Pulmonary artery pressure variation in patients with connective tissue disease: 24 hour ambulatory pulmonary artery pressure monitoring
- aPulmonary Vascular Unit, Department of Respiratory Medicine, bClinical Research Initiative, University of Glasgow, Department of Cardiology, cWest Glasgow Hospitals University NHS Trust, Western Infirmary, Glasgow G11 6NT, UK Centre for Rheumatic Diseases, Glasgow Royal Infirmary University NHS Trust, Royal Infirmary, Glasgow G4 0SF, UK
- Dr A J Peacock.
- Received 7 October 1997
- Revision requested 21 January 1998
- Revised 16 March 1998
- Accepted 26 May 1998
Abstract
BACKGROUND The specific contribution of secondary pulmonary hypertension to the morbidity and mortality of patients with underlying lung disease can be difficult to assess from single measurements of pulmonary artery pressure. We have studied patients with secondary pulmonary hypertension using an ambulatory system for measuring continuous pulmonary artery pressure (PAP). We chose to study patients with connective tissue disease because they represent a group at high risk of pulmonary vascular disease, but with little disturbance of lung function.
METHODS Six patients (five with progressive systemic sclerosis and one with systemic lupus erythematosis) were studied. They underwent preliminary cardiopulmonary investigations followed by Doppler echocardiography, right heart catheterisation, and ambulatory pulmonary artery pressure monitoring to measure changes in pressure over a 24 hour period including during a formal exercise test.
RESULTS All patients had pulmonary hypertension as measured by Doppler echocardiography with estimated pulmonary artery systolic pressures of 40–100 mm Hg. Pulmonary function testing revealed virtually normal spirometric values (mean FEV1 86.9% predicted) but marked reduction in CO gas transfer factor (Kco 57.8% predicted). Exercise responses were impaired with mean Vo 2max 50.6% predicted. Ambulatory PAP monitoring indicated significant changes in pressures with variation in posture and activity throughout 24 hours. Resting PAP did not predict the change in PAP seen on exercise.
CONCLUSION Conventional methods of assessment of the pulmonary circulation based on single measurements in the supine position may underestimate the stresses faced by the right side of the circulation. This ambulatory system allows monitoring of pulmonary haemodynamics continuously over 24 hours during normal activities of daily living. These measurements may increase our understanding of the contribution made by secondary pulmonary hypertension to the morbidity and mortality of the underlying lung disease.
- secondary pulmonary hypertension
- connective tissue disease
- Doppler echocardiography
- cardiac catheterisation
- micromanometer tipped pulmonary artery catheter
- ambulatory pulmonary pressure monitoring
- ambulatory pressure variations
- pulse pressure
