Regional and global left ventricular function in infants with anomalous origin of the left coronary artery from the pulmonary trunk: Preoperative and postoperative assessment

Abstract

Anomalous origin of the left coronary artery from the pulmonary trunk (ALCA) remains a diagnostic as well as a therapeutic problem. The purposes of this study were: (1) to analyze left ventricular mechanics, including regional wall motion, in infants with ALCA, (2) to determine if the pattern of wall motion in infants with ALCA distinguishes these patients from those with congestive cardiomyopathy of other causes, and (3) to evaluate the potential for recovery of left ventricular function after successful restoration of a dual coronary artery system. Left ventricular mechanics were studied before and serially after surgery in six infants (2 to 13 months old) with ALCA. Fifteen age-matched normal subjects and seven age-matched patients with idiopathic congestive cardiomyopathy were also studied for comparison. Preoperatively, the end-diastolic volume in infants with ALCA was about four times larger than normal and did not differ from that in infants with CM; the myocardial volume was also about three times larger than normal, similar to that in the patients with CM. The myocardial volume/end-diastolic volume ratio was extremely low in patients with ALCA and in those with CM. The infants with ALCA did not exhibit specific segmental wall motion abnormalities but rather had global hypokinesis indistinguishable from that in the patients with CM. After successful repair, end-diastolic volume index rapidly decreased, reaching near normal values by 7 to 22 months after surgery, while myocardial volume index decreased at a slower rate, leading to an early phase of 'overshoot hypertrophy' but reaching normal values by 7 to 22 months after surgery. The global and regional indexes of left ventricular function improved dramatically by 7 to 22 months after surgery, with the ejection fraction reaching the normal range and nine of the 13 left ventricular segments in short- and long-term axis views exhibiting a normal shortening fracton. In conclusion (1) the regional wall motion pattern in infants with ALCA is not diagnostically useful for distinguishing ALCA from other causes of idiopathic congestive cardiomyopathy, (2) as in cardiomyopathy, preoperative left ventricular dysfunction in ALCA is severe and associated with inadequate left ventricular hypertrophy, (3) there is potential for nearly complete recovery of global and regional left ventricular function after successful repair of ALCA in early infancy.