Quantitative evaluation of cardiopulmonary functional reserve in treated patients with pulmonary embolism / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>There is no research, either at home or abroad, focusing on assessing the cardiopulmonary functional reserve and exercise tolerance in patients with pulmonary embolism (PE), but the benefits of early exercise are well recognized. The goals of this study were to assess cardiopulmonary functional reserve in treated PE patients using the inert gas rebreathing method of the cardiopulmonary exercise test (CPET), and to compare it with traditional methods.</p><p><b>METHODS</b>CPET on the bicycle ergometer were performed in 40 patients with age, gender, body mass index, systolic blood pressure, and pulmonary function matched. The first group was the PE group composed of 16 PE patients (5 male, 11 female) who were given the standard antithrombotic therapy for two weeks. The second group was composed of 24 normal individuals (10 male, 14 female). Both groups were evaluated by cardiac ultrasound examination, 6-minute walking test (6MWT), and CPET.</p><p><b>RESULTS</b>(1) Right ventricular systolic pressure (RVSP) in the PE group increased significantly compared to the control group, (34.81 ± 8.15) mmHg to (19.75 ± 3.47) mmHg (P < 0.01). But neither right atrial end-systolic diameter (RASD) nor right ventricular end-diastolic diameter (RVDD) in the PE patients had changed when compared with the controls. The 6-minute walk distance was significantly reduced in the PE patients compared with normal subjects, (447.81 ± 79.20) m vs. (513.75 ± 31.45) m (P < 0.01). Both anaerobic threshold oxygen consumption (VO(2)AT) and peak oxygen consumption (VO(2)peak) were significantly lower in patients with PE, while CO(2) equivalent ventilation (VE/VCO(2) slope) was higher; VO(2)AT (9.44 ± 3.82) ml×kg(-1)×min(-1) vs. (14.62 ± 2.93) ml×kg(-1)×min(-1) (P < 0.01) and VO2peak (12.26 ± 4.06) ml×kg(-1)×min(-1) vs. (23.46 ± 6.15) ml×kg(-1)×min(-1) (P < 0.01) and VE/VCO(2) slope 35.47 ± 6.66 vs. 26.94 ± 3.16 (P < 0.01). There was no significant difference in resting cardiac output (CO) between the PE and normal groups, whereas peak cardiac output (peak CO) and the difference between exercise and resting cardiac output (ΔCO) were both significantly reduced in the PE group; peak CO (5.97 ± 2.25) L/min to (8.50 ± 3.13) L/min (P < 0.01), ΔCO (1.29 ± 1.59) L/min to (3.97 ± 2.02) L/min (P < 0.01). (2) The 6-minute walk distance did not correlated with CPET except for the VO2 peak in patients with PE, r = 0.675 (P < 0.01).</p><p><b>CONCLUSIONS</b>The cardiopulmonary functional reserve was reduced in patients with PE. CPET is an accurate, quantitative evaluation of cardiopulmonary functional reserve for PE patients.</p>

The effects of aerobic exercise on cardiac output during exercise in patients with chronic heart failure / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the effects of aerobic exercise on cardiac output during exercise in patients with chronic heart failure (CHF).</p><p><b>METHODS</b>A total of 50 CHF patients (echocardiography measured left ventricular ejection fraction < 0.49) were enrolled in the study and randomly divided into aerobic exercise group (n = 25) and control group (n = 25). Cardiopulmonary exercise testing (CPET) was performed. Patients of aerobic exercise group underwent aerobic exercise according to aerobic exercise prescription and exercise intensity is decided by anaerobic threshold before 10 J/s (1 minute before) of the oxygen consumption. After 6 supervised aerobic exercise training sessions in the hospital, patients were asked to perform the home-based aerobic exercise training. Patients in control group were required to maintain daily physical activities. CPET were reviewed 3 months later.</p><p><b>RESULTS</b>Cardiac output (CO), peak CO, peak cardiac power output (peak CPO), resting heart rate (HR), heart rate at AT (HRAT), HR peak, resting mean arterial pressure (MAP), peak MAP at baseline were similar between aerobic exercise group and control [(4.2 ± 2.0) L/min vs. (3.3 ± 1.0) L/min, (6.2 ± 2.7) L/min vs. (5.2 ± 1.8) L/min, (1.8 ± 2.9) L/min vs. (2.0 ± 1.8) L/min, (1.3 ± 0.5) J/s vs. (1.2 ± 0.5) J/s, (76.8 ± 13.5) beats/min vs. (73.4 ± 11.9) beats/min, (91.5 ± 11.3) beats/min vs. (92.6 ± 12.4) beats/min, (106.0 ± 12.9) beats/min vs. (108.3 ± 17.4) beats/min, (80.8 ± 9.9) mm Hg (1 mm Hg = 0.133 kPa) vs. (87.6 ± 13.3) mm Hg, (98.8 ± 12.4) mm Hg vs. (102.7 ± 13.9) mm Hg, all P > 0.05]. Compared to baseline, CO, peak CO, peak CPO, HR, HRAT, HR peak, MAP, peak MAP after 3 months were similar between aerobic exercise group and control (all P > 0.05). The differences between baseline and 3 months later expressed as ΔCO, Δpeak CO, Δpeak CPO, ΔHR, ΔHRAT, ΔHR peak, ΔMAP, Δpeak MAP were also similar between aerobic exercise group and control group [(-0.7 ± 2.4) L/min vs. (0.7 ± 2.0) L/min, (1.1 ± 2.6) L/min vs. (1.4 ± 2.1) L/min, (0.1 ± 3.7) L/min vs. (-0.2 ± 2.5) L/min, (0.2 ± 1.0) J/s vs. (0.2 ± 0.5) J/s, (-0.4 ± 7.6) beats/min vs. (1.9 ± 9.9) beats/min, (3.4 ± 11.3) beats/min vs. (-2.8 ± 7.6) beats/min, (8.9 ± 14.5) beats/min vs. (3.7 ± 14.4) beats/min, (1.5 ± 12.8) mm Hg vs. (-1.3 ± 11.1) mm Hg, (6.4 ± 18.9) mm Hg vs. (1.3 ± 12.3) mm Hg, all P > 0.05].</p><p><b>CONCLUSION</b>Three months aerobic exercise training did not improve cardiac output and related parameters during exercise in this cohort patients with CHF.</p>

Relationship of left heart size and left ventricular mass with exercise capacity in chronic heart failure / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Impaired exercise capacity is one of the most common clinical manifestations in patients with chronic heart failure (CHF). The severity of reduced exercise capacity is an indicator of disease prognosis. The aim of the current study was to investigate the association between left heart size and mass with exercise capacity.</p><p><b>METHODS</b>A total of 74 patients were enrolled in the study, with 37 having congestive heart failure (left ventricular ejection fraction (LVEF) < 0.45) and the other 37 with coronary heart disease (by coronary angiography) serving as the control group (LVEF > 0.55). Echocardiography and cardiopulmonary exercise test were performed. The multiply linear regression model was used to evaluate the association between echocardiogrphic indices and exercise capacities.</p><p><b>RESULTS</b>The study showed that left ventricular end diastolic/systolic diameter (LVEDD/LVESD), left atrial diameter (LAD) and left ventricular mass index (LVMI) were significantly enlarged in patients with chronic heart failure compared with controls (P < 0.01). The VO(2)AT, Peak VO(2), Load AT, and Load Peak in chronic heart failure patients were also significantly reduced compared with controls (P < 0.05), VE/VCO(2) slope was increased in patients with chronic heart failure (P < 0.01). Multivariate linear regression analysis indicated that the patients' exercise capacity was significantly associated with the left heart size and mass, however, the direction and/or strength of the associations sometimes varied in chronic heart failure patients and controls. Load AT correlated negatively with LVEDD in chronic heart failure patients (P = 0.012), while Load AT correlated positively with LVEDD in control patients (P = 0.006). VE/VCO(2) slope correlated positively with LAD (B = 0.477, P < 0.0001) in chronic heart failure patients, while the VE/VCO(2) slope correlated negatively with LAD in control patients (P = 0.009).</p><p><b>CONCLUSION</b>The study indicates that the size of LVEDD and LAD are important determinants of exercise capacity in patients with CHF, which may be helpful to identify exercise tolerance for routine monitoring of systolic heart failure.</p>

Beta1-adrenergic receptor (Arg389Gly) polymorphism and response to bisoprolol in patients with chronic heart failure / 中华心血管病杂志

<p><b>OBJECTIVE</b>The purpose of this study was to investigate the relation between the Arg389Gly polymorphism of the beta(1)-AR gene and chronic heart failure (CHF) and to evaluate the effect of this polymorphism on clinical response to beta-adrenoceptor blockade (bisoprolol) in patients with CHF.</p><p><b>METHODS</b>One hundred and ten patients with stable CHF receiving basic therapy for heart failure were included. Before initiation and 3 months after the maximal tolerated dose of bisoprolol was reached, all indices (including BP, HR, LAD, LVEDD, LVESD, LVEF, BNP level, 6 min walk distance) were measured and compared with the Arg389Gly genotypes, which identified by PCR-restriction fragment length polymorphism analysis. We also determined the Arg389Gly genotypes in 100 healthy control subjects, and compared the distribution of Arg389Gly genotypes with that in CHF.</p><p><b>RESULTS</b>No difference was observed between the two groups in any of the three genotypes (CC, CG and GG). The prevalences of the three genotypes in normal subjects and patients with CHF were Arg389Arg 0.53 vs. 0.51, Arg389Gly 0.40 vs. 0.40, Gly38Gly 0.07 vs. 0.09, respectively. After 3 months of bisoprolol usage, a significant improvement in LVEF was observed in CC group, which increased from (36.7 +/- 8.63)% to (44.1 +/- 9.53)%, CG group, from (35.76 +/- 8.39)% to (42.90 +/- 9.41)%, but not GG group, from (36.00 +/- 5.66)% to (37.33 +/- 5.64)%. The improvement in BNP was also observed in CC [from (502.93 +/- 160.80) ng/L to (325.26 +/- 135.63) ng/L], CG [from (525.76 +/- 157.66) ng/L to (331.79 +/- 133.97) ng/L], but not GG [from (505.33 +/- 125.07) ng/L to (429.67 +/- 182.39) ng/L]. Arg389-homozygous patients showed a substantially greater improvement in LVEF and BNP, compared with Gly389-homozygous patients (all P < 0.01).</p><p><b>CONCLUSIONS</b>There was no difference in the prevalence of the three genotypes between healthy and CHF subjects. The Gly389 polymorphism of the beta(1)-AR gene was not associated with an increased risk of CHF. The Arg389 variant of the beta(1)-AR gene was associated with a greater response to bisoprolol than that of the Gly389 variant in patients with CHF.</p>