Background Hydroxychloroquine/chloroquine (HCQ/CQ) treatment for COVID‐19 was associated with QT interval prolongation and arrhythmia risks. This study aimed to investigate QTc interval and ventricular repolarization dispersion changes, as markers of arrhythmia risks, after HCQ/CQ administration with/without azithromycin (AZT) during COVID‐19 pandemic. Methods A prospective observational study was performed in two academic hospitals in Indonesia. Adult patients who received HCQ/CQ alone and HCQ/CQ + AZT concomitant treatments for COVID‐19 infection were enrolled. Baseline and post HCQ/CQ treatment electrocardiograms were obtained. Baseline and post HCQ/CQ treatment QT interval by Bazett (B‐QTc) and Fridericia (F‐QTc) formulas and ventricular repolarization dispersion indices by Tpeak‐Tend (Tp‐e) interval and Tpeak‐Tend/QT (Tp‐e/QT) ratio were calculated and analyzed. Results The study enrolled 55 (HCQ/CQ alone) and 77 subjects (HCQ/CQ + AZT concomitant). F‐QTc interval significantly lengthened in subjects with HCQ/CQ + AZT (mean difference 11.89 ms [P = .028]). The incidences of severe B‐QTc and F‐QTc lengthening were 13.1% and 12.3%, B‐QTc and F‐QTc prolongation were 25.4% and 12.3%, and severe B‐QTc and F‐QTc prolongation were 6.2% and 3.2%. Tp‐e interval lengthened significantly from baseline to posttreatment in HCQ/CQ alone and HCQ/CQ + AZT (mean difference 10.83 ms [P = .006] and 18.73 ms [P < .001], respectively). Tp‐e/QT ratio increased significantly from baseline to posttreatment in HCQ/CQ + AZT concomitant (mean difference 0.035 [P < .001]). No fatal arrhytmia occurred. Conclusions During COVID‐19 pandemic, HCQ/CQ + AZT concomitant treatment caused significant F‐QTc lengthening, significantly increased Tp‐e interval and increased Tp‐e/QT ratio. HCQ/CQ alone only caused significant increase of Tp‐e interval. Incidences of severe QTc lengthening and prolongation were low in both HCQ/CQ alone and HCQ/CQ + AZT concomitant.

Abstrak

Background COVID-19 has become a global pandemic. Vaccines are currently used to reduce the morbidity and mortality of the disease. However, research regarding the use of the vaccine is still ongoing. Atrial fibrillation (AF) is one of the rare findings after receiving the COVID-19 vaccine. Case Summary A man, 64 years old, presented to the ER with palpitation an hour before admission. He refused to have any angina symptoms. Previously, he got a Sinovac-Coronavac injection one day before. On examination, BP 100/60, HR 114, RR 24, SpO2 99% room air, sub-febrile, other findings within normal limits. ECG showed AF with rapid ventricular response. A routine blood test showed no abnormality, rapid antigen SARS-COV2 negative, and hs Troponin I (hsTn-I) 2.5 ng/L. The patient was diagnosed with atrial fibrillation and given oxygen, amiodarone, aspirin, atorvastatin, and serial ECG post-therapy. ECG post therapy converted into sinus rhythm after 26 hours. Discussion Acute SARS-CoV-2 infection increases the susceptibility to new-onset atrial fibrillation (NOAF), but the pathophysiology is not well understood. After receiving the COVID-19 vaccine, the immune system will mimic primary infection. It was unclear why our patients developed NOAF. However, we found an observational zone hs-TnI value and a sub-febrile temperature. Troponin might be elevated in critically ill patients even without myocardial involvement, but this patient is in a good state. However, the correlation between atrial fibrillation and the COVID-19 vaccine is not well understood because of the lack of data.

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Background: Electrocardiogram (ECG) has become a crucial examination in the management of cardiac emergencies. Accordingly, improvement of ECG interpretation skills is mandatory for general practitioners as the front-liners in emergency cases. The Mobile ECG application was developed as mobile learning media to facilitate continuing improvement of ECG interpretation skills.Aims: This study aimed to investigate the impact of the Mobile ECG application toward ECG interpretation skills of general practitioners and medical students and evaluate its usability.Methods: A pilot quasi-experimental study was conducted in a 1-week timeframe using webinar and the Mobile ECG application. Subjects were recruited through consecutive sampling. They met the following criteria: 1) registered as general practitioners or medical students, 2) completed the basic ECG pre and post-tests, and 3) agreed to participate in the study. The Mobile ECG is a web-based application which consists of modules, quizzes, and gallery of ECG interpretations. Pre and post-test analysis and system usability scale (SUS) questionnaire were used to evaluate the impact and usability of the application.Results: A total of 252 subjects were recruited and 80.2% were general practitioners. There was a significant increase in post-test scores compared to pre-test (p=0.000) for all subjects. General practitioners significantly gained more score increment than medical students (1.08 vs 0.16, p=0.001). Based on the SUS score of 67.5, the application was marginally accepted by the users.Conclusion: To conclude, the implementation of the Mobile ECG application did improve basic ECG interpretation skills. According to the SUS score, this application still needs improvement.