Left Ventricular Pacing In Patients Research Articles

Dynamic optimization of CRT pacing using a novel algorithm improves survival in a real-world cohort of patients

Abstract Background The AdaptivCRT (aCRT) algorithm continuously adjusts cardiac resynchronization therapy (CRT) according to intrinsic atrioventricular (AV) conduction status, providing synchronized left-ventricular pacing in patients (pts) with a normal PR interval and adaptive biventricular (BiV) pacing in pts with a prolonged PR interval. Prior secondary analyses of prospective trials demonstrated a reduction in mortality and atrial fibrillation incidence with aCRT. Objective To compare mortality in a large real-world population of pts with and without aCRT using electronic health record (EHR) data. Methods An Optum® de-identified EHR dataset and Medtronic CareLink device data were linked to identify pts (age>18 years) with a CRT implanted between 2014–2018 who survived ≥35 days post implant and with a documented baseline left ventricular ejection fraction (LVEF). Pts were grouped with aCRT set to either Adaptive BiV+LV (aCRT group) or standard CRT (control group). Two pt subgroups were identified: (i) pts with left bundle branch block (LBBB) and no AV block, (ii) pts with either no LBBB or with AV block. Kaplan-Meier curves and log-rank were used to estimate and compare survival between treatment and control groups in both the full cohort and subgroups. Multivariate Cox regression was used to estimate the aCRT treatment effect while controlling for baseline characteristics. Results Among 8624 patients implanted with a CRT device with EHR data available for a median of 23.5 months post implant [IQR: 12.6, 37.3], 3994 patients had the aCRT feature activated. Pts in the aCRT group were younger (median 69 [IQR:60, 76] vs 73 [IQR: 65, 79] years), more frequently female (35% vs 26%), and more frequently had LBBB (72% vs 51%); p's<0.001. Median QRS duration was 150ms (IQR: 133, 164) for the aCRT group and 152ms (IQR: 134, 172) for the control group (p<0.001). Median LVEF was 22% (IQR: 18, 30) for the aCRT group and 25% (IQR: 20, 30) for the control group (p<0.001). Through 60 months post implant, the overall mortality rate was 23.6% (95% CI: 20.7%-26.3%) for the aCRT group and 37.6% for the control group (95% CI: 34.9%-40.1%), p<0.001. Subgroup analysis demonstrated a significant reduction in mortality with aCRT in both pts with LBBB without AV block (Figure, left panel) and pts without LBBB and with AV block (Figure, right panel). After accounting for baseline differences, the reduction in mortality remained significant in the LBBB/no AV block group (HR: 0.54, 95% CI: 0.39–0.76, p<0.001) and trended toward significance in the no LBBB/with AV block group (HR: 0.89, 95% CI: 0.79–1.01; p=0.08). Conclusion In a large, real-world population of pts implanted with CRT devices, the AdaptivCRT algorithm was associated with significantly reduced mortality, with a greater reduction observed among pts with LBBB and without AV block. These results are being tested prospectively in the ongoing AdaptResponse multi-national, randomized clinical trial. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Medtronic, Inc. Cumulative probability of death by group

Real-world behavior of CRT pacing using the AdaptivCRT algorithm on patient outcomes: Effect on mortality and atrial fibrillation incidence.

BackgroundThe AdaptivCRT (aCRT) algorithm continuously adjusts cardiac resynchronization therapy (CRT) according to intrinsic atrioventricular conduction, providing synchronized left ventricular pacing in patients with normal PR interval and adaptive BiV pacing in patients with prolonged PR interval. Previous analyses demonstrated an association between aCRT and clinical benefit. We evaluated the incidence of patient mortality and atrial fibrillation (AF) with aCRT compared with standard CRT in a real‐world population.Methods and ResultsPatients enrolled in the Medtronic Personalized CRT Registry and implanted with a CRT from 2013‐2018 were divided into aCRT ON or standard CRT groups based upon device‐stored data. A Frailty survival model was used to evaluate the potential survival benefit of aCRT, accounting for patient heterogeneity and center variability. Daily AF burden and first device‐detected AF episodes of various durations were recorded by the device during follow‐up.A total of 1814 CRT patients with no reported long‐standing AF history at implant were included. Mean follow‐up time was 26.1 ± 16.5 months and 1162 patients (64.1%) had aCRT ON. Patient survival probability at 36 months was 88.3% for aCRT ON and 83.7% for standard CRT (covariate‐adjusted hazard ratio [HR] = 0.71, 95% CI: 0.53‐0.96, P = .028). Mean AF burden during follow‐up was consistently lower in aCRT ON patients compared with standard CRT. At 36 months, the probability of AF was lower in patients with aCRT ON, regardless of which AF definition threshold was applied (6 minutes‐30 days, all P < .001).ConclusionUse of the AdaptivCRT algorithm was associated with improved patient survival and lower incidence of AF in a real‐world, prospective, nonrandomized registry.

Left ventricular pacing in patients with preexisting tricuspid valve disease.

BackgroundConventional right ventricular (RV) pacing is increasingly recognised to cause tricuspid valve (TV) injury or dysfunction, in part due to the need to pass the lead through the valve. This may be especially problematic in patients with preexisting TV disease or prior TV surgery. An alternative in this situation is to implant a left ventricular (LV) lead instead of ventricular pacing.MethodsWe performed a single‐center retrospective analysis of 26 patients with tricuspid valve surgery/disease who received a LV pacing lead in the coronary veins to avoid crossing the tricuspid valve, with or without a right atrial lead. A matched control population was obtained from patients receiving conventional right ventricular pacing and outcomes were compared. Main outcomes of interest were lead stability, electrical lead parameters and change in echocardiographic parameters such as left ventricular ejection fraction (LVEF) during long‐term follow‐up.ResultsSuccessful left ventricular pacing was established in 25 out of the 26 cases with one case converted to a RV lead due to lead dislodgement. During the 2.96 ± 1.0 year follow‐up, 24 of 25 (96.0%) leads were functional with stable pacing and sensing parameters, and 1 of 25 (4.0%) was extracted for due to device infection following an episode of thrombophlebitis.ConclusionWe conclude that in patients with existing tricuspid valve disease or surgery, ventricular pacing via the coronary veins is a feasible, safe, and reliable alternative to right ventricular pacing.

Relationship Between Changes in Pulse Pressure and Frequency Domain Components of Heart Rate Variability During Short-Term Left Ventricular Pacing in Patients with Cardiac Resynchronization Therapy.

BackgroundThe aim of the study was to explore the relationship between changes in pulse pressure (PP) and frequency domain heart rate variability (HRV) components caused by left ventricular pacing in patients with implanted cardiac resynchronization therapy (CRT).Material/MethodsForty patients (mean age 63±8.5 years) with chronic heart failure (CHF) and implanted CRT were enrolled in the study. The simultaneous 5-minute recording of beat-to-beat arterial systolic and diastolic blood pressure (SBP and DBP) by Finometer and standard electrocardiogram with CRT switched off (CRT/0) and left ventricular pacing (CRT/LV) was performed. PP (PP=SBP-DBP) and low- and high-frequency (LF and HF) HRV components were calculated, and the relationship between these parameters was analyzed.ResultsShort-term CRT/LV in comparison to CRT/0 caused a statistically significant increase in the values of PP (P<0.05), LF (P<0.05), and HF (P<0.05). A statistically significant correlation between ΔPP and ΔHF (R=0.7384, P<0.05) was observed. The ΔHF of 6 ms2 during short-term CRT/LV predicted a PP increase of ≥10% with 84.21% sensitivity and 85.71% specificity.ConclusionsDuring short-term left ventricular pacing in patients with CRT, a significant correlation between ΔPP and ΔHF was observed. ΔHF ≥6 ms2 may serve as a tool in the selection of a suitable site for placement of a left ventricular lead.

Do patients with heart failure and right bundle branch block need biventricular pacing? A case of significant QRS narrowing by right ventricular pacing alone

We report the case of a 56-year-old male with ischemic cardiomyopathy, severe left ventricular dysfunction and right bundle branch block (RBBB) with a wide QRS duration (180ms) who received dual-chamber implantable cardioverter–defibrillator for primary prevention of sudden death. After having placed the right ventricular lead in the middle of the inter-ventricular septum, a significant narrowing of QRS duration was observed, thus obtaining “de facto” a cardiac resynchronization therapy (CRT). This type of cardiac pacing could be an alternative to conventional CRT with left ventricular pacing in patients with wide QRS due to RBBB. The long-term effects of this RV only pacing strategy with ICD in patients with heart failure yet remain to be determined.

Adverse impact of chronic subpulmonary left ventricular pacing on systemic right ventricular function in patients with congenitally corrected transposition of the great arteries

BackgroundPatients with congenitally corrected transposition of the great arteries (ccTGA) are at high risk of heart block requiring subpulmonary left ventricular (LV) pacing. Long-term right ventricular (RV) pacing in congenitally normal hearts is associated with LV dysfunction. We examined the effects of univentricular subpulmonary LV pacing on the systemic RV in a ccTGA cohort. MethodsccTGA patients with two echocardiographic studies at least 6months apart were included. Records of 52 patients, 22 with pacing, were retrospectively reviewed. Seven patients with biventricular pacing were included for comparison. ResultsThe LV-Paced Group experienced deterioration in the RV fractional area change (RVFAC) (28.7±10.0 vs. 21.9±9.1%; P=0.003), systemic atrioventricular valve regurgitation (P=0.019) and RV dilatation (end-diastolic area 32.7±8.7 vs. 37.2±9.0cm2; P=0.004). There was a corresponding deterioration in NYHA class (P=0.013). Multivariate Cox regression analysis showed that pacing was an independent predictor of deteriorating RV function and RV dilation (hazard ratio 2.7(10–7.0) and 4.7(1.1–20.6) respectively). None of these parameters changed significantly in the Un-paced Group. The CRT Group showed improvement in RVFAC (22.0% to 30.7% (P=0.030) and NYHA class (P=0.030), despite having lower baseline RVFAC (22.0±5.7 vs. 31±9.7%; P=0.025) and greater dyssynchrony (RV total isovolumic time 13.4±2.1 vs. 9.3±4.2s/min; P=0.016) when compared to the Un-Paced Group. ConclusionsUniventricular subpulmonary LV pacing in patients with ccTGA predicted deterioration in RV function and RV dilatation over time associated with deteriorating NYHA class. Alternative primary pacing strategies such as biventricular pacing may need consideration in this vulnerable group already highly prone to mortality from systemic RV failure.

Temporary left ventricular resynchronization therapy in cardiogenic shock: A new pacing paradigm to fight an old foe?

Clinical cardiogenic shock is characterized by tissue hypoperfusion resulting from cardiac dysfunction. Severe left ventricular (LV) dysfunction (usually from myocardial infarction) is the most common cause; however, arrhythmias, acute valvular dysfunction,ventricular rupture, or ventricular septal defect may also result in shock. Hemodynamic criteria for cardiogenic shock include a systolic blood pressure o90 mm Hg, a cardiac index o2.2 L/min/m 2 , and a pulmonary capillary wedge pressure 418 mm Hg. 1 Pharmacotherapy has primarily consisted of inotropic and vasopressor support. Unfortunately, the use of these agents may increase myocardial oxygen consumption, result in arrhythmogenesis, or decrease renal and splanchnic blood flow. To date, mechanical options for patients with drug refractory have included intra-aortic balloon pump (IABP) counterpulsation and percutaneous LV assist devices. Although percutaneous LV assist devices provide superior hemodynamic support compared with IABP, the use of these devices does not appear to improve early survival in patients with cardiogenic shock. 2 Complications associated with these devices include arterial damage, limb ischemia, sepsis, coagulopathy/bleeding, and stroke. 3 In this issue of HeartRhythm, Eitel et al 4 entice us to consider temporary LV pacing in patients with QRS prolongation due to left bundle branch morphology, drug-refractory cardiogenic shock, and asynchronous LV contraction. The study includes a small number of eclectic patients, is uncontrolled, and reveals no statistically significant findings. Nevertheless, it may portend a promising therapeutic adjunct in a clinical scenario where many, possibly the majority, of affected patients die. The potential for long-term survival following cardiogenic shock emphasizes the importance of improving short-term survival, which remains unacceptably low despite optimal intensive care. 4,5 Today, cardiac resynchronization therapy (CRT) is well studied and widely embraced. It is important, however, to remember that the first clinical report of biventricular (BiV) pacing was followed by uncontrolled studies (such as that of Eitel et al) demonstrating marked short-term improvements in hemodynamics and symptoms. 6

Optimizing Hemodynamics in Heart Failure Patients by Systematic Screening of Left Ventricular Pacing Sites: The Lateral Left Ventricular Wall and the Coronary Sinus Are Rarely the Best Sites

We sought to evaluate the impact of the left ventricular (LV) pacing site on hemodynamic response to cardiac resynchronization therapy (CRT). CRT reduces morbidity and mortality in heart failure patients. However, 20% to 40% of eligible patients may not fully benefit from CRT device implantation. We hypothesized that selecting the optimal LV pacing site could be critical in this issue. Thirty-five patients with nonischemic dilated cardiomyopathy referred for CRT device implantation were studied. Intraventricular dyssynchrony and latest activated LV wall were defined by tissue Doppler imaging analysis before the study. Eleven predetermined LV pacing sites were systematically assessed in random order: basal and mid-cavity (septal, anterior, lateral, inferior), apex, coronary sinus (CS), and the endocardial site facing the CS pacing site. For each patient, +dP/dTmax, −dP/dTmin, pulse pressure, and end-systolic pressure during baseline (AAI) and DDD LV pacing were compared. Two atrioventricular delays were tested. Major interindividual and intraindividual variations of hemodynamic response depending on the LV pacing site were observed. Compared with baseline, LV DDD pacing at the best LV position significantly improved +dP/dTmax(+31 ± 26%, p < 0.001) and was superior to pacing the CS (+15 ± 23%, p < 0.001), the lateral LV wall (+18 ± 22%, p < 0.001), or the latest activated LV wall (+11 ± 17%, p < 0.001). The pacing site is a primary determinant of the hemodynamic response to LV pacing in patients with nonischemic dilated cardiomyopathy. Pacing at the best LV site is associated acutely with fewer nonresponders and twice the improvement in +dP/dTmaxobserved with CS pacing.

Abstract 5926: Cardiac Electrical Resynchronization Therapy Combining HIS Bundle and Left Ventricular Pacing is Effective in the Treatment of Severe Heart Failure

Introduction: It is known that Cardiac Resynchronization Therapy (CRT) combining right ventricular (RV) apex pacing and left ventricular pacing (LVP) is ineffective in up to 35% of heart failure (HF) patients. Our hypothesis is that RV apical pacing bypasses the rapidly conducting right bundle and may further impede ventricular activation with LBBB hence a more physiological CRT is via HIS Bundle pacing (HBP) and LVP. We report of our early experience with Cardiac Electrical Resynchronization Therapy (CERT) incorporating HBP with LVP in patients with severe HF. Methods: Patients indicated for CRT were approached for CERT. In addition to an atrial and LV lead, patients also received a HBP lead. An active fixation lead (SelectSecure/Site® Medtronic) was used directly for HIS Bundle mapping and pacing. HBP implant thresholds, procedure and fluoroscopy times, pre and post implant QRS, PR interval, and NYHA class were collected. Student t -test was used for analysis. Results: 15 patients (13 male, mean age 70yrs) referred for CRT underwent successful CERT with mean follow up of 3.5±4.3 months. The mean implant HBP threshold, procedure and fluoroscopy time were 1.6V/0.6ms, 150min, and 26min respectively. All patients had QRS shortening with a mean of 64±21ms (pre CERT 182ms, post CERT 118ms, p&lt;0.0001, figure ) and mean PR shortening of 81±101ms (pre CERT 254ms, post CERT 173ms, p&lt;0.05). 13 patients had improvement of at least one NYHA class. Conclusions: HBP with LVP is effective in achieving electrical resynchronization, and has resulted in early improvement of HF symptoms. Evidence of reverse remodeling is pending. CERT needs to be further validated before considering for wide adoption.

Transseptal endocardial left ventricular pacing: An alternative technique for coronary sinus lead placement in cardiac resynchronization therapy

Coronary sinus (CS) lead placement for transvenous left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) has a failure rate at implant and short-term follow-up between 10% and 15%. The purpose of this study was to assess the feasibility of transseptal endocardial LV pacing in patients in whom transvenous CS lead placement had failed. An atrial transseptal LV lead placement was attempted in 10 patients (six females, age 69.4 +/- 9.6 years), in whom CS lead placement for CRT had failed. After transseptal puncture and septal dilatation from the femoral route, the left atrium was cannulated with a combination of catheters and guide wires from the left or right subclavian vein. After advancement of this guide catheter into the LV, a standard bipolar screw-in lead could be implanted in the posterolateral wall. All patients were maintained on anticoagulant therapy with warfarin after implant. An LV lead could be successfully implanted in nine of the 10 patients. The stimulation threshold was 0.78 +/- 0.24 V, and the R-wave amplitude was 14.2 +/- 9.7 mV. At 2 months' follow-up, the stimulation threshold was 1.48 +/- 0.35 V with a 0.064 +/- 0.027 ms pulse width. There was no phrenic nerve stimulation observed in any of the patients. There were no thromboembolic complications at follow-up. LV transseptal endocardial lead implantation from the pectoral area is a feasible approach in patients with a failed CS approach and in whom epicardial surgical lead placement is not an option. Longer follow-up is warranted to determine the risk of thromboembolic complications.

Invasive Optimization of Cardiac Resynchronization Therapy: Role of Sequential Biventricular and Left Ventricular Pacing

Aim of this invasive study was to characterize and quantify changes in left ventricular (LV) systolic function due to sequential biventricular pacing (BV) as compared to right atrial triggered simultaneous BV (BV(0)), LV, and right ventricular (RV) pacing in patients with congestive heart failure (CHF). In 22 CHF patients, all in sinus rhythm, temporary multisite pacing was performed prior to implantation of a permanent system. LV systolic function was evaluated invasively by the maximum rate of LV pressure increase (dP/dt(max)). Sequential BV pacing was performed with preactivation of either ventricle at 20-80 ms. In comparison to RV pacing, LV and BV(0) pacing increased dP/dt(max) by 33.9 +/- 19.3% and 34.0 +/- 22.6%, respectively (P < 0.001). In 9 patients, optimized sequential BV pacing further improved dP/dt(max) by 8.5 +/- 4.8% compared to BV(0) (range 3.3-17.1, P < 0.05). In 10 patients exhibiting a PR interval < or =200 ms, LV pacing was either superior (n = 6) or equal to BV(0) pacing (n = 4). In these 10 patients, LV pacing yielded a 7.4 +/- 8.0% higher dP/dt(max) than BV(0) pacing (P < 0.05). Using sequential BV pacing, generally with LV preactivation, moderate improvements in LV systolic function can be achieved in selected patients. Baseline PR interval may aid in the selection of the optimum cardiac resynchronization therapy (CRT) mode, favoring LV pacing in patients with a PR interval < or =200 ms.

Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

ObjectivesWe tested the hypothesis that left ventricular (LV) pacing is superior to right ventricular (RV) apical pacing in patients undergoing atrioventricular (AV) junction ablation and pacing for permanent atrial fibrillation. BackgroundThe potential benefit of LV over RV pacing needs to be evaluated without the confounding effect of other variables that can influence cardiac performance. MethodsAn acute intrapatient comparison of the QRS width and echocardiographic parameters between RV versus LV pacing was performed within 24 h after ablation in 44 patients. Both modes of pacing were also compared with pre-implantation values. ResultsCompared with RV pacing, LV pacing caused a 5.7% increase in the ejection fraction (EF) and a 16.7% decrease in the mitral regurgitation (MR) score; the QRS width was 4.8% shorter with LV pacing. Similar results were observed in patients with or without systolic dysfunction and/or native left bundle branch block, except for a greater improvement in MR in the latter group. Compared with pre-ablation measures, the EF increased by 11.2% and 17.6% with RV and LV pacing, respectively; the MR score decreased by 0% and 16.7%; and the diastolic filling time increased by 12.7% and 15.6%. ConclusionsRhythm regularization achieved with AV junction ablation improved EF with both RV and LV pacing; LV pacing provided an additional modest but favorable hemodynamic effect, as reflected by a further increase of EF and reduction of MR. The effect seems to be equal in patients with both depressed and preserved systolic functions and in those with and without native left bundle branch block.

P-171 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

P-171 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

P-171 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

P-171 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

18.2 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

18.2 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

18.2 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

18.2 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

18.2 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

18.2 Acute comparative effect of right and left ventricular pacing in patients with permanent atrial fibrillation

P2131 Long-term comparison of coronary venous leads versus epicardial leads for left-ventricular pacing in patients receiving cardiac resynchronization therapy

P2131 Long-term comparison of coronary venous leads versus epicardial leads for left-ventricular pacing in patients receiving cardiac resynchronization therapy

P2778 Acute comparative effect of right- and left-ventricular pacing in patients with permanent atrial fibrillation

P2778 Acute comparative effect of right- and left-ventricular pacing in patients with permanent atrial fibrillation