Clinical experience of surgical treatment on hypertrophic obstructive cardiomyopathy

Abstract

To evaluate the surgical outcome of hypertrophic obstructive cardiomyopathy (HOCM). From October 1996 to December 2007, 54 HOCM patients underwent surgical treatment. There were 37 males and 17 females ranging from 6 to 68 years old (36 +/- 16) with body weight 27-83 (60 +/- 14) kg. Operation was performed under general anesthesia and cardiopulmonary bypass (CPB) with the moderate systemic temperature and low volume blood flow. The concomitant operations included coronary artery bypass grafting in 5 cases, mitral valve plasty in 5 cases, mitral valve replacement in 9 cases, tricuspid valve plasty in 2 cases, aortic valve replacement in 4 cases and closure of patent ductus arteriosus in 2 cases. Preoperative and postoperative left ventricular (LV), left ventricular outflow tract (LVOT), left atrium (LA), mitral valve function and value of LVEF were evaluated by transesophageal echocardiograph examination. The time of CPB and aortic occlusion were 40 to 290 minutes (107 +/- 52) and 27 to 195 min (70 +/- 36 min) respectively. The endotracheal intubation durations were 5 to 21 hours (14 +/- 15) and ICU duration 11 to 183 hours (45 +/- 34). Comparing with the pre-operative echocardiographic parameters, the size of left atrium (42 +/- 8 vs 35 +/- 7), pressure gradients through LVOT (106 +/- 44 mm Hg vs 24 +/- 19 mm Hg), the thickness of septum (27 +/- 6 mm vs 19 +/- 5 mm) and the value of EF (70 +/- 10 vs 61 +/- 9) obviously decreased postoperatively (P < 0.05). The surviving patients had either no mitral valve regurgitation or only mild mitral valve regurgitation. Four (7.4%) patients died during the perioperative period. The cause of death included severe low cardiac output, heart failure, severe ventricular arrhythmias and severe acute renal failure. There were 4 patients with a complete AV block postoperatively and 3 were implanted permanent pacemakers. The left bundle branch block or left anterior hemiblock were found in 26 cases, intraventricular conduction defect in 6 cases and type I AV block in 4 cases. All surviving patients were in NYHA functional class I/II during the follow-up of 1 month to 10 years. Surgical outcome for HOCM patients is satisfactory. Most HOCM patients achieve such a satisfactory relief of LV outflow tract obstruction as to lead a better life.