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Background: Previous studies have reported the presence of subtle abnormalities in the right ventricular outflow tract (RVOT) in patients with apparently normal hearts and ventricular arrhythmias (VAs) from the RVOT, including the presence of low voltage areas (LVAs). This LVAs seem to be associated with the presence of ST‐segment elevation in V1 or V2 leads at the level of the 2nd intercostal space (ICS). Objective: Our aim was to validate an electrocardiographic marker of LVAs in the RVOT in patients with idiopathic outflow tract VAs. Methods: A total of 120 patients were studied, 84 patients referred for ablation of idiopathic VAs with an inferior axis by the same operator, and a control group of 36 patients without VAs. Structural heart disease including arrhythmogenic right ventricular cardiomyopathy was ruled out in all patients. An electrocardiogram was performed with V1–V2 at the 2nd ICS, and ST‐segment elevation ≥1 mm and T‐wave inversion beyond V1 were assessed. Bipolar voltage map of the RVOT was performed in sinus rhythm (0.5–1.5 mV color display). Areas with electrograms <1.5 mV were considered LVAs, and their presence was assessed. We compared three groups, VAs from the RVOT (n = 66), VAs from the LVOT (n = 18) and Control group (n = 36). ST‐elevation, T‐wave inversion and left versus right side of the VAs were tested as predictors of LVAs, respective odds ratio (ORs) (95% confidence interval [CI]) and p values, were calculated with univariate logist regression. Variables with a p <.005 were included in the multivariate analysis. Results: ST‐segment elevation, T‐wave inversion and LVAs were present in the RVOT group, LVOT group and Control group as follows: (62%, 17%, and 6%, p <.0001), (33%, 29%, and 0%, p =.001) and (62%, 25%, and 14%, p <.0001). The ST‐segment elevation, T‐wave inversion and right‐sided VAs were all predictors of LVAs, respective unadjusted ORs (95% CI), p values were, 32.31 (11.33–92.13), p <.0001, 4.137 (1.615–10.60), p =.003 and 8.200 (3.309–20.32), p <.0001. After adjustment, the only independent predictor of LVAs was the ST‐segment elevation, with an adjusted OR (95% CI) of 20.94 (6.787–64.61), p <.0001. Conclusion: LVAs were frequently present in patients with idiopathic VAs. ST‐segment elevation was the only independent predictor of their presence. [ABSTRACT FROM AUTHOR]

Introduction: Frequently, low voltage areas (LVAs) and diastolic potentials (DPs) are present at ablation sites in sinus rhythm in patients with idiopathic premature ventricular contractions (PVCs). Objective: Validate these findings as substrates for PVCs and evaluate the feasibility of a simplified substrate approach based on LVAs and DPs for ablation of idiopathic outflow tract PVCs, in patients with a low PVC burden during the procedure. Methods: Prospective single‐arm clinical trial at two centers with comparison with a historical group, matched to age and gender. The study group consisted of consecutive patients referred for ablation of frequent idiopathic PVCs with inferior axis, that presented with less than two PVCs/min in first 5 min of the procedure. The ablation was based on fast mapping of the right ventricular outflow tract in sinus rhythm looking for LVAs and DPs, defined as isolated small amplitude potentials occurring after the T wave of the surface echocardiogram. The area with LVAs and DPs was tagged, and a simplified activation mapping of the PVCs was done in that area. The procedure time, success rate, and recurrence rate were compared with the historical group in whom ablation was performed based on activation and pace mapping only. A validation group without PVCs was also studied to assess the prevalence of LVAs and DPs in the general population. Results: The study (n = 38), historical (n = 38), and validation (n = 38) groups did not differ in relation to age or gender. Prevalence of LVAs and DPs was significantly higher in the study group in comparison with the validation group, respectively, 71% versus 11%, p < 0.0001 and 87% versus 8%, p < 0.0001. Procedure time was significantly lower in the study group when comparing to the historical group, 130 (100–164) versus 183 (160–203) min, p < 0.0001 and the success rate was significantly higher, 90% versus 64%, p = 0.013. The recurrence rate in patients with a successful ablation was not significantly different between both groups, Log‐rank = 0.125. Conclusion: The prevalence of LVAs and DPs was significantly higher in the study group than in the validation group. The proposed approach proved to be feasible, faster, and more efficient than the historical approach. [ABSTRACT FROM AUTHOR]

Introduction: Premature ventricular contractions (PVC) have been associated with mortality and heart failure (HF) regardless the presence of structural heart disease (SHD). The aim of this study was assessing the impact of burden and complexity of PVCs on prognosis, according to presence of SHD. Methods: 312 patients were retrospectively evaluated out of 1967 consecutive patients referred for 24‐hr Holter at a single hospital, with a PVC count >1% of total beats. Two groups with and without SHD. PVC burden (PVC%), presence of complex forms, incidence of all‐cause death, combined outcomes of all‐cause death and cardiovascular hospitalizations, HF death and HF hospitalizations and, sudden death (SD) or hospitalizations due to ventricular arrhythmias (VA)were assessed. Results: Premature ventricular contraction burden was 2.7 (IQR: 1.6–6.7). SHD patients had more polymorphic PVCs, 77% versus 65%, p =.022, triplets and episodes of non‐sustained ventricular tachycardia (NSVT): 44% versus 27%, p =.002; 30% versus 12%, p <.0001. In idiopathic patients, a PVC% in the third quartile was independently associated with all‐cause mortality hazard ratio (HR) 2.288 (1.042–5.026) p =.039, but not in SHD. The complexity of the PVCs was not independently associated with outcomes in both groups. In SHD group, NSVT was associated with lower survival free from SD and VA hospitalizations, p =.028; after multivariable, there was a trend for a higher arrhythmic outcome with NSVT, HR 3.896 (0.903–16.81) p =.068. Conclusion: Premature ventricular contractions in SHD showed more complex patterns. In idiopathic patients, a higher PVC count was associated with higher mortality but not is SHD patients. Complexity was not independently associated with worse prognosis. [ABSTRACT FROM AUTHOR]

Background: Silent atrial fibrillation is a frequent etiology of cryptogenic stroke. Spontaneous conversion of atrial fibrillation to sinus rhythm results in atrial stunning. Objective: To evaluate if the presence of a lower left atrial appendage peak emptying velocity (LAAV) after a cryptogenic stroke is associated with the occurrence of atrial fibrillation (AF). Methods: We retrospectively selected consecutive patients with an acute ischemic stroke that had a transoesophageal echocardiogram (TEE) performed in the first 30 days of the acute event. Documented AF or potential cardioembolic sources in the TEE were considered exclusion criteria. We assessed the LAAV. During follow‐up, we evaluated the occurrence of new‐onset AF and the combined endpoint of death or new ischemic stroke. Results: We studied 73 consecutive patients, during a mean follow‐up period of 54.9 ± 19.3 months. Seven developed AF, and 13 had the combined endpoint. LAAV was independently associated with AF occurrence (HR: 0.93, 95% CI: 0.88–0.99; P = .016). Patients with a LAAV ≤ 46.5 cm/s (AUC: 0.766, 95% CI: 0.579–0.954; P = .021) had a lower survival rate free from AF occurrence (Log‐rank, P < .001) and free from the combined endpoint of death or ischemic stroke (Log‐rank, P = .010). Conclusion: A lower LAAV was associated with AF occurrence and the combined endpoint of death or ischemic stroke after an initial episode of cryptogenic stroke. Patients with this finding could eventually benefit from long‐term cardiac rhythm monitoring. [ABSTRACT FROM AUTHOR]

A patient with an implantable cardioverter‐defibrillator (ICD) (Abbott®) had episodes of slow monomorphic ventricular tachycardia (VT) and his ICD was programmed with three tachycardia zones. During the follow‐up, he received an inappropriate shock. Upon interrogation (of the device), trigeminal pattern binned as ventricular sensing (VS)—VS—ventricular fibrillation (VF) was detected. VF was assumed according to binning system. When VF is present, discrimination algorithms are not available and five consecutive sinus beats are necessary to reset binning system. Catheter ablation was performed to treat VT in order to reprogram tachycardia zones. [ABSTRACT FROM AUTHOR]