Right Ventricular Pacing-Induced Heart Failure after Mitral Valve Replacement.

UNLABELLED: It is an unfortunate fact that pacing-induced heart failure after cardiac surgery is frequently ignored by medical professionals. A 60-year-old woman with chronic atrial fibrillation with a single-lead right ventricular permanent pacemaker for a prolonged ventricular pause underwent mitral valve replacement 6 months later for severe stenosis (NYHA functional class III). The patient's pacing rate was increased from the preoperative level of 60 beats per minute (bpm) to 70 bpm in order to facilitate weaning from the cardiopulmonary bypass. However, her postoperative low cardiac output continued to progress, despite the presence of inotropes. The patient's cold limbs and oliguria persisted until she underwent echocardiographic imaging, which showed dyssynchronous ventricular contraction 29 days post-surgery but which improved after the pacing rate was reduced below her spontaneous rate. Ultimately, clinicians should exercise caution when increasing right ventricular pacing for postoperative stunned myocardium. Due to the problems that can arise from an increased pacing rate, postoperative pacing strategy in patients complicated with low cardiac output after mitral valve replacement merits further discussion.

KEY WORDS: Dyssynchrony; Mitral valve replacement; Right ventricular pacing; Stunned myocardium.