Assessment of left sided filling dynamics in diastolic dysfunction using cardiac computed tomography

• Cardiac CT can produce semi-automatic simultaneous left atrial and ventricular volume curves.
• CT-derived volume curves enable evaluation of atrial function and atrioventricular interactions, which are closely related to diastolic function.
• Diastolic dysfunction progression is characterized by changes in atrial emptying patterns.
• Cardiac CT can distinguish normal from abnormal diastolic function.

BackgroundLeft ventricular (LV) diastolic dysfunction (DD) often accompanies coronary artery disease but is difficult to assess since it involves a complex interaction between LV filling and left atrial (LA) emptying.ObjectiveTo characterize simultaneous changes in LA and LV volumes using cardiac computed tomography (CT) in a group of patients with various grades of DD based on echocardiography.MethodsWe identified 35 patients with DD by echocardiography, who had also undergone cardiac CT, and 35 age-matched normal controls. LV and LA volumes were measured every 10% of the RR interval, using semi-automatic software. From these, – systolic, early-diastolic and late-diastolic volume changes were calculated, and additional parameters of diastolic filling derived. Conduit volume was defined as the difference between the LV and LA early-diastolic volume change.ResultsPatients with DD had significantly larger LV mass, and LA volumes, reduced early emptying volumes and increased conduit volume as percent of early LV filling (All p < 0.001). LA function, manifesting as total emptying fraction (LATEF), decreased proportionately with worsening grades of DD (p < 0.001). LA contractile function was maintained until advanced grade-3 DD. By receiver operating characteristic analysis, LATEF had an AUC of 0.88 to separate between normals and DD. At a threshold of <42.5%, LATEF has 97% sensitivity and 69% specificity to detect DD.ConclusionsDD is characterized by reduced LA function and an alteration in the relative contributions of the atrial emptying and conduit volume components of early LV filling. In patients undergoing cardiac CT, it is possible to identify the presence and severity of DD.