Persistent QTc Prolongation Due to Hypocalcemia from Hypoparathyroidism in a Heart Failure Patient: A Case Report

The QT interval on an electrocardiogram reflects ventricular depolarization and repolarization, with prolonged QTc indicating a defect in myocardial repolarization. This condition increases the risk of arrhythmias, torsade’s de pointes, and sudden cardiac death. We present the case of a 40-year-old female with heart failure and reduced ejection fraction who exhibited persistent QTc prolongation due to hypocalcemia resulting from hypoparathyroidism secondary to a thyroidectomy performed 15 years prior. Management included standard heart failure treatment alongside active vitamin D and calcium supplementation, leading to clinical improvement. This case underscores the importance of early identification and management of secondary causes of QTc prolongation in heart failure patients.