Albert D. Kistin

Termination of Reciprocating Tachycardia by Atrial Stimulation

Recurrent tachycardia in a 10-year-old child with acute rheumatic carditis was interpreted as being produced by a reciprocating (circus) mechanism involving either the normal atrioventricular pathway or the anomalous pathway of the Wolff-Parkinson-White syndrome. The tachycardia could be stopped by appropriately timed, electrically induced, atrial premature systoles, which apparently interrupted the circus movement.

Retrograde conduction to the atria in ventricular tachycardia.

CONTRARY to the prevalent view that retrograde conduction to the atria in ventricular tachycardia is rare, the author has recorded tracings consistent with such conduction relatively frequently with simultaneous standard and esophageal leads. The standard electrocardiographic tracings often fail to demonstrate atrial activity accurately, because the atrial deflections are small and lost in the deflections of the ectopic ventricular activity. This is apparent from a comparison of lead II with the simultaneously recorded esophageal lead in most of the illustrations of this paper, and probably explains why so few cases of ventriculo-atrial (V-A) conduction in ventricular tachycardia have heretofore been recognized. Sir Thomas Lewis described the first clinical case of ventricular tachycardia in 19092 and observed that in dogs retrograde conduction to the atria was common.3 A review of the clinical literature by Foster and Thayer in 19504 yielded only three cases of 1:1 V-A conduction and six cases of V-A conduction with variable block. These authors concluded from the illustrations of 81 published cases of ventricular tachycardia that in 40 it was impossible to recognize the atrial activity. The interpretation of V-A conduction was made in standard electrocardiographic leads1 5-26 and recently in esophageal lea.ds.25, 27-32

Simultaneous esophageal and standard electrocardiographic leads for the study of cardiac arrhythmias

Abstract The value of esophageal leads for the study of cardiac arrhythmias is well established, but we found difficulties in some cases; (1) It may be impossible to distinguish P and QRS or to separate them when they are superimposed, because their component rapid deflections may be similar, and their relative sizes may vary widely, P being equal to, larger, or smaller than QRS; and (2) Differences in configuration of QRS and even P may be more apparent in other leads. These difficulties may be obviated by the use of a simultaneous standard lead. The complementary value of simultaneous standard and esophageal leads is illustrated in six cases: (1) atrial tachycardia (flutter) with multifocal ventricular ectopic systoles or variations in ventricular conduction; (2) A-V dissociation with interference, different atrial foci discernible only in the E lead, and different QRS complexes discernible only in Lead III; (3) atrial tachycardia (flutter) with alternating bidirectional P waves; (4) atrial parasystole, difference in atrial foci apparent in the standard leads, but not in the E lead; (5) ventricular tachycardia with retrograde conduction to the atria; and (6) double reciprocal beats (return extrasystoles) after ventricular ectopic systoles. The arrhythmia of Case 3 has not previously been described and that of Case 6 only once. Their recognition is an indication of the value of the method.

Atrial Reciprocal Rhythm

IN THE PAST reciprocal rhythm in man has been associated mostly with AV nodal rhythm; there are several reviews of the literature.1-4 In the described cases the AV nodal impulse activates first the ventricles, then after some delay the atria; somewhere in its course to or toward the atria the impulse presumably turns back to activate the ventricles again. This phenomenon was first recognized in electrocardiograms of man by White.5 Mines6 had previously observed a similar phenomenon in experimental animals, the impulse originating in an atrium or ventricle, traveling to the other chamber, then back to the chamber of origin, then back again to the other chamber, etc., etc. for a number of cycles. Pan7 applied this explanation to human polygraphic tracings in which he believed the impulse originated in a ventricular premature systole, traveled to the atria and then back to the ventricles. The phenomenon was possibly represented but not recognized in polygraphic tracings of Wenckebach.89 Recent studies indicate that reciprocal rhythm in man may be initiated by ventricular premature systoles far more frequently than has heretofore been suspected and may often account for the ventricular systole which follows the commonplace interpolated ventricular premature systole.10 The present study is concerned with reciprocal rhythm in the other direction; an impulse that originates in the SA node or an atrium turns back somewhere in its course to or toward the ventricles to activate the atria again. The study is based on the electrocardiograms of five patients that seem consistent

Reevaluation of Electrocardiographic and Bedside Criteria for Diagnosis of Ventricular Tachycardia

Electrically induced ventricular and atrial tachycardias were observed in 12 cases, and ventriculoatrial (V-A) and atrioventricular (A-V) relationships were studied. It was noted that retrograde V-A conduction is a common phenomenon and that A-V dissociation is not a prerequisite for diagnosis of ventricular tachycardia. Conduction through the A-V node occurred readily in both antegrade and retrograde directions; and, all grades of block from first to complete and including the Wenckebach phenomenon were observed in both directions. The intensity of the first heart sound and the amplitude of the jugular a wave were governed directly by the temporal relationship between the P and the QRS regardless of whether conduction was antegrade, atrioventricular, or retrograde, ventriculoatrial.It is concluded that at present no electrocardiographic or bedside criteria are available for an unequivocal diagnosis of ventricular tachycardia and that further studies are needed.

Atrioventricular Junctional Premature and Escape Beats with Altered QRS and Fusion

The interval between an ectopic QRS and a retrograde P wave measured in simultaneous esophageal and other leads may help to identify beats which originate in the atrio-ventricular (A-V) junction. In six cases beats which seem to originate in the A-V junction are associated with a QRS which differs in configuration from the QRS of sinus origin, and in each case atrial premature systoles which give rise to normal QRS complexes occur in tracings which contain the A-V junctional beats also. Comparison of the QRS of the atrial premature systoles with the QRS of the A-V junctional beats with respect to the time of occurrence in the cardiac cycle and the duration of the preceding cycle makes it seem unlikely that the altered QRS of the A-V junctional beats can be explained by aberrant conduction during incomplete recovery. In five of the cases, fusion QRS complexes occur, suggesting activation of the ventricles partly by an impulse of sinus origin and partly by the impulse of A-V junctional origin. These observations support the interpretation previously made by others that impulses of A-V junctional origin may reach the ventricles by pathways other than the usual A-V pathway. If such beats as are described here occur at all frequently, then the diagnostic value of fusion, heretofore considered an almost conclusive criterion of a ventricular focus, may be impaired.

Ebstein's anomaly of the tricuspid valve: Angiocardiographic diagnosis

Abstract Angiocardiograms are described which are believed to be characteristic of Ebsteins anomaly of the tricuspid valve, and the other clinical features in one case are presented. The division of the right ventricle into a proximal atrialized portion and a distal functioning portion is demonstrable by angiocardiography in this case.

Atrial Rhythm in Ventricular Tachycardia Occurring During Cardiac Catheterization

The atrial rhythm was studied in 38 patients during runs of tachycardia of five or more beats in sequence which occurred during cardiac catheterization and whose ventricular site of origin could be established with considerable confidence. Simultaneous esophageal and other leads were recorded. The most frequent mechanism was retrograde conduction to the atria with varying degrees of V-A (ventriculo-atrial) block which occurred in 26 of the 38 patients. Runs of ventricular tachycardia with one-to-one V-A conduction occurred in 13 patients. Runs with an independent atrial rhythm (A-V dissociation) occurred in nine patients. Varying atrial mechanisms during different runs of tachycardia occurred in 11 patients. The minimum QRS-to-retrograde P intervals in 24 of 35 patients with V-A conduction were within 0.03 sec of P-R interval. The briefest QRS-to-retrograde P interval observed was 0.09 sec. Reciprocal beats occurred in eight of 35 patients with V-A conduction.