Search

Background: Sleep apnea, as measured by polysomnography, is associated with adverse outcomes in heart failure. The DASAP-HF (Diagnosis and Treatment of Sleep Apnea in Patient With Heart Failure) study previously demonstrated that the respiratory disturbance index (RDI) computed by the ApneaScan algorithm (Boston Scientific) accurately identifies severe sleep apnea in implantable cardioverter-defibrillator (ICD) patients.Objective: The purpose of the long-term study phase was to assess the incidence of clinical events after 24 months and investigate the association with RDI values.Methods: Patients with left ventricular ejection fraction ≤35% implanted with an ICD were enrolled and followed-up for 24 months. The RDI calculated at 1 month after implantation was used to stratify patients (below or above 30 episodes/h). The endpoints were all-cause death and a combination of all-cause death or cardiovascular hospitalization.Results: Of the 265 enrolled patients, 224 had usable RDI values. Severe sleep apnea (RDI ≥30 episodes/h) was diagnosed in 115 patients (51%). These patients were more frequently male (84% vs 72%; P = .030) and had higher creatinine levels. During median follow-up of 25 months, 19 patients (8%) died. Cardiovascular hospitalizations were reported in 19 patients (8%). The risk of all-cause death was higher in patients with RDI ≥30 episodes/h (hazard ratio [HR] 3.33; 95% confidence interval [CI] 1.35-8.21; P = .023), as well as the risk of all-cause death or cardiovascular hospitalization (HR 1.94; 95% CI 1.01-3.76; P = .048). At multivariate analysis, independent predictors of death were RDI ≥30 episodes/h (HR 4.02; 95% CI 1.16-13.97; P = .029) and creatinine levels (HR 2.36; 95% CI 1.26-4.42; P = .008).Conclusion: In heart failure patients implanted with an ICD, higher RDI values are associated with death and cardiovascular hospitalizations. Device-detected severe sleep apnea independently predicts death. [ABSTRACT FROM AUTHOR]

Background: Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are attractive for preventing sudden cardiac death in hypertrophic cardiomyopathy (HCM) as they mitigate risks of transvenous leads in young patients. However, S-ICDs may be associated with increased inappropriate shock (IAS) in HCM patients.Objective: The purpose of this study was to assess the incidence and predictors of appropriate shock and IAS in a contemporary HCM S-ICD cohort.Methods: We collected electrocardiographic and clinical data from HCM patients who underwent S-ICD implantation at 4 centers. Etiologies of all S-ICD shocks were adjudicated. We used Firth penalized logistic regression to derive adjusted odds ratios (aORs) for predictors of IAS.Results: Eighty-eight HCM patients received S-ICDs (81 for primary and 7 for secondary prevention) with a mean follow-up of 2.7 years. Five patients (5.7%) had 9 IAS episodes (3.8 IAS per 100 patient-years) most often because of sinus tachycardia and/or T-wave oversensing. Independent predictors of IAS were higher 12-lead electrocardiographic R-wave amplitude (aOR 2.55 per 1 mV; 95% confidence interval 1.15-6.38) and abnormal T-wave inversions (aOR 0.16; 95% confidence interval 0.02-0.97). There were 2 appropriate shocks in 7 secondary prevention patients and none in 81 primary prevention patients, despite 96% meeting Enhanced American College of Cardiology/American Heart Association criteria and the mean European HCM Risk-SCD score predicting 5.7% 5-year risk. No patients had sudden death or untreated sustained ventricular arrhythmias.Conclusion: In this multicenter HCM S-ICD study, IAS were rare and appropriate shocks confined to secondary prevention patients. The R-wave amplitude increased IAS risk, whereas T-wave inversions were protective. HCM primary prevention implantable cardioverter-defibrillator guidelines overestimated the risk of appropriate shocks in our cohort. [ABSTRACT FROM AUTHOR]

• Real word data on atrial fibrillation (AF) patients with concomitant structural heart disease (SHD) underwent pulmonary vein isolation cryoablation. • The AF recurrence was not related to the type of AF (paroxysmal and persistent). • The AF recurrence was lower than previously reported in patients with SHD. Pulmonary vein isolation (PVI) is an accepted strategy for paroxysmal atrial fibrillation (PAF) and persistent AF (PerAF) ablation. Limited data are available on outcomes of cryoballoon (CB) PVI in patients with structural heart disease (SHD). The purpose is to assess the clinical efficacy of a single CB-PVI procedure in patients with PAF or PerAF who also have SHD. From April 2012, 460 AF patients with concomitant SHD underwent CB-PVI and were followed prospectively in the framework of the 1STOP ClinicalService® project. Data on procedural outcomes and long-term freedom from AF recurrence were evaluated. Out of 460 subjects, 282 patients (61%) had PAF and 178 (39%) PerAF. SHD patients were predominantly male (80.9%), old (62.8 ± 8.9 years), with preserved functional capacity (New York Heart Association class >1: 39.4%), high cardioembolic risk (CHA 2 DS 2 VASc score ≥2: 69.3%), and conserved left ventricular ejection fraction (56.5 ± 8% LVEF). Both subjects with PAF and PerAF had similar baseline clinical characteristics except for left atrial diameter (43.8 ± 7 vs. 45.7 ± 7 mm) and area (22.9 ± 5.2 vs. 25.1 ± 4.4 cm2), respectively. Procedure time and fluoroscopic time as well as the rate of procedural complications were not different between subjects with PAF and PerAF. After a mean follow-up of 12 months, antiarrhythmic drug therapy had dropped from 71.7% before ablation to 33.6% post-ablation (p < 0.001) and the freedom from symptomatic AF recurrence was 78% for PAF and 77% for PerAF (p = 0.793). Furthermore, atrial arrhythmia recurrence rate was not related to SHD. In a large multicenter, real-world cohort, CB-PVI was used to treat patients with PAF and PerAF who also had SHD. The arrhythmia recurrence after a single procedure was not related to either the degree of cardiac structural remodeling or the type of AF, and the rate of AF recurrence was lower than previously reported in patients with SHD in other cohort series using focal radiofrequency catheter ablation. Clinical trial registration : clinicaltrials.gov (NCT01007474). [ABSTRACT FROM AUTHOR]

Background: Professional guidelines are based on the best available evidence. However, patients treated in clinical practice may differ from those included in reference trials.Objective: The aim of this study was to evaluate the effects of cardiac resynchronization therapy (CRT) in a large population of patients implanted with a CRT device stratified in accordance with the 2016 European heart failure (HF) guidelines.Methods: We collected data on 930 consecutive patients from the Cardiac Resynchronization Therapy MOdular REgistry. The primary end point was a composite of death and HF hospitalization.Results: Five hundred sixty-three (60.5%) patients met class I indications, 145 (15.6%) class IIa, 108 (11.6%) class IIb, and 114 (12.3%) class III. After a median follow-up of 1001 days, 120 (14.7%) patients who had an indication to CRT had died and 71 (8.7%) had been hospitalized for HF. The time to the end point was longer in patients with a class I indication (hazard ratio 0.55; 95% confidence interval 0.39-0.76; P = .0001). After 12 months, left ventricular (LV) end-systolic volume had decreased by ≥15% in 61.5% (320/520) of patients whereas in 57.5% (389/676) of patients the absolute LV ejection fraction improvement was ≥5%. Adherence to class I was also associated with an absolute LV ejection fraction increase of >5% (P = .0142) and an LV end-systolic volume decrease of ≥15% (P = .0055).Conclusion: In our population, ∼60% of patients underwent implantation according to the 2016 European HF guidelines class I indication. Adherence to class I was associated with a lower death and HF hospitalization rates and better LV reverse remodeling. [ABSTRACT FROM AUTHOR]

Background: Pulmonary vein isolation (PVI) is a cornerstone ablation strategy in the management of patients with atrial fibrillation (AF). Consensus guidelines and statements recommend PVI during the index catheter ablation procedure in patients with paroxysmal and persistent AF.Objective: The objective of this analysis was to evaluate patients with persistent and long-standing persistent AF who were treated with the cryoballoon ablation catheter by PVI technique.Methods: Consecutive patients with drug-refractory symptomatic persistent and long-standing persistent AF who underwent cryoballoon catheter ablation by a PVI-only procedure were prospectively included in this single-arm multicenter evaluation. Data on procedural characteristics, safety, and long-term freedom from AF recurrence were analyzed.Results: Four hundred eighty-six subjects (mean age 60.8 ± 9.3 years; 389 (80%) men; 434 (89.3%) with persistent AF; 52 (10.7%) with long-standing persistent AF; left atrial diameter 44.6 ± 6.2 mm) underwent cryoballoon ablation in 35 Italian centers. The mean procedure time (skin-to-skin) was 109.9 ± 52.9 minutes, and the mean fluoroscopy time was 29.6 ± 14.5 minutes. Periprocedural complications were observed in 21 subjects (4.3%), and the acute PVI success rate was 97.6% across all patients. Using a 90-day blanking period, the single procedure Kaplan-Meier estimates of AF event-free survival were 63.9% at 12 months and 51.5% at 18 months.Conclusion: In this multicenter evaluation of cryoballoon ablation, the PVI procedure was safe, effective, and efficient with regard to the treatment of patients with persistent and long-standing persistent AF. The reasonable mid-term success rates agree with current clinical studies that establish PVI as a cornerstone index ablation strategy. [ABSTRACT FROM AUTHOR]

Background: Sleep apnea (SA) is a relevant issue in the management of patients with heart failure for risk stratification and for implementing treatment strategies.Objective: The purpose of this study was to evaluate in patients with implantable cardioverter-defibrillators (ICDs) the performance of the respiratory disturbance index (RDI) computed by the ApneaScan algorithm (Boston Scientific Inc., Natick, MA) as a discriminator of severe SA.Methods: ICD-indicated patients with left ventricular ejection fraction ≤35% were enrolled. One month after implantation, patients underwent a polysomnographic study. We evaluated the accuracy of the RDI for the prediction of severe SA (apnea-hypopnea index [AHI] ≥30 episodes/h) and the agreement between RDI and AHI during the sleep study night.Results: Two hundred sixty-five patients were enrolled to obtain the required sample of 173 patients with AHI and RDI data for analysis. The mean AHI was 21 ± 15 episodes/h and severe SA was diagnosed in 38 patients (22%), while the mean RDI was 33 ± 13 episodes/h. On the basis of the receiver operating characteristic curve analysis of RDI values, the area under the curve was 0.77 (95% confidence interval [CI] 0.70-0.83; P < .001). At an RDI value of 31 episodes/h, severe SA was detected with 87% (95% CI 72%-96%) sensitivity and 56% (95% CI 48%-66%) specificity. RDI closely correlated with AHI recorded during the same night (r = 0.74; 95% CI 0.57-0.84; P < .001), and the Bland-Altman agreement analysis revealed a bias of 11 episodes/h, with limits of agreement being -10 to 32 episodes/h.Conclusion: The RDI accurately identified severe SA and demonstrated good agreement with AHI. Therefore, it may serve as an efficient tool for screening patients at risk of SA. [ABSTRACT FROM AUTHOR]

This review will focus on the feasibility of long term His bundle pacing and its effects on left ventricle (LV) hemodynamics. Compared with right ventricular pacing, His bundle pacing results in a more physiological electro-mechanical activation that contributes to preserve LV function. Moreover some studies showed a similar effect to biventricular pacing in patients with heart failure and left bundle branch block. Recent observations indicate that His bundle pacing should be considered as an optimal site to pace right ventricle in patients who are candidates for cardiac resynchronization therapy. [ABSTRACT FROM AUTHOR]

Background Many trials demonstrated the beneficial effects on hospitalizations and mortality of cardiac resynchronization therapy (CRT). The purpose of this study was to evaluate CRT effects on functional performance and cognition, two determinants of disability, frailty development and survival. Methods All consecutive patients receiving a CRT device were evaluated at baseline and at the 6-month follow-up. Functional profile was assessed with the Short Physical Performance Battery (SPPB), a measure exploring balance, gait, strength and endurance, highly predictive of incident disability and mortality. The Mini-Mental State Examination (MMSE) was used to study the cognitive profile. Results We enrolled 54 patients; two of them died during the follow-up, two refused to continue the study. Age was 67 ± 10 years (men: 80%, LVEF: 28 ± 5%); medical therapy was optimized (ACE-I/ARB: 84%, beta-blockers: 80%). After 6 months, CRT was associated with the improvement of LVEF (35 ± 8 vs. 28 ± 5%, p < 0.001) and NYHA Class (1.8 ± 0.6 vs. 2.6 ± 0.5, p < 0.001), and with the reduction of left ventricular end-systolic diameter (50 ± 9 vs. 57 ± 9 mm, p < 0.001). SPPB improved in its total score (10.3 ± 2.0 vs. 9.1 ± 2.7, p < 0.001) and in the scores exploring gait speed and strength and endurance. These changes were associated with a better cognitive profile (MMSE score: 27.0 ± 3.5 vs. 25.9 ± 4.8, p = 0.009). Advanced age was an independent predictor of improved functional performance and cognition. Conclusions CRT is associated with higher functional and cognitive profile after only 6 months of therapy. These findings let us hypothesize a powerful effect of treatment to slow disability and frailty development in heart failure. [ABSTRACT FROM AUTHOR]

Background: Cryoablation (CA) is an emerging tool for the treatment of supraventricular tachyarrhythmias. Determinants of long-term success still need clarification.Objective: The purpose of this study was to assess which patients' and procedural features affect the long-term efficacy of CA for typical atrioventricular nodal reentrant tachycardia (AVNRT).Methods: Eighty-five consecutive patients undergoing CA for typical AVNRT were divided into 3 groups of age: group A, ≤20 years, n = 20 (23.5%); group B, 21-50 years, n = 30 (35.3%); group C, ≥51 years, n = 35 (41.2%). CA was performed for 5 minutes at -75°C in all; 4-minute bonus CA was delivered if not contraindicated (ie, transient PR interval lengthening during the first application and narrow triangle of Koch). The efficacy end point was the absence of recurrences at 12-month follow-up.Results: CA was acutely successful in all 85 patients (100%). Bonus ablation was performed in 69 (81.2%). No permanent complications were observed. At follow-up, AVNRT recurrences occurred in 9 patients (10.6%): group A, 0 (0%); group B, 2 (6.7%), group C, 7 (20%). Incidence of recurrences was significantly different between age groups (P = .047) and between patients receiving (7.2%) and not receiving (25.0%) bonus CA (P = .038). In multivariable analysis, age groups (odds ratio [OR] 5.917; 95% confidence interval [CI] 1.372-25.518; P = .017) and bonus CA (OR 0.115; 95% CI 0.018-0.724; P = .021) were the only independent predictors of recurrences. Furthermore, age as a continuous variable remained statistically associated with recurrences (OR 1.046; 95% CI 1.002-1.091; P = .038).Conclusion: CA is effective and safe for typical AVNRT ablation. Younger age and bonus CA administration are independent predictors of success at 12 months. Incidence of recurrences is low in patients younger than 21 years. [ABSTRACT FROM AUTHOR]

Introduction “Cardiac memory” (CM) refers to a change in repolarization induced by an altered pathway of activation, manifested after resumption of spontaneous ventricular activation (SVA). Aims To investigate for the first time in humans the effects of left ventricular (LV) pacing on CM development through vectorcardiography (VCG). Methods We studied 28 patients with heart failure (HF) and left bundle branch block (LBBB) treated with cardiac resynchronization therapy (CRT). Fourteen patients underwent biventricular (BIV) stimulation; the other 14 underwent LV stimulation only. VCG was acquired during SVA at baseline and during AAI and DDD pacing immediately after and 7 and 90 days after the implant. Results At baseline, in both groups, the QRS and T vectors angles were those specific of LBBB pattern. During DDD pacing, QRS vector angle changed to the right and upward in BIV patients while no significant differences were observed in LV patients. During AAI pacing, T vector angle changed significantly in BIV patients, following the direction of the paced QRS and amplitude significantly increased. In LV patients no significant differences in T vector angles were observed. Only T vector amplitude significantly increased at 7 days (p = 0.03) and at 90 days (p = 0.008 vs baseline). Conclusion In patients with LBBB, BIV pacing induces cardiac memory development as a significant change in T vector magnitude and angle, while LV pacing doesn’t induce significant modifications in QRS and T vector angles and CM is manifested only as a significant T vector amplitude change. [ABSTRACT FROM AUTHOR]

Aims To investigate the LBBB Selvester Scoring System (LBBB-SSc) and the Simplified-SSc prognostic impact in predicting response to CRT, all cause and cardiac mortality, heart failure (HF) hospitalizations and onset of arrhythmias in HF patients undergoing CRT. Methods We retrospectively evaluated LBBB-SSc and Simplified-SSc of 172 consecutive HF patients with true-LBBB who underwent CRT. Response to CRT was defined as the improvement of LVEF of at least 10% or as the reduction of LVESV of at least 15% at 6-month follow-up. Logistic regression analysis and Cox proportional hazard analysis were performed to evaluate each endpoint related risk according to LBBB-SSc and Simplified-SSc. Results The LBBB-SSc and the Simplified-SSc were inversely correlated with response to CRT. Myocardial scar at both scores was independently associated to non-response to CRT. No correlation was observed between LBBB-SSc or Simplified-SSc and other endpoints. Conclusions In HF patients with true-LBBB, Simplified-SSc is able to predict response to CRT. [ABSTRACT FROM AUTHOR]

Abstract: Background: Inflammatory markers are involved in heart failure (HF) pathophysiology. However, the link between these markers and reverse remodeling as well as major adverse cardiac events (HF death, sudden death, and unplanned cardiac rehospitalizations) in patients who undergo cardiac resynchronization therapy (CRT) has not been evaluated. Methods and Results: We recorded major adverse cardiac events of 140 patients (on optimized medical therapy, left ventricular ejection fraction 29.9 ± 9.6%, New York Heart Association Class III-IV, with intraventricular dyssynchrony) who underwent CRT (enrolled since April 2004). Moreover, we evaluated before and after 6 months of CRT: interleukin-6, high-sensitivity C-reactive protein, New York Heart Association class, quality of life (score on Minnesota Living with Heart Failure questionnaire), 6-minute walking test, left ventricular end-diastolic and end-systolic volumes (nonindexed and indexed by body surface area), and left ventricular ejection fraction. Adverse cardiac events were observed in 40 patients (28.6%): 22 deaths and 18 cardiac unplanned rehospitalizations. Only patients without adverse events during follow-up showed a significant reduction of inflammatory markers and left ventricular volumes (reverse remodeling), despite a significant improvement of clinical status observed in both groups of patients. Conclusions: The reduction of inflammatory status seems to be linked to reverse remodeling as well as to a better clinical prognosis in patients with HF who underwent CRT. [Copyright &y& Elsevier]

Background: Atrial tachyarrhythmias (AT) are considered progressive diseases. Several rhythm control therapies for treatment of AT have been proposed.Objectives: The Italian AT500 Registry was designed to prospectively study long-term AT evolution in patients paced for the brady-tachy form of sinus node disease (BT-SND).Methods: Three hundred forty-six BT-SND patients received an antitachycardia dual-chamber pacemaker and were followed-up for a minimum of 12 months (median 19 months). Prevention and antitachycardia pacing (ATP) features were enabled in all patients.Results: During the observation period, 224 (65%) patients were treated by antiarrhythmic drugs and 45 (13%) patients were cardioverted. Five patients suffered a stroke, 4 transient ischemic attack, 22 permanent AT, and 98 AT recurrences longer than 7 days. AT mean cycle length changed from 246 to 270 ms, and the percentage of patients with AT-related hospitalizations significantly decreased with an annual 28% relative reduction. AT burden and the percentage of patients with AT recurrences longer than 2 days remained constant with time in the overall population but decreased significantly in the subgroup of patients who did not develop permanent AT. High ATP efficacy was associated with an increasingly higher prevention of AT recurrences longer than 2 days.Conclusion: In a long-term observation of BT-SND patients, AT-related hospitalizations decreased significantly and mean AT cycle length increased significantly. The data suggest that rhythm control therapies induce inversion of AT progression. [ABSTRACT FROM AUTHOR]

Simultaneous stimulation of 2 left ventricular (LV) sites could enhance the effectiveness of cardiac resynchronization therapy (CRT). The aim of this study was to evaluate the acute hemodynamic response to dual-site LV CRT. Two LV pacing leads were successfully implanted in 12 CRT candidates (New York Heart Association classes III to IV, QRS ≥120 ms). Target positions were the lateral or posterolateral vein (site A) and anterior or anterolateral vein (site B). A conductance catheter was placed in the left ventricle for pressure–volume measurements. Tested CRT configurations were alternated by atrial overdrive pacing at a fixed rate and included site A and B single-site CRT and dual-site LV CRT (2 LV sites plus right ventricular apex) at 4 atrioventricular intervals. Overall, single-site LV CRT significantly enhanced stroke volume, stroke work, maximum pressure derivative, and conductance-derived indexes of LV synchrony when delivered in site A, whereas no significant changes were noticed with pacing in site B. Specifically, site-A pacing resulted in a higher stroke volume increase (LV pacing site associated with the best hemodynamic response [best-LV]) in 8 patients, and site-B pacing, in 4 patients. At intermediate atrioventricular intervals, dual-site LV CRT resulted in improved stroke volume, stroke work, maximum pressure derivative, and LV synchrony with respect to single-site CRT when delivered at the best-LV (all p <0.05). However, single-site CRT at best-LV produced results similar to dual-site LV CRT when the atrioventricular interval was optimized in each patient. In conclusion, adding a second LV lead does not result in further improvement in acute hemodynamic response with respect to standard CRT when the single LV pacing site and atrioventricular interval are optimal. [Copyright &y& Elsevier]

Dual-chamber pacing with His bundle pacing has theoretical advantages over conventional right ventricular (RV) apical pacing. We compared indexes of left ventricular (LV) function during acute dual-chamber pacing from the His bundle and other RV and LV pacing sites. Twelve patients (6 men; 63 ± 11 years) with a standard indication for electrophysiologic study were included. Average QRS duration was 100 ± 19 ms. Ejection fraction was 48 ± 15%. A pressure–volume catheter was positioned in the left ventricle through the femoral arterial access. Pressure–volume loops were collected during atrial (AAI) and dual-chamber overdrive pacing at 82 ± 15 beats/min after 2 minutes of hemodynamic stabilization. Ventricular pacing catheter position was randomized between the RV apex, RV septal, and free wall portions of the outflow tract, LV free wall, and His bundle. His bundle capture was verified from surface electrocardiographic morphometry using standard criteria. Atrioventricular delay was set to the P wave–His duration −10 ms to minimize the effects of fusion (96 ± 22 ms). LV only pacing, but not His pacing, resulted in improved stroke work and stroke volume compared with alternate site RV pacing. No changes in +dP/dt, LV end-systolic pressure. LV end-diastolic pressure, or cycle efficiency, were observed between RV pacing sites. In conclusion, acute His bundle pacing did not improve LV function compared with alternate site RV pacing and may be inferior to LV pacing. [Copyright &y& Elsevier]

Abstract: Background: Cardiac resynchronization therapy (CRT) is an emerging treatment for heart failure patients with left bundle branch block; in these patients left ventricle filling pattern (LVFP) abnormalities are recognized as cause of symptoms and predictors of outcome. We investigated the effects of CRT on diastolic function and the prognostic value of LVFP in patients on CRT. Methods: 65 patients treated with CRT were studied over a 12 months period. At baseline, according to defined echocardiographic criteria, restrictive LVFP (RFP) was present in 25 patients, whereas 40 patients showed no-RFP. Results: After CRT, opposite changes occurred in the two groups. In no-RFP patients, early-to-atrial filling velocity ratio (E / A) increased from 0.8±0.3 to 1.0±0.6 (p =0.006) and E wave deceleration time (DT) decreased from 234±83 ms to 196±51 ms (p =0.028). In 13 RFP patients, E / A decreased from 2.2±0.9 to 0.8±0.5 and DT increased from 128±43 ms to 205±52 ms (both p <0.001), leading to reversal of RFP. In both groups, clinical, functional and echographic benefits were evident, with mortality rates of 5% (2/40) and 15% (2/13) respectively. The remaining patients showed persistence of RFP (E / A and DT unchanged), no improvement and a mortality rate of 42% (5/12) (p =0.005, versus no-RFP). Conclusions: CRT improves diastolic function, inducing also reversal of LVFP in a consistent number of RFP patients. The persistence of RFP after CRT is associated to an extremely poor prognosis. [Copyright &y& Elsevier]

In 21 patients implanted with a biventricular pacing device with programmable interventricular delay (VVd), the myocardial performance index (MPI) was evaluated during spontaneous sinus rhythm, simultaneous biventricular pacing, and sequential biventricular pacing at different VVds and atrioventricular delays (AVds). The AVd-VVd combination associated with the minimum MPI defined patient-tailored biventricular pacing. Simultaneous biventricular pacing significantly improved MPI compared with spontaneous sinus rhythm. An additional improvement was obtained by tailored biventricular pacing. The optimal AVds were significantly shorter during right ventricular preactivation than during left ventricular preactivation. [Copyright &y& Elsevier]