Reperfusing the Myocardium- A Damocle’s sword

In a review article “Reperfusing the Myocardium- A Damocle’s sword published in Indian heart journal, Dr. V.K.Shah and associates have very vividly outlined the advantages and disadvantages of reperfusion of Myocardium.

According to authors the return of blood flow after periodic ischemia is often accompanied by myocardial injury, commonly known as lethal reperfusion injury (RI). Experimental studies have shown that 50% of muscle die of ischemia and another 50% die because of reperfusion. It is characterized by myocardial, vascular, or electrophysiological dysfunction that is induced by the restoration of blood flow to previously ischemic tissue. This phenomenon reduces the efficiency of the present modalities used to combat the ischemic myocardium. Moreover, despite an improved understanding of the pathophysiology of this process and encouraging preclinical trials of multiple agents, most of the clinical trials to prevent RI have been disappointing and leaves us at ground zero to explore newer approaches.

Speaking to Specialty Dialogues,Dr. V.K.Shah said "The advent of thrombolytic treatment in the 1980’s changed the landscape for the treatment of acute MI. With this, we understood the pathophysiology of this disease better. With the advent of PAMI in early 2000, the mortality of acute MI dropped in single digits. While Reperfusion was the treatment of choice to decrease the mortality in the hospital, It increased the morbidity and increased congestive failure by almost 22% at 1-year post-reperfusion."

The primary reason was that though it established reperfusion, it also increased reperfusion injury damaging more muscle. Experimental trials have shown that Ischemia damages 50% of muscle and another 50% of the muscle dies because of reperfusion injury. Reperfusion is not a rosy phenomenon as thought earlier and can be a double-edged sword, he said.