Cardiac resynchronization therapy (CRT) is a therapeutic option of increasing importance for chronic heart failure (CHF) and criteria for implantation now concern a large amount of patient populations. As a consequence, subjects with ongoing CRT (or immediately after CRT implantation) are more often referred to Cardiac Rehabilitation (CR) programmes, and it has been recently estimated that about one third of CHF patients attending CR in Italy currently have this kind of device. The presence of CRT represents a modulating factor for exercise prescription and monitoring, since CRT patients may be considered per se as a target group for CR. Exercise therapy (ET) increases benefits from CRT on functional capacity, and recent evidence suggests an adjuvant role of ET in improving cardiovascular prognosis also. Both aerobic endurance and resistance training activities may involve CHF patients with CRT, while the potential role of aerobic interval training needs more studies and evidence. Prescription of an ET program should be associated with information regarding device programming and possible limiting factors associated with pacing therapy, tailoring of the basic principles of ET (in terms of type of exercise, intensity and program duration) in this patient group is mandatory.
Cardiac resynchronization therapy in heart failureHeart failure (HF) is a clinical syndrome characterized by typical symptoms (e.g., breathlessness, ankle swelling and fatigue) leading to marked disability and impaired life expectancy. The prevalence of HF is approximately 1-2% of the adult population in developed countries, rising to ≥10% among people >70 years of age [1][2][3]. Cardiac resynchronization therapy (CRT) represents an important advancement in HF treatment by targeting ventricular dyssynchrony, a condition occurring in up to a third of patients with severe systolic HF [4]. CRT is based on the addiction of a third left ventricular pacing lead to a standard pacemaker (CRT-P) or defibrillator system (CRT-D) that generally includes only two right side leads (Figure 1) The left side lead is generally placed into the lateral or posterolateral wall of the left ventricle, and when the two leads are activated, a coordinated pacing of the left ventricle and right ventricle is obtained [5]. Several randomized, controlled clinical studies have demonstrated that CRT has several positive clinical effects, including: improvement in cardiac function and structure, quality of life and exercise capacity, as well as reduction in heart failure hospitalization and mortality from progressive heart failure (Table 1). Moreover, by improving cardiac performance and efficiency, CRT favorably impacts cardiac autonomic control, potentially contributing to reverse remodeling of the left ventricle [6]. As in the case of implantable cardioverter defibrillator (ICD) devices [7], implantation policies may have significant impact on public health expenditure and appropriate patient selection for CRT is needed in order to maximize its benefits and cost-eff...