Assessing the facilities and healthcare services for heart failure: Taiwan versus European countries.

BACKGROUND/PURPOSE: The present study was designed to evaluate the local cardiology infrastructure and services for heart failure (HF) care in Taiwan hospitals and to compare the HF care with the hospitals in European countries. METHODS: Available data from a total of 98 medical centers and regional hospitals in Taiwan were analyzed. Each facility was given a single copy of the questionnaire between September and December 2019, and service records were extracted from the National Health Insurance Database. European data were adopted from the 2017 European Society of Cardiology Atlas. RESULTS: The number of cardiologists per million populations in Taiwan was 57.4, and it was lower than the European median (72.8). The median percentages of interventional and electrophysiologists among cardiologists were 64% and 15% in Taiwan, which were both higher than the European median values (12% and 5%, respectively). The accessibility rates to implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT) in Taiwan were both higher (3.4 and 3.0 centers per million populations) comparing to those in European countries (median 1.6 and 1.5 centers per million populations). Comparing to 67 hospitals without HF care teams in Taiwan, 31 hospitals (31.6%) with HF teams have significantly more cardiology staff, enhanced procedural capabilities with more alternatives on oral or intravenous HF relevant medications. CONCLUSION: Our analysis clearly demonstrated discrepancies in cardiology subspecialties and CRT/ICD accessibilities between European countries and Taiwan. Variations in HF-focused services and facilities plus HF-directed medications have demonstrated significant differences among Taiwanese hospitals with or without HF care team.

Focal cryoablation of atrioventricular node reentrant tachycardia: a review and comparison of data.

PURPOSE OF REVIEW: Atrioventricular node reentrant tachycardia (AVNRT) is the most common mechanism of supraventricular tachycardia. Radiofrequency ablation has been the most prevalent method for slow pathway ablation but carries risk of atrioventricular node injury. Focal cryoablation has been utilized as an alternative ablation modality; however, there has been concern about decreased efficacy, resulting in a higher rate of recurrence postablation. We also report outcomes from two international centers using an 8-mm cryocatheter and complete a thorough comparison of existing data on ablation of AVNRT. RECENT FINDINGS: Previous reviews included studies from 2006 onward. These studies included use of the 4 mm focal cryocatheter, which has largely been abandoned in current adult practice. We will cite more contemporary studies within the past 10 years, which also includes use of the 6 and 8 mm cryocatheter. SUMMARY: The use of focal cryoablation allows for reversible injury during AVNRT ablation, providing safety from permanent atrioventricular node injury. With the appropriate ablation endpoints, 8 mm focal cryoablation is more effective for permanent lesion formation, leading to lower recurrences.

Successful Surgical Salvage for a Patient with Ruptured Coronary Sinus during Percutaneous Ablation for Atrial Fibrillation: A Case Report.

Herein, we describe the rare anatomy of an abnormal shunt from the left atrium to the coronary sinus, which ruptured during a percutaneous ablation for atrial fibrillation. The iatrogenic lesion was successfully repaired after emergent extracorporeal membrane oxygenation set up followed by surgical exploration. The patient's postoperative course was uneventful, and she was regularly followed up without any complications.

Dyslipidemia, Not Inflammatory Markers or Adipokines, Contributes Significantly to a Higher SYNTAX Score in Stable Coronary Artery Disease (from the Taichung CAD Study).

BACKGROUND: The SYNTAX score is an index of coronary severity used to determine the revascularization strategy of a patient. Our previous study confirmed that the SYNTAX score is helpful in predicting major adverse cardiac events in patients with stable coronary artery disease (CAD). However, few studies have comprehensively investigated the predictors for SYNTAX scores in patients with stable CAD, including conventional risk factors, lipid parameters, inflammatory markers and adipokines. METHODS: The coronary severities of 181 revascularization-naïve CAD patients who had received coronary angiograms were coded using SYNTAX scores. Conventional risk factors, inflammatory markers, and adipokines were investigated in order to determine the independent predictors for SYNTAX severity in the patients with stable CAD. RESULTS: The SYNTAX severity score was divided according to the generally accepted criterion (low: ≤ 22, intermediate-high: ≥ 23). In univariate comparisons, the intermediate-high SYNTAX group had a significantly higher low-density lipoprotein cholesterol (LDL-C) level compared to the low SYNTAX score group (p = 0.046). In binary logistic regression, LDL-C, total cholesterol, ratio of total cholesterol/high-density lipoprotein cholesterol (HDL-C) and pre- admission statin use were significant predictors for a higher SYNTAX severity score in the patients with stable CAD. In contrast, circulating adipokines, high-sensitivity C-reactive protein and HDL-C alone were not. CONCLUSIONS: In revascularization-naïve CAD patients, dyslipidemia, including elevated LDL-C, total cholesterol, total cholesterol/HDL-C ratio and pre-index admission statin use, were associated with an intermediate-high SYNTAX severity score.

Outcome of rescue ablation in patients with refractory ventricular electrical storm requiring mechanical circulation support.

BACKGROUND: The management of refractory electrical storm (ES) requiring mechanical circulation support (MCS) remains a clinical challenge in structural heart disease (SHD). OBJECTIVE: The study sought to explore the 30-day and 1-year outcome of rescue ablation for refractory ES requiring MCS in SHD. METHODS: A total of 81 patients (mean age: 55.3 ± 18.9, 73 men [90.1%]) undergoing ablation were investigated, including 26 patients with ES requiring MCS (group 1) and 55 patients without (group 2). The 30-day and 1-year outcome, including mortality and recurrent ventricular tachyarrhythmias (VAs) receiving appropriate implantable cardioverter defibrillators therapies, were assessed. RESULTS: The patients in group 1 were characterized by older age, more ischemic cardiomyopathies, worse left ventricular ejection fraction, and more comorbidities. Thirty days after ablation, overall events were seen in 15 patients (mortality in 10 and recurrent VA in 7), including pumping failure-related mortality in 6 (60%). During a 30-day follow-up, higher mortality was noted in group 1. After a 1-year follow-up, in spite of the higher mortality in group 1 (P < .001), the overall events and VA recurrences were similar between these two groups (P = .154 and P = .466, respectively). There was a significant reduction of VA burden in both groups and two patients had recurrent ES. CONCLUSION: Higher 30-day mortality was observed in patients undergoing rescue ablation for refractory ES requiring MCS, and pumping failure was the major cause of periprocedural death. Rescue ablation successfully prevented VA recurrences and resulted in a comparable 1-year prognosis between ES with and without MCS.

Hypoglycaemic episodes increase the risk of ventricular arrhythmia and sudden cardiac arrest in patients with type 2 diabetes-A nationwide cohort study.

BACKGROUND: The impact of hypoglycaemic episode (HE) on the risk of ventricular arrhythmia (VA) and sudden cardiac arrest (SCA) remains unclear. We hypothesized that HE increases the risk of both VA and SCA and that glucose-lowering agents causing HE also increase the risk of VA/SCA in patients with type 2 diabetes (T2D). METHODS: Patients aged 20 years or older with newly diagnosed T2D were identified using the Taiwan National Health Insurance Database. HE was defined as the presentation of hypoglycaemic coma or specified/unspecified hypoglycaemia. The control group consisted of T2D patients without HE. The primary outcome was the occurrence of VA (including ventricular tachycardia and fibrillation) and SCA during the defined follow-up periods. A multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for VA or SCA. RESULTS: A total of 54 303 patients were screened, with 1037 patients with HE assigned to the HE group and 4148 frequency-matched patients without HE constituting the control group. During a mean follow-up period of 3.3 ± 2.5 years, 29 VA/SCA events occurred. Compared with the control group, HE group had a higher incidence of VA/SCA (adjusted HR: 2.42, P = .04). Patients who had used insulin for glycaemic control showed an increased risk of VA/SCA compared with patients who did not receive insulin (adjusted HR: 3.05, P = .01). CONCLUSIONS: The HEs in patients with T2D increased the risk of VA/SCA, compared with those who did not experience HEs. Use of insulin also independently increased the risk of VA/SCA.

Precordial T-Wave Inversions in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy Who Present with the Initial Features of Right Ventricular Outflow Tract Arrhythmia.

BACKGROUND: Precordial T-wave inversion (TWI) is an important diagnostic criterion for arrhythmogenic right ventricular cardiomyopathy (ARVC). OBJECTIVE: This study aimed to characterize the initial repolarization features of definite ARVC in patients who first presented with right ventricular outflow tract ventricular arrhythmia (RVOT-VA) and TWI. METHODS: Patients who presented with RVOT-VA and TWI ≥ V2 were retrospectively assessed. The initial characteristics of repolarization between patients with and without a final diagnosis of definite ARVC during follow-up were compared. RESULTS: TWI ≥ V2 was observed in 61 of 553 patients (mean age: 44.1 ± 14.7 years; 14 men) with RVOT-VAs. After an average follow-up time of 54.9 ± 33.7 months, 31 (50.8%) patients were classified into the definite ARVC group and 30 (49.2%) into the non-definite ARVC group. The disappearance of precordial TWI ≥ V2 was observed in eight (13.1%) patients after the elimination of RVOT-VAs. In a multivariate analysis of the initial electrocardiogram features, only fragmented QRS [odds ratio (OR): 15.45, 95% confidence interval (CI): 1.61-148.26, p = 0.02] and precordial V2 TpTe interval (OR: 1.03, 95% CI: 1.01-1.06, p = 0.02) could independently predict definite ARVC during longitudinal follow-up. An initial V2 TpTe cutoff value > 88.5 ms could predict the final diagnosis of definite ARVC, with a sensitivity and specificity of 74.2% and 78.6%, respectively. CONCLUSIONS: Despite the high risk of ARVC in RVOT-VAs and TWI ≥ V2, "normalization" of TWI was observed after ventricular arrhythmia elimination in 13.1% of the patients. Fragmented QRS and longer V2 TpTe interval were associated with definite ARVC during longitudinal follow-up.

Glitazones and alpha-glucosidase inhibitors as the second-line oral anti-diabetic agents added to metformin reduce cardiovascular risk in Type 2 diabetes patients: a nationwide cohort observational study.

OBJECTIVE: Metformin is the standard first-line drug for patients with Type 2 diabetes (T2DM). However, the optimal second-line oral anti-diabetic agent (ADA) remains unclear. We investigated the cardiovascular risk of various ADAs used as add-on medication to metformin in T2DM patients from a nationwide cohort. METHODS: T2DM patients using different add-on oral ADAs after an initial metformin therapy of > 90 days were identified from the Taiwan National Health Insurance Database. Five classes of ADAs, including sulphonylureas (SU), glinides, thiazolidinediones (TZD), alpha-glucosidase inhibitors (AGI), and dipeptidyl peptidase-4 inhibitors (DPP-4I) were selected for analysis. The reference group was the SU added to metformin. Patients were excluded if aged < 20 years, had a history of stroke or acute coronary syndrome (ACS), or were receiving insulin treatment. The primary outcomes included any major adverse cardiovascular event (MACE) including ACS, ischemic/hemorrhagic stroke, and death. A Cox regression model was used to estimate the hazard ratio (HR) for MACE. RESULTS: A total of 26,742 patients receiving their add-on drug to metformin of either SU (n = 24,277), glinides (n = 962), TZD (n = 581), AGI (n = 808), or DPP-4I (n = 114) were analyzed. After a mean follow-up duration of 6.6 ± 3.4 years, a total of 4775 MACEs occurred. Compared with the SU+metformin group (reference), the TZD+metformin (adjusted HR: 0.66; 95% CI 0.50-0.88, p = 0.004) and AGI+metformin (adjusted HR: 0.74; 95% CI 0.59-0.94, p = 0.01) groups showed a significantly lower risk of MACE. CONCLUSION: Both TZD and AGI, when used as an add-on drug to metformin were associated with lower MACE risk when compared with SU added to metformin in this retrospective cohort study. Trial registration CE13152B-3. Registered 7 Mar, 2013, retrospectively registered.

Left Atrial Size and Left Ventricular End-Systolic Dimension Predict the Progression of Paroxysmal Atrial Fibrillation After Catheter Ablation.

INTRODUCTION: Although rare, some paroxysmal atrial fibrillations (AF) still progress despite radiofrequency (RF) ablation. In the study, we evaluated the long-term efficacy of RF ablation and the predictors of AF progression. METHODS: A total of 589 paroxysmal AF patients (404 men and 185 women; aged 54 ± 12 years) who received 3-dimensional mapping and ablation were enrolled. Their clinical parameters and electrophysiological characteristics were collected. They were divided into Group 1 (N = 13, with AF progression) and Group 2 (N = 576, no AF progression). AF progression was defined as recurrence of persistent AF. RESULTS: Group 1 patients had larger left atrial (LA) diameter, larger left ventricle (LV) end-systolic and end-diastolic diameters, poorer LV systolic function, and more amiodarone use at baseline. After 1.2 ± 0.5 procedures, 123 (21%) patients experienced recurrence during 56 ± 29 months' follow-up. In the multivariate analysis, LA diameter (P = 0.018, HR = 1.12, 95% CI = 1.02-1.24) and LV end-systolic diameter (P = 0.005, HR = 1.10, 95% CI = 1.03-1.17) independently predicted AF progression. LA diameter >43 mm and LV end-systolic diameter >31 mm were the best cut-off values for predicting AF progression by ROC analysis. AF progression rate achieved 19% if they had both larger LA diameter (>43 mm) and LV end-systolic diameter (>31 mm). CONCLUSION: RF ablation prevents the progression of paroxysmal AF effectively, except in patients with increased LA diameter and LV end-systolic diameter on echocardiogram, suggesting more aggressive rhythm control therapies should be considered in these patients.

Impact of cardiac reverse remodeling after cardiac resynchronization therapy assessed by myocardial perfusion imaging on ventricular arrhythmia.

BACKGROUND: Although cardiac resynchronization therapy (CRT) has been a useful treatment of heart failure, patients with CRT are still in risk of sudden cardiac death due to ventricular arrhythmia. The aim of this study was to investigate the impact of cardiac reverse remodeling after CRT on the prevalence of ventricular tachycardia or fibrillation (VT/VF). METHODS AND RESULTS: Forty-one heart failure patients (26 men, age 66 ± 10 years), who were implanted with CRT for at least 12 months, were enrolled. All patients received myocardial perfusion imaging (MPI) under CRT pacing to evaluate left ventricle (LV) function, dyssynchrony, and scar. VT/VF episodes during the follow-up period after MPI were recorded by the CRT devices. Sixteen patients (N = 16/41, 39%) were found to have VT/VF. Multivariate Cox regression analysis and receiver operating characteristic curve analysis showed that five risk factors were significant predictors of VT/VF, including increased left ventricle ejection fraction (LVEF) by ≤7% after CRT, low LVEF after CRT (≤30%), change of intrinsic QRS duration (iQRSd) by ≤7 ms, wide iQRSd after CRT (≥121 ms), and high systolic dyssynchrony after CRT (phase standard deviation ≥45.6°). For those patients with all of the 5 risk factors, 85.7% or more developed VT/VF. CONCLUSIONS: The characteristics of cardiac reverse remodeling after CRT as assessed by MPI are associated with the prevalence of ventricular arrhythmia.

Prediction of Both Electrical and Mechanical Reverse Remodeling on Acute Electrocardiogram Changes After Cardiac Resynchronization Therapy.

BACKGROUND: The development of both electrical reverse remodeling and mechanical reverse remodeling (ERR+MRR) after cardiac resynchronization therapy (CRT) implantation could reduce the incidence of lethal arrhythmia, hence the prediction of ERR+MRR is clinically important.Methods and Results:Eighty-three patients (54 male; 67±12 years old) with CRT >6 months were enrolled. ERR was defined as baseline intrinsic QRS duration (iQRSd) shortening ≥10 ms in lead II on ECG after CRT, and MRR as improvement in LVEF ≥25% on echocardiography after CRT. Acute ECG changes were measured by comparing the pre-implant and immediate post-implant ECG. Ventricular arrhythmia episodes, including ventricular tachycardia and ventricular fibrillation, detected by the implanted device were recorded. Patients were classified as ERR only (n=12), MRR only (n=23), ERR+MRR (n=26), or non-responder (ERR- & MRR-, n=22). On multivariate regression analysis, difference between baseline intrinsic QRS and paced QRS duration (∆QRSd) >35 ms was a significant predictor of ERR+MRR (sensitivity, 68%; specificity, 64%; AUC, 0.7; P=0.003), and paced QTc >443 ms was a negative predictor of ERR+MRR (sensitivity, 78%; specificity, 60%; AUC, 0.7; P=0.002). On Cox proportional hazard modeling, ERR+MRR may reduce risk of ventricular arrhythma around 70% compared with non-responder (HR, 0.29; 95% CI: 0.13-0.65). CONCLUSIONS: Acute ECG changes after CRT were useful predictors of ERR+MRR. ERR+MRR was also a protective factor for ventricular arrhythmia.

Moderate Hypothermia (33 °C) Decreases the Susceptibility to Pacing-Induced Ventricular Fibrillation Compared with Severe Hypothermia (30 °C) by Attenuating Spatially Discordant Alternans in Isolated Rabbit Hearts.

BACKGROUND: Severe hypothermia (SH, 30 °C) increases the risk of pacing-induced ventricular fibrillation (PIVF) by enhancing spatially discordant alternans (SDA). Whether moderate hypothermia (MH, 33 °C), which is clinically used for therapeutic hypothermia, also facilitates SDA remains unclear. We hypothesized that MH attenuates SDA occurrence compared with that achieved by SH, and decreases the susceptibility of PIVF. METHODS: Using an optical mapping system, action potential duration (APD)/conduction velocity restitutions and thresholds of APD alternans were determined by S1 pacing in Langendorff-perfused isolated rabbit hearts. In the MH group (n = 7), S1 pacing was performed at baseline (37 °C), after 5-min MH, and after 5-min rewarming (37 °C). In the SH group (n = 9), pacing was also performed at baseline (37 °C), after 5-min SH, and after 5-min rewarming (37 °C). The thresholds of APD alternans were defined as the longest S1 pacing cycle length at which APD alternans were detected. RESULTS: Although the thresholds of APD alternans were not different between the MH (273 ± 46 ms) and the SH (300 ± 35 ms) (p = 0.281) groups, SDA threshold was shorter (at a faster heart rate) during MH (228 ± 33 ms) than that during SH (289 ± 42 ms) (p = 0.028). At APD alternans threshold, SH hearts showed more SDA than that during MH (SH: 7 hearts, MH: 2 hearts, p = 0.049). SDA could be induced in all 9 SH hearts (100%), while only 4 MH hearts (57%) had SDA (p = 0.029). The PIVF inducibility during SH (44 ± 53%) was higher than that during MH (0%) (p = 0.043). CONCLUSIONS: Compared with SH, the MH group showed greater attenuation of SDA and decreased the susceptibility of PIVF. Therefore, MH is safer as a procedural guideline for use in clinical therapeutic hypothermia than SH. KEY WORDS: Cardiac alternans; Conduction velocity; Hypothermia; Optical mapping.

Leptin to adiponectin ratio as a useful predictor for cardiac syndrome X.

OBJECTIVE: The role of adipokines in the development of cardiac syndrome X (CSX) remains unknown. METHODS: Fifty-nine CSX subjects were retrospectively enrolled from our catheterization databank. Another 54 subjects with valvular heart disease or arrhythmia served as controls. Adipokines were measured by ELISA tests. RESULTS: The CSX had lower circulating adiponectin but higher leptin and higher leptin/adiponectin ratio (×1000) (3.78 ± 4.96 vs. 2.14 ± 5.67, p < 0.001) than those of the controls. In a multivariate analysis, a higher leptin/adiponectin ratio was a predictor of CSX, while insulin-resistance index was not. CONCLUSIONS: Adipokines may be implicated in the pathogenesis of CSX.

Catheter Ablation With Morphologic Repetitiveness Mapping for Persistent Atrial Fibrillation.

Importance: Catheter ablation for persistent atrial fibrillation (AF) has shown limited success. Objective: To determine whether AF drivers could be accurately identified by periodicity and similarity (PRISM) mapping ablation results for persistent AF when added to pulmonary vein isolation (PVI). Design, Setting, and Participants: This prospective randomized clinical trial was performed between June 1, 2019, and December 31, 2020, and included patients with persistent AF enrolled in 3 centers across Asia. Data were analyzed on October 1, 2022. Intervention: Patients were assigned to the PRISM-guided approach (group 1) or the conventional approach (group 2) at a 1:1 ratio. Main Outcomes and Measures: The primary outcome was freedom from AF or other atrial arrhythmia for longer than 30 seconds at 6 and 12 months. Results: A total of 170 patients (mean [SD] age, 62.0 [12.3] years; 136 men [80.0%]) were enrolled (85 patients in group 1 and 85 patients in group 2). More group 1 patients achieved freedom from AF at 12 months compared with group 2 patients (60 [70.6%] vs 40 [47.1%]). Multivariate analysis indicated that the PRISM-guided approach was associated with freedom from the recurrence of atrial arrhythmia (hazard ratio, 0.53 [95% CI, 0.33-0.85]). Conclusions and Relevance: The waveform similarity and recurrence pattern derived from high-density mapping might provide an improved guiding approach for ablation of persistent AF. Compared with the conventional procedure, this novel specific substrate ablation strategy reduced the frequency of recurrent AF and increased the likelihood of maintenance of sinus rhythm. Trial Registration: ClinicalTrials.gov Identifier: NCT05333952.

Pre-clinical detection of amiodarone-induced acute fibrosing alveolitis by intra-thoracic impedance monitor of an implantable cardioverter-defibrillator.

A 66-year-old male received an implant of a dual-chamber implantable cardioverter-defibrillator (ICD) and was prescribed amiodarone (400 mg/day). The intra-thoracic impedance monitor in the ICD antecedently detected amiodarone-induced acute fibrosing alveolitis >3 months prior to clinical symptoms.

Long-term outcomes and left ventricular diastolic function of sarcomere mutation-positive and mutation-negative patients with hypertrophic cardiomyopathy: a prospective cohort study.

AIMS: Hypertrophic cardiomyopathy (HCM) is an inheritable disease that leads to sudden cardiac death and heart failure (HF). Sarcomere mutations (SMs) have been associated with HF. However, the differences in ventricular function between SM-positive and SM-negative HCM patients are poorly characterized. METHODS AND RESULTS: Of the prospectively enrolled 374 unrelated HCM patients in Taiwan, 115 patients underwent both 91 cardiomyopathy-related gene screening and cardiovascular magnetic resonance (45.6 ± 10.6 years old, 76.5% were male). Forty pathogenic/likely pathogenic mutations were identified in 52 patients by next-generation sequencing. The SM-positive group were younger at first cardiovascular event (P = 0.04) and progression to diastolic HF (P = 0.02) with higher N-terminal pro-brain natriuretic peptide (NT-proBNP) [New York Heart Association (NYHA) Class III/IV symptoms with left ventricular ejection fraction > 55%] than the SM-negative group (P < 0.001). SM-positive patients had a greater extent of late gadolinium enhancement (P = 0.01), larger left atrial diameter (P = 0.03), higher normalized peak filling rate (PFR) and PFR ratio, and a greater reduction in global longitudinal strain than SM-negative patients (all P ≤ 0.01). During mean lifelong follow-up time (49.2 ± 15.6 years), SM-positive was a predictor of earlier HF (NYHA Class III/IV symptoms) after multivariate adjustment (hazard ratio 3.5; 95% confidence interval 1.3-9.7; P = 0.015). CONCLUSION: SM-positive HCM patients had a higher extent of myocardial fibrosis and more severe ventricular diastolic dysfunction than those without, which may contribute to earlier onset of advanced HF, suggesting the importance of close surveillance and early treatment throughout life.

Ventricular divergence correlates with epicardial wavebreaks and predicts ventricular arrhythmia in isolated rabbit hearts during therapeutic hypothermia.

INTRODUCTION: High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence. METHOD AND RESULTS: Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p<0.001). CONCLUSION: Ventricular divergence correlated with, and might be predictive of epicardial wavebreaks during PVS at TH. Rotigaptide decreased both the ventricular divergence and epicardial wavebreaks, and reduced the probability of pacing-induced VF during TH.