Exercise-Induced Pulmonary Hypertension: A Valid Entity or Another Factor of Confusion?

Abstract

Exercise-induced pulmonary hypertension EIPH has been defined as an increase in mean pulmonary arterial pressure (mPAP) during exercise in otherwise normal values at rest. EIPH reflects heart and/or lung dysfunction and may precede the development of manifest pulmonary hypertension (PH) in a proportion of patients. It is also associated with decreased life expectancy in patients with heart failure with reduced ejection fraction (HFrEF) or left ventricle (LV) valvular diseases. Diastolic dysfunction exacerbated during exercise relates to increased LV filling pressure and left atrial pressure (LAP). In this context backward, transmitted pressure alone or accompanied with backward blood flow promotes EIPH. The gold standard of EIPH assessment remains the right heart catheterization during exercise, which is an accurate but invasive method. Alternatively, non-invasive diagnostic modalities include exercise stress echocardiography (ESE) and cardiopulmonary exercise testing (CPET). Both diagnostic tests are performed under gradually increasing physical stress using treadmill and ergo-cycling protocols. Escalating workload during the exercise is analogous to the physiological response to real exercise. The results of the latter techniques show good correlation with invasive measurements, but they suffer from lack of validation and cut-off value determination. Although it is not officially recommended, there are accumulated data supporting the importance of EIPH diagnosis in the assessment of other mild/subclinical or probably fatal diseases in patients with latent PH or heart failure or LV valvular disease, respectively. Nevertheless, larger, prospective studies are required to ensure its role in clinical practice.

Pulmonary Hypertension in Left Ventricular Valvular Diseases: A Comprehensive Review on Pathophysiology and Prognostic Value

“…An elevation of mPAP > 20 mmHg measured in the resting RHC sets the diagnosis of PH [ 4 ]. EIPH is considered by many scientists as a precursor stage of PH and it is defined as a rise in mPAP > 30 mmHg and PVR > 3 WU during exercise [ 11 , 12 ]. The most frequently used modalities for PH diagnosis include TTE, RHC, and in a few specialized centers, CPET [ 4 , 15 ].…”

“…Nowadays, a growing body of evidence has remarkably supported the re-introduction of EIPH in the diagnostic algorithm of PH. EIPH is considered by many scientists as a precursor stage of PH, which means that earlier initiation of treatment may be related to better prognosis [ 12 ]. Exercise stress echocardiography (ESE) has been proposed for the assessment of PASP during exercise testing (treadmill or ergocycle).…”

“…EIPH in LV valvular diseases reflects exercise-triggered hemodynamic changes and its presence can be a premature indicator of the severity of LV valvulopathy [ 12 ]. EIPH seems to derive from increased LVFP and LAP upon exertion [ 12 ].…”

“…EIPH in LV valvular diseases reflects exercise-triggered hemodynamic changes and its presence can be a premature indicator of the severity of LV valvulopathy [ 12 ]. EIPH seems to derive from increased LVFP and LAP upon exertion [ 12 ]. A backward transmission of elevated LVFP and LAP to the pulmonary circulation explains the increase in PASP during exercise [ 28 ].…”

“…Besides this, the backward blood flow from the LA to pulmonary circulation in patients with MR is augmented during exercise due to the exaggerated movement of mitral valve annulus. Thereby, at least moderate MR contributes to EIPH leading to pulmonary congestion [ 12 ].…”