The interaction of activation-repolarisation coupling and restitution properties in humans

Hanson, Ben, Sutton, Peter, Elameri, Nasser, Gray, Marcus, Critchley, Hugo and Taggart, Peter (2009) The interaction of activation-repolarisation coupling and restitution properties in humans. Circulation: Arrhythmia and Electrophysiology, 2 2: 162-170. doi:10.1161/CIRCEP.108.785352

Author Hanson, Ben
Sutton, Peter
Elameri, Nasser
Gray, Marcus
Critchley, Hugo
Taggart, Peter
Title The interaction of activation-repolarisation coupling and restitution properties in humans
Journal name Circulation: Arrhythmia and Electrophysiology   Check publisher's open access policy
ISSN 1941-3149
Publication date 2009-04
Sub-type Article (original research)
DOI 10.1161/CIRCEP.108.785352
Volume 2
Issue 2
Start page 162
End page 170
Total pages 9
Place of publication Philadelphia, PA, United States
Publisher Lippincott Williams & Wilkins
Language eng
Formatted abstract
Background: Dynamic modulation of repolarization is important in arrhythmogenesis. An inverse relation exists in myocardium between activation time (AT) and action potential duration (APD). We hypothesized that resulting gradients of APD and diastolic interval (DI) interact with restitution properties and modulate the timing of repolarization.

Methods and Results: Activation-recovery intervals (ARI) were acquired from reconstructed noncontact unipolar electrograms from the left ventricular endocardium in 9 patients (7 male) with normal ventricles. At a basic paced cycle length (median, 450 ms), ARIs shortened along the path of activation, with a mandatory reciprocal increase of DIs. In the median patient, this range of DIs started at 230 ms at the site of earliest activation and increased to 279 ms at the site of latest activation at a basic cycle length of 450 ms. Four consecutive standard S1 to S2 restitution curves were performed. At sites with a longer ARI (and therefore shorter DI) close to the site of stimulation, premature stimulation produced more shortening of ARIs; therefore, the time course of restitution was steeper than at more distal sites. At normal heart rate, the decrease in ARIs along the conduction pathway compensated for later activation. Thus, dispersion in repolarization time (RT) is smaller than dispersion in ARI in a heart with a steep negative AT-ARI relationship. This protective effect is lost in hearts without such a relationship. In the patients with a steep AT-ARI relationship at basic cycle length, this relation is lost after premature stimulation and is a function of prematurity. Thus, dispersion in RT is larger after shortly coupled extra stimuli in patients with a steep AT-ARI relationship.

Conclusions: A complex interplay exists between activation-repolarization coupling and restitution properties, largely driven by ARI and DI gradients. This plays a significant role in the dynamics of repolarization in humans.
Keyword Arrhythmia
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Centre for Advanced Imaging Publications
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Citation counts: TR Web of Science Citation Count  Cited 24 times in Thomson Reuters Web of Science Article | Citations
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Created: Tue, 30 Oct 2012, 11:22:51 EST by Sandrine Ducrot on behalf of Centre for Advanced Imaging