Myocardial protection in cardiac surgery: how limited are the options? A comprehensive literature review

Abstract

For patients undergoing cardiopulmonary bypass, myocardial protection is a key for successful recovery and improved outcomes following cardiac surgery that requires cardiac arrest. Different solutions, components and modes of delivery have evolved over the last few decades to optimise myocardial protection. These include cold and warm and blood and crystalloid solution through antegrade, retrograde or combined cardioplegia delivery approach. However, each method has its own advantages and disadvantages, posing a challenge to establish a gold-standard cardioplegic solution with an optimised mode of delivery for enhanced myocardial protection during cardiac surgery. The aim of this review is to provide a brief history of the development of cardioplegia, explain the electrophysiological concepts behind myocardial protection in cardioplegia, analyse the current literature and summarise existing evidence that warrants the use of varying cardioplegic techniques. We provide a comprehensive and comparative overview of the effectiveness of each technique in achieving optimal cardioprotection and propose novel techniques for optimising myocardial protection in the future.

Myocardial infarction after cardiac surgery: When to intervene?

“…Many of them are related to the extent of myocardial tissue damage, potential ischemic injury, and the technical aspects of the surgery inclusive of any related cardioplegia applied. 3 In this review, we focus on 2 common etiologies of MI after coronary and valvular surgeries. harvesting approaches, vessel selection (ie, venous vs arterial), myocardial-preservation solutions (ie, normal saline, heparinized blood, crystalloid solution, etc.…”

Theoretical and Practical Aspects in the Use of Bretschneider Cardioplegia

“…Researchers, reviewing the efficiency of this cardioprotective agent, quantified it in the perioperative period of muscular deterioration (newly onset muscular hypokinesia, akinesia, or dyskinesia plus myocardial enzymes). In addition, ECG traces were analyzed for possible rhythm disorders or new Q-waves [ 44 , 45 , 46 , 47 , 48 , 49 ]. The term “micro-necrosis” refers to elevated values of cardiac enzymes in the absence of conventional markers for myocardial infarction (ECG, echocardiographic), occasionally an identifying mark for improper intraoperative cardioprotection.…”

“…Subsequently, cardiac functioning was assessed after resuming cardiac activity compared to hearts arrested with depolarizing agents. The superiority of hyperpolarization solutions stands out, suggesting better protection when it comes to adequately arresting the heart [ 45 , 52 ].…”

“…The hyperpolarization effect extracellular hyponatremia prevents Na + from opening blocking the rapid depolarizing phase, keeping the RMP at a level close to the value of resting potential. The Mg 2+ content in both types of solutions acts as an L-type Ca 2+ channel blocker, through Ca 2+ dislocation [ 38 , 45 ].…”

Commentary: It's not all in the sauce

“…Others include membrane stabilizers, buffers, calcium channel blockers, antioxidants, selected electrolytes, nitric oxide, and more. 7 This well-designed small pilot study will need confirmation in animals and then ultimately in humans. 3 This work may offer incrementally improved myocardial protection during hypothermia, especially in long aortic crossclamp times and in donor heart preservation.…”