Non-invasive serial electrophysiologic testing using an implanted pacemaker to track chest wall stimuli

Noninvasive diagnosis and treatment of atrial flutter utilizing previously implanted dual chamber pacemaker

Patients with previously implanted dual chamber pacemakers (PM) may develop atrial flutter (AFL). The Siemens-Pacesetter AFP and Genesis PM have the capability of noninvasively synchronizing to a standard external electrophysiology (EP) stimulator. Any arrhythmia termination or induction protocol may be used with a refractory period limitation of approximately 127 msec (472 ppm). The PM stimulation sequence is directly controlled by the APS Model 370EP Programmer which acts as an interface between the PM and EP stimulator. All testing is conducted with the PM functioning in a single chamber mode. The external EP stimulation is detected by the programmer and a 37 KHz coded radio frequency transmission is used to control the PM stimulation in a 1:1 fashion. Real-time intracardiac electrograms (IEG) can be recorded from either the atrial (A) or ventricular lead. The IEG can be used for: (1) hard-copy for diagnosis and cycle length determination; (2) monitoring during and after the procedure; and (3) a synchronization signal to the EP stimulator. Two patients presented with three episodes of AFL with A rates ranging from 220-290 bpm. An A-IEG was obtained in each case to document the exact rhythm and rate. Rapid A pacing from 300-340 ppm was accomplished using a standard external rapid A pacemaker in concert with the 370EP programmer and PM. In two episodes, the AFL accelerated to transient A fibrillation followed by spontaneous conversion to sinus rhythm (SR). In the other episode, the AFL converted directly to SR.(ABSTRACT TRUNCATED AT 250 WORDS)

A new advancement in noninvasive electrophysiology: a standard laboratory stimulator pulse coupled with an implanted pacemaker

A new device for coupling the pulse from a standard laboratory stimulator to commercially available implanted pacemakers for use in noninvasive electrophysiology testing has been developed. When programmed to an electrophysiology mode, a 37 kHz carrier wave, generated by the programmer, maintains communication with the implanted pacemaker. Stimuli generated from a standard lab stimulator cause a break in the carrier wave and an output from the pacemaker. Cycle lengths as short as 127 msec can be attained. In addition to standard electrophysiology testing, this noninvasive electrophysiological technique can be used to fibrillate the heart to test the efficacy of automatic implantable cardioverter/defibrillators.

Noninvasive serial electrophysiological testing using an implanted pacemaker for management of recurrent ventricular tachycardia

An implanted multiprogrammable pacemaker capable of performing both premature and burst stimulation can be teamed with a special external programmer for noninvasive electrophysiological testing. Such studies, combined with indications from provocative pharmacologic tests, allowed us to formulate effective antiarrhythmic therapies for three patients suffering from post-infarction, recurrent sustained ventricular tachycardia.

Treatment of life-threatening ventricular arrhythmias by a combination of antiarrhythmic drugs and right ventricular pacing

Thirteen patients with intractable ventricular arrhythmias were studied; they underwent long-term treatment by a combination of antiarrhythmic drugs and ventricular pacing. Eleven patients had a history of tachycardia and two had torsade de pointes; eleven of thirteen had had cardioversion and/or defibrillation. Prior to permanent pacemaker implantation, temporary pacing in the VVI mode was used in combination with one or more of the following drugs: amiodarone, aprindine, digitalis, metoprolol, mexiletine, procainamide, pindolol, propranolol, or quinidine. Various pacing rates were tried; when permanent pacing was instituted, a unipolar system which was at least rate-programmable was used. Right ventricular VVI pacing, combined with drug therapy, was successful in ten of thirteen patients. Five of the ten patients are alive and free of arrhythmias after 78, 72, 72, 54, and 11 months, respectively. Although five patients died (after 60, 48, 30, 24, and 9 months, respectively), none of the deaths were related to arrhythmias. We suggest that in patients with ventricular arrhythmias refractory to conventional treatment, a therapeutic trial of right ventricular VVI pacing in combination with a drug regimen be used.