Left Ventricular Pre-ejection Intervals Research Articles

Hemodynamic Doppler echocardiographic evaluation of permanent His bundle and biventricular pacing after AV nodal ablation.

placing after atrioventricular (AV) nodal ablation for permanent atrial fibrillation (AF) may include cardiac resynchronization therapy (CRT) with either His bundle pacing (HBP) or biventricular pacing (BVP), or conventional single site right ventricular apical pacing (RVAP). To determine the relationship between pacing method and hemodynamic outcome, we used Doppler echocardiographic methods to evaluate left ventricular (LV) hemodynamics after AV nodal ablation and either HBP, BVP, or RVAP.Method20 patients were evaluated > 6 months after AV nodal ablation, 10 each with chronic HBP or BVP, and all with RVAP lead. Doppler echocardiography was used to measure 3 parameters indicative of CRT: 1) LV dP/dt, 2) the LV pre-ejection interval, and 3) myocardial performance index, relative to intra-patient RVAP.ResultsPrimary endpoint of LV dP/dt on average improved by > 17% with both HBP and BVP, compared to RVAP. HBP but not BVP, had improvement across all three parameters.ConclusionHBP provides LV electromechanical synchrony across multiple echo Doppler parameters. Both HBP and BVP were hemodynamically superior to RVAP following AV nodal ablation.

Electromechanical dyssynchrony and short-term outcomes of readmission and death, among heart failure patients in Aminu Kano teaching hospital, Kano State, Nigeria

Background: Cardiac dyssynchrony refers to a difference in the timing of contractions in different chambers and/or segments of the heart. Left ventricular (LV) dyssynchrony is frequently seen in patients with heart failure (HF) and is a poor prognostic marker if left untreated. The impact of cardiac dyssynchrony among HF patients in Nigeria is unknown. We set out to assess the role of electromechanical dyssynchrony in short-term outcomes in terms of readmission and 6-month mortality among HF patients in our hospital. Methods: We conducted a prospective observational study among adult HF patients in our hospital. Electrical and mechanical dyssynchrony were measured using electrocardiography and echocardiography, respectively. Data on the outcome of readmission and death within 6 months were collected. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) version 16 software. Results: A total of 100 participants were recruited for this study. Electrical dyssynchrony (Duration of QRS complex on ECG > 120ms) was found in 11%, 8 (73%) of them had QRS width between 120 and 150 ms, while in three, the QRS width was >150 ms. The prevalence of interventricular dyssynchrony (LV preejection interval – right ventricular preejection interval ≥40 ms) was found to be 79%, while that of intraventricular (septal to posterior wall motion delay >130 ms) was 75%. Nineteen percent of the study participants were readmitted with worsening HF symptoms, while up to 37% died within the 6 months follow-up period. Electrical dyssynchrony was a significant predictor of short-term readmission and death. There was also a statistically significant difference (P Conclusion: The presence of electromechanical dyssynchrony is associated with a poor short-term outcome of readmission and death. More studies are needed in our country to fully define the burden of dyssynchrony among HF patients in our environment.

Electrocardiographic correlates of mechanical dyssynchrony in recipients of cardiac resynchronization therapy devices

The relationship between electrical and mechanical indices of cardiac dyssynchronization in systolic heart failure (HF) remains poorly understood. We examined retrospectively this relationship by using the daily practice tools in cardiology in recipients of cardiac resynchronization therapy (CRT) systems. We studied 119 consecutive patients in sinus rhythm and QRS ≥ 120 ms (mean: 160 ± 17 ms) undergoing CRT device implantation. P wave duration, PR, ePR (end of P wave to QRS onset), QT, RR-QT, JT and QRS axis and morphology were putative predictors of atrioventricular (diastolic filling time [DFT]/RR), interventricular mechanical dyssynchrony (IVMD) and left intraventricular mechanical dyssynchrony (left ventricular pre-ejection interval [PEI] and other measures) assessed by transthoracic echocardiography (TTE). Correlations between TTE and electrocardiographic measurements were examined by linear regression. Statistically significant but relatively weak correlations were found between heart rate (r=-0.5), JT (r=0.3), QT (r=0.3), RR-QT intervals (r=0.5) and DFT/RR, though not with PR and QRS intervals. Weak correlations were found between: (a) QRS (r=0.3) and QT interval (r=0.3) and (b) IVMD > 40 ms; and between (a) ePR (r=-0.2), QRS (r=0.4), QT interval (r=0.3) and (b) LVPEI, though not with other indices of intraventricular dyssynchrony. The correlations between electrical and the evaluated mechanical indices of cardiac dyssynchrony were generally weak in heart failure candidates for CRT. These data may help to explain the discordance between electrocardiographic and echocardiographic criteria of ventricular dyssynchrony in predicting the effect of CRT.

Extraordinarily Favorable Left Ventricular Reverse Remodeling through Long‐Term Cardiac Resynchronization: Super‐Response to Cardiac Resynchronization

Some chronic heart failure (CHF) patients show remarkable improvement in left ventricular (LV) remodeling after cardiac resynchronization therapy (CRT), for unclear reasons. This study aimed at identifying predictors of an extraordinarily favorable response to CRT. We studied 136 CRT patients (104 men, median 66 years, QRS 162 ms, left ventricular ejection fraction 24 ± 7%, 70% coronary disease, all left bundle branch block [LBBB]). We measured LV end diastolic diameter (LVEDD) before and after long-term (9.4 ± 6.3 months) CRT. At baseline, LV pre-ejection interval (LVPEI), interventricular mechanical delay (IVMD), LV dyssynchrony (standard deviation of electromechanical delays [SDEMD] in eight LV segments), exercise capacity (pVO(2)), and ventilatory efficiency (VE/VCO(2)) were assessed. Patients with a LVEDD reduction beyond the 80th percentile (high responders [HR]) were compared to low responders (LR). In the HR group (n = 22), LVEDD was reduced from 71 to 52 mm (LR 64-61 mm, P < 0.001). HR had predominantly nonischemic heart disease (HR: 72%, LR: 44%, P = 0.019), tended to have a wider QRS (HR: 178 ms, LR: 162 ms, P = 0.066), had a longer LVPEI (HR: 179 ms, LR: 155 ms, P = 0.004), wider IVMD (HR: 60 ms, LR 48 ms, P = 0.05), larger LVEDD (P = 0.002), higher SDEMD (HR: 69 ms, LR: 46 ms, P = 0.044), but higher pVO(2) (HR: 17.5 mL/min/kg, LR: 13.5 mL/kg/min, P = 0.025) and lower VE/VCO(2) (HR: 31, LR: 35, P = 0.043), all compared to LR patients. Extraordinarily favorable reverse LV remodeling through CRT in CHF and LBBB appears to require a particularly dilated LV due to nonischemic heart disease with pronounced electromechanical alteration, but with a fairly preserved functional capacity before CRT.

Right ventricular outflow pacing induces less regional wall motion abnormalities in the left ventricle compared with apical pacing

This study aimed to explore if the right ventricular outflow tract (RVOT) pacing is superior to right ventricular apical (RVA) pacing on the overall left ventricular (LV) function and regional wall motion. Sixty patients with atrio-ventricular (AV) block and normal ejection fraction undergoing dual-chamber pacemaker implantation were randomized to permanent ventricular stimulation either in the RVOT or the RVA. Left ventricular volume, ejection fraction, and LV regional wall motion were assessed by echocardiography. Right ventricular apical pacing had prolonged QRS duration, compared with RVOT pacing (154.1 ± 26.5 vs. 120.9 ± 22.3, P< 0.05). There were also significant differences in LV pre-ejection interval and interventricular mechanical delay (IVMD) at 12-month follow-up between the two groups, but none in the LV volume, left ventricular ejection fraction, and index of systolic synchrony (Ts-SD). During RVA pacing, the average peak systolic velocity (Sm) of 12 LV segments [3.5, 95% confidence interval (CI) 3.2-3.8 cm/s] had a trend of being lower compared with RVOT pacing (3.9, 95% CI 3.5-4.1 cm/s) (P= 0.09). Further analysis showed that the Sm at the inferior wall and posterior-septum wall was significantly decreased during RVA pacing compared with RVOT pacing. There were no significant differences for other LV segments. The RVOT pacing in AV block patients over 1 year may be superior to RVA pacing in terms of regional LV performance, LV global electromechanical delay, and IVMD, although intraventricular dyssynchrony and LV volumes do not differ. Larger trials with clinical endpoints are warranted to conclusively define the advantages of RVOT or RV septal pacing.

Echocardiographic Dyssynchrony and Health Status Outcomes From Cardiac Resynchronization Therapy: Insights From the PROSPECT Trial

This study sought to assess the prognostic utility of echocardiographic dyssynchrony for health status improvement after cardiac resynchronization therapy (CRT). Echocardiographic measures of dyssynchrony have been proposed for patient selection for CRT, but prospective validation studies are lacking. A prospective cohort of 324 patients from 53 centers with moderate to severe heart failure, left ventricular dysfunction, QRS > or =130 ms, and available echocardiographic and health status information were identified from the PROSPECT (Predictors of Response to Cardiac Re-Synchronization Therapy) trial, which evaluated the prognostic utility of dyssynchrony measures in CRT recipients. The association of 12 echocardiographic dyssynchrony parameters with 6-month improvement in health status, as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ), was assessed both as a continuous variable and by responder status (DeltaKCCQ > or =+10 points reflecting moderate to large improvement). Of 12 pre-defined dyssynchrony parameters, only 3 were consistently reported: interventricular mechanical delay (IVMD), left ventricular filling time relative to the cardiac cycle (LVFT), and left ventricular pre-ejection interval. After multivariable adjustment, IVMD (+5.18, 95% confidence interval [CI]: +0.76 to +9.60; p = 0.02) and LVFT (+5.19, 95% CI: +0.45 to +0.94; p = 0.03) were independently associated with 6-month improvements in KCCQ. Patients with 6-month improvements in KCCQ had lower subsequent mortality (adjusted hazard ratio [HR] for each 5-point improvement: 0.83; 95% CI: 0.72 to 0.93; p = 0.03). Additionally, IVMD was associated with CRT responder status (for DeltaKCCQ > or =+10 points: odds ratio [OR]: 1.85; 95% CI: 1.12 to 3.05; p = 0.03), whereas LVFT was not (OR: 1.63; 95% CI: 0.85 to 3.11; p = 0.14). Patients classified as health status responders had a 76% lower subsequent risk of all-cause mortality (adjusted HR: 0.24; 95% CI: 0.07 to 0.84; p = 0.03). The presence of pre-implantation IVMD and LVFT was associated with 6-month health status improvement, and IVMD was associated with a significant CRT response. These echocardiographic factors may help clinicians counsel patients regarding their likelihood of symptomatic improvement with CRT. ( Predictors of Response to Cardiac Re-Synchronization Therapy; NCT00253357).

Baseline Doppler parameters are useful predictors of chronic left ventricular reduction in size by cardiac resynchronization therapy

The identification of responders to cardiac resynchronization therapy (CRT) in patients with left ventricular (LV) dysfunction and left bundle branch block (LBBB) remains difficult. We aimed to define the predictive value of conventional Doppler parameters. In 73 patients (65 +/- 9 years, 51 male, 36 ischaemic, 37 non-ischaemic cardiomyopathy, QRS 167 +/- 31 ms, LVEF 23 +/- 6%) with LBBB, a CRT device was implanted. LV pre-ejection interval (PEI), interventricular mechanical delay (IVMD), LV filling time (FT), and myocardial performance index (MPI) were assessed at baseline and on optimized CRT. Left ventricular end-diastolic diameter (EDD) was obtained at baseline and after 10.6 +/- 6.7 months. end-diastolic diameter diminished from 66.3 +/- 8.1 to 59.9 +/- 9.6 mm (P < 0.001). Initial LVPEI (r = 0.41, P < 0.001), baseline IVMD (r = 0.34, P = 0.003), acute LVPEI shortening (r = 0.33, P = 0.006), and baseline LVEDD (r = 0.32, P = 0.007) correlated with LVEDD reduction. An LVPEI > or =140 ms had a 82% accuracy to predict long-term LVEDD reduction (sensitivity 86%, specificity 67%, positive and negative predictive values 91 and 56%, respectively). Multivariate analysis solely revealed baseline LVPEI as predictor of LVEDD reduction. FT and MPI correlated only with their respective improvements. Left ventricular pre-ejection interval and IVMD predict favourable LV remodelling on CRT. The additional application of tissue Doppler parameters may further increase specificity and negative predictive value.