Yoshiyuki Hama

The changes in regional myocardial surface area during coronary occlusion and reperfusion

SummaryFor the analysis of regional myocardial function, the measurement of regional myocardial surface area (RMA) was performed on the epicardial surface of myocardial segment lengths in a direction parallel to the superficial myocardial fibers (SLa) and at right angles to the first (SLb). In eight anesthetized dogs with opened-chests, measurements were done during a 60 s left anterior descending coronary artery occlusion and reperfusion. In the ischemic region, coronary occlusion resulted in dyskinesis in RMA, and the reduction of it during the ejection phase (ERA) decreased significantly at 10 s (p<0.05) and thereafter (p<0.01). Regional myocardial work (EWA) from the pressure-area loops during the ejection phase also decreased significantly at 10 s (p<0.05) and thereafter (p<0.01). The end-diastolic RMA (EDRMA) increased significantly at 30 s (p<0.01) and thereafter (p<0.01). In the non-ischemic region, compensatory changes were shown, namely ERA, EWA and EDRMA, increased significantly during occlusion. After reperfusion, recovery to the control level was prompt, and only EDRMA remained the increased value after 30 s (p<0.01). Between SLa and SLb, characteristics differed from each other, which suggested that the directional differences of SLs should be considered when regional myocardial function is assessed from unidirectional SL. The changes in RMA reflect both changes of SLa and SLb during coronary occlusion and reperfusion, and were more marked than each SL. Thus, the usefulness of RMA to assess regional myocardial function was demonstrated during coronary occlusion and reperfusion.

Safety and Efficacy of Short-Time Compression with Kaolin-Filled Pad after Catheter Ablation

Background: Bleeding and vascular access site complications are an important cause of morbidity after percutaneous femoral procedures. The aim of this study was to evaluate the safety and efficacy of a novel hemostatic device for femoral closure after catheter ablation, in adjunct to short-time compression. Methods: Fourteen consecutive patients (57% male, mean age 64±12 years) undergoing catheter ablation of atrial fibrillation (50%), supraventricular tachycardia (36%), atrial flutter (7%) and premature ventricular contraction (7%) by femoral approach received arterial sheath and multiple venous sheath removal with the QuikClot gauze use. Results: The mean ACT value at hemostasis time was 288 s (range 200–319 s). Hemostasis was achieved in a mean time of 6.0±1.5 min. Only one patient suffered re-bleeding, who was administered aspirin, clopidogrel and warfarin concurrently. Neither major bleeding, nor hematoma occurred. Conclusions: QuikClot gauze could obtain prompt hemostasis. Attention needs to be paid with patients treated with aspirin, clopidogrel and warfarin concurrently.