Abstrait

Failure of ventricular capture and pacemaker exit block secondary to moderate hyperkalemia

Pau Alonso, Raquel Lopez, Maria Jose Sancho-Tello, Ana Andres, Oscar Cano, Joaquin Osca & Jose Olague

An 81-year-old woman was admitted to our institution with bradycardia, weakness and presyncope. At admission physical examination revealed a pulse rate of 42 per minute, blood pressure of 95 / 50 mmHg, and an oxygen saturation of 93 % on room air. The interrogation of the device showed a correct ventricular sensing and a threshold for ventricular pacing of 6.5 V at 1 ms pulse width. Analytic test showed a creatinine 3.78 mg / dl, Urea 187 mg / dl, sodium 133 mEq / L, potassium 6.2 mEq / L, and pH 7.37. Our patient showed a moderate acute hyperkalemia, which caused pacemaker exit block and capture failure.