Left atrial function in acute transient left ventricular ischemia produced during percutaneous transluminal coronary angioplasty of the left anterior descending coronary artery

Abstract

Left atrial (LA) function was studied in 32 patients during percutaneous transluminal coronary angioplasty of the proximal left anterior descending artery with a dual micromanometer positioned transseptally in the left atrium and in the left ventricle. In 10 patients LA and left ventricular (LV) cineangiography was performed 30 minutes before percutaneous transluminal coronary angioplasty and 30 seconds after the occlusion of the left anterior descending coronary artery. Thirty seconds after left anterior descending occlusion, LV peak systolic pressure decreased from 135 ± 12 to 106 ± 9 mm Hg (p < 0.05) and LV maximum dP dt decreased from 1,634 ± 136 to 1,137 ± 127 mm Hg/s (p < 0.01). Simultaneously, LA mean pressure increased from 11 ± 2 to 29 ± 1 mm Hg (p < 0.001) and LA maximum dP dt increased from 177 ± 13 to 381 ± 21 mm Hg (p < 0.001). There was a difference between LV end-diastolic pressure and LA mean pressure of 1.5 mm Hg at rest and 7.8 mm Hg during ischemia and LA pulse pressure increased from 16 ± 3 to 26 ± 3 mm Hg (p < 0.05) together with increase of LA A and V waves peak pressure. LV stroke volume index decreased from 46 ± 5 to 43 ± 3 ml/m 2 (difference not significant). The LA maximal volume increased from 18 ± 2 to 29 ± 3 ml/m 2 (p < 0.001). LA volume before LA contraction increased from 29 ± 2 to 54 ± 3 ml/m 2 (p < 0.001). The LA stroke volume increased from 23 ± 2 to 35 ± 4 ml/m 2 (p < 0.001) and the ratio of contribution of LA contraction to LV stroke volume index increased from 26 ± 5 to 57 ± 9% (p < 0.001). LV isovolumic relaxation time shortened from 82 ± 7 to 57 ± 5 ms (p < 0.001). Thus, left atrial function plays an important role in maintaining overall cardiac function during LV ischemia by reactive hyperactivity.