Myocardial radiopaque markers used to quantify minor axis shortening for follow-up studies in experimental surgery. I. Recording and analysis techniques. II. Comparison with contractility indices.
This work further validates the use of radiopaque epicardial marker motion for quantifying myocardial shortening in long duration follow-up studies. Mean velocity and extent of minor axis shortening were determined in 8 dogs filmed daily for 6--10 days postoperative. As an independent measure of contractility, peak dP/dt was also determined. A useful approximation to the mean ejection slope was developed which uses the end diastolic minor axis 50 msec after the Q wave, and end systolic minor axis 150 msec after the Q wave of the ECG.
D000818:Animals; D006348:Cardiac Surgical Procedures; D004285:Dogs; D004562:Electrocardiography; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging*; D008722:Methods; D009200:Myocardial Contraction; D011859:Radiography; D013679:Technology, Radiologic / Q000295:instrumentation*