BME.03 Reducing Risk of Phrenic Nerve Damage during Cryoballoon Ablation

• Klea Hondro
• Miya Maloloyon
• Guderian Maslian
• Kim Anh Nguyen

Atrial fibrillation is the most common type of heart arrhythmia with symptoms including heart palpitations, fatigue, and chest pain. Atrial fibrillation is caused by unwanted electrical signals in the left atrium originating from the pulmonary veins. One solution to this condition is to undergo a cryoballoon ablation where extremely cold temperatures are used to kill the cardiac tissues that cause the unwanted electrical signals. However, a common issue that arises during this procedure is phrenic nerve injury. This complication is due to the proximity of the phrenic nerve to the target ablation area, typically occurring when ablating at the superior right pulmonary vein. This injury can lead to dyspnea in patients for up to a year. In our project we propose a model to explore heat energy transfer through heart tissue. Ultimately, for the purpose of discovering a solution to preventing phrenic nerve injury. The model consists of an agar-water heart model, a coolant, a water bath, temperature sensors, and an Arduino circuit. Verification trials of the cryoballoon analog proved to be inconclusive due to a few obstacles. The main issue we faced was the ability to apply an extreme cold temperature to the ablation site. In order to simulate the ablation temperatures, dry ice was initially applied but proved difficult to work with. Subsequent experiments will deliver cold temperatures with metal dowel rod kept at -80 degrees Celsius. Ideally, the model can be used to test new cryoablation procedures that will have a lower probability of damaging the phrenic nerve compared to current methods.