Auricular premature systole

Berliner, Kurt; Lewithin, Leon P.

doi:10.1016/0002-8703(45)90478-9

Cited by 12 publications

(3 citation statements)

References 7 publications

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“…Aberrant conduction of premature supraventricular systoles with short coupling has long been clinically observed, and correlated with the degree of prematurity (11). It is not unusual, however, to find very early premature beats without accompanying QRS aberrance.…”

Section: Relationship Of Asykichrony To Aberrancementioning

confidence: 99%

Asynchrony of Conduction within the Canine Specialized Purkinje Fiber System

Anderson

Greenspan

Bandura

et al. 1970

Circulation Research

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Asynchrony of conduction may prove to be an important mechanism for reentrant arrhythmias. The purpose of these experiments was to explore asynchronous conduction in the distal branches of the canine Purkinje system. Microelectrodes were placed in Purkinje bundle preparations resembling a T configuration, thereby permitting assessment of differential conduction times induced by premature beats (S 2 ).Equal conduction depression was observed in the post extrasystolic beat (Sj) at wide coupling intervals (S 2 -S j ). Asynchrony of conduction was frequently observed in response to narrow coupling intervals. These differential conduction times induced disparities of activation times greater than 50 msec. In fibers exhibiting preferential depressed conduction, local block was observed with further decrease in the coupling interval. Disparities of activation times at very short' S2-S! coupling times could be markedly increased by minimal decrease in coupling intervals (in the order of 1 to 5 msec). Conduction depression was not clearly dependent upon the level of "take-off' 1 potential or action potential duration. Asynchronous conduction may thus be induced by narrow coupling of premature beats and could account for reentry.ADDITIONAL KEY WORDS elecrrophysiology action potential aberrance premature impulses conduction depression reentry• Asynchrony of conduction is of clinical importance because it may represent a mechanism for reentry. Polyphasic complexes have been recorded over the surface of the basal portion of the left septal surface, suggesting the existence of asynchrony in the initial branches of the left main bundle (1). The purpose of this paper is to explore the problem of asynchrony in the more distal From the

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Section: Relationship Of Asykichrony To Aberrancementioning

confidence: 99%

Asynchrony of Conduction within the Canine Specialized Purkinje Fiber System

Anderson

Greenspan

Bandura

et al. 1970

Circulation Research

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“…Shortening of the electrical systole is a feature of auricular premature systoles not heretofore known, and its significance is not yet understood. Observations on the Q-T interval of normal beats were published by us (Berliner, 1931). Since then, knowledge of this subject has not materially increased.…”

Section: Resultsmentioning

confidence: 99%

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confidence: 99%

Auricular Premature Systoles: The Duration of the Electrical Systole

Berliner¹

1946

Heart

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In a recent electrocardiographic investigation (Berliner and Lewithin, 1945) the aberration of the ventricular complex of auricular premature systoles (APS)* was studied. Variations in amplitude, duration, direction, and configuration were found and described in detail. In the course of that investigation, a new feature of the APS, shortening of the electrical systole (Q-T interval), was discovered. This subject has since been studied by careful measurements which are reported in the present paper. MATERIAL AND METHODWe used 100 electrocardiograms of different patients in this study, selected from the records of over 250 patients exhibiting APS. The selection was made on the basis of technical qualities of the tracings. We chose only clear records in which the exact end-points of the T waves were easily discernible. Tracings blurred by muscle tremor or technical defects were eliminated; as were such perfect records in which low amplitude of the T waves made accurate measurement of the Q-T interval impossible; and also all those records in which the APS were found to occur at the beginning of a tracing or at its very end (with the exception of Fig. 2A). Records with inverted T waves were purposely included.Of the four leads available in practically all cases, we selected that lead in which the endpoints of the T waves were most distinct, and analyzed one APS of that lead. The degree of prematurity of this APS and the degree of its aberration were determined first, and for this purpose the criteria established in the previous study were again used. Measurements were then made on five successive heart beats, the two beats preceding the APS, the APS itself, and the two beats following it. All measurements were made with the aid of a magnifying glass.The duration of QRS and RS-T t was measured in each of the five beats. The Q-T intervals were then obtained by adding up the values for QRS and RS-T. In the normal beat just preceding the APS, however, RS-T and Q-T could usually not be measured because the P wave of the APS was superimposed on its T wave. That was the reason why the beat preceding it was also mheasured and was chosen as the normal for purposes of comparison. QRS, RS-T, and Q-T of the APS were compared with the respective intervals of the -n6rmal beat and the post-extrasystolic beat. Examples are given in the legend to Fig. 1. RESULTSQRS duration and Q-T interval. In 47 of our 100 APS, the duration of QRS did not differ from that of the normal beats or the difference was too minute for measurement. In 23, QRS duration was shortened; this shortening never exceeded 0-02 second. In 30 the QRS complexes were prolonged. The prolongation was marked (0'02 second or more) in 15 of these. Marked prolongation was usually associated with other features of aberration, viz. * APS will be used as an abbreviation for auricular premature systole(s) throughout this paper. t By RS-T interval we mean the interval beginning at the RS-Tjunction and ending at the end of the T wave.

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Intraventricular Block

Rosenman¹

1950

Arch Intern Med (Chic)

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Auricular premature systole

Cited by 12 publications

References 7 publications

Asynchrony of Conduction within the Canine Specialized Purkinje Fiber System

Asynchrony of Conduction within the Canine Specialized Purkinje Fiber System

Auricular Premature Systoles: The Duration of the Electrical Systole

Intraventricular Block

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