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Estimation of Left Ventricular Filling Pressure by Assessment of Left Atrial Contractile Function Using Cardiovascular Magnetic Resonance Volumetry

The purpose of this study was to assess the relationship between left atrial contractile function, as quantified by cardiac magnetic resonance (CMR) volumetry, and left ventricular end-diastolic pressure (LVEDP). We assessed 26 patients with impaired left ventricular systolic function using steady-state free precession CMR volumetry. The percentage of left atrial contraction contribution (ACC) to left ventricular (LV) filling was determined. It was calculated by dividing LV volume resulting from LA contraction by LV stroke volume (LVSV). We used, as a reference group, data from a previously published study of 120 normal subjects where ACC was calculated using the same method. All patients had Doppler echocardiography, where E/Ea ratio was calculated, and left heart catheterization was done to measure LVEDP. There was no difference between ACC in patients with LVEDP less than 20 mmHg and ACC in normal subjects (P=0.2). There was a significant difference between ACC in patients with LVEDP more than 20mmHg and normal subjects (P<0.0001). When ACC was adjusted for age, i.e. dividing ACC percentage by age, a value less than 0.41 detected elevated LVEDP (>20mmHg) with a sensitivity and specificity of 93% and 88%, respectively. In patients with impaired LV systolic function, the quantification of ACC to LV filling using CMR volumetry is a simple and reliable method to assess LVEDP.