High-Intensity Focused Ultrasound in Interventricular Septal Myocardial Ablation

High-intensity focused ultrasound (HIFU) can cause necrotic damage in deep tissues through thermal ablation and cavitation, without significant damage to the surrounding tissues. High blood perfusion of heart affects the energy deposition. This study aimed to evaluate the effect of cooling of coronary blood flow for HIFU ablation.Continuous and pulsed HIFU (2000 J) at duty cycles of 100% and 25% were examined for their capacity to ablate the perfused porcine heart tissue in vitro. After ablation, grayscale changes and pathological features were observed or measured, and the area and volume of tissue necrosis were calculated.The cardiomyocytes in the lesions underwent necrosis with a clear boundary. The endocardial surface was intact without necrosis. The three-dimensional morphology of the lesions appeared approximately as ellipsoids. With the increase in perfusion speed, the necrotic volume in the target area was gradually reduced.HIFU has the potential to become a new minimally invasive surgery for ventricular septal myocardial ablation. Reduction of coronary blood flow can improve the ablation effect.