CONTINUOUS MONITORING OF GLOBAL LEFT-VENTRICULAR EJECTION FRACTION DURING PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

Continuous monitoring of left ventricular (LV) function during percuta nous transluminal coronary angioplasty (PTCA) was performed in 40 pati ents (53 +/- 2 years) with a miniature, nuclear detector system after labeling the patients' red blood cells with technetium-99m, Balloon di lation (113 seconds, range 60 to 240) induced on average a 0.12 ejecti on fraction (EF) unit (19%) decrease in the LVEF, which was explained by a 34% increase in end-systolic counts. Balloon dilation of the left anterior descending artery (n = 23) produced a decrease in the LVEF o f 0.17 +/- 0.13 EF units compared with the decrease of 0.06 +/- 0.07 E F units in patients undergoing dilation of the left circumflex artery (n = 9) and 0.05 +/- 0.04 EF units in patients treated for a stenosis of the right coronary artery (n = 8), (p = 0.02), Balloon deflation wa s associated with an immediate return to pre-PTCA levels. In 10 patien ts with 2 identical balloon occlusions, the second occlusion led to a significantly less decrease in the LVEF (0.41 +/- 0.14 vs 0.44 +/- 0.1 5) and electrocardiographic ST-segment deviation (88 +/- 54 mu V vs 65 +/- 42 mu V) than the first, We conclude that PTCA is associated with an abrupt transient decrease in the LVEF, The effect of balloon occlu sion of the left anterior descending artery is more pronounced than ba lloon occlusion of the left circumflex and the right coronary arteries . Neither single nor multiple balloon occlusions were associated with post-PTCA global LV dysfunction, whereas the lesser degree of LV dysfu nction and electrocardiographic signs of myocardial ischemia during th e second of 2 identical balloon occlusions suggests that preconditioni ng con be induced during PTCA. (C) 1998 by Excerpta Medica, Inc.