Fixed and Variable Coupling of Ventricular Extrasystoles

Talbot, S.

doi:10.1159/000169624

Cited by 7 publications

(4 citation statements)

References 6 publications

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“…In this study only two patients had parasystole using acceptable criteria (Talbot, 1973;Scherf and Schott, 1953), and other studies have shown that parasystole occurs in less than 5°4 of patients with aucte myociardial infarction (Baxter and McGuiness, 1974). The variable coupling was usually non-parasystolic (Talbot, 1973), although some recordings could have been interpreted as intermittent parasystole or parasystole with variable exit block. Such rhythms may be automatic in origin.…”

Section: Discussionmentioning

confidence: 47%

“…If there were > 600 msec between such extrasystoles the rhythm was considered idioventricular. Extrasystoles were considered ventricular on the usual criteria (Lipman and Massie, 1965;Talbot, 1973). Differentiation from aberrant conduction was based on the criteria of Marriott (Sandler and Marriott, 1965) but when in doubt the rhythm was considered supraventricular.…”

Section: Methodsmentioning

confidence: 99%

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Prognostic importance of ventricular extrasystoles in acute myocardial infarction

Talbot

1977

Postgraduate Medical Journal

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SummaryVentricular arrhythmias were recorded in 233 patients in a prospective study of patients with acute myocardial infarction. In over 95°o of patients antiarrhythmic therapy was not given until the onset of ventricular tachycardia, ventricular fibrillation, or persistent idioventricular rhythm. There was a mortality of 18%y during the patients' stay in hospital. The most important features of ventricular ectopic activity, which preceded these severe ventricular arrhythmias in the first 48 hr, were multiformity, variation of coupling intervals of >01 sec, the R-on-T phenomenon, double ventricular extrasystoles and ventricular bigeminy. The number of single ventricular extrasystoles per minute was related to the probability of these severe ventricular arrhythmias but to a lesser degree. It was found that if all the patients with the first two prognostic features were removed, the number of single ventricular extrasystoles was not of significant import and the other features were less important.Three-quarters of the severe arrhythmias occurred in the first 24 hr and during this period 60%y were preceded by either multiform ventricular extrasystoles or extrasystoles with variable coupling. The importance of these findings in relation to prophylactic therapy is discussed.

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Section: Discussionmentioning

confidence: 47%

Section: Methodsmentioning

confidence: 99%

Prognostic importance of ventricular extrasystoles in acute myocardial infarction

Talbot

1977

Postgraduate Medical Journal

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“…The perti nent literature suggests that these variants may be produced either by a varying exit block from a rapid parasystolic focus [2,17,19], or by concealed or manifest re-entry created by slowed conduction within an area of enhanced phase 4 activity [4,20]. Similar mechanisms have been invoked to explain the appearance of random, nonparasystolic ventricular extrasystoles [19,24,25], It has been noted on the screening of routine electrocardiograms that such extrasystoles and even slow ventricular tachycardia with an irregular rate have been associated with cardiac disease and with other serious arrhythmias [23].…”

Section: Discussionmentioning

confidence: 99%

Ventricular Rhythms in Acute Myocardial Infarction

Hasin¹,

Rogel²

1976

Cardiology

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Ectopic ventricular activity in acute myocardial infarction is considered to be benign if it is slow and regular (accelerated idioventricular rhythm), but ominous when rapid (ventricular tachycardia). However, it has been observed in an increasing number of reports that these two types may coexist in the same patient, altering thereby the clinical significance of both. In the present study electrocardiograms were analyzed of 55 patients hospitalized for acute myocardial infarction, in whom idioventricular rhythm occurred. It was found that three major types of ventricular rhythms could be identified: a regular-stable rhythm, an irregular-unstable one, and a third variant which was a combination of these two types. The stable ventricular rhythm was self limited and harmless. The unstable and combined types which were characterized by random coupling times and varying interbeat intervals, were frequently associated with re-entrant beats and fast ventricular rates and therefore a potentially ominous prognosis. It is suggested that the Ca⁺⁺ dependent slow diastolic depolarization may be the mechanism responsible for the unstable ventricular rhythm, and the reasons for this assumption are discussed. A therapeutic approach based on the above considerations is described.

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“…Earlier studies have shown that rigid categorization of extrasystoles into those with fixed coupling and those which are parasystolic, is unsatisfactory.6 Up to one-third of patients have extrasystoles with variable coupling, but there is no evidence of parasystole. 6 We have found that variation of coupling intervals increases when the dominant rhythm is slow and it seems logical to relate the range of actual coupling intervals to the range that is possible. However, even if more liberal criteria of fixed coupling are employed, many extrasystoles still have variable coupling but are nonparasystolic.…”

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confidence: 99%