COVID-19 Myocarditis Presenting With New-Onset Heart Failure With Mildly Reduced Ejection Fraction and Rare Ventricular Quadrigeminy.

COVID-19 is linked to diverse cardiovascular complications, including myocarditis, new-onset heart failure, and ventricular arrhythmias. Although premature ventricular contractions and bigeminy are recognized, the specific pattern of quadrigeminy remains rarely documented in this setting. A 57-year-old male with untreated hypertension presented with acute exertional chest pressure, dyspnea, and nocturnal wheezing over two weeks. On arrival, BP was 176/100 mmHg, HR was 101 bpm, and O2 saturation was 93% on room air. ECG showed sinus tachycardia with bigeminy and trigeminy, without QT or QTc prolongation. Lab results showed troponin 0.04 ng/mL, B-type natriuretic peptide (BNP) 241 pg/mL, and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) was positive. Chest CT revealed pulmonary edema, and echocardiogram showed a left ventricular ejection fraction (LVEF) of 40-45% with myocardial speckling. Telemetry showed runs of bigeminy, trigeminy, and quadrigeminy. He was diagnosed with acute hypoxic respiratory failure and COVID-19 myocarditis complicated by heart failure with mildly reduced ejection fraction (HFmrEF) and ventricular arrhythmias. Long-term follow-up is ongoing. This single-case report is based on comprehensive clinical, laboratory, electrocardiographic, telemetry, and imaging data from a community hospital admission. However, the limitations of this report are that this was a single case without cardiac MRI or biopsy confirmation. Hence, causality cannot be definitively established. To conclude, COVID-19 infection can cause myocarditis complicated by HFmrEF with rare arrhythmias, including quadrigeminy. Careful evaluation and individualized treatment are critical for optimal outcomes.