Electrocardiographic ST-segment elevation and changes in the regional work of the left ventricle during coronary angioplasty.
This study evaluated the reduction in regional work of the left ventricle caused by acute myocardial ischemia during coronary angioplasty, and correlated it with ST-segment elevation. Regional work of the left ventricular myocardium, which is derived from a stress-strain loop, is a useful index of the function of a diseased heart. However, the effects of transient ischemia on the regional work of the myocardium have not been fully elucidated. The subjects consisted of 25 patients who had proximal left anterior descending artery stenosis with normal wall motion and without collateral circulation. The patients were classified as showing ST-segment elevation > or = 0.2 mV (group A, 10 patients), or ST-segment elevation < 0.2mV (group B, 15 patients) during coronary angioplasty. Group A showed a greater reduction in the regional work of the interventricular septum than group B. Regional work recovered to the baseline level 30 s after balloon deflation in group B, but took 40 s in group A. A greater ST elevation during balloon inflation was associated with a greater, prolonged reduction of work performance in the ischemic region and a greater concomitant increase in the opposite nonischemic region.
Division of Cardiology, Gunma Prefectural Cardiovascular Center, Maebashi, Japan.
N
N
Isobe
S
S
Oshima
K
K
Taniguchi
H
H
Hoshizaki
H
H
Adachi
T
T
Toyama
S
S
Naito
A
A
Nogami
M
M
Sugawara
D000208:Acute Disease; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D001794:Blood Pressure; D004562:Electrocardiography; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000150:complications; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications*; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000209:etiology* / Q000503:physiopathology