Journal Article

Arrhythmogenic mechanisms in left ventricular hypertrophy

R. Wolk

in EP Europace

Published on behalf of European Heart Rhythm Association of the European Society of Cardiology (ESC)

Volume 2, issue 3, pages 216-223
Published in print July 2000 | ISSN: 1099-5129
Published online July 2000 | e-ISSN: 1532-2092 | DOI: http://dx.doi.org/10.1053/eupc.2000.0110
Arrhythmogenic mechanisms in left ventricular hypertrophy

Show Summary Details

Preview

An important mechanism contributing to the high mortality and sudden death in patients with left ventricular hypertrophy (LVH) is ventricular arrhythmia. Part of the risk is associated with the pro-arrhythmic electrophysiological phenotype of the hypertrophied myocardium. The most consistently observed abnormality is prolongation of the action potential duration and refractoriness, which sets the stage for arrhythmias based on early or delayed afterdepolarizations and triggered activity. In addition, non-uniform prolongation of the action potential in LVH may be pro-arrhythmic by leading to increased dispersion of repolarization or refractoriness and favouring re-entry. The occurrence of delayed afterdepolarization-induced triggered activity and other ventricular arrhythmias are also related to the impaired ability to handle intracellular calcium due to changes in the density of ryanodine receptors and the Ca2+-ATPase of the sarcoplasmic reticulum. Slowing and fractionation of ventricular conduction, creating the conditions for micro-reentry and arrhythmogenesis, are characteristic of severe LVH, as isthe expression of the Ifcurrent (which may be a source of increased automaticity).

The pro-arrhythmic potential of LVH is also related to the presence of coexisting ‘extrinsic’ factors. The most important and pro-arrhythmic association of LVH is that with myocardial ischaemia. Other conditions include neuroendocrine factors, ventricular wall stress or electrolyte disturbances. The electrophysiological mechanisms of the interactions between these ‘extrinsic’ factors and LVH have not been fully elucidated. Further research into these mechanisms is required and may have important implications for our understanding of the mechanisms of cardiac arrhythmias in LVH and the appropriate use of antiarrhythmic drug therapy.

Keywords: Sudden death; hypertrophy; arrhythmias; ischaemia

Journal Article.  0 words. 

Subjects: Cardiovascular Medicine

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.