Left Ventricular Outflow Tract Obstruction after Ross-Konno Operation

Abstract

INTRODUCTION: SAM (systolic anterior motion) is defined as the dynamic motion of the anterior mitral valve leaflet to the left ventricular outflow tract (LVOT) during systole. In this study, we present a case which we encountered with significant left ventricular outflow tract obstruction (LVOTO) related to SAM and developed after Ross-Konno operation. METHOD: A 4-month, 6.2 kg girl underwent balloon valvuloplasty due to bicuspid aortic stenosis when she was one-month. Ross-Konno operation was performed on the patient due to residual aortic stenosis (peak gradient of 140 mm Hg) and severe aortic regurgitation. Intraoperative echocardiography (ECHO) showed a peak gradient of 25 mmHg between the LV-Aorta. RESULTS: In the ICU at postoperative 3. hour, when tachycardia began with the patient's hemodynamic deterioration, SAM in ECHO and concomitant LVOTO (Peak grad: 140 mmHg) and 2nd degree MY was identified. Pulmonary edema was observed along with a decrease in oxygen saturation. The treatment initiated for removing the patient from hyperdynamic state and reducing the volume deficit. Sedation and analgesia were increased. The low-dose dobutamine was stopped. Tachycardia was attempted to take control with beta-blockers. The same treatment was continued on day 2, but the frequency of patient's tachycardia has not been reduced despite high doses of beta blockers. Heart rate was controlled by Amiodarone. On day 4, mitral regurgitation was slightly decreased while the LV-Aorta gradient was measured between 50 -60 mmHg. On day 5, SAM has diminished greatly (20 mmHg). The patient was extubated 6th day and was discharged on the 12th day without any problem. One year after, LVOT gradient was not detected in the ECHO. DISCUSSION: In adult patients, although a variety of surgical procedures for the removal of SAM had been reported, no experience in infants exists in the literature on these techniques. Despite intensive medical treatment, it may take longer than expected. We