St Thomas' cardioplegia solution

St Thomas' cardioplegia solution (also known as St. Thomas' Hospital cardioplegic solution) is a crystalloid cardioplegic solution used in cardiothoracic surgery to induce and maintain electromechanical cardiac arrest, thereby protecting the myocardium during ischemic periods. It exists in two commercially available formulations: No. 1 (MacCarthy) and No. 2 (Plegisol, originally by Abbott Laboratories), with No. 2 generally considered superior. The primary active ingredient is potassium (potassium ions), which arrests the heart by suppressing its electrical activity. The solution is administered by infusion into the coronary circulation (typically anterograde via the aortic root) at hypothermic temperatures (4–10°C) immediately after aortic clamping, with repeat dosing every 20–30 minutes throughout the cross-clamp period. The biological target is cardiac ion channels/membrane potential, specifically via potassium-mediated depolarization arrest. Its modality is a small-molecule/electrolyte crystalloid solution. The indication is myocardial protection during cardiac surgery requiring cardioplegic arrest.

Brand names

Plegisol

Other names

St. Thomas' Hospital cardioplegic solutionSt Thomas' Hospital cardioplegic solution No. 2St Thomas' Hospital cardioplegic solution No. 1St Thomas' solutionSolute Cardioplegique SLF 103