Mitral valve prolapse with ventricular arrhythmias: does it carries a worse prognosis?

The association of mitral valve prolapse (MVP) with ventricular arrhythmias has long been known and has generally been considered a benign condition. In recent years, however, a small but not negligible risk of malignant ventricular arrhythmias and sudden cardiac death has been documented in the large population of subjects with MVP. The main predictors of major arrhythmic risk identified so far include history of syncope, ventricular repolarization abnormalities in the inferior-lateral electrocardiogram leads, right bundle branch block morphology of ventricular ectopic beats, finding of areas of myocardial fibrosis on cardiac magnetic resonance, and mitral annular disjunction (MAD) on echocardiogram, as well as a possible pro-arrhythmic genetic substrate. The stratification of arrhythmic risk, with the active search for red flags and in particular of MAD, is important to identify patients with the malignant arrhythmic variant of MVP in whom to implement closer surveillance and possible therapeutic interventions.

Electrocardiographic Imaging of Repolarization Abnormalities

Background Dispersion and gradients in repolarization have been associated with life‐threatening arrhythmias, but are difficult to quantify precisely from surface electrocardiography. The objective of this study was to evaluate electrocardiographic imaging (ECGI) to noninvasively detect repolarization‐based abnormalities. Methods and Results Ex vivo data were obtained from Langendorff‐perfused pig hearts (n=8) and a human donor heart. Unipolar electrograms were recorded simultaneously during sinus rhythm from an epicardial sock and the torso‐shaped tank within which the heart was suspended. Regional repolarization heterogeneities were introduced through perfusion of dofetilide and pinacidil into separate perfusion beds. In vivo data included torso and epicardial potentials recorded simultaneously in anesthetized, closed‐chest pigs (n=5), during sinus rhythm, and ventricular pacing. For both data sets, ECGI accurately reconstructed T‐wave electrogram morphologies when compared with those recorded by the sock (ex vivo: correlation coefficient, 0.85 [0.52–0.96], in vivo: correlation coefficient, 0.86 [0.52–0.96]) and repolarization time maps (ex‐vivo: correlation coefficient, 0.73 [0.63–0.83], in vivo: correlation coefficient, 0.76 [0.67–0.82]). ECGI‐reconstructed repolarization time distributions were strongly correlated to those measured by the sock (both data sets, R 2 ≥0.92). Although the position of the gradient was slightly shifted by 8.3 (0–13.9) mm, the mean, max, and SD between ECGI and recorded gradient values were highly correlated ( R 2 =0.87, 0.75, and 0.86 respectively). There was no significant difference in ECGI accuracy between ex vivo and in vivo data. Conclusions ECGI reliably and accurately maps potentially critical repolarization abnormalities. This noninvasive approach allows imaging and quantifying individual parameters of abnormal repolarization‐based substrates in patients with arrhythmogenesis, to improve diagnosis and risk stratification.

Electrocardiographic characteristics of patients with coronavirus disease 2019 (COVID-2019) related pneumonia at first presentation

Funding Acknowledgements Type of funding sources: None. Purpose To evaluate electrocardiographic (ECG) characteristics at first presentation in patients with possible coronavirus disease (COVID-19) pneumonia. Methods and results 356 patients presenting at the emergency room with possible COVID-19 pneumonia based on clinical presentation and computed tomography findings were included and subdivided into a COVID-19 positive group ([COVID-19-positive], n = 231, 65%) and a COVID-19 negative group ([COVID-19-negative], n = 125, 35%) based on polymerase chain reaction tests. The study population was predominantly middle aged-elderly (67 ± 14 year; n = 235, 66% male). Mortality rate was 24% after 1-month follow-up. There were no significant (NS) differences in sex, age, and mortality between the COVID-19-positive and COVID-19-negative group. Atrial fibrillation (AF) was common (9%), though its prevalence was NS (regression analyses adjusted for age and sex) different in the COVID-19-positive vs. the COVID-19-negative group. ECG characteristics reflecting atrial enlargement and repolarization abnormalities were frequently present (<38% and 14% respectively). No significant differences were found between the COVID-19-positive vs. the COVID-19-negative group for the majority of morphological ECG characteristics (Figure 1 for more detailed data). Conclusion AF and ECG characteristics reflecting atrial enlargement and repolarization abnormalities are commonly present in COVID-19 patients. The prevalence of these ECG characteristics however do NS differ from their COVID-19-negative counterparts. Abstract Figure.