Search

Aims Identifying heart failure (HF) patients who will benefit from cardiac resynchronization therapy (CRT) remains challenging. We evaluated whether virtual pacing in a digital twin (DT) of the patient's heart could be used to predict the degree of left ventricular (LV) reverse remodelling post-CRT. Methods and results Forty-five HF patients with wide QRS complex (≥130 ms) and reduced LV ejection fraction (≤35%) receiving CRT were retrospectively enrolled. Echocardiography was performed before (baseline) and 6 months after CRT implantation to obtain LV volumes and 18-segment longitudinal strain. A previously developed algorithm was used to generate 45 DTs by personalizing the CircAdapt model to each patient's baseline measurements. From each DT, baseline septal-to-lateral myocardial work difference (MWLW-S,DT) and maximum rate of LV systolic pressure rise (dP/dtmax,DT) were derived. Biventricular pacing was then simulated using patient-specific atrioventricular delay and lead location. Virtual pacing–induced changes ΔMWLW-S,DT and ΔdP/dtmax,DT were correlated with real-world LV end-systolic volume change at 6-month follow-up (ΔLVESV). The DT's baseline MWLW-S,DT and virtual pacing–induced ΔMWLW-S,DT were both significantly associated with the real patient's reverse remodelling ΔLVESV (r = −0.60, P < 0.001 and r = 0.62, P < 0.001, respectively), while correlation between ΔdP/dtmax,DT and ΔLVESV was considerably weaker (r = −0.34, P = 0.02). Conclusion Our results suggest that the reduction of septal-to-lateral work imbalance by virtual pacing in the DT can predict real-world post-CRT LV reverse remodelling. This DT approach could prove to be an additional tool in selecting HF patients for CRT and has the potential to provide valuable insights in optimization of CRT delivery. [ABSTRACT FROM AUTHOR]

Aims Data on repolarization parameters in cardiac resynchronization therapy (CRT) are scarce. We investigated the association of baseline T-wave area, with both clinical and echocardiographic outcomes of CRT in a large, multi-centre cohort of CRT recipients. Also, we evaluated the association between the baseline T-wave area and QRS area. Methods and results In this retrospective study, 1355 consecutive CRT recipients were evaluated. Pre-implantation T-wave and QRS area were calculated from vectorcardiograms. Echocardiographic response was defined as a reduction of ≥15% in left ventricular end-systolic volume between 3 and 12 months after implantation. The clinical outcome was a combination of all-cause mortality, heart transplantation, and left ventricular assist device implantation. Left ventricular end-systolic volume reduction was largest in patients with QRS area ≥ 109 μVs and T-wave area ≥ 66 μVs compared with QRS area ≥ 109 μVs and T-wave area < 66 μVs (P = 0.004), QRS area < 109 μVs and T-wave area ≥ 66 μVs (P < 0.001) and QRS area < 109 μVs and T-wave area < 66 μVs (P < 0.001). Event-free survival rate was higher in the subgroup of patients with QRS area ≥ 109 μVs and T-wave area ≥ 66 μVs (n = 616, P < 0.001) and QRS area ≥ 109 μVs and T-wave area < 66 μVs (n = 100, P < 0.001) than the other subgroups. In the multivariate analysis, T-wave area remained associated with echocardiographic response (P = 0.008), but not with the clinical outcome (P = 0.143), when QRS area was included in the model. Conclusion Baseline T-wave area has a significant association with both clinical and echocardiographic outcomes after CRT. The association of T-wave area with echocardiographic response is independent from QRS area; the association with clinical outcome, however, is not. [ABSTRACT FROM AUTHOR]

Aims An automated method for determination of short-term variability (STV) of repolarization on intracardiac electrograms (STV-ARIauto) has previously been developed for arrhythmic risk monitoring by cardiac implantable devices, and has proved effective in predicting ventricular arrhythmias (VA) and guiding preventive high-rate pacing (HRP) in a canine model. Current study aimed to assess (i) STV-ARIauto in relation to VA occurrence and secondarily (ii-a) to confirm the predictive capacity of STV from the QT interval and (ii-b) explore the effect of HRP on arrhythmic outcomes in a porcine model of acute myocardial infarction (MI). Methods and results Myocardial infarction was induced in 15 pigs. In 7/15 pigs, STV-QT was assessed at baseline, occlusion, 1 min before VA, and just before VA. Eight of the 15 pigs were additionally monitored with an electrogram catheter in the right ventricle, underwent echocardiography at baseline and reperfusion, and were randomized to paced or control group. Paced group received atrial pacing at 20 beats per min faster than sinus rhythm 1 min after occlusion. Short-term variability increased prior to VA in both STV modalities. The percentage change in STV from baseline to successive timepoints correlated well between STV-QT and STV-ARIauto. High-rate pacing did not improve arrhythmic outcomes and was accompanied by a stronger decrease in ejection fraction. Conclusion STV-ARIauto values increase before VA onset, alike STV-QT in a porcine model of MI, indicating imminent arrhythmias. This highlights the potential of automatic monitoring of arrhythmic risk by cardiac devices through STV-ARIauto and subsequently initiates preventive strategies. Continuous HRP during onset of acute MI did not improve arrhythmic outcomes. [ABSTRACT FROM AUTHOR]

Aims Pacing remote from the latest electrically activated site (LEAS) in the left ventricle (LV) may diminish response to cardiac resynchronization therapy (CRT). We tested whether proximity of LV pacing site (LVPS) to LEAS, determined by non-invasive three-dimensional electrical activation mapping [electrocardiographic Imaging (ECGI)], increased likelihood of CRT response. Methods and results Consecutive CRT patients underwent ECGI and chest/heart computed tomography 6–24 months of post-implant. Latest electrically activated site and the distance to LVPS (dp) were assessed. Left ventricular end-systolic volume (LVESV) reduction of ≥15% at clinical follow-up defined response. Logistic regression probabilistically modelled non-response; variables included demographics, heart failure classification, left bundle branch block (LBBB), ischaemic heart disease (IHD), atrial fibrillation, QRS duration, baseline ejection fraction (EF) and LVESV, comorbidities, use of CRT optimization algorithm, angiotensin-converting enzyme inhibitor(ACE)/angiotensin-receptor blocker (ARB), beta-blocker, diuretics, and dp. Of 111 studied patients [64 ± 11 years, EF 28 ± 6%, implant duration 12 ± 5 months (mean ± SD), 98% had LBBB, 38% IHD], 67% responded at 10 ± 3 months post CRT-implant. Latest electrically activated sites were outside the mid-to-basal lateral segments in 35% of the patients. dp was 42 ± 23 mm [31 ± 14 mm for responders vs. 63 ± 24 mm non-responders (P < 0.001)]. Longer dp and the lack of use of CRT optimization algorithm were the only independent predictors of non-response [area under the curve (AUC) 0.906]. dp of 47 mm delineated responders and non-responders (AUC 0.931). Conclusion The distance between LV pacing site and latest electrical activation is a strong independent predictor for CRT response. Non-invasive electrical evaluation to characterize intrinsic activation and guide LV lead deployment may improve CRT efficacy. [ABSTRACT FROM AUTHOR]

Aims Altered ventricular activation (AVA) causes intraventricular mechanical dyssynchrony (MD) and impedes contraction, promoting pro-arrhythmic electrical remodelling in the chronic atrioventricular block (CAVB) dog. We aimed to study arrhythmogenic and electromechanical outcomes of different degrees of AVA. Methods and results Following atrioventricular block, AVA was established through idioventricular rhythm (IVR; n = 29), right ventricular apex (RVA; n = 12) pacing or biventricular pacing [cardiac resynchronization therapy (CRT); n = 10]. After ≥3 weeks of bradycardic remodelling, Torsade de Pointes arrhythmia (TdP) inducibility, defined as ≥3 TdP/10 min, was tested with specific IKr -blocker dofetilide (25 μg/kg/5 min). Mechanical dyssynchrony was assessed by echocardiography as time-to-peak (TTP) of left ventricular (LV) free-wall minus septum (ΔTTP). Electrical intraventricular dyssynchrony was assessed as slope of regression line correlating intraventricular LV activation time (AT) and activation recovery interval (ARI). Under sinus rhythm, contraction occurred synchronous (ΔTTP: −8.6 ± 28.9 ms), and latest activated regions seemingly had slightly longer repolarization (AT–ARI slope: −0.4). Acute AV block increased MD in all groups, but following ≥3 weeks of remodelling IVR animals became significantly more TdP inducible (19/29 IVR vs. 5/12 RVA and 2/10 CRT, both P < 0.05 vs. IVR). After chronic AVA, intraventricular MD was lowest in CRT animals (ΔTTP: −8.5 ± 31.2 vs. 55.80 ± 20.0 and 82.7 ± 106.2 ms in CRT, IVR, and RVA, respectively, P < 0.05 RVA vs. CRT). Although dofetilide steepened negative AT–ARI slope in all groups, this heterogeneity in dofetilide-induced ARI prolongation seemed least pronounced in CRT animals (slope to −0.8, −3.2 and −4.5 in CRT, IVR and RVA, respectively). Conclusion Severity of intraventricular MD affects the extent of electrical remodelling and pro-arrhythmic outcome in the CAVB dog model. [ABSTRACT FROM AUTHOR]

Aims: While electrocardiogram (ECG) characteristics have been associated with life-threatening ventricular arrhythmias (LTVA) in dilated cardiomyopathy (DCM), they typically rely on human-derived parameters. Deep neural networks (DNNs) can discover complex ECG patterns, but the interpretation is hampered by their 'black-box' characteristics. We aimed to detect DCM patients at risk of LTVA using an inherently explainable DNN.Methods and Results: In this two-phase study, we first developed a variational autoencoder DNN on more than 1 million 12-lead median beat ECGs, compressing the ECG into 21 different factors (F): FactorECG. Next, we used two cohorts with a combined total of 695 DCM patients and entered these factors in a Cox regression for the composite LTVA outcome, which was defined as sudden cardiac arrest, spontaneous sustained ventricular tachycardia, or implantable cardioverter-defibrillator treated ventricular arrhythmia. Most patients were male (n = 442, 64%) with a median age of 54 years [interquartile range (IQR) 44-62], and median left ventricular ejection fraction of 30% (IQR 23-39). A total of 115 patients (16.5%) reached the study outcome. Factors F8 (prolonged PR-interval and P-wave duration, P < 0.005), F15 (reduced P-wave height, P = 0.04), F25 (increased right bundle branch delay, P = 0.02), F27 (P-wave axis P < 0.005), and F32 (reduced QRS-T voltages P = 0.03) were significantly associated with LTVA.Conclusion: Inherently explainable DNNs can detect patients at risk of LTVA which is mainly driven by P-wave abnormalities. [ABSTRACT FROM AUTHOR]

Aims: Investigate haemodynamic effects, and their mechanisms, of restoring atrioventricular (AV)-coupling using pacemaker therapy in normal and failing hearts in a combined computational-experimental-clinical study.Methods and Results: Computer simulations were performed in the CircAdapt model of the normal and failing human heart and circulation. Experiments were performed in a porcine model of AV dromotropathy. In a proof-of-principle clinical study, left ventricular (LV) pressure and volume were measured in 22 heart failure (HF) patients (LV ejection fraction <35%) with prolonged PR interval (>230 ms) and narrow or non-left bundle branch block QRS complex. Computer simulations and animal studies in normal hearts showed that restoring of AV-coupling with unchanged ventricular activation sequence significantly increased LV filling, mean arterial pressure, and cardiac output by 10-15%. In computer simulations of failing hearts and in HF patients, reducing PR interval by biventricular (BiV) pacing (patients: from 300 ± 61 to 137 ± 30 ms) resulted in significant increases in LV stroke volume and stroke work (patients: 34 ± 40% and 26 ± 31%, respectively). However, worsening of ventricular dyssynchrony by using right ventricular (RV) pacing abrogated the benefit of restoring AV-coupling. In model simulations, animals and patients, the increase of LV filling and associated improvement of LV pump function coincided with both larger mitral inflow (E- and A-wave area) and reduction of diastolic mitral regurgitation.Conclusion: Restoration of AV-coupling by BiV pacing in normal and failing hearts with prolonged AV conduction leads to considerable haemodynamic improvement. These results indicate that BiV or physiological pacing, but not RV pacing, may improve cardiac function in patients with HF and prolonged PR interval. [ABSTRACT FROM AUTHOR]

Aims: Remote patient monitoring (RPM) systems offer a promising alternative to conventional In-Clinic check-ups, hereby reducing unnecessary clinic visits. Especially with the rise of the COVID-19 pandemic, this reduction is of paramount importance. Regarding the association between RPM and clinical outcomes, findings of previous studies have been inconsistent. The aim of this study is to elucidate the effect of partly substituting In-Clinic visits by RPM on clinical outcomes in implantable cardioverter-defibrillator (ICD) patients.Methods and Results: The study included 595 heart failure patients (LVEF ≤35%; NYHA Class II/III) implanted with an ICD compatible with the Boston Scientific LATITUDE™ system. Participants were randomized to RPM plus an annual In-Clinic visit or 3-6 months In-Clinic check-ups alone. The investigated endpoints after 2 years of follow-up included a composite of all-cause mortality and cardiac hospitalization, mortality and cardiac hospitalization as independent endpoints and ICD therapy. The incidence of mortality and hospitalization did not differ significantly as independent, nor as composite endpoint between the RPM and In-Clinic group (all Ps <0.05). The results were similar regarding ICD therapy, except for appropriate ICD therapy (odds ratio 0.50; 95% confidence interval 0.26-0.98; P = 0.04). Exploratory subgroup analyses indicated that the effect of RPM differs between patients with specific characteristics, i.e. ≥60 years and permanent atrial fibrillation (all Ps < 0.05).Conclusion: RPM is non-inferior to conventional In-Clinic visits regarding clinical outcomes. Routine In-Clinic follow-up may partly be substituted by RPM without jeopardizing safety and efficiency, and thus reducing unnecessary In-Clinic visits.Clinicaltrials.gov Identifier: NCT01691586. [ABSTRACT FROM AUTHOR]

Aims: This study was performed to develop and externally validate prediction models for appropriate implantable cardioverter-defibrillator (ICD) shock and mortality to identify subgroups with insufficient benefit from ICD implantation.Methods and Results: We recruited patients scheduled for primary prevention ICD implantation and reduced left ventricular function. Bootstrapping-based Cox proportional hazards and Fine and Gray competing risk models with likely candidate predictors were developed for all-cause mortality and appropriate ICD shock, respectively. Between 2014 and 2018, we included 1441 consecutive patients in the development and 1450 patients in the validation cohort. During a median follow-up of 2.4 (IQR 2.1-2.8) years, 109 (7.6%) patients received appropriate ICD shock and 193 (13.4%) died in the development cohort. During a median follow-up of 2.7 (IQR 2.0-3.4) years, 105 (7.2%) received appropriate ICD shock and 223 (15.4%) died in the validation cohort. Selected predictors of appropriate ICD shock were gender, NSVT, ACE/ARB use, atrial fibrillation history, Aldosterone-antagonist use, Digoxin use, eGFR, (N)OAC use, and peripheral vascular disease. Selected predictors of all-cause mortality were age, diuretic use, sodium, NT-pro-BNP, and ACE/ARB use. C-statistic was 0.61 and 0.60 at respectively internal and external validation for appropriate ICD shock and 0.74 at both internal and external validation for mortality.Conclusion: Although this cohort study was specifically designed to develop prediction models, risk stratification still remains challenging and no large group with insufficient benefit of ICD implantation was found. However, the prediction models have some clinical utility as we present several scenarios where ICD implantation might be postponed. [ABSTRACT FROM AUTHOR]

Aims: The European REMOTE-CIED study is the first randomized trial primarily designed to evaluate the effect of remote patient monitoring (RPM) on patient-reported outcomes in the first 2 years after implantation of an implantable cardioverter-defibrillator (ICD).Methods and Results: The sample consisted of 595 European heart failure patients implanted with an ICD compatible with the Boston Scientific LATITUDE® RPM system. Patients were randomized to RPM plus a yearly in-clinic ICD check-up vs. 3-6-month in-clinic check-ups alone. At five points during the 2-year follow-up, patients completed questionnaires including the Kansas City Cardiomyopathy Questionnaire and Florida Patient Acceptance Survey (FPAS) to assess their heart failure-specific health status and ICD acceptance, respectively. Information on clinical status was obtained from patients' medical records. Linear regression models were used to compare scores between groups over time. Intention-to-treat and per-protocol analyses showed no significant group differences in patients' health status and ICD acceptance (subscale) scores (all Ps > 0.05). Exploratory subgroup analyses indicated a temporary improvement in device acceptance (FPAS total score) at 6-month follow-up for secondary prophylactic in-clinic patients only (P < 0.001). No other significant subgroup differences were observed.Conclusion: Large clinical trials have indicated that RPM can safely and effectively replace most in-clinic check-ups of ICD patients. The REMOTE-CIED trial results show that patient-reported health status and ICD acceptance do not differ between patients on RPM and patients receiving in-clinic check-ups alone in the first 2 years after ICD implantation.ClinicalTrials.gov Identifier: NCT01691586. [ABSTRACT FROM AUTHOR]

Aims: This study aims to define an atrioventricular (AV) delay optimization method for cardiac resynchronization therapy (CRT) with a quadripolar left ventricular (LV) lead based on intrinsic conduction intervals.Methods and Results: Heart failure patients with a left bundle branch block underwent CRT implantation with a quadripolar LV lead. Invasive LV pressure-volume loops were recorded during four biventricular and three multi-point pacing (MPP) settings, using four patient-specific paced AV delays. Haemodynamic response was defined as change in stroke work (Δ%SW) compared to intrinsic rhythm and was related to the following conduction intervals: right atrial pacing to right ventricular sensing interval (RAp-RVs), Q to LV sensing interval normalized to QRS duration (QLV/QRSd), PR-interval, and P-wave duration. In 44 patients, the largest Δ%SW (104 ± 76%) occurred at a paced AV delay of 128 ± 32 ms, at 47 ± 9% of RAp-RVs. Optimal AV delay of biventricular pacing (126 ± 26 ms) did not differ from MPP (126 ± 21 ms, P = 0.29). Intra-class correlation coefficient between optimal AV delays of different pacing configurations was 0.64 (0.45-0.78, P < 0.001). Although not statistically significant, Δ%SW at 50% of RAp-RVs (98 ± 74%) was closer to the maximal achievable Δ%SW increase than a fixed interval of 120 ms (96 ± 73%, P = 0.60). RAp-RVs, QLV/QRSd, PR interval, and P-wave duration were associated with the optimal AV delay in univariate analysis, but only RAp-RVs remained significantly associated in multivariate analysis (R = 0.69).Conclusion: The AV delay that provides highest haemodynamic response is similar for various LV pacing configurations and for MPP. An AV delay ∼50% of RAp-RVs creates an acute haemodynamic response close to the maximal patient-specific response. [ABSTRACT FROM AUTHOR]

Aims: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in systolic heart failure patients with ventricular conduction delay. Variability of individual response to CRT warrants improved patient selection. The Markers and Response to CRT (MARC) study was designed to investigate markers related to response to CRT.Methods and results: We prospectively studied the ability of 11 clinical, 11 electrocardiographic, 4 echocardiographic, and 16 blood biomarkers to predict CRT response in 240 patients. Response was measured by the reduction of indexed left ventricular end-systolic volume (LVESVi) at 6 months follow-up. Biomarkers were related to LVESVi change using log-linear regression on continuous scale. Covariates that were significant univariately were included in a multivariable model. The final model was utilized to compose a response score. Age was 67 ± 10 years, 63% were male, 46% had ischaemic aetiology, LV ejection fraction was 26 ± 8%, LVESVi was 75 ± 31 mL/m2, and QRS was 178 ± 23 ms. At 6 months LVESVi was reduced to 58 ± 31 mL/m2 (relative reduction of 22 ± 24%), 130 patients (61%) showed ≥ 15% LVESVi reduction. In univariate analysis 17 parameters were significantly associated with LVESVi change. In the final model age, QRSAREA (using vectorcardiography) and two echocardiographic markers (interventricular mechanical delay and apical rocking) remained significantly associated with the amount of reverse ventricular remodelling. This CAVIAR (CRT-Age-Vectorcardiographic QRSAREA -Interventricular Mechanical delay-Apical Rocking) response score also predicted clinical outcome assessed by heart failure hospitalizations and all-cause mortality.Conclusions: The CAVIAR response score predicts the amount of reverse remodelling after CRT and may be used to improve patient selection. Clinical Trials: NCT01519908. [ABSTRACT FROM AUTHOR]

Aims This study aimed to determine the additional acute haemodynamic effect of atrioventricular (AV) and interventricular (VV) delay optimization compared with current nominal cardiac resynchronization therapy (CRT) device settings, and to explore whether clinical characteristics correlate to the effect of optimization. Methods and results Fifty CRT patients were prospectively enrolled. The optimal AV and VV delays were guided by relative improvement in maximum rate of left ventricular (LV) pressure rise (%dP/dtmax). A significant improvement in %dP/dtmax was obtained by optimization in 23–33% (sensed AV delay), 32–57% (paced AV delay), and 45% of patients (VV delay). Adjustment of the device nominal VV delay from 0 to 40 ms LV pre-activation would diminish the proportion of patients with additional effect of individual optimization from 45 to 15%. Heart failure aetiology [ischaemic 2 ± 2 vs. non-ischaemic 1 ± 1 percentage points (PP) %dP/dtmax, P= 0.013], gender (men 2 ± 2 vs. women 1 ± 1 PP %dP/dtmax, P= 0.012) and intrinsic PR interval (R= 0.49, P= 0.002) correlated to the degree of effect of AV delay optimization. Women yielded more effect of VV delay optimization (4 ± 3 vs. 2 ± 1 PP %dP/dtmax, P= 0.026). Conclusion Compared with the best of the currently available device nominal AV and VV delays, 23–45% of CRT patients can yield additional acute haemodynamic effect by individual optimization of the delays. A new nominal VV delay of 40 ms LV pre-activation is recommended. Male gender, ischaemic aetiology, and longer PR interval are associated with a larger effect of individual optimization. [ABSTRACT FROM PUBLISHER]

Aims The EUTrigTreat clinical study has been designed as a prospective multicentre observational study and aims to (i) risk stratify patients with an implantable cardioverter defibrillator (ICD) for mortality and shock risk using multiple novel and established risk markers, (ii) explore a link between repolarization biomarkers and genetics of ion (Ca2+, Na+, K+) metabolism, (iii) compare the results of invasive and non-invasive electrophysiological (EP) testing, (iv) assess changes of non-invasive risk stratification tests over time, and (v) associate arrythmogenomic risk through 19 candidate genes. Methods and results Patients with clinical ICD indication are eligible for the trial. Upon inclusion, patients will undergo non-invasive risk stratification, including beat-to-beat variability of repolarization (BVR), T-wave alternans, T-wave morphology variables, ambient arrhythmias from Holter, heart rate variability, and heart rate turbulence. Non-invasive or invasive programmed electrical stimulation will assess inducibility of ventricular arrhythmias, with the latter including recordings of monophasic action potentials and assessment of restitution properties. Established candidate genes are screened for variants. The primary endpoint is all-cause mortality, while one of the secondary endpoints is ICD shock risk. A mean follow-up of 3.3 years is anticipated. Non-invasive testing will be repeated annually during follow-up. It has been calculated that 700 patients are required to identify risk predictors of the primary endpoint, with a possible increase to 1000 patients based on interim risk analysis. Conclusion The EUTrigTreat clinical study aims to overcome current shortcomings in sudden cardiac death risk stratification and to answer several related research questions. The initial patient recruitment is expected to be completed in July 2012, and follow-up is expected to end in September 2014. [ABSTRACT FROM PUBLISHER]

Aims Pulmonary vein antrum isolation (PVAI) is an effective treatment for atrial fibrillation (AF); however, its impact on left atrial (LA) size is unknown. This study evaluates the impact of PVAI on LA size, and whether LA size differs between patients with a successful outcome and patients with AF recurrences. Methods and results Seventy-nine patients (76% male, mean age 56 ± 8 years) with symptomatic, drug refractory AF (70% paroxysmal, 30% persistent/permanent) underwent radiofrequency PVAI. Ablation lesions were created encircling right and left pulmonary venous ostia in pairs. The endpoint was complete isolation of all pulmonary veins. Magnetic resonance imaging was performed before and 4 months after PVAI and LA volume was measured by manually tracing the LA area. Clinical follow-up was at 1, 3, 6, 12, and 24 months. Rhythm status was determined by history, electrocardiogram, and 48 h Holter monitoring. After a mean follow-up of 12 ± 5 months, 62 patients (78%) were free of AF (72% without antiarrhythmic drugs). In the total group, LA volume decreased from 104 ± 27 mL to 91 ± 25 mL, P < 0.001. Patients with a successful outcome showed a decrease in LA volume of 103 ± 27 mL to 89 ± 24 mL, P < 0.001. Among patients with AF recurrences, LA volume decreased from 105 ± 29 mL to 95 ± 27 mL, P = 0.012. No significant difference was seen between the change in LA volume in both subgroups, P = 0.27. Conclusion Pulmonary vein antrum isolation in patients with AF resulted in a significant decrease of LA size. There was no relation between the decrease in LA size and the recurrence of AF after PVAI. [ABSTRACT FROM PUBLISHER]

Aims: Optimal left ventricular (LV) lead position improves the response to cardiac resynchronization therapy (CRT). However, in some patients it is not possible to position the LV lead at an optimal pacing site. The aim of this study was to determine whether optimization of the pacing settings atrioventricular delay (AVD) and interventricular delay (VVD) can compensate for a non-optimal LV pacing site. [ABSTRACT FROM PUBLISHER]