Exercise-Induced Pulmonary Hypertension: What Is New?

Figures

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  Figure 1. During exercise, cardiac output increases substantially. In healthy individuals, the pulmonary circulation accommodates this increased flow through vascular recruitment and distension, resulting in only a modest rise in pulmonary artery pressure. Consequently, the mPAP/CO slope remains relatively low (<3 mmHg/L/min). Patients with pulmonary vascular disease, reduced pulmonary vascular compliance, or abnormal left-heart filling pressures exhibit a disproportionate increase in pulmonary artery pressure relative to flow, resulting in an elevated mPAP/CO slope (>3 mmHg/L/min).

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  Figure 2. During exercise, cardiac output increases substantially to meet metabolic demands. In healthy individuals, the left ventricle and left atrium accommodate this increased blood flow with only a modest rise in filling pressures. Consequently, PAWP increases only slightly relative to the increase in cardiac output. When the left ventricle is stiff or has impaired diastolic reserve, as occurs in heart failure with preserved ejection fraction (HFpEF), filling pressures rise disproportionately.

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  Figure 3. Algorithm for interpreting exercise hemodynamics. The algorithm is structured around the mPAP/CO slope and PAWP/CO slope, consistent with the 2022 ESC/ERS guidelines. Step 1: Perform exercise RHC. Step 2: Is the mPAP/CO slope > 3 mmHg·L−1·min−1? If No (≤3 mmHg·L−1·min−1): normal pulmonary vascular response to exercise and EIPH not present. If Yes (>3 mmHg·L−1·min−1): Exercise PH is present; proceed to assessment of PAWP/CO slope. Step 3: Evaluate PAWP/CO slope: If PAWP/CO slope ≤ 2 mmHg·L−1·min−1 it suggests a pre-capillary pattern such as early pulmonary vascular disease. If PAWP/CO slope > 2 mmHg·L−1·min−1 it suggests a post-capillary pattern such as HFpEF, left atrial dysfunction, or valvular heart disease.