Atrial fibrillation and heart failure.

Abstract

Atrial fibrillation (AF) and congestive heart failure (CHF) are the new epidemics of the third millennium due to ageing of the population and the success of new therapies for acute cardiac illnesses that, in the past, were fatal. The interactions between AF and CHF are only partially understood, and the effectiveness of drugs as well as that of non-pharmacological interventions remains often disappointing. Furthermore, few studies have been planned with a view to evaluate specifically the combined clinical setting of atrial tachyarrhythmias and CHF. Antiarrhythmic drugs have been widely used in preparation for cardioversion of AF and maintenance of sinus rhythm, though they have a limited and, usually, temporary efficacy [1]. Furthermore, in patients suffering from CHF, the choice is limited to class III drugs (mainly amiodarone) in view of the adverse cardiovascular effects of class I drugs. Noteworthy new frontiers in the pharmacological treatment of these patients are angiotensin-converting enzyme inhibitors [2] and angiotensin-1 receptor blockers [3], which may prevent AF by unloading the left atrium and by preventing electrical remodelling and interstitial fibrosis via a direct action on atrial myocytes. The limitations of antiarrhythmic drug therapy have prompted the growing use of device therapy to treat patients with refractory AF. The antiarrhythmic benefits of atrial or dual chamber pacing, as opposed to single chamber ventricular pacing, in reducing the rates of AF recurrences and in slowing the progression to permanent AF have been established in large prospective trials which enroled patients with either sinus node disease or mixed conventional indications for permanent pacing [4–9]. In this respect, the impact of ventricular pacing on haemodynamic function is a major consideration. Physiological pacing by a sequential dual chamber system and an optimised, individually programmed, atrio-ventricular (AV) delay may contribute major improvements in haemodynamic function and clinical …