Chronotropic incompetence (CI; failure to reach the targeted heart rate (HR) on exercise) and a delayed HR recovery (HRR; 12 beats decline within the first minute after cessation) reflect autonomic dysfunction (AD) and predict adverse cardiac prognosis. As chronic obstructive pulmonary disease (COPD) is known to be associated with AD, we hypothesized that these patients may manifest these responses on exercise. The prevalence and predictors of these responses in COPD and their association with its severity have not been evaluated. Normoxemic, stable male patients with COPD (n ¼ 39) and 11 healthy controls underwent lung function testing and incremental leg ergometry. HR responses were monitored during exercise and recovery to compute the HRR and CI. Of all the patients, 33 (84.6%) had at least one of the two exercise responses as abnormal, with the majority (23, 58.9%) having both an abnormal HRR and CI. The frequency of abnormal responses increased with increasing Global Initiative for Chronic Obstructive Lung Disease stage and body mass index, airflow obstruction, dyspnoea and exercise capacity index. After adjusting for smoking history and post-bronchodilator forced expiratory volume in 1 second, only a reduced diffusion capacity for carbon monoxide predicted abnormal HRR, though weakly. We concluded that abnormal HRR and CI are common in patients with COPD. These responses are observed with increasing frequency as the severity of disease increases.

SettingOur study was conducted at a tertiary care center for respiratory illnesses (Viswanathan Chest Hospital, Vallabhbhai Patel Chest Institute (VPCI), University of Delhi, Delhi, India). Patients were enrolled in the study from the outpatient clinic.ObjectiveTo assess the effects of pulmonary rehabilitation (PR) in patients with chronic lung impairment from previously treated tuberculosis (CLIPTB), on exercise capacity (six-minute walk distance), pulmonary function tests, quality of life and markers of systemic inflammation.DesignProspective cohort study including 29 patients who had finished anti-tubercular therapy and currently had symptoms of dyspnea with or without cough secondary to CLIPTB.ResultSignificant improvement in six-minute walk distance (488 meters at baseline vs 526 meters post PR intervention, p-value 0.033) and chronic respiratory questionnaire score (17.21 at baseline vs 18.96 post PR intervention, p-value 0.025) with pulmonary rehabilitation was noted. Pulmonary function tests, inflammatory markers and mid-thigh muscle mass trended towards improvement with pulmonary rehabilitation but were not statistically significant.ConclusionOur study shows that pulmonary rehabilitation is an effective intervention in post-tuberculosis patients and should be recommended.

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Similar gains in functional exercise capacity were achieved on completion of initial and repeat PR programs. The large decrement in the 6MWD between PR programs spaced 25 months apart suggests that a shorter time period is needed between programs.