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Titolo:
Responses to constant work rate bicycle ergometry exercise in primary pulmonary hypertension: The effect of inhaled nitric oxide
Autore:
Riley, MS; Porszasz, J; Engelen, MPKJ; Shapiro, SM; Brundage, BH; Wasserman, K;
Indirizzi:
Univ Calif Los Angeles, Harbor Med Ctr, Div Resp & Crit Care Physiol & Med, Torrance, CA 90509 USA Univ Calif Los Angeles Torrance CA USA 90509 Med, Torrance, CA 90509 USA Univ Calif Los Angeles, Harbor Med Ctr, St Johns Cardiovasc Res Ctr, Div Cardiol, Torrance, CA 90509 USA Univ Calif Los Angeles Torrance CA USA 90509 diol, Torrance, CA 90509 USA
Titolo Testata:
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
fascicolo: 2, volume: 36, anno: 2000,
pagine: 547 - 556
SICI:
0735-1097(200008)36:2<547:RTCWRB>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHRONIC HEART-FAILURE; CHRONIC CARDIAC-FAILURE; OXYGEN-UPTAKE KINETICS; ALVEOLAR GAS-EXCHANGE; SKELETAL-MUSCLE; VASCULAR-DISEASE; METABOLISM; FLOW;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
35
Recensione:
Indirizzi per estratti:
Indirizzo: Riley, MS Belfast City Hosp, 93 Lisburn Rd, Belfast BT9 7AB, Antrim, NorthIreland Belfast City Hosp 93 Lisburn Rd Belfast Antrim North Ireland BT9 7AB
Citazione:
M.S. Riley et al., "Responses to constant work rate bicycle ergometry exercise in primary pulmonary hypertension: The effect of inhaled nitric oxide", J AM COL C, 36(2), 2000, pp. 547-556

Abstract

OBJECTIVES The purpose of this study was to investigate the responses oipatients with primary pulmonary hypertension (PPH) to constant work rate exercise and to examine the effect of nitric oxide (NO) inhalation. BACKGROUND Maximal exercise tolerance is reduced in PPH, but gas exchange responses to constant work rate exercise have not been defined. We hypothesized that increased pulmonary vascular resistance in PPH would reduce the rate of rise of minute oxygen consumption in response to a given work rate. Because NO may lower pulmonary Vascular pressures in PPH, we also postulated that inhaled NO might ameliorate gas exchange abnormalities. METHODS Nine PPH patients and nine matched normal subjects performed 6-minduration constant work rate cycle ergometry exercise (33.9 +/- 13.4 W). Patients performed two experiments: breathing air and breathing air with NO (20 ppm). Preexercise right ventricular systolic pressure was assessed by Doppler echocardiography. Normal subjects performed the air experiment only. Gas exchange and heart rate responses were characterized by fitting monoexponential curves. RESULTS In PPH patients, resting right ventricular systolic pressure fell after NO inhalation (from 83.8 +/- 16.9 to 73.9 +/- 21.6 mm Hg, p < 0.01, analysis of variance with Tukey correction), but not after breathing air alone (from 88.0 +/- 20.8 to 86.7 +/- 20.6 mm Hg, p = NS). Nitric oxide did not affect any of the gas exchange responses. Minute oxygen consumption was similar by the end of exercise in patients and normals, but increased more slowly in patients (mean response time [MRT]: air, 63.17 +/- 14.99 s; NO, 61.60 +/- 15.45 s) than normals (MRT, 32.73 +/- 14.79, p < 0.01, analysis of variance, Tukey test). Minute oxygen consumption kinetics during recovery were slower in patients (MRT air: 82.50 +/- 29.94 s; NO, 73.36 +/- 15.87 s) than in normals (MRT, 34.59 +/- 7.11 s, p < 0.01). Heart rate kinetics during exercise and recovery were significantly slower in patients than in normals. CONCLUSIONS The cardiac output response is impaired in PPH. Nitric oxide lowered pulmonary artery pressure at rest, but failed to improve exercise gas exchange responses. (C) 2000 by the American College of Cardiology.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 06/07/20 alle ore 08:01:14