Segmental Myocardial Wall Motion and Myocardial Ischemia
Segmental wall motion abnormalities reliably occur with acute ischemia and can be detected during angina pectoris, with myocardial infarction, and during stress in patients with significant coronary artery disease. Some chronic contraction abnormalities can be reversed by successful revascularization surgery, as well as by physiological interventions that reduce ischemia by improving the myocardial oxygen sypply-demand ratio[2–5]. Demonstration of reversible asynergy during intervention ventriculography can aid in selecting low-risk patients who will benefit from aortocoronary bypass surgery, whereas irreversible asynergy signifies infarction and is associated with a poorer prognosis after surgery. Furthermore, the extent and location of segmental contraction abnormalities determines the level of global ventricular pump function which is a major determinant of morbidity and mortality after myocardial infarction[6,7]. The chapter will describe the effects of acute ischemia upon the mechanical behavior of myocardial segments, and will review the use of cardiokymography to detect and record cardiac motion in man.
KeywordsDepression Ischemia Epinephrine Catecholamine Propranolol
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