Routine evaluation of left ventricular diastolic function by cardiovascular magnetic resonance: A practical approach

Background: Cardiovascular magnetic resonance (CMR) has excellent capabilities to assess ventricular systolic function. Current clinical scenarios warrant routine evaluation of ventricular diastolic function for complete evaluation, especially in congestive heart failure patients. To our knowledge, no systematic assessment of diastolic function over a range of lusitropy has been performed using CMR. Methods and Results: Left ventricular diastolic function was assessed in 31 subjects (10 controls) who underwent CMR and compared with Transthoracic echocardiogram (TTE) evaluation of mitral valve (MV) and pulmonary vein (PV) blood flow. Blood flow in the MV and PV were successfully imaged by CMR for all cases (31/31,100%) while TTE evaluated flow in all MV (31/31,100%) but only 21/31 PV (68%) cases. Velocities of MV flow (E and A) measured by CMR correlated well with TTE (r = 0.81, p < 0.001), but demonstrated a systematic underestimation by CMR compared to TTE (slope = 0.77). Bland-Altman analysis of the E: A ratio and deceleration time (DT) calculated from each modality showed excellent agreement (bias -0.29, and -10.3 ms for E: A and DT, respectively). When assessing morphology using TTE, CMR correctly identified patients as having normal or abnormal inflow conditions. Conclusion: We have shown that there is homology between CMR and TTE for the assessment of diastolic inflow over a wide range of conditions, including normal, impaired relaxation and restrictive. There is excellent agreement of quantitative velocity measurements between CMR and TTE. Diastolic blood flow assessment by CMR can be performed in a single scan, with times ranging from 20 sec to 3 min, and we show that there is good indication for applying CMR to assess diastolic conditions, either as an adjunctive test when evaluating systolic function, or even as a primary test when TTE data cannot be obtained.