[Dynamic 2-chamber overdrive stimulation with an implantable pacemaker system as a method for terminating slow...

A case report is given on a new method for treatment of drug-resistant slow ventricular tachycardias by automatic dynamic overdrive stimulation, using an implantable pacemaker system. In a 60-year-old patient with coronary heart disease and ventricular tachycardia refractory to drug therapy, an antitachycardia Medtronic pacemaker (type SP 0501) was implanted in October 1984 and used successfully in 65 attacks during 13 months. However, when trying to terminate the tachycardia by means of programmed stimulation, acceleration of the ectopic ventricular rate occurred at 8 occasions. The administration of the experimental antiarrhythmic drug diprafenone (Class Ic) resulted in a reduction of the ventricular frequency but not of the rate of attacks. Then the Vitatron Quintech DDD pacemaker was implanted, providing the chance of terminating the now reduced ventricular rate by the dynamic overdrive mode.