Evaluation of left atrial contraction contribution to left ventricular filling using cardiovascular magnetic resonance

PURPOSE: To describe a new method to quantify the left atrial contraction contribution (ACC) to left ventricular (LV) filling using cardiovascular magnetic resonance (CMR). MATERIALS AND METHODS: We assessed 120 normal subjects (50% female) using steady-state free precession CMR volumetry. Volumes measurements were performed using short axis and rotational long axis views. The percentage of ACC was calculated by dividing the LV filling volume resulting from left atrial (LA) contraction by the LV stroke volume (LVSV). RESULTS: The described method was well reproducible. The ACC in normal subjects was 15 ± 5% for ages 55 years. When adjusted for age, ie, dividing the ACC percentage by age, a value between 0.4 and 0.7 was found to represent the normal range of ACC at any age. CONCLUSION: The study presents a new and accurate CMR volumetric method to quantify ACC to LV filling. ACC ranges from 10%-40%, depending on age.