Mechanoelectric coupling as a fundamental surrogate in ventricular arrhythmia?

Abstract

1350-6277 © 2000 Lippincott Williams & Wilkins Introduction William of Occam (1280-1349) was an English theologian and philosopher (the prevailing government and church regarded him as subversive). He stated: 'Entia non sunt multiplicanda praeter necessitatum'. This is otherwise known as Occam's Razor. Roughly interpreted as far as science is concerned, it proposed that rather than five hypotheses to explain (say) five observations, it is preferable to invoke one hypothesis to explain all of them. Cardiovascular clinical correlates from the perspective of predicting sudden arrhythmic death, run the gamut from the fairly abstract, such as indices employing non-linear dynamics ('chaos') and heart rate variability, through to electrophysiological phenomena such as late potentials, QT dispersion, and alternans; then on to mechanical indices such as ejection fraction. They even include psychosocial factors, which may be related to autonomic imbalance. Although some of these aspects have been related to mechanical factors in previous reviews [1-7], this article is not just-yet another one. It re-assembles and summarizes the data and presents a different viewpoint.' It bears on the possibility that many of the mechanical and arrhythmic factors impinge on a common pathway. It examines the previously published correlates and evidence and suggests that abnormalities in cardiac load provide some putative common path in the cascades of the clinical and monitoring observations. Boldly posed, it asks whether mechanoelectric coupling, or feedback, can be an embracing clinical correlate.