akinetic segment
Area of myocardium that shows no contractile motion, indicating severe ischemia or infarction, relevant for surgical revascularization decisions.
Full Definition
A segment of the myocardium that demonstrates complete absence of contractile motion during systole, as assessed by echocardiography, cardiac catheterization, or direct visualization during surgery. Akinetic segments indicate severe myocardial damage, typically from complete occlusion of the supplying coronary artery or extensive myocardial infarction. Unlike dyskinetic segments (which move paradoxically outward during systole), akinetic segments remain stationary throughout the cardiac cycle. In cardiac surgery, identification of akinetic segments is crucial for determining the extent of revascularization needed and assessing myocardial viability. Segments with preserved wall thickness may benefit from revascularization if viable tissue remains, while thin, scarred akinetic segments may require aneurysmectomy or ventricular reconstruction. The presence and extent of akinetic segments significantly impact surgical planning and prognosis.
Usage
Usage note: Distinguish clearly from hypokinetic (reduced motion) and dyskinetic (paradoxical motion) in reports.
In Context
- "Preoperative echocardiography revealed an akinetic anterior wall segment corresponding to the LAD territory." — preoperative assessment
- "The akinetic inferior wall showed preserved thickness on MRI, suggesting viability for revascularization." — cardiac imaging report