Grading diastolic function by echocardiography: hemodynamic validation of existing guidelines

Background: While echocardiographic grading of left ventricular (LV) diastolic dysfunction (DD) is used every day, the relationship between echocardiographic DD grade and hemodynamic abnormalities is uncertain.

Methods: We identified 460 consecutive patients who underwent transthoracic echocardiography within 24 h of elective left heart catheterization and had: normal sinus rhythm, no confounding structural heart disease, no change in medications between catheterization and echo, and complete echocardiographic data. Patients were grouped based on echocardiographic DD grade. Hemodynamic tracings were used to determine time constant of isovolumic pressure decay (Tau), LV end-diastolic pressure (LVEDP) and end-diastolic volume index at a pressure of 20 mmHg (EDVi20).

Results: Normal diastolic function was found in 55 (12.0%) patients, while 132 (28.7%) patients had grade 1, 156 (33.9%) grade 2 and 117 (25.4%) grade 3 DD. The median value for Tau was 46.9 ms for the overall population (interquartile range 38.6-58.1 ms), with a prevalence of a prolonged Tau (> 48 ms) of 47.5%. While there was an association between DD grade and Tau (p = 0.003), LV dysfunction (ejection fraction < 50%) was more strongly associated with increased Tau (p < 0.001) than was DD grade (p < 0.19). There was also an association between DD grade and LVEDP (p < 0.001), with both LV dysfunction (p = 0.029) and DD grade (p < 0.001) independently associated with LVEDP. Calculated EDVi20 was related to DD grade, but this relationship was driven by findings of paradoxically increased compliance in patients with severe DD.

Conclusions: Although echocardiographic grading of DD was related to invasive hemodynamics in this population, the relationship was modest.