Exercise echocardiography in pulmonary hypertension

Abstract

Doppler echocardiography plays a key role in the detection of pulmonary hypertension, the leading cause of right ventricular (RV) dysfunction. Reliable estimates of pulmonary pressures and cardiac output (CO) can be obtained at rest, allowing for screening and diagnosis of pulmonary arterial hypertension (PAH), a group of diseases characterized by increased pulmonary vascular resistance progressing to RV failure and death. However, these resting indices poorly correlate with symptoms, exercise response, and have modest prognosis significance. This is partially explained by the limited information obtained from pressure measurements on the severity of RV dysfunction, the major determinant of exercise response and prognosis in PAH. Exercise echocardiography (Ex-echo) may provide significant additional information in the understanding and the management of the disease. In asymptomatic subjects at risk of PAH, it may uncover abnormal increases in pulmonary pressure and CO during exercise, which may be reflecting early stage disease. In addition, the technique may be useful to better understand the physiology of exercise limitation, a typical manifestation of PAH. Several limitations need to be considered when using Ex-echo in the management of PAH, including the absence of a clear consistent definition of normal values, an unknown threshold for abnormal response and the limited quantitative information on RV function provided by simple pressure analysis. Newer echocardiographic techniques such as Tissue-Doppler imaging, and strain and strain rate analysis may provide further insights in the understanding of RV dysfunction. However, technical limitations currently prevent their application to Ex-echo. Clinical studies are underway to better explore the potential role of Ex-echo in the management of PAH.

Detection of Exercise‐Induced Pulmonary Arterial Hypertension by Cardiopulmonary Exercise Testing

“…Similarly, PAP measured only at rest fails to detect a significant percentage of patients with exercise‐induced PAH (EIPAH). EIPAH is a poorly understood entity 4–12. Some believe that EIPAH is an early and more treatable phase that precedes resting PAH, whereas others suggest that it may be a stable variant of the disease 5,6,13–15.…”

Non-invasive measurement of the response of right ventricular pressure to exercise, and its relation to aerobic capacity

“…The upper normal limit of the response in normally trained individuals seems to be higher than commonly assumed. 9 The number of examined individuals in our study is high compared to other studies with a comparable focus that investigated mixed groups of normally trained subjects and athletes made up of 20 3 to 40 individuals. 1 Our study group has a sufficient distribution of age and gender to allow conclusions to be drawn concerning adolescents and young adults.…”

“…2 International guidelines define the normal upper limits of pulmonary arterial systolic pressure at rest, but there is a general uncertainty about the upper limits for both pulmonary and right ventricular systolic pressures during exercise. 9,10 A value of 40 millimetres of mercury, or in some papers 45 millimetres of mercury, is proposed as the upper normal limit during exercise. 2,3,11 Recent studies, however, have shown an abnormal response of right ventricular systolic pressure above 45 millimetres of mercury during exercise in healthy, normal individuals, 12 and also in healthy carriers of mutations in the bone morphogenetic protein receptor type 2 gene.…”

Exercise‐Induced Pulmonary Hypertension in Scleroderma Patients: A Common Finding but with Elusive Pathophysiology

“…23 The exercise echocardiogram is a reliable noninvasive technique to detect latent or exerciseinduced PH not evident by standard resting Doppler echocardiography. 24 In normal subjects, exercise PASP should be <43 mmHg 12 ; however, in patients aged 50 years or older, 47% surpassed a pulmonary artery mean pressure (PAMP) of 30 mmHg during maximal exercise. 25 Due to very different peak exercise PAP cutoffs, it is difficult to calculate the real prevalence of PH in SSc patients and its clinical relevancy.…”