Thermal thresholds of cardiovascular HL-1 cell destruction by cryothermal exposure.

The use of thermal based therapies for treatment of atrial fibrillation is increasing. While numerous reports are available in the literature regarding the efficacy of cryotherapy on pulmonary vein survival, there are no reports specifically at the cellular level that establish thermal thresholds and mechanisms of cellular destruction. The current article reports on the response of HL-1 cardiomyocytes to cooling rates and end temperatures during cryothermal exposure. The focus is on establishment of in vitro thresholds while also establishing mechanisms of action due to biophysical events (i.e. intracellular ice formation and water transport).