[Cardiac defibrillation with the aid of ultrasound].
It was established in 15 canine experiments that ultrasound with a 500 kcps frequency and 10 W/cm2 intensity exerts a defibrillating and antiarrhythmic effect and arrests cardiac fibrillation in 27.7% of the cases. Electrophysiological studies on isolated right ventricles of rabbits in oxygenation chambers demonstrated that the antiarrhythmic action of the ultrasound manifests itself via a prolongation of the refractory period of the myocardial cells. Ultrasound of a 4 W/cm2 intensity and 30 sec duration increases the refractory period up to 37%. Any further increase of intensity and duration of the ultrasonic action results in a shortening of the refractory period and inhibition of the electrical activity of the myocardial cells.
D000818:Animals; D004285:Dogs; D004562:Electrocardiography; D006801:Humans; D011817:Rabbits; D014464:Ultrasonic Therapy; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000628:therapy*
Izuchenie vozmozhnosti defibrilliatsii serdtsa s pomoshch'iu ul'trazvuka