Jorge Pinto Ribeiro

Inspiratory muscle training improves blood flow to resting and exercising limbs in patients with chronic heart failure.

OBJECTIVES We tested the hypothesis that inspiratory muscle loading could result in exaggerated peripheral vasoconstriction in resting and exercising limbs and that inspiratory muscle training (IMT) could attenuate this effect in patients with chronic heart failure (CHF) and inspiratory muscle weakness. BACKGROUND Inspiratory muscle training improves functional capacity of patients with CHF, but the mechanisms of this effect are unknown. METHODS Eighteen patients with CHF and inspiratory muscle weakness (maximal inspiratory pressure <70% of predicted) and 10 healthy volunteers participated in the study. Inspiratory muscle loading was induced by the addition of inspiratory resistance of 60% of maximal inspiratory pressure, while blood flow to the resting calf (CBF) and exercising forearm (FBF) were measured by venous occlusion plethysmography. For the patients with CHF, blood flow measurements as well as ultrasound determination of diaphragm thickness were made before and after a 4-week program of IMT. RESULTS With inspiratory muscle loading, CHF patients demonstrated a more marked reduction in resting CBF and showed an attenuated rise in exercising FBF when compared with control subjects. After 4 weeks of IMT, CHF patients presented hypertrophy of the diaphragm and improved resting CBF and exercise FBF with inspiratory muscle loading. CONCLUSIONS In patients with CHF and inspiratory muscle weakness, inspiratory muscle loading results in marked reduction of blood flow to resting and exercising limbs. Inspiratory muscle training improves limb blood flow under inspiratory loading in these patients.

Intrinsic sinus and atrioventricular node electrophysiologic adaptations in endurance athletes.

OBJECTIVES In the present study, we evaluated sinus and atrioventricular (AV) node electrophysiology of endurance athletes and untrained individuals before and after autonomic pharmacologic blockade. BACKGROUND Endurance athletes present a higher prevalence of sinus bradycardia and AV conduction abnormalities, as compared with untrained individuals. Previous data from our laboratory suggest that nonautonomic factors may be responsible for the longer AV node refractory period found in well-trained athletes. METHODS Six aerobically trained male athletes and six healthy male individuals with similar ages and normal rest electrocardiograms were studied. Maximal oxygen uptake (O(2)max) was measured by cardiopulmonary testing. The sinus cycle length (SCL), AV conduction intervals, sinus node recovery time (SNRT), Wenckebach cycle (WC) and anterograde effective refractory period (ERP) of the AV node were evaluated by invasive electrophysiologic studies at baseline, after intravenous atropine (0.04 mg/kg) and after addition of intravenous propranolol (0.2 mg/kg). RESULTS Athletes had a significantly higher O(2)max as compared with untrained individuals. The SCL was longer in athletes at baseline, after atropine and after the addition of propranolol for double-autonomic blockade. The mean maximal SNRT/SCL was longer in athletes after atropine and after propranolol. The WC and anterograde ERP of the AV node were longer in athletes at baseline, after atropine and after propranolol. CONCLUSIONS Under double-pharmacologic blockade, we demonstrated that sinus automaticity and AV node conduction changes of endurance athletes are related to intrinsic physiology and not to autonomic influences.

Pre-and Postoperative Cardiopulmonary Rehabilitation in Hospitalized Patients Undergoing Coronary Artery Bypass Surgery : A Randomized Controlled Trial

Herdy AH, Marcchi PLB, Vila A, Tavares C, Collaço J, Niebauer J, Ribeiro JP: Pre- and postoperative cardiopulmonary rehabilitation in hospitalized patients undergoing coronary artery bypass surgery: a randomized controlled trial. Am J Phys Med Rehabil 2008;87:714–719. Objective:Patients who have to wait in the hospital for coronary artery bypass surgery (CABG) are exposed to the potential risks of immobilization. This clinical trial was conducted to evaluate the effects of an in-hospital cardiopulmonary rehabilitation program performed before and after CABG on postoperative outcomes. Design:Fifty-six patients who had to wait for CABG in-hospital were randomly assigned to a cardiopulmonary rehabilitation (Rehab; n = 29) or to usual care (Control; n = 27). In the Rehab group, intervention lasted for at least 5 days preoperatively until discharge. The program consisted of phase I cardiac rehabilitation associated with respiratory physical therapy. Outcomes were blindly evaluated. Results:By hospital discharge, Rehab patients presented a shorter time to endotracheal extubation (1054 ± 376 vs. 1340 ± 666 min, P = 0.05), a reduction in the incidence of pleural effusion (relative risk [RR] = 0.2; 95% confidence interval [CI]: 0.5–0.8), atelectasis (RR = 0.15; 95% CI: 0.03–0.8), pneumonia (0 vs. 7 cases, [P = 0.004]), and atrial fibrillation or flutter (RR = 0.2; 95% CI: 0.05–0.8). Length of in-hospital stay after surgery was also reduced in the Rehab group (5.9 ± 1.1 vs. 10.3 ± 4.6 days [P < 0.001]). Conclusion:Pre- and postoperative cardiopulmonary rehabilitation in patients who await CABG in the hospital is superior to standard care and leads to a reduced rate of postoperative complications and shorter hospital stay.

Addition of inspiratory muscle training to aerobic training improves cardiorespiratory responses to exercise in patients with heart failure and inspiratory muscle weakness

BACKGROUND This small clinical trial tested the hypothesis that the addition of inspiratory muscle training (IMT) to aerobic exercise training (AE) results in further improvement in cardiorespiratory responses to exercise than those obtained with AE in patients with chronic heart failure (CHF) and inspiratory muscle weakness (IMW). METHODS Twenty-four patients with CHF and IMW (maximal inspiratory pressure <70% of predicted) were randomly assigned to a 12-week program of AE plus IMT (AE + IMT, n = 12) or to AE alone (AE, n = 12). Before and after intervention, the following measures were obtained: maximal inspiratory muscle pressure (PI(max)), peak oxygen uptake (Vo(2)peak), peak circulatory power, oxygen uptake efficiency slope, ventilatory efficiency, ventilatory oscillation, oxygen uptake kinetics during recovery (T(1/2)Vo(2)), 6-minute walk test distance, and quality of life scores. RESULTS Compared to AE, AE + IMT resulted in additional significant improvement in PI(max) (110% vs 72%), Vo(2)peak (40% vs 21%), circulatory power, oxygen uptake efficiency slope, ventilatory efficiency, ventilatory oscillation, and T(1/2)Vo(2). Six-minute walk distance and quality of life scores improved similarly in the 2 groups. CONCLUSION This randomized trial demonstrates that the addition of IMT to AE results in improvement in cardiorespiratory responses to exercise in selected patients with CHF and IMW. The clinical significance of these findings should be addressed by larger randomized trials.

Aerobic exercise and submaximal functional capacity in overweight pregnant women: a randomized trial.

Objective: To evaluate the effects of aerobic training on submaximal cardiorespiratory capacity in overweight pregnant women. Methods: We conducted a randomized clinical trial in a referral center prenatal clinic during the period 2000–2002. Of 132 overweight (body mass index 26–31 kg/m2) but otherwise healthy volunteers, at 20 years of age or older, with gestational age of 20 weeks or less, and without diabetes or hypertension, 92 consented to participate and were randomized. Intervention consisted of 3 one-hour aerobic exercise sessions per week; the control group received weekly relaxation and focus group discussions. The main outcome measure was submaximal exercise capacity evaluated by oxygen uptake at the anaerobic (first ventilatory) threshold during cardiopulmonary treadmill testing 12 weeks after randomization. Results: Oxygen uptake at the anaerobic threshold increased 18% (15.9 ± 2.6 to 18.1 ± 3.1 mL · min−1 · kg−1) in the exercise group but decreased 16% (16.9 ± 3.0 to 15.8 ± 2.6 mL · min−1 · kg−1) among the control group. Oxygen consumption at the anaerobic threshold, adjusted through analysis of covariance for baseline oxygen uptake, was 2.68 (95% confidence interval 1.23 to 4.12) mL · min−1 · kg−1 greater in the exercise group. Women in the exercise group were approximately 5 times more likely than those in the control group to have regular or good cardiorespiratory capacity (12/38 versus 2/38; relative risk 5.2, 95% confidence interval 1.2 to 22.0, number needed to treat 5). Conclusion: Aerobic training in overweight pregnant women substantially increases submaximal exercise capacity, overcoming the otherwise negative effects of pregnancy in this regard. Additional studies are required to evaluate its effect on major clinical outcomes. LEVEL OF EVIDENCE: I

Metabolic and ventilatory responses to steady state exercise relative to lactate thresholds

SummaryThe metabolic and ventilatory responses to steady state submaximal exercise on the cycle ergometer were compared at four intensities in 8 healthy subjects. The trials were performed so that, after a 10 min adaptation period, power output was adjusted to maintain steady state

Dietary intervention prevents dyslipidemia associated with highly active antiretroviral therapy in human immunodeficiency virus type 1-infected individuals: a randomized trial.

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Metabolic predictors of middle-distance swimming performance.

for 30 min at values equivalent to: (1) the aerobic threshold (AeT); (2) between the aerobic and the anaerobic threshold (AeTAnT); (3) the anaerobic threshold (AnT); and (4) between the anaerobic threshold and