic distance between the anterior mitral leaflet and interventricular septum, septal base function and the angle between LV systolic flow and the protruding mitral leaflets. In addition, pulse Doppler recordings at a point 2.5 cm apical to the mitral valve were acquired and analyzed for peak and mean ejection velocity, peak acceleration rate and the ratio of acceleration time to ejection time (AT/ET).RESULTSSignificant changes were observed after the procedure, with widening in the LVOT, thinning and akinesis of the septal base, decrease in the angle between LV systolic flow and the protruding mitral leaflets, a decrease in peak acceleration rate and an increase in AT/ET. All of these variables had significant relations with the decrease in LVOT obstruction (r = 0.5 to 0.79, p < 0.01). These correlations were then evaluated in a test group of 15 patients who underwent echocardiographic examinations at baseline, acutely in the catheterization laboratory with ethanol injection and at six weeks post NSRT. Acute changes in peak acceleration rate (r = 0.65) and AT/ET (r = 0.73) related significantly (p < 0.01) to the decrease in LVOT obstruction with ethanol. At six weeks, changes similar to those noted in the initial group were observed in LVOT geometry, the angle between LV systolic flow and the protruding mitral leaflets, peak acceleration rate and AT/ET. In both populations combined, these parameters accounted for 72% to 77% of the variance in gradient reduction.CONCLUSIONSChanges in LV ejection dynamics and septal base function account in part for the acute relief of LVOT gradient after NSRT. The long-term relief of obstruction is dependent on remodeling of LVOT as well as the changes in LV ejection.

Doppler echocardiography of the main stems of the pulmonary arteries in the normal human fetus.

The objective of this study was to describe the normal blood flow velocity waveforms in the main branches of the right and left pulmonary arteries in the human fetus and to establish reference ranges for different Doppler parameters during the second half of pregnancy. Cross-sectional data were collected from 86 healthy human singleton fetuses between 18 and 38 weeks of gestation. With advancing gestation a significant increase (p < 0.001) in the peak systolic velocity, time averaged velocity and time velocity integral was observed. The pulsatility index decreased significantly (p < 0.05) in the same period, suggesting a decrease in the pulmonary arterial vascular resistance. The acceleration time (AT) and the ratio of AT to ejection time (AT/ET), described in postnatal cardiology as having an inverse correlation with mean arterial pressure, increased significantly (p < 0.001). This is possibly the result of decreased pulmonary arterial pressure. The data show that Doppler examination of blood flow in the main stem of both the right and the left pulmonary arteries of the fetus is feasible, and increases insight into the lung perfusion of the human fetus. The observed changes throughout gestation are in accordance with animal experiments showing an increase in perfusion as well as a decrease in the vascular resistance and pressure.

Evaluation of Neonatal Cerebral Hemodynamics by Doppler Color Flow Mapping

Using Doppler color flow mapping (DCFM), neonatal cerebral hemodynamics were evaluated by comparing Doppler blood flow patterns between the right internal carotid (ICA) and middle cerebral arteries (MCA) . Transfontanellar right ICA as well as transcranial MCA blood flow patterns were obtained for 30 fullterm neonates in the first or second day after birth. The peak flow velocity (PFV), end-diastolic flow velocity (EDFV), mean flow velocity (MFV), the ratio of acceleration time to ejection time (AT/ET) as well as the time difference between the pre-ejection period (PEP) of the ascending aorta and that of the cerebral artery (ΔPEP) were measured. The PFV, EDFV as well as the MFV of MCA were relatively higher than those of ICA (p<0.01) . Also the ΔPEP of MCA was longer than that of ICA. However there was no difference in the AT/ET between ICA and MCA.We therefore consider that by using DCFM, it is possible to evaluate and compare the regional cerebral hemodynamics in neonates in assosiation with their systemic hemodynamics.