See Also: Biography of Barouh Berkovits
Effect of Multiple Simultaneous Activation Sites (Biventricular Pacing) on Ventricular Depolarization and Ventricular Arrhythmias
In 1976 Barouh V. Berkovits developed a VVT pacemaker capable of sending the earliest ventricular depolarization from 2 to 10 epicardial sites and simultaneously stimulating all ventricular sites. Studies in the infarcted ventricular dog heart proved that all ventricular sites could be simultaneously activated but ventricular tachycardia could not be terminated (Figure 8). In this experiment simultaneous activation of both right and left ventricular sites corrected the conduction delay between RV and LV sites (compare the left and right hand portions of the strip) but failed to shorten the QRS duration of the ventricular arrhythmia. Local conduction delay in the region of the region of the infarcted myocardium probably led to microreentry and the continuation of ventricular tachycardia. Reexamination of the figures from this study revealed a flaw in the method of sensing the earliest sire of ventricular polarization at the onset of a ventricular arrhythmia. Notably, the surface ECG should have been used to sense the initial depolarization rather than a local epicardial site. Further studies are now in progress to investigate the use of biventricular pacing to terminate ventricular arrhythmias.
Dreifus LS, Ogawa S, Watanabe Y, Dreifus HN, Berkovits BV. In: Cardiac Pacing. Proceedings of the Vth International Symposium Tokyo, March 14-18, 1976. Ed. by Watanabe, Y. Amsterdam. Excerpta Medica, 1977. pp. 33-39.
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Biventricular Pacing
Programmed stimulation was alternatively performed exclusively from the right ventricular endocardium, exclusively from the left ventricular epicardium and simultaneously from both ventricles in 8 patients who did not have coronary artery disease or bundle branch block. The latter had no untoward effects and was not more dangerous than exclusive right ventricular, or exclusive left ventricular, stimulation. In 3 patients, pacemaker-induced repetitive firing occurred during right and left ventricular pacing. Persistence of this phenomenon (in these 3 patients) during simultaneous biventricular stimulation is in keeping either with a microreentry occurring in the vicinity of the electrodes or with a macroreentry involving the bundle branches. This study suggests that simultaneous atrial and ventricular activation (or pacing) can be achieved by connecting one pacemaker pole to an atrial electrode and the other pole to a ventricular electrode. This modality of stimulation can be effective in preventing or abolishing some types of reciprocating atrioventricular tachycardias.
Befeler B, Berkovits BV, Aranda JM, Sung RJ, Moleiro F, Castellanos A. Programmed simultaneous biventricular stimulation in men, with special reference to its use in the evaluation of intraventricular reentry. Eur J Cardiol 1979; 9:369-378.
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Self Adapting Autodecremental Overdrive Pacing
We have developed and tested an external beat-by-beat self-adapting autodecremental overdrive pacing system for termination of ventricular tachycardia (VT) in patients with recurring symptomatic VT undergoing programmed ventricular stimulation and serial drug testing. With this device, we sought to test the hypothesis that this beat-by-beat autodecremental overdrive pacing method may be more effective and theoretically safer for the termination of VT. We compared this method to previously described antitachycardia pacing methods, in particular those used in commercially available implantable antitachycardia pacemakers. The graphic displays termination of VT by self-adapting autodecremental overdrive pacing. The arrows denote pacer stimuli in the decremental overdrive pacing train. A train of seven decremental pacing stimuli are delivered, each of which is decremented by a value of 3.5% of the VT cycle length. Transient entrainment of the reentry circuit is observed with persistence of the VT upon cessation of pacing. Persistence of tachycardia is detected by the Dysrhythmia Research Instrument and a subsequent train of eight decremental stimuli is delivered. Termination of the VT results. RVA = right ventricular apical electrogram; HBE = His bundle electrogram.
Charos GS, Haffajee CI, Gold RL, Bishop RL, Berkovits BV, Alpert JS. A theoretical and practically more effective method for interruption of ventricular tachycardia: self-adapting autodecremental overdrive pacing. Circulation 1986; 73:309-315.
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Studies with an Implantable Multimodal A-V Pacemaker for Reciprocating Atrioventricular Tachycardias
The efficacy of a recently developed programmable implantable pacemaker which can be used in the management of supraventricular tachycardias (with or without, associated brady-arrhythmias) was evaluated. Although this pacemaker functions primarily in a DVI-DVO mode, it was also made to operate in a DOO mode. The study was performed in six patients with reciprocating atrioventricular tachycardias (four of the long P-R - short R-P type and two of the short P-R - long R-P type). Both DVI-DVO and DOO pacing abolished all episodes of tachycardia in five of the patients. However, DOO pacing was also capable of initiating episodes of tachycardia in two of the six patients. The events observed in two of the patients raise the possibility that ventriculoatrial sequential pacing may be required in some tachycardias of the short P-R - long R-P type.
Castellanos A, Waxman HL, Moleiro F, Berkovits BV, Sung RJ. Preliminary studies with an implantable multimodal A-V pacemaker for reciprocating atrioventricular tachycardia. PACE 1980;3:257-265
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