Search

In December 2019, SARS-CoV-2, was discovered as the agent of COVID-19 disease. Cardiac arrhythmias have been reported as frequent but their incidence is unknown. The aim of this research was to assess the real incidence of cardiac arrhythmias among COVID-19 patients admitted to Portuguese hospitals and to understand the underlying prognostic implications.

Atrial fibrillation (AF) is the most common sustained arrhythmia, with significant burden for patients. Catheter ablation is safe and superior for symptom improvement. The purpose of this work was to assess how clinical practice compares with current scientific evidence and quality indicators for AF ablation.

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.

Introduction:Previous studies reporting on electrocardiographic imaging (ECGI), using an epicardial-only system, have suggested a bad accuracyHypothesis:Assess the accuracy and coherence of two endo-epicardial ECGI systems using different cardiac sources.Methods:We performed 61 ECGI procedures in 48 patients referred for ablation of frequent idiopathic premature ventricular contractions (PVCs) at our center. The Amycard (EP Solutions SA, Switzerland) system based on the extracellular potential, was used in 26 patients, the VIVO (Catheter Precision, NJ USA) systems based on the equivalent double layer model in 9, and both in 13 patients. The localisation of the PVCs based on ECGI was done using a segmental model with 22 segments on the left ventricle, to include the classical 17 segment model plus the aortic cusps and the papillary muscles, and 12 segments on the right ventricle including 4 on the right ventricular outflow tract (RVOT). A perfect match (PM) was defined as a predicted location within the same anatomic segment, whereas a near match (NM) as a predicted location within the same segment or a contiguous one.Results:Ablation was performed in 42 patients, successful in 76%. The origin of the PVCs was the RVOT in 22 patients, right ventricle in 5, coronary cusps in 3, left ventricle in 3, LV summit in 3, LVOT in 2, papillary muscles in 2, moderator band in 1 and aortomitral continuity in 1. The agreement between the predicted site and the invasive mapping with both systems is depicted in the table. The percentage of PM and NM was not significantly different. In the 13 patients that had the ECGI performed with both systems, we found a NM in 100% and a PM in 70%. (Figure).Conclusions:ECGI is an accurate diagnostic tool with reproducible results regardless the cardiac source used for analysis.

Introduction:Previous studies have reported that activation speed across the right ventricular outflow tract (RVOT) can distinguish premature ventricular contractions (PVCs) with a RVOT origin from PVCs with a left ventricular outflow tract (LVOT) origin.Hypothesis:Validate the non-invasive electrocardiographic mapping (ECGI) for assessment of RVOT endocardial activation duration (AD) during PVCs and assess the value of AD as a predictor of the origin of the PVCs.Methods:We studied 15 consecutive patients, 8 males, median age 56 (42-65) years that underwent ablation of frequent (> 10.000 per 24 h) idiopathic PVCs with inferior axis and had an ECGI performed before ablation. The ECGI was performed with the Amycard system, and all ablations were done with Stereotaxis and Carto system. Isochronal activation maps of the PVCs were obtained with the activation direction method (ADM) of the ECGI, and with the Carto isochronal activation map (10 ms isochrones). Total RVOT AD was measured as the time interval between the earliest and the latest activated region. Agreement between the two methods was performed using linear regression and Bland-Altman plot. The cutoff value of AD to predict PVC origin was calculated with ROC curve.Results:PVCs originated from the RVOT in 9 (60%) patients. The median (Q1-Q3) RVOT AD measured with ECGI was 50 (36-70) and with Carto 50 (37-72) ms. The agreement between both methods was good with an R2of 0.699, p<0.0001, Bland-Altman plot in figure, and example of the same patient measured with Carto and ECGI. The AD was significantly higher in PVCs from the RVOT vs LVOT, both with ECGI and Carto, respectively 67 (54-74) vs 36 (33-40) ms, p<0.0001 and 68 (57-77) vs 35 (30-41) ms, p<0.0001. The cutoff value of 43 ms for AD measured with ECGI predicted the origin of the PVCs with a sensitivity and specificity of 100%.Conclusions:We found good agreement between ECGI and Carto. The AD obtained with ECGI was accurate to predict the origin of the PVCs.