title: 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.
abstract: 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.
mesh_terms: 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*