Force pattern of hypoxic myocardium applied to oxygenated muscle preparations: comparison with effects of regional ischemia on the contraction of non-ischemic myocardium.
OBJECTIVE
To examine the basis for local wall motion abnormalities commonly seen in patients with ischemic heart disease, computer-controlled isolated muscle studies were carried out.


METHODS
Force patterns of physiologically sequenced contractions (PSCs) from rat left ventricular muscle preparations under well-oxygenated conditions and during periods of hypoxia and reoxygenation were recorded and stored in a computer. Force patterns of hypoxic-reoxygenating and oxygenated myocardium were applied to oxygenated and hypoxic-reoxygenating myocardium, respectively.


RESULTS
Observed patterns of shortening and lengthening closely resemble those obtained from ischemic and non-ischemic myocardial segments using ultrasonic crystals in intact dog hearts during coronary occlusion and reperfusion, and are similar to findings reported in angiographic studies of humans with coronary artery disease.


CONCLUSIONS
The current study, demonstrating motions of oxygenated isolated muscle preparations which are similar to those in perfused segments of intact hearts with regional ischemia, supports the concept that the multiple motions of both ischemic and non-ischemic segments seen in regional myocardial disease can be explained by interactions of strongly and weakly contracting muscle during the physiologic cardiac cycle.
Shimizu
G
G
Department of Medicine, Aino Hanazono Hospital, Osaka, Japan.
Wiegner
A W
AW
Gaasch
W H
WH
Conrad
C H
CH
Cicogna
A C
AC
Bing
O H
OH
D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D008905:Minicomputers; D009200:Myocardial Contraction / Q000502:physiology*; D017202:Myocardial Ischemia / Q000503:physiopathology*; D015425:Myocardial Reperfusion; D010210:Papillary Muscles / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains