Superior Myocardial Protection Using “Polarizing” Adenosine, Lidocaine, and Mg2+ Cardioplegia in Humans

Myocardial protection with current methods of cardioplegia is still incomplete (1–3). Several studies have shown that hyperkalemic solution may lead to cell injury (1,2). Adenosine-lidocaine-magnesium (ALM) is a new normokalemic, “polarizing” method of cardioplegia that arrests the heart at its resting membrane potential (1). Pre-clinical studies have shown ALM to provide improved protection compared with hyperkalemic solutions (1,2). A recent clinical trial also observed improved outcomes with ALM-enriched hyperkalemic cardioplegia (3). We hypothesized that normokalemic, “full-polarizing” ALM microplegia from induction to reanimation provides improved myocardial protection compared with hyperkalemic arrest (3).