Heart & Lung xxx (2014) 1e5
Contents lists available at ScienceDirect
Heart & Lung journal homepage: www.heartandlung.org
Differences in pulmonary function and exercise capacity in patients with idiopathic dilated cardiomyopathy and idiopathic pulmonary arterial hypertension Wei-Hua Liu, MD, Qin Luo, MD, PhD, Zhi-Hong Liu, MD, PhD *, Qing Zhao, MD, PhD, Qun-Ying Xi, MD, Zhi-Hui Zhao, MD, PhD State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 2 January 2014 Received in revised form 25 March 2014 Accepted 1 April 2014 Available online xxx
Objectives: We observed the pulmonary function and exercise capacity of idiopathic dilated cardiomyopathy (IDCM) and idiopathic pulmonary arterial hypertension (IPAH) patients using cardiopulmonary exercise testing (CPX). We evaluated and compared the two groups. Background: Pulmonary abnormalities and decreased exercise capacity are common in IDCM and IPAH. Little is known about the differences in these two syndromes. Methods: Sixty-three patients were involved the study, 23 with IDCM and 40 with IPAH. All patients underwent pulmonary function testing at rest and CPX. Results: Patients with IPAH had a higher peak respiratory frequency (32.40 7.88 vs 29.60 6.50 b/min), peak dead space volume/tidal volume (29.33 4.55 vs 26.30 3.31%), peak end-tidal partial pressure of O2 (125.18 5.88 vs 115.17 6.06 mm Hg), peak minute ventilation/CO2 production (50.14 13.26 vs 33.50 6.80 L/min/L/min), and a lower peak oxygen uptake (1262.70 333.34 vs 742.76 194.72 ml/min), peak minute ventilation (38.20 13.07 vs 45.33 12.31 L), peak oxygen uptake/heart rate (5.11 1.47 vs 9.43 2.79 ml/b) and peak end-tidal partial pressure of CO2 (23.73 5.39 vs 35.30 5.45 mm Hg) during exercise. Conclusions: Compared to IDCM, patients with IPAH had worse pulmonary function and exercise capacity resulting from severe ventilation/perfusion mismatching and gas exchange abnormalities. Ó 2014 Elsevier Inc. All rights reserved.
Keywords: Cardiopulmonary exercise testing Pulmonary function Right heart failure Pulmonary arterial hypertension Dilated cardiomyopathy
Introduction Chronic heart failure (CHF) and chronic right heart failure caused by pulmonary arterial hypertension (PAH) are two complex disease states. Dyspnea and decreased exercise capacity are common in both. Heart, lung, kidney and the musculature are involved Abbreviations: CHF, chronic heart failure; PAH, pulmonary arterial hypertension; V/Q, ventilation/perfusion; CPX, cardiopulmonary exercise testing; IDCM, idiopathic dilated cardiomyopathy; IPAH, idiopathic pulmonary arterial hypertension; NYHA, New York Heart Association; FEV1, forced expiratory volume at 1 s; FVC, forced vital capacity; VD, dead space volume; VT, tidal volume; VE, minute ventilation; VCO2, CO2 production; EIS, exercise-induced right-to-left shunt; MVV, maximal voluntary ventilation; LVEF, left ventricular ejection fraction; LV, left ventricle; RV, right ventricle; mPAP, mean pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure; CI, cardiac index; BMI, body mass index; AT, Anaerobic threshold; PetO2, end-tidal partial pressure of O2; VO2, oxygen uptake; HR, heart rate; PetCO2, end-tidal partial pressure of CO2. * Corresponding author. Fuwai Hospital, No. 167 Beilishi Road, Beijing 100037, China. Tel.: þ86 01088398196; fax: þ86 01088396589. E-mail address: [email protected] (Z.-H. Liu). 0147-9563/$ e see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.hrtlng.2014.04.001
in both CHF and PAH. There are abnormalities in pulmonary function abnormalities at both rest and exercise in patients with CHF and chronic right heart failure caused by PAH.1e6 Pulmonary abnormalities in CHF are due to cardiac enlargement, interstitial edema, and fatigue of respiratory muscles. Ventilation/perfusion (V/Q) inequalities play a great role in pulmonary abnormalities caused by PAH. Little was known about the differences in pulmonary function and exercise capacity of CHF and chronic right heart failure patients. Cardiopulmonary exercise testing (CPX) is considered the “gold standard” for studying cardiovascular, pulmonary and metabolic adaptations to exercise in heart diseases. CPX had become an important assessment technique in the evaluation of pathophysiology and prognosis of patients with CHF and PAH.7 We hypothesized that pulmonary function and exercise capacity were different in CHF and chronic right heart failure patients. We observed successive patients with idiopathic dilated cardiomyopathy (IDCM) and idiopathic pulmonary arterial hypertension (IPAH), and measured pulmonary function and exercise capacity
2
W.-H. Liu et al. / Heart & Lung xxx (2014) 1e5
differences. This study may be helpful in understanding the pulmonary function and exercise capacity changes that are present in these patients and the differences in pulmonary abnormalities and exercise capacity in these two diseases. Methods Patients Sixty-three stable patients (23 patients with IDCM, 40 patients with IPAH) with New York Heart Association (NYHA) functional class II/III were referred by a single cardiologist from Fuwai Hospital between October 2010 and December 2012. IDCM was diagnosed according to the American Heart Association scientific statement on definitions and classification of cardiomyopathies.8 IPAH diagnosis was made according to the American College of Cardiology Foundation/American Heart Association document on PAH.9 Exclusion criteria were forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio
Contents lists available at ScienceDirect
Heart & Lung journal homepage: www.heartandlung.org
Differences in pulmonary function and exercise capacity in patients with idiopathic dilated cardiomyopathy and idiopathic pulmonary arterial hypertension Wei-Hua Liu, MD, Qin Luo, MD, PhD, Zhi-Hong Liu, MD, PhD *, Qing Zhao, MD, PhD, Qun-Ying Xi, MD, Zhi-Hui Zhao, MD, PhD State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 2 January 2014 Received in revised form 25 March 2014 Accepted 1 April 2014 Available online xxx
Objectives: We observed the pulmonary function and exercise capacity of idiopathic dilated cardiomyopathy (IDCM) and idiopathic pulmonary arterial hypertension (IPAH) patients using cardiopulmonary exercise testing (CPX). We evaluated and compared the two groups. Background: Pulmonary abnormalities and decreased exercise capacity are common in IDCM and IPAH. Little is known about the differences in these two syndromes. Methods: Sixty-three patients were involved the study, 23 with IDCM and 40 with IPAH. All patients underwent pulmonary function testing at rest and CPX. Results: Patients with IPAH had a higher peak respiratory frequency (32.40 7.88 vs 29.60 6.50 b/min), peak dead space volume/tidal volume (29.33 4.55 vs 26.30 3.31%), peak end-tidal partial pressure of O2 (125.18 5.88 vs 115.17 6.06 mm Hg), peak minute ventilation/CO2 production (50.14 13.26 vs 33.50 6.80 L/min/L/min), and a lower peak oxygen uptake (1262.70 333.34 vs 742.76 194.72 ml/min), peak minute ventilation (38.20 13.07 vs 45.33 12.31 L), peak oxygen uptake/heart rate (5.11 1.47 vs 9.43 2.79 ml/b) and peak end-tidal partial pressure of CO2 (23.73 5.39 vs 35.30 5.45 mm Hg) during exercise. Conclusions: Compared to IDCM, patients with IPAH had worse pulmonary function and exercise capacity resulting from severe ventilation/perfusion mismatching and gas exchange abnormalities. Ó 2014 Elsevier Inc. All rights reserved.
Keywords: Cardiopulmonary exercise testing Pulmonary function Right heart failure Pulmonary arterial hypertension Dilated cardiomyopathy
Introduction Chronic heart failure (CHF) and chronic right heart failure caused by pulmonary arterial hypertension (PAH) are two complex disease states. Dyspnea and decreased exercise capacity are common in both. Heart, lung, kidney and the musculature are involved Abbreviations: CHF, chronic heart failure; PAH, pulmonary arterial hypertension; V/Q, ventilation/perfusion; CPX, cardiopulmonary exercise testing; IDCM, idiopathic dilated cardiomyopathy; IPAH, idiopathic pulmonary arterial hypertension; NYHA, New York Heart Association; FEV1, forced expiratory volume at 1 s; FVC, forced vital capacity; VD, dead space volume; VT, tidal volume; VE, minute ventilation; VCO2, CO2 production; EIS, exercise-induced right-to-left shunt; MVV, maximal voluntary ventilation; LVEF, left ventricular ejection fraction; LV, left ventricle; RV, right ventricle; mPAP, mean pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure; CI, cardiac index; BMI, body mass index; AT, Anaerobic threshold; PetO2, end-tidal partial pressure of O2; VO2, oxygen uptake; HR, heart rate; PetCO2, end-tidal partial pressure of CO2. * Corresponding author. Fuwai Hospital, No. 167 Beilishi Road, Beijing 100037, China. Tel.: þ86 01088398196; fax: þ86 01088396589. E-mail address: [email protected] (Z.-H. Liu). 0147-9563/$ e see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.hrtlng.2014.04.001
in both CHF and PAH. There are abnormalities in pulmonary function abnormalities at both rest and exercise in patients with CHF and chronic right heart failure caused by PAH.1e6 Pulmonary abnormalities in CHF are due to cardiac enlargement, interstitial edema, and fatigue of respiratory muscles. Ventilation/perfusion (V/Q) inequalities play a great role in pulmonary abnormalities caused by PAH. Little was known about the differences in pulmonary function and exercise capacity of CHF and chronic right heart failure patients. Cardiopulmonary exercise testing (CPX) is considered the “gold standard” for studying cardiovascular, pulmonary and metabolic adaptations to exercise in heart diseases. CPX had become an important assessment technique in the evaluation of pathophysiology and prognosis of patients with CHF and PAH.7 We hypothesized that pulmonary function and exercise capacity were different in CHF and chronic right heart failure patients. We observed successive patients with idiopathic dilated cardiomyopathy (IDCM) and idiopathic pulmonary arterial hypertension (IPAH), and measured pulmonary function and exercise capacity
2
W.-H. Liu et al. / Heart & Lung xxx (2014) 1e5
differences. This study may be helpful in understanding the pulmonary function and exercise capacity changes that are present in these patients and the differences in pulmonary abnormalities and exercise capacity in these two diseases. Methods Patients Sixty-three stable patients (23 patients with IDCM, 40 patients with IPAH) with New York Heart Association (NYHA) functional class II/III were referred by a single cardiologist from Fuwai Hospital between October 2010 and December 2012. IDCM was diagnosed according to the American Heart Association scientific statement on definitions and classification of cardiomyopathies.8 IPAH diagnosis was made according to the American College of Cardiology Foundation/American Heart Association document on PAH.9 Exclusion criteria were forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio
