HRV measurements are beneficial in exercise training prescription in moderately active men and women. Women benefit from HRV guidance by achieving significant improvement in fitness with a lower training load.

Heart rate (HR) variability (HRV) during ambulatory recordings may be affected by individual differences in daily physical activity (PA). However, the influence of various levels of PA on different measures of HRV is not exactly known. We examined the association between simultaneously measured HRV and objective PA data obtained with an accelerometer during waking hours among 45 healthy adults. Bouts of PA were identified from minute-by-minute accelerometer data as metabolic equivalent (METs) values and calculated as mean METs for 30 min. HRV was analyzed concurrently. Within-individual correlation analyses and sign tests were performed to study the relationships between various HRV indexes and PA. The mean PA time was 15:44 +/- 1:01 h, and the mean MET was 1.91 +/- 0.14. HR and sample entropy, but not the other measures of HRV, had a significant relationship with PA, as shown by both correlation analyses (r = 0.64, P = 0.021, and r = -0.55, P = 0.022, respectively) and sign tests (P < 0.0001 for both). Beat-to-beat R-R interval fluctuation expressed as SD1 also demonstrated a significant relation to PA according to the sign test (P = 0.037) and a trend of association according to the correlation analysis (r = -0.40, P = 0.129). The complexity measure of HRV, in addition to average HR and the short-term index of HRV (SD1), is significantly influenced by the level of PA during ambulatory conditions. Long-term HRV indexes remained relatively stable at various activity levels, making them the most robust indexes for the assessment of cardiac autonomic function during free-running ambulatory conditions.

The benign natural course of the patients with the "Brugada sign" suggests that in asymptomatic subjects without a family history of sudden cardiac death, type 2 or 3 Brugada ECG pattern is a normal variant rather than a specific predictor of life-threatening ventricular arrhythmias.

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OBJECTIVELeisure-time physical activity (LTPA) and exercise training are essential parts of current guidelines for patients with coronary artery disease (CAD). However, the contributions of LTPA and exercise training to cardiovascular (CV) risk in CAD patients with type 2 diabetes (T2D) are not well established. RESEARCH DESIGN AND METHODSWe examined the effects of LTPA (n = 539 and n = 507; with and without T2D, respectively) and 2-year controlled, home-based exercise training (n = 63 plus 64 control subjects with T2D and n = 72 plus 68 control subjects without T2D) on the CV risk profile and composite end point among CAD patients. RESULTSDuring the 2-year follow-up, patients with reduced LTPA at baseline had an increased risk of CV events (adjusted hazard ratio 2.3 [95% CI 1.1-5.1; P = 0.033], 2.1 [1.1-4.2; P = 0.027], and 2.0 [1.0-3.9; P = 0.044] for no LTPA, LTPA irregularly, and LTPA two to three times weekly, respectively) compared with those with LTPA more than three times weekly. Among patients who completed the 2-year exercise intervention, exercise training resulted in favorable changes in exercise capacity both in CAD patients with T2D (+0.2 6 0.8 vs. 20.1 6 0.8 MET, P = 0.030) and without T2D (+0.3 6 0.7 vs. 20.1 6 0.5 MET, P = 0.002) as compared with the control group but did not have any significant effects on major metabolic or autonomic nervous system risk factors in CAD patients with or without T2D. CONCLUSIONSThere is an inverse association between habitual LTPA and short-term CV outcome, but controlled, home-based exercise training has only minor effects on the CV risk profile in CAD patients with T2D.Physical activity and exercise training with well-known health benefits are key elements in the management of coronary artery disease (CAD) (1,2) and type 2 diabetes (T2D) (3). Although current guidelines for patients with CAD or T2D recommend physical activity daily, many patients do not become or remain regularly active (4-6). Almost half of patients with CAD do not attend recommended rehabilitation programs (7), and among attending patients, the dropout rate is even

OBJECTIVE Cardiovascular autonomic dysfunction is a common finding among patients with coronary artery disease (CAD) and type 2 diabetes (T2D). The reasons and prognostic value of autonomic dysfunction in CAD patients with T2D are not well known. RESEARCH DESIGN AND METHODS We examined the association between heart rate recovery (HRR), 24-h heart rate (HR) variability (SD of normal R-R interval [SDNN]), and HR turbulence (HRT), and echocardiographic parameters, metabolic, inflammatory, and coronary risk variables, exercise capacity, and the presence of T2D among 1,060 patients with CAD (mean age 67 ± 8 years; 69% males; 50% patients with T2D). Second, we investigated how autonomic function predicts a composite end point of cardiovascular death, acute coronary event, stroke, and hospitalization for heart failure during a 2-year follow-up. RESULTS In multiple linear regression model, exercise capacity was a strong predictor of HRR (R = 0.34, P < 0.001), SDNN (R = 0.33, P < 0.001), and HRT (R = 0.13, P = 0.001). In univariate analyses, a composite end point was predicted by reduced HRR (hazard ratio 1.7 [95% CI 1.1-2.6]; P = 0.020), reduced SDNN (2.0 [95% CI 1.2-3.1]; P = 0.005), and blunted HRT (2.1 [1.3-3.4]; P = 0.003) only in patients with T2D. After multivariate adjustment, none of the autonomic markers predicted the end point, but high-sensitivity C-reactive protein (hs-CRP) remained an independent predictor. CONCLUSIONS Cardiovascular autonomic function in CAD patients is associated with several variables, including exercise capacity. Autonomic dysfunction predicts short-term cardiovascular events among CAD patients with T2D, but it is not as strong an independent predictor as hs-CRP.

We tested the hypothesis that acute post-exercise change in blood pressure (BP) may predict exercise training responses in BP in patients with coronary artery disease (CAD). Patients with CAD (n = 116, age 62 ± 5 years, 85 men) underwent BP assessments at rest and during 10-min recovery following a symptom-limited exercise test before and after the 6-month training intervention (one strength and 3-4 aerobic moderate-intensity exercises weekly). Post-exercise change in systolic BP (SBP) was calculated by subtracting resting SBP from lowest post-exercise SBP. The training-induced change in resting SBP was −2 ± 13 mmHg (p = 0.064), ranging from −42 to 35 mmHg. Larger post-exercise decrease in SBP and baseline resting SBP predicted a larger training-induced decrement in SBP (β = 0.46 and β = −0.44, respectively, p < 0.001 for both). Acute post-exercise decrease in SBP provided additive value to baseline resting SBP in the prediction of training-induced change in resting SBP (R2 from 0.20 to 0.26, p = 0.002). After further adjustments for other potential confounders (sex, age, baseline body mass index, realized training load), post-exercise decrease in SBP still predicted the training response in resting SBP (β = 0.26, p = 0.015). Acute post-exercise change in SBP was associated with training-induced change in resting SBP in patients with CAD, providing significant predictive information beyond baseline resting SBP.

Summary Background Promotion of and adherence to increased physical activity (PA) is an important part of the prevention and treatment of coronary artery disease (CAD). We hypothesized that individually tailored home‐based exercise prescriptions will increase long‐term PA and maximal exercise capacity among CAD patients without and with type 2 diabetes (CAD+T2D). Methods Physical activity of patients with CAD (n = 44) and CAD+T2D (n = 39), matched by age, sex and ejection fraction, was measured over 5 days with an accelerometer pre‐ and postexercise prescription. PA was assessed as the average time per day of moderate (METs = 2–5) and high (METs > 5) intensities. Six‐month exercise prescriptions were introduced based on individual maximal heart rate reserve. Results At the baseline, patients with CAD+T2D engaged in less moderate‐intensity PA (2:40 ± 1:23 versus 3:24 ± 1:17 h, P = 0·014) and exhibited a non‐significant trend to reduced high‐intensity PA (2:08 ± 2:57 versus 5:02 ± 9:19 min, P = 0·091) compared with patients with CAD. High‐intensity PA increased markedly in CAD (5:02 ± 9:19 versus 9:59 ± 15:03 min) and patients with CAD+T2D (2:08 ± 2:57 versus 6:14 ± 10:18 min) after exercise prescription (main effect for time P = 0·001). Also maximal exercise capacity increased in both groups (main effect for time P<0·001). Conclusion Patients with CAD with T2D are physically less active than CAD patients without diabetes in their daily life. Individually tailored home‐based exercise prescriptions are an effective way to promote more active lifestyles and improve fitness in both patient groups.