Is arterial stiffness a contributing factor to atrial fibrillation in patients with hypertension? A preliminary investigation

BACKGROUND: Atrial fibrillation (AF) is the most common tachyarrhythmia encountered by clinicians. When AF occurs in patients with structural disorders, hypertension is most common. Hypertension may provoke or enable AF to occur through several mechanisms. One could be the resultant effects of increased afterload on the left ventricle and consequent changes in the left atrium. The latter could be the direct linear effect of elevated diastolic atrial pressure and its proximate effect on atrial electrophysiology. Alternatively, it may be a more indirect and complex relationship involving chronic morphologic, electrophysiologic, and secretory consequences in the atrium consequent to a chronically reduced left ventricular (LV) compliance. METHODS: To assess this relationship, the arterial stiffness index (ASI) was determined in 53 hypertensive patients (29 with AF, 24 without) and 17 nonhypertensive controls with AF and its relationship to ventricular hypertrophy and AF was determined. All except 5 patients with AF had paroxysmal AF (PAF); the other 5 were in sinus rhythm status after cardioversion of a persistent AF episode. RESULTS: The ASI was significantly higher in patients with hypertension, both with and without AF than in lone AF patients, but did not distinguish between hypertensives with and without AF. The ASI was higher in the presence of LV hypertrophy (LVH). CONCLUSIONS: The ASI and LVH cannot be used to predict the risk of AF in hypertensive patients and the development of AF in hypertensives is more complex than just that of the immediate effect of elevated ventricular pressure on atrial pressure and stretch. Rather, AF is linked through the chronic alterations that are consequent to atrial hypertension.