Predictive value of cardiac autonomic indexes and MIBG washout in ICD recipients with mild to moderate heart failure.

Objective: We aimed at evaluating the combined use of heart rate variability (HRV), baroreflex sensitivity (BRS), and MIBG imaging in the risk stratification for sudden cardiac death (SCD) of patients with mild to moderate heart failure.

Methods: Twenty-five patients (17 male and 8 female, mean age 63 +/- 5 years, mean LVEF 36 +/- 3%) with a recently implanted defibrillator (ICD) and mild (NYHA I-II) heart failure due to either ischemic (n = 15) or dilated (n = 10) cardiomyopathy were studied. One week after ICD implantation they underwent (a) baroreflex sensitivity (BRS) evaluation to bolus phenylephrine by the Oxford method, (b) 24-h heart rate variability (HRV) assessment, and (c) MIBG imaging.

Repeated exercise stress testing identifies early and late preconditioning.

Background: The warm-up phenomenon has been considered to trigger preconditioning. We investigated whether repeated exercise treadmill tests in humans are capable of inducing adaptation to ischemia by triggering both the early and late phase of preconditioning.

Methods: In 25 consecutive patients with stable coronary artery disease, four repeated treadmill tests were performed.