Heme oxygenase/carbon monoxide system and cardiac conduction system.

The heme oxygenase/carbon monoxide system is well-established as a critical regulator of contractile cardiomyocyte development. Although the heme oxygenase/carbon monoxide system is known to have protective effects against arrhythmias by reducing oxidative stress and preserving mitochondrial function in general myocardium, its specific impact on components of the cardiac conduction system, such as the sinoatrial and atrioventricular nodes, is unclear. On the one hand, the antioxidant and anti-inflammatory properties of the heme oxygenase/carbon monoxide system are believed to help maintain normal electrical conduction and prevent arrhythmias. On the other hand, pathological conditions such as age-related sick sinus syndrome have been linked to dysfunction of the heme oxygenase/carbon monoxide system, even though carbon monoxide is detrimental at toxic levels. This review synthesizes the current evidence on the dual nature of the heme oxygenase/carbon monoxide system in the cardiac conduction system. This review highlights the critical need for further investigation of the heme oxygenase/carbon monoxide system's physiological roles and therapeutic potential for conduction pathologies.