Abstract 20451: Evaluation of Diastole with MRI of Atrioventricular Junction Displacement
Introduction: Diastolic dysfunction can be found with normal and abnormal ejection fraction (EF). With increasing wall thickness (WT), the left ventricle (LV) has an increased tendency towards diastolic dysfunction. Diastolic dysfunction may further progress to heart failure. We sought to assess the potential of using MRI of AV displacement as a simple means to characterize LV diastolic performance.
Methods: Conventional cine MRI performed on 35 patients (35–68 yrs; Avanto, Siemens) with a history of heart failure but EF≥45% was retrospectively selected for analysis. Patients were divided into three groups based on WT measured at end-diastole: normal WT (NT, WT≤10mm, n=14), mild LV hypertrophy (MH, 10<WT≤ 15mm, n=11), and moderate-to-severe hypertrophy (H, WT>15mm, n=10). They were compared with 15 normal subjects (25–63 yrs; Tim Trio, Siemens), divided into two groups: NG1<40 yrs (n=10) and NG2≥40 yrs (n=5). AV junction (AVJ) was tracked in 2-chamber long-axis images (2CH) (red dot in Fig. 1a) and projected onto a reference line drawn from the LV apex towards the base (green line in Fig.1a). AVJ displacement was measured relative to end-diastole. Three parameters were selected for analysis: (1) maximum displacement (Maxd), (2) time at half-maximum diastolic displacement (T1/2maxd) and (3) velocity at half-maximum diastolic displacement (V1/2maxd) (Fig. 1b).
Results: Maxd is decreased in patient groups, compared to normal groups (Fig. 2); H, with further increase in WT, shows further reduced displacement, compared to MH and NT. Patient groups also have increased T1/2maxd and decreased V1/2maxd, compared to normal groups. NG2 subjects show similar trends, compared to NG1.
Discussion: Using cine MRI, AVJ displacement and associated LV diastolic relaxation rates show a strong relation with LV WT; older normal subjects also show differences. Therefore, this simple method provides a potentially valuable noninvasive method to assess LV diastolic dysfunction.
- © 2010 by American Heart Association, Inc.