Extracorporeal acute cardiac pacing by high intensity focused ultrasound

Ultrasound has been shown to produce Premature Ventricular Contractions (PVCs). Clinical interest in this phenomenon arises mainly from observations of arrhythmias occurring during diagnostic ultrasound (US) examinations or lithotripsy. Two clinical applications in which acute cardiac pacing by ultrasound may be valuable are preoperative patient screening in cardiac resynchronization therapy surgery; Emergency cardiac pacing, following an event of cardiac arrest. Yet, previously demonstrated success rate of extra-systole induction by High Intensity Focused Ultrasound (HIFU) in rats is 5-8%. This stands in contrast to previous work in rodents using US and contrast agents (UCAs), where success rates of close to 100% were reported.