Vagaries of acceleration dependent aberration.

Correspondence to Dr Charles Fisch, Krannert Institute of Cardiology, 1111 West Tenth Street, Indianapolis, IN 46202, USA. The earliest electrocardiogram illustrating bizarre intraventricular conduction of supraventricular impulses was published by Sir Thomas Lewis in 1910.' In a subsequent communication Lewis labelled this form of abnormal conduction "aberration" and the ventricular complexes as "aberrant beats."2 In that same paper he also proposed a mechanism for the aberration, namely ". . . disturbances of conduction in the smaller branches of this system and it is held that definite branches are affected in this manner, though these branches cannot be identified at the present time". The underlying milieu for aberration proposed by Lewis stood the tests of further observation and experimentation. Altered, asynchronous conduction has been demonstrated for all segments of the His-Purkinje system as well as the Purkinjemyocardial junctional areas and, rarely, as a result of preferential atrioventricular and, perhaps, His bundle conduction. The mechanisms responsible for initiating the conduction alterations are, however, even more complex as attested to by the vast number of published reports, both basic and clinical, on aberrancy that has been generated since Lewis' initial observations. In 1983, on the occasion of the 75th anniversary of Sir Thomas Lewis' description of aberration, Dr Dennis Krikler, Editor of the British Heart Journal, invited an editorial on that subject.3 As our contribution to this Festschrift issue of the British Heart Journal honouring Dr Krikler, we have elected to continue that discussion and focus on the vagaries of acceleration dependent aberration. The subject is particularly well suited to Dr Krikler's long time interest in the history of cardiology and, in particular, in tracing the development of concepts in electrophysiology. We have collated scattered reports on eccentric forms of acceleration dependent aberration and on mechanisms that could explain the vagaries proposed in the hope that further interest in the mechanisms underlying aberration will be stimulated. The material comes from our files and our earlier publications.