Pulmonary Artery Pressure and Right Ventricular Function during Exercise

pp 238-243

Abstract

Background
The physiological behavior of pulmonary artery pressure during exercise has not been precisely established yet. There is lack of agreement in the published literature about the abnormal values of pulmonary artery pressure (PAP) during exercise in the absence of mitral valve disease. Indeed, the last guidelines do not recommend using mean pulmonary artery pressure value ≥ 30 mmHg during exercise to define pulmonary hypertension. There is scarce information about the hemodynamic and functional response of the right ventricle (RV) during exercise and if it is useful to discriminate between a physiological or abnormal response of the pulmonary artery pressure.

Objective
To determine the behavior of PAP during exercise and to compare the echocardiographic parameters of systolic and diastolic RV function in relation to PAP levels.

Material and Methods
A total of 94 patients without significant heart disease were included. Systolic pulmonary artery pressure (SPAP) at rest and maximum exercise during exercise stress echocardiography was adequately measured in all patients. The population was divided into two groups according to the value of pulmonary artery pressure during exercise: A) PAP <50 mmHg (56) B) PAP ≥50 mmHg (38). We also compared the variables of RV systolic function (S-wave measured by tissue Doppler imaging) and diastolic function (using pulsed Doppler echocardiography in the inlet tract and tissue Doppler echocardiography in the lateral wall).

Results
During exercise, 40% of the analyzed population reached a PAP ≥50 mm mmHg. This value was associated with greater age, female gender and elevated values of SPAP at rest. The parameters of RV diastolic function did not present significant differences. The group with PAP ≥ 50 mmHg during exercise presented a less increase in the S-wave measured by tissue Doppler imaging as an expression of a compensatory reduced RV contractile performance.

Conclusions
A high percentage of the population developed PAP ≥50 mmHg during exercise. The variables of RV diastolic function did not show significant differences and the group with PAP ≥50 mmHg during exercise presented compensatory reduced RV contractile performance as an expression of subclinical dysfunction.