Impact of exercise rehabilitation on cardiac neuronal function in heart failure: an iodine-123 metaiodobenzylguanidine scintigraphy study

Abstract

Exercise training can induce important haemodynamic and metabolic adaptations in patients with chronic heart failure due to severe left ventricular dysfunction. This study examined the impact of exercise rehabilitation on cardiac neuronal function using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy, Fourteen patients (11 men, 3 women; mean age 48 years; range: 36-66 years) with stable chronic heart failure of NYHA class II-III and an initial resting radionuclide left ventricular ejection fraction (LVEF) < 50% were enrolled in the study. Patients underwent progressive, supervised endurance training (treadmill test, Bruce protocol) during a 6-month period (60 sessions, 3 sessions per week) at a cardiac rehabilitation referral centre in order to measure exercise parameters. Planar 123I-MIBG scintigraphy provided measurements of cardiac neuronal uptake (heart-mediastinum ratio activity, 4 h after intravenous injection of 185 MBq of MIBG). Radionuclide LVEF was also assessed at the outset and after 6 months of exercise training. Workload (801 +/- 428 vs 1229 +/- 245 kpm.min-1, P = 0.001), exercise duration (504 +/- 190 vs 649 +/- 125 s, P = 0.02), and myocardial MIBG uptake (135% +/- 19% vs 156% +/- 25%, P = 0.02) increased significantly after rehabilitation. However, LVEF did not change significantly (23% +/- 9% vs 21% +/- 10%, p = NS). It is concluded that exercise rehabilitation induces improvement of cardiac neuronal function without having negative effects on cardiac contractility in patients with stable chronic heart failure.

Effects of cardiac rehabilitation and exercise training on autonomic regulation in patients with coronary artery disease

“…Extrapolating from data obtained in athletes, an improved cardiopulmonary baroreflex could be the result of an augmented inhibitory influence of cardiopulmonary receptors 33 possibly linked to the improved respiratory performance. Likewise, training induced an improved cardiac neuronal function, in the absence of changes in left ventricular performance, 34 in patients with CHF. A likely role of more powerful vagal mechanisms 35 after exercise training is further suggested by the increase in R-R interval and R-R variance observed in this study in the cardiac rehabilitation group.…”

Assessment of Cardiac Sympathetic Innervation in Heart Failure and Lethal Arrhythmias: Therapeutic and Prognostic Implications

“…However, in most of those studies [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] the number of patients enrolled was small, patients were followed up for only a short period with a primary end point of functional or symptomatic improvement but not mortality, Fig. (2).…”

Pulmonary Function, Working Capacity and Strength in Young Adults With Marfan Syndrome

“…Several studies have shown that patients with coronary diseases and cystic fibrosis, respectively, benefit from physical training (29,30). One of the most important variables to show improvement of the cardiac function was lowering of the heart rate at a given submaximal work rate (15).…”