[Atrial fibrillation and QT prolongation due to proton pump inhibitor-induced hypomagnesemia].

Proton pump inhibitors are widely prescribed but their long-term use can expose patients to adverse effects. Some of these are not very well known, including hypomagnesemia. Hypomagnesemia can be manifested by cardiac complications such as supraventricular arrhythmia or QT prolongation, increasing the risk of torsade de pointe. We present a case of atrial fibrillation triggered by severe hypomagnesemia secondary to proton pump inhibitor use and exacerbated by thiazide diuretic treatment. Conversion to sinus rhythm showed a prolonged corrected QT interval. We approach the pathophysiology and the electrophysiologic effects of hypomagnesemia.