[Abnormal septal motion following non-surgical closure of the patent ductus arteriosus].

Abnormal ventricular septal motion is usually observed after open heart surgery, but its mechanism is not fully understood. Our previous study suggested that a sudden reduction of left ventricular (LV) volume overload after corrective surgery would be one mechanism, showing that postoperative abnormal septal motion is more frequent in patients who have preoperative LV volume overload. The purpose of this study was to investigate further the direct effect of LV volume alone on the ventricular septal motion in 22 patients who underwent non-surgical closure of a patent ductus arteriosus (PDA) by the Porstmann's method. The non-surgical closure of a PDA reduced LV diastolic diameter (LVDd) from 55.7 +/- 7.3 mm to 48.1 +/- 5.2 mm (P less than 0.001), and LV systolic diameter (LVDs) from 36.3 +/- 7.0 mm to 34.1 +/- 7.0 mm (p less than 0.01). Septal motion decreased in amplitude from 8.5 +/- 2.4 mm to 3.8 +/- 3.4 mm (p less than 0.01) and eight (36%) patients developed abnormal septal motion, while LV posterior wall excursions remained unchanged. When compared these eight patients with 14 without abnormal septal motion, the magnitude of postoperative LVDd reduction (delta LVDd) and its ratio to preoperative volume (delta LVDd/pre op LVDd) were significantly greater in patients with abnormal septal motion. Thus sudden reduction in LV volume overload alone could induce abnormal septal motion without altering other factors such as adhesion of the pericardium.(ABSTRACT TRUNCATED AT 250 WORDS)