OBJECTIVE Left ventricle function directly impacts left atrial (LA) conduit function, and LA conduit strain is associated with exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF). Pulmonary capillary wedge pressure (PCWP) before and during exercise is the current gold standard for diagnosing HFpEF. Post-exercise ΔPCWP can lead to worse long-term outcomes. This study examined the correlation between LA strain and post-exercise ΔPCWP in patients with HFpEF. METHODS We enrolled 100 subjects, including 74 with HFpEF and 26 with non-cardiac dyspnea, from November 2017 to December 2020. Subjects underwent echocardiography, invasive cardiac catheterization, and expired gas analysis at rest and during exercise. Arterial blood pressure, right atrial pressure, pulmonary artery pressure, and PCWP were recorded during cardiac catheterization. Cardiac output, stroke volume, pulmonary vascular resistance, pulmonary artery compliance, systemic vascular resistance, and LV stroke work were calculated using standard formulas. RESULTS Exercise LA conduit strain significantly correlated with both post-exercise ΔPCWP (r =  - 0.707, p < 0.001) and exercise PCWP (r =  - 0.659; p < 0.001). Exercise LA conduit strain differentiated patients who did and did not meet the 2016 European Society of Cardiology HFpEF criteria with an area under the curve of 0.69 (95% confidence interval, 0.548-0.831) using a cutoff value of 14.25, with a sensitivity of 0.64 and a specificity of 0.68. CONCLUSIONS Exercise LA conduit strain significantly correlates with post-exercise ΔPCWP and has a comparable power to identify patients with HFpEF. Additional studies are warranted to confirm the ability of LA conduit strain to predict long-term outcomes among patients with HFpEF. CONCLUSIONS Exercise left atrial conduit strain was highly associated with the difference of post-exercise pulmonary capillary wedge pressure and may indicate increased mortality risk in patients with heart failure with preserved ejection fraction, and also has comparable diagnostic ability. CONCLUSIONS • Left atrial conduit strain is associated with exercise intolerance in patients with heart failure with preserved ejection fraction. • Left atrial conduit strain during exercise can identify patients with heart failure with preserved ejection fraction. • Exercise left atrial conduit strain significantly correlates with the difference of pulmonary capillary wedge pressure during and before exercise which might predict the long-term outcomes of heart failure with preserved ejection fraction patients.