Ventricular pacing: A cause of reversible severe mitral regurgitation

Abstract

Transesophageal color flow Doppler assessment of degree of mitral valve regurgitation during open heart surgery is increasingly used as an on-line guide for surgical intervention. Factors that influence the degree ofmitral regurgitation, such as alteration in preload and afterload fluctuations, are routinely accounted for in the assessment of the mechanisms and severity of mitral regurgitation. The case reported here underscores the magnitude ofventricular pacemaker-related mitral regurgitation, which is not readily anticipated in the intraoperative evaluation of mitral regurgitation. A 71-year-old woman (166 cm; 89 kg) with a history of valvular heart disease was scheduled for coronary artery bypass grafting and mitral valve repair or replacement. She had intermittent chest pain during dally activities and progressive shortness of breath. She had a history of systemic hypertension and a type II diabetes but no previous myocardial infarction. She also had a pacemaker of unknown model (VVI mode) with a ventricular lead implanted in 1989 (in Russia) because of syncope. Syncopal episodes did not reoccur after pacemaker implantation. Preoperative medications included captopril, digoxin, furosemide, potassium, and insulin. An electrocardiogram showed sinus rhythm, complete atrioventricular block, and a ventricularly paced rhythm. Cardiac catheterization revealed a cardiac output of 2.8 L/min, right atrial pressure of 26 mmHg, pulmonary artery pressures 78/34 mmHg and pulmonary capillary wedge pressure of 42 mm Hg. Coronary angiography demonstrated luminal narrowing of the left anterior descending coronary artery and left circumflex coronary artery and total midvessel occlusion of the right coronary artery. Left ventricular ejection fraction was 30%. Mitral regurgitation was classified as severe. Immediately after contrast left ventriculography, pulmonary edema developed. Transthoracic echocardiography