Isovolumic relaxation intraventricular pressure difference predicts elevated left ventricular end-diastolic pressure in patients with coronary artery disease

Current guideline for evaluating diastolic function requires multiple parameters to identify patients with elevated left ventricular end-diastolic pressure (LVEDP). However, the intermediate result still exists and may cause LVEDP undetermined. Previous studies have shown intraventricular pressure difference (IVPDs) are required for normal LV filling, but the relationship between IVPDs and LVEDP is unknown. In this study, we analyzed the relationship between IVPDs and LVEDP in 54 patients with coronary artery disease (CAD). LVEDP was prospectively measured at the time of coronary intervention and LVEDP > 15 mmHg was considered as elevated LV filling pressure. Simultaneous echocardiographic data was collected prior to the intervention. The relative intraventricular pressure was calculated using the vector flow mapping method. The IVPD was defined as the pressure difference from the apex to the base of LV. From 54 patients presenting with CAD, elevated LVEDP occurred in 30(55.6%). To analyze the changing trend of IVPD with LVEDP, CAD patients were further divided into group I with normal LVEDP (12.7 ± 3.1 mmHg) and group II with elevated LVEDP (26.0 ± 7.2 mmHg). In early diastole, both isovolumic relaxation period and rapid filling period showed decreased IVPD in CAD patients, but only the reduction in isovolumic relaxation period (IVPD-IVR) was statistical different between patients with elevated LVEDP and normal LVEDP (1.03 ± 0.42 mmHg vs. 2.25 ± 1.21 mmHg, p < 0.01). IVPD-IVR had the best correlation with LVEDP (r=-0.499, p < 0.01) among IVPDs. Lower IVPD-IVR was associated with higher risk of elevated LVEDP. Evaluating IVPD-IVR might improve the diagnostic algorithm for predicting elevated LVEDP.