Influence of arterial hypertension on left atrial structure and function

Abstract

There has been a growing interest recently in the relationship between arterial hypertension and atrial fibrillation. The role of hypertension as risk factor for atrial fibrillation is established but still incompletely understood. Both hypertension and atrial fibrillation are independent risk factors of stroke, and among subjects with atrial fibrillation, hypertension increases the risk of stroke. In hypertensive patients the risk of atrial fibrillation is two-fold higher than in normotensives. Hypertension can lead not only to the left ventricular hypertrophy but also to the increase of left atrial pressure and dilatation of the left atrium. This in consequence leads to increased arhythmogenesis of the atrial myocardium. It has been demonstrated that angiotensin II and aldosterone, hormones regulating blood pressure levels, can cause fibrosis of atria. Increased atrial fibrosis is basis for development of reentry loop, which initiates and propagates atrial fibrillation. Those two hormones are also involved in electrical atrial remodeling - a process that causes new recurrences of atrial fibrillation after cardioversion and leads to chronic atrial fibrillation. Some classes of antihypertensive drugs, i.e. ACE inhibitors, angiotensin receptor blockers and verapamil can inhibit these processes, that has been shown both in hypertensive and normotensive subjects. Prevention of the atrial fibrillation should be used as a one of the criteria of antihypertensive drugs efficacy.