REVISITING THE “ISCHEMIC CASCADE” WITH CONTEMPORARY METHODS

Abstract

Objective: The current understanding for acute ischemia is based on the concept for the “ischemic cascade”. According to it, coronary occlusion induces a predefined consequence of phenomena, in which every consecutive process occurs after induction from the previous one. We sought to investigate the temporary correlation between electrical and mechanical changes at the time of acute ischemia in a pig model. Design and method: We made closed and open chest experiments with 4 pigs. We registered simultaneously intracoronary ECG (icECG) from a balloon-occluded artery, fluoroscopic movement of a regular PCI wire, echocardiography, contrast echocardiography – to confirm perfusion region and hemodynamic monitoring. We compared the time events, that occurred on icECG, epicardial electrode ECG (eECG), echocardiography, movement of the intracoronary regular PCI wire. The study was funded by the Bulgarian National Science Fund Research Grant for Fundamental Scientific Research 2021 KP-06-X53/15 and approved by the Bulgarian Food Agency. Results: Our preliminary results showed that icECG and the movement of the PCI wire during acute myocardial ischemia at the time of balloon occlusion, go simultaneously. The wall motion on echocardiography was with a time lag. When we compared the icECG form different sites of the coronary arteries, there was a time lag and lower magnitude of the ST segment elevation at distance from the site of the total occlusion. Conclusions: Based on these preliminary results with simultaneous registration of the icECG and PCI wire movement, we conclude that the electrical and mechanical phenomena at the time of acute ischemia occur simultaneously as assessed with contemporary methods. The regular PCI wire can be used for both purposes. This can be applied in humans for the detection of ischemia at the time of intracoronary interventions, which improve patient care and reduce procedural risk.