A noninvasive or minimally invasive treatment of cardiac arrhythmia such as supraventricular and ventricular arrhythmias, specifically atrial fibrillation and ventricular tachycardia, by treating the tissue with heat produced by ultrasound, including High Intensity Focused Ultrasound or HIFU. A transducer inside the body emits a pulse to assist in focusing the HIFU pulse at the proper location to treat the desired tissue.
