Association between right ventricle two- and three-dimensional echocardiography and exercise capacity in patients with reduced left ventricular ejection fraction.

INTRODUCTION: Echocardiography represents the most commonly performed noninvasive cardiac imaging test for patients with heart failure (HF). The aim of this study was to assess the relationship between exercise capacity parameters (peak oxygen consumption (VO2) and the minute ventilation-carbon dioxide production relationship (VE/VCO2)), two-dimensional speckle-tracking echocardiography (2D-STE) and three-dimensional echocardiography (3DE) imaging of right ventricular (RV) function in HF patients with reduced ejection fraction (EF). MATERIAL AND METHODS: This cross-sectional study included 54 patients with diagnosed ischemic LV systolic dysfunction (HF with reduced EF <40%) divided in subgroups based on the proposed values of the analyzed cardiopulmonary exercise testing (CPET) variables: VO2 peak ≤ 15 ml/kg/min, VO2 peak > 15 ml/kg/min, VE/VCO2 slope < 36 and VE/VCO2 slope ≥ 36. All patients underwent a physical examination, laboratory testing, conventional echocardiography, 2D-STE, 3DE, and CPET. RESULTS: RV fractional area change (FAC), 2D RV global longitudinal strain (GLS), 3D RV EF were significantly decreased, and RV basal diameter (BD), systolic pulmonary artery pressure (SPAP), tricuspid annular plane systolic excursion (TAPSE), ratio between tricuspid flow and tissue Doppler derived e' of the lateral tricuspid annulus (TV E/e') were significantly increased in the subgroups of subjects with a worse VO2 peak and VE/VCO2 slope values. There was a significant positive correlation between the peak VO2 values and TAPSE, 2D RV GLS, 3D RV SV, and 3D RV EF as well as a significantly inverse correlation with VE/VCO2 slope. CONCLUSIONS: The observed significant correlation between the examined parameters suggests that 2D RV GLS and 3D RV EF, SV are associated with exercise capacity in patients with reduced HF.

Heart rate variability and increased risk for developing type 2 diabetes mellitus.

BACKGROUND/AIM: To our knowledge there are no data about the relationship between elevated risk for developing type 2 diabetes mellitus (DM2) and altered cardiac autonomic function. The aim of this study was to evaluate the association between heart rate variability (HRV) and slightly increased risk for DM2. METHODS: We evaluated 69 subjects (50.0 ± 14.4 years; 30 male) without DM2, coronary artery disease and arrhythmias. The subjects were divided into two groups according to the Finnish Diabetes Risk Score (FINDRISC): group I (n = 39) included subjects with 12 > FINDRISC ≥ 7; group II (n = 30) subjects with FINDRISC < 7. HRV was derived from 24-h electrocardiogram. We used time domain variables and frequency domain analysis performed over the entire 24-h period, during the day (06-22 h) and overnight (22-06 h). RESULTS: Standard deviation of the average normal RR intervals was significantly lower in the group with increased risk for DM2 compared to the group II (127.1 ± 26.6 ms vs 149.6 ± 57.6 ms; p = 0.035). Other time domain measures were similar in both groups. The group I demonstrated significantly reduced frequency domain measures, total power--TP (7.2 ± 0.3 ln/ms2 vs 7.3 ± 0.3 ln/ms2; p = 0.029), and low frequency--LF (5.9 ± 0.4 ln/ms2 vs 6.3 ± 0.6 In/ms2; p = 0.006), over entire 24 h, as well as TP (7.1 ± 0.3 In/ms2 vs 7.3 ± 0.3 In/ms2; p = 0.004), very low frequency (6.2 ± 0.2 In/ms2 vs 6.3 ± 0.2 In/ms2; p = 0.030), LF (5.9 ± 0.4 In/ms2 vs 6.2 ± 0.3 In/ms2; p = 0.000) and high frequency (5.7 ± 0.4 In/ms2 vs 5.9 ± 0.4 In/ms2; p = 0.011) during the daytime compared to the group II. Nocturnal frequency domain analysis was similar between the groups. The low diurnal frequency was independently related to elevated risk for diabetes mellitus (beta = -0,331; p = 0.006). CONCLUSION: The obtained results suggest that even slightly elevated risk for developing diabetes mellitus may be related to impaired HRV.

Beta blockers therapy is associated with improved left ventricular systolic function and sustained exercise capacity in elderly patients with heart failure. CIBIS-ELD sub-study.

BACKGROUND: Exercise capacity is critical for therapy and prognosis in patients with heart failure (HF). Effect of beta-blockers (BB) on exercise capacity in elderly patients with HF remains unclear. OBJECTIVES: To assess contribution of BB to functional capacity and left ventricular (LV) function in the elderly with HF. DESIGN: According to the protocol of CIBIS-ELD study group, elderly patients were treated with BB during 12 weeks. In CPET subgroup, an integral part of the CIBIS ELD study group, patients were performed Doppler echocardiography and cardiopulmonary exercise testing (CPET) before BB therapy and after 12 weeks. SETTING: Randomized patients with HF beta blockers naïve. PARTICIPANTS: thirty patients with HF aged over 65 years were included in CPET subgroup, while 847 were incorporated in CIBIS ELD study group. RESULTS: Heart rate (HR) and systolic blood pressure (SBP) after BB significantly decreased at rest (p<0.001) and during exercise (p<0.05), with sustained level of peak VO2. Observed changes of resting HR and peak HR were closely correlated (p<0.001). Significant improvement of LV ejection fraction after BB was obtained (p=0.003) and symptoms of breathlessness were reduced (p=0.001). Left ventricular diastolic dysfunction at rest significantly contributed to exercise capacity (p=0.019). CONCLUSIONS: Beta-blockers in elderly patients with HF are related to a significant decrease of HR and SBP, improvement of systolic LV function and sustained exercise tolerance. Resting LV diastolic dysfunction is strongly associated with lower exercise capacity.

Cardiopulmonary exercise testing and its relation to oxidative stress in patients with hypertension.

An increase in reactive oxygen species has been implicated in the pathologies of hypertension. This study was designed to evaluate antioxidant activity in hypertensive patients and to assess the relationship between oxidative stress and exercise tolerance in hypertensive patients with mild left ventricular diastolic dysfunction (LVDD). A total of 42 patients, aged 51±9 years, with a long history of hypertension and mild LVDD (mitral flow velocities-E/A <1, deceleration time of E >220 ms, and preserved ejection fraction-EF >50%), and 30 controls without cardiovascular disease, aged 50±7 years, underwent cardiopulmonary exercise testing (CPET). Peak oxygen uptake (peak VO(2)), oxygen pulse (VO(2)/heart rate (HR)) and ventilatory anaerobic threshold (VAT) were obtained during CPET. Antioxidant activity of superoxide dismutase (SOD) and glutathione peroxidase in the blood was measured before and after exercise. Reduced peak VO(2) (1715±426 vs. 2083±465 ml min(-1), P<0.001), VO(2)/HR (12.0±2.8 vs. 14.6±3.3 ml per beat, P<0.001) and percentage of peak VO(2) at VAT (55.5±15.8% vs. 64.5±14.7%, P=0.007) were observed in hypertensive patients, compared with controls. Antioxidant protection was significantly attenuated in hypertensive patients, compared with controls, before (945 vs. 1006, P=0.012) and after exercise (954 vs. 1051, P<0.001). The level of SOD before and after exercise was significantly associated with LVDD in hypertensive patients (P=0.012 and 0.02, respectively). In addition, the degree of LVDD before exercise (E/A) influenced the degree of exercise capability (peak VO(2)) (P=0.016). Asymptomatic hypertensive patients with mild LVDD had reduced cardiopulmonary capacity, accurately identified by CPET. The redox state in hypertensive patients was significantly related to LVDD and exercise tolerance. Attenuated antioxidant protection was associated with long-term hypertension.