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Titolo:
Gas exchange responses to continuous incremental cycle ergometry exercise in primary pulmonary hypertension in humans
Autore:
Riley, MS; Porszasz, J; Engelen, MPKJ; Brundage, BH; Wasserman, K;
Indirizzi:
Belfast City Hosp, Belfast BT9 7AB, Antrim, North Ireland Belfast City Hosp Belfast Antrim North Ireland BT9 7AB rim, North Ireland Harbor UCLA Med Ctr, St Johns Cardiovasc Res Ctr, Div Resp & Crit Care Physiol & Med, Torrance, CA 90509 USA Harbor UCLA Med Ctr Torrance CA USA 90509 l & Med, Torrance, CA 90509 USA Harbor UCLA Med Ctr, St Johns Cardiovasc Res Ctr, Div Cardiol, Torrance, CA 90509 USA Harbor UCLA Med Ctr Torrance CA USA 90509 Cardiol, Torrance, CA 90509 USA AZM Longziekten, NL-6202 AZ Maastricht, Netherlands AZM Longziekten Maastricht Netherlands NL-6202 AZ aastricht, Netherlands
Titolo Testata:
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY
fascicolo: 1, volume: 83, anno: 2000,
pagine: 63 - 70
SICI:
1439-6319(200009)83:1<63:GERTCI>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHRONIC HEART-FAILURE; OXYGEN-UPTAKE KINETICS; CHRONIC CARDIAC-FAILURE; SKELETAL-MUSCLE; ANAEROBIC THRESHOLD; WORK RATE; LACTATE CONCENTRATION; VASCULAR-DISEASE; PERFORMANCE; VENTILATION;
Keywords:
incremental exercise; primary pulmonary hypertension; oxygen consumption-work rate relationship;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
42
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., "Gas exchange responses to continuous incremental cycle ergometry exercise in primary pulmonary hypertension in humans", EUR J A PHY, 83(1), 2000, pp. 63-70

Abstract

In patients suffering from primary pulmonary hypertension (PPH), a raised pulmonary vascular resistance may limit the ability to increase pulmonary blood flow as work rate increases. We hypothesised that oxygen uptake ((V)over dot O-2) may not rise appropriately with increasing work rate during incremental cardiopulmonary exercise tests. Nine PPH patients and nine normal subjects performed symptom-limited maximal continuous incremental cycle ergometry exercise. Mean peak (V)over dot O-2 [1.00 (SD 0.22) compared to 2.58(SD 0.64) l.min(-1)] and mean (V)over dot O-2 at lactic acidosis threshold[LAT, 0.73 (SD 0.17)compared to 1.46 (SD 0.21.l) ml.min(-1)] were much lower in patients than in normal subjects (both P < 0.01, two-way ANOVA with Tukey test). The mean rate of change of (V) over dot O-2 with increasing work rate above the LAT [5.9 (SD 2.1) compared to 9.4 (SD 1.3) ml.min(-1) W-1 P < 0.01)] was also much lower in patients than in normal subjects [apparent delta efficiency 60.3 (SD 38.8)% in patients compared to 31.0 (SD 4.9)% in normal subjects]. The patients displayed lower mean values of end-tidal partial pressure of carbon dioxide than the normal subjects at peak exercise[29.7 (SD 6.8) compared to 43.4 (SD 5.8) mmHg, P < 0.01] and mean oxyhaemoglobin saturation [89.1 (SD 4.1) compared to 93.6 (SD 1.8)%, P < 0.05]. Mean ventilatory equivalents for CO2 [49.3 (SD 11.4) compared to 35.0 (SD 7.3), P < 0.05] and O-2 [44.2 (SD 10.7) compared to 29.9 (SD 5.1), P < 0.05] were greater in patients than normal subjects. The sub-normal slopes for the (V)over dot O-2-work-rate relationship above the LAT indicated severe impairment of the circulatory response to exercise in patients with PPH. The ventilatory abnormalities in PPH suggested that the lung had become an inefficient gas exchange organ because of impaired perfusion of the ventilated lung.

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Documento generato il 08/07/20 alle ore 08:12:32