Effects of unsupported arm training on arm exercise-related perception in COPD patients.

We hypothesized that arm training might affect unsupported arm exercise-related perception by decreasing motor output to arm/torso muscles in patients with chronic obstructive pulmonary disease (COPD). Eleven patients were studied at 80% of peak incremental arm exercise, before and after unsupported arm training. Training increased endurance time, decreased respiratory effort and much more arm effort (by Borg scale) without affecting chest wall dynamic hyperinflation or configuration. Ventilatory response to carbon dioxide output was the same before and after training so that at isotime the reduction in ventilation correlated strongly with a simultaneous reduction in metabolic output. These changes reflect a reduced ventilatory drive. We conclude that: (i) a reduced level of ventilation, relative to a decrease in central motor output, is the contribution of arm training to symptom alleviation during unsupported arm exercise in COPD patients, and (ii) arm training improved patients' exercise-related perception without affecting chest wall operational volumes or configuration.

Effects of the Nuss procedure on chest wall kinematics in adolescents with pectus excavatum.

No data are available on the effects of the Nuss procedure on volumes of chest wall compartments (the upper rib cage, lower rib cage and abdomen) in adolescents with pectus excavatum. We used optoelectronic plethysmography to provide a quantitative description of chest wall kinematics before and 6 months after the Nuss procedure at rest and during maximal voluntary ventilation in 13 subjects with pectus excavatum. An average 11% increase in chest wall volume was accommodated within the upper rib cage (p=0.0001) and to a lesser extent within the abdomen and lower rib cage. Tidal volumes did not significantly change during the study. The repair effect on chest wall kinematics did not correlate with the Haller index of deformity at baseline. Six months of the Nuss procedure do increase chest wall volume without affecting chest wall displacement and rib cage configuration.

Chest wall kinematics in young subjects with Pectus excavatum.

Quantifying chest wall kinematics and rib cage distortion during ventilatory effort in subjects with Pectus excavatum (PE) has yet to be defined. We studied 24 patients: 19 during maximal voluntary ventilation (MVV) and 5 during MVV and cycling exercise (CE). By optoelectronic plethysmography (OEP) we assessed operational volumes in upper rib cage, lower rib cage and abdomen. Ten age-matched healthy subjects served as controls. Patients exhibited mild restrictive lung defect. During MVV end-inspiratory and end-expiratory volumes of chest wall compartments increased progressively in controls, whereas most patients avoided dynamic hyperinflation by setting operational volumes at values lower than controls. Mild rib cage distortion was found in three patients at rest, but neither in patients nor in controls did MVV or CE consistently affect coordinated motion of the rib cage. Rib cage displacement was not correlated with a CT-scan severity index. Conclusions, mild rib cage distortion rarely occurs in PE patients with mild restrictive defect. OEP contributes to clinical evaluation of PE patients.

Mechanisms of dyspnoea and its language in patients with asthma.

This study hypothesises that regardless of the global score of dyspnoea intensity, different descriptors may be selected by asthmatic patients during short cardiopulmonary exercise test (sCPET) and methacholine (Mch) inhalation. It also examines whether different qualitative dyspnoea sensations can help explain the underlying mechanisms of the symptom. Minute ventilation (V'E), tidal volume (VT) and inspiratory capacity (IC) were measured in 22 stable asthmatic patients, and the sensation of dyspnoea during Mch inhalation and sCPET was quantitatively (Borg scale) and qualitatively (descriptors) assessed. The work rate and oxygen uptake (V'O2) were also measured during sCPET. Airway obstruction and hyperinflation, as measured by IC reduction, were the best correlates for dyspnoea with Mch. During sCPET, changes in WR, V'O2, V'E and VT significantly correlated with Borg score, with V'E being the best predictor of dyspnoea; IC decreased in eight patients. Furthermore, chest tightness (68%) was the highest reported descriptor during Mch inhalation, whereas work/effort (72%) was the highest during sCPET. In conclusion, obstruction/hyperinflation and work rate are highly reliable predictors of Borg rating of dyspnoea during methacholine inhalation and short cardiopulmonary exercise testing, respectively. Regardless of the global score of intensity dyspnoea, different descriptors may be selected by patients during short cardiopulmonary exercise testing and methacholine inhalation. Various qualities of dyspnoea result from different pathophysiological abnormalities.

Amlodipine in ischaemic left ventricular dysfunction with mild to moderate heart failure.

OBJECTIVE: In this study, we evaluated the effectiveness of amlodipine in patients with severe ischaemic left ventricular dysfunction (LVD) and mild to moderate heart failure, but not current angina, assessing the effects of the drug on symptoms, left ventricular function and exercise capacity. PATIENTS AND METHODS: We studied 36 patients with ischaemic LVD (radionuclide ejection fraction <40%, left ventricular end-diastolic dimension >60mm) and mild to moderate heart failure (NYHA class II or III) without angina treated with ACE inhibitors (36 of 36), digitalis (34 of 36) and diuretics (30 of 36). Among the 36 recruited patients, 33 fulfilled the study protocol, including 2 weeks of run-in (standard therapy), 8 weeks of treatment (standard therapy + amlodipine 5mg once daily) and 2 weeks of washout (standard therapy). Symptoms graded on a 10-point scale (heart failure score; a higher score representing improvement in symptoms), radionuclide left ventricular ejection fraction (rLVEF), echocardiographic left ventricular end-diastolic dimension (LVEDD), peak aerobic capacity (VO(2max)), exercise time (ET) and total work load (TWL) were measured after run-in, treatment and washout periods. All patients underwent coronary angiography and (201)Thallium (Tl) myocardial scintigraphy. RESULTS: With respect to baseline and washout, after amlodipine treatment the HF score improved (6.6 +/- 1.3 after amlodipine vs 5.9 +/- 1 at baseline and 5.9 +/- 1.1 at washout; p < 0.02), rLVEF increased (33.12 +/- 9.02% vs 29.74 +/- 7.72% and 30.02 +/- 7.39%, respectively; p < 0.001), and VO(2max) (14.35 +/- 4.05 ml/kg/min vs 12.68 +/- 3.21 ml/kg/min and 12.62 +/- 3.59 ml/kg/min, respectively; p < 0.003), ET (440 +/- 169 sec vs 395 +/- 158 sec and 402 +/- 162 sec, respectively; p < 0.02) and TWL (2183.2 +/- 439 kpm vs 1615.5 +/- 427 kpm and 1708.8 +/- 437 kpm, respectively; p < 0.01) were also increased. The increase in VO(2max) was related to systolic blood pressure at rest and at the peak of exercise, and to the presence of viable and/or ischaemic myocardium at (201)Tl myocardial scintigraphy. CONCLUSION: Amlodipine, in addition to standard therapy (including in all cases an ACE inhibitor), reduced symptoms and improved exercise capacity and ventricular function in patients with mild to moderate heart failure due to myocardial ischaemia. Thus, amlodipine is useful in patients with ischaemic LVD and heart failure without angina. The improvement in exercise capacity was greater in patients with scintigraphic evidence of viable and/or ischaemic myocardium and higher blood pressure. However, our study presented some limitations (i.e. an open study with few patients), and only generated a hypothesis that could lead to a wider, multicentre, cooperative trial. Treatment of patients with chronic ischaemic left ventricular dysfunction (LVD) with heart failure symptoms but without angina is a difficult clinical problem. Despite the fact that surgical myocardial revascularisation may improve survival, most patients are not good candidates for surgery. Thus, 'polypharmacy' remains the principal option for these individuals. ACE inhibitors have become a cornerstone in the treatment of all forms of LVD, and have been demonstrated to improve functional class and survival. Nitrates, digitalis and diuretics are also commonly used for their effects on symptoms. Despite there being no evidence that calcium antagonists are useful for the treatment of heart failure or impaired ventricular function after myocardial infarction, these drugs are still prescribed to many patients with ischaemic LVD. However, it is possible that the concomitant administration of ACE inhibitors could reduce the reflex neurohumoral activity caused by some calcium antagonists, while preserving some of the beneficial properties of these agents. Among other calcium antagonists, amlodipine does not adversely affect the clinical status of patients. Some studies have shown that it reduces symptoms, improves exercise tolerance and does not result in neurohormonal stimulation. Moreover, amlodipine appears to have a mortality benefit in patients with dilated cardiomyopathy but not in patients with underlying coronary disease where it appears to have a 'neutral' effect. Thus, it is not clear whether amlodipine is useful in patients with ischaemic LVD, particularly in patients with silent coronary artery disease. In this study, we evaluated the effectiveness of amlodipine, in addition to standard therapy, in patients with ischaemic LVD and mild to moderate heart failure, assessing the effects of the drug on symptoms, LV function and exercise capacity.