Increased Susceptibility to Atrial Tachyarrhythmia in Spontaneously Hypertensive Rat Hearts
- 1 March 2007
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Hypertension
- Vol. 49 (3), 498-505
- https://doi.org/10.1161/01.hyp.0000257123.95372.ab
Abstract
Although hypertension is the most prevalent risk factor for atrial fibrillation, there is currently no information available from animal models of hypertension regarding the development of atrial remodeling or increased susceptibility to atrial tachyarrhythmia. Therefore, we examined the susceptibility to atrial tachyarrhythmia and the development of atrial remodeling in excised perfused hearts from male spontaneously hypertensive rats in comparison with age-matched male Wistar–Kyoto normotensive controls at age 3 and 11 months, corresponding with early hypertension and pre-heart failure stages, respectively. The incidence and duration of left atrial tachyarrhythmia induced by burst pacing was greater in hearts from 11-month–old hypertensive animals than either in age-matched controls or in 3-month–old hypertensive rats, although there was no difference between hypertensive and normotensive hearts at 3 months. Thus, hypertension was associated with the development of an arrhythmic substrate. Atrial effective refractory period and the duration of monophasic action potentials recorded from the left atrium were not altered with either hypertension or age, although there were changes in the whole-cell Ca 2+ current density of isolated left atrial myocytes. On the other hand, Masson’s trichrome staining of wax-embedded sections of left atrium revealed markedly greater interstitial fibrosis in 11-month–old hypertensive rats compared with controls. These data constitute the first experimental evidence that hypertension is associated with the development of a substrate for atrial tachyarrhythmia involving left atrial fibrosis without changes in the atrial effective refractory period and demonstrate that the spontaneously hypertensive rat represents a suitable model for investigating hypertension-associated atrial remodeling.Keywords
This publication has 36 references indexed in Scilit:
- Functional Expression of the TRPM4 Cationic Current in Ventricular Cardiomyocytes From Spontaneously Hypertensive RatsHypertension, 2006
- Remodeling of the Cardiac Pacemaker L-Type Calcium Current and Its β-Adrenergic Responsiveness in Hypertension After Neuronal NO Synthase Gene TransferHypertension, 2006
- Angiotensin II Type 1 Receptor Blocker Prevents Atrial Structural Remodeling in Rats with Hypertension Induced by Chronic Nitric Oxide InhibitionHypertension Research, 2006
- Role of up-regulation of in action potential shortening associated with atrial fibrillation in humansCardiovascular Research, 2005
- In Vivo Cardiac Gene Transfer of Kv4.3 Abrogates the Hypertrophic Response in Rats After Aortic StenosisCirculation, 2004
- Evidence for a Novel K+Channel Modulated by α1A-Adrenoceptors in Cardiac MyocytesPublished by American Society for Pharmacology & Experimental Therapeutics (ASPET) ,2004
- Atrial Fibrillation in the Goat Induces Changes in Monophasic Action Potential and mRNA Expression of Ion Channels Involved in RepolarizationJournal of Cardiovascular Electrophysiology, 2000
- Ionic basis of action potential prolongation of hypertrophied cardiac myocytes isolated from hypertensive rats of different agesCardiovascular Research, 1994
- Left atrial pressure in normotensive and spontaneously hypertensive ratsActa Physiologica Scandinavica, 1979
- Performance of the hypertrophied left ventricle in spontaneously hypertensive rat. Effects of changes in preload and afterloadActa Physiologica Scandinavica, 1979