Seven day continuous ambulatory electrocardiographic telemetric study with pocket electrocardiographic recording device for detecting hydroxychloroquin induced arrhythmias

BACKGROUND & AIMS The use of hydroxycholoroquin for COVID 19 treatment and prophylaxis raised issues concerning its cardiac safety owing to possibility of QT prolongation and arrhythmias. 1 There was no study on long term electrocardiographic telemetry monitoring of patients taking hydroxychloroquin and we planned a continuous electrocardiographic holter telemetry of these patients for a period of seven days. Methods Healthcare workers taking hydroxycholoroquin as pre exposure prophylaxis, patients taking hydroxychloroquin were monitored by holter electrocardiographic telemetry with continuous beat to beat analysis for seven days with capacity to report any arrhythmic event or significant QT prolongation instantly to medical faculty. Results 25 participants with mean age 42.4 ± 14.1 years, 40% females. 20% patients needed to stop HCQ. Four patients developed QT prolongation > 500 ms and needed to stop HCQ, one patient had accelerated idioventricular rhythm and stopped treatment. one had short episodes of atrial fibrillation. No malignant arrhythmia or ventricular arrhythmia or torsades were noted. No episode of significant conduction disturbance and arrhythmic death noted. Baseline mean QTc was 423.96 ± 32.18 ms, mean QTc corrected at 24 hours 438.93 ± 37.95, mean QTc 451.879 ± 37.99 at 48 hours, change in baseline mean QTc to max QTc was 30.74 ± 21.75 ms at 48 hours. All those develop QTc prolongation > 500 ms were greater than 50 years of age. Conclusion Ambulatory telemetry ECG monitoring seems to detect early QT prolongation and stopping drug timely prevented malignant arrhythmias. HCQ seems to have less risk of QT prolongation in young healthy individuals.