Left atrial global strain supports left atrial end-diastolic volume as a measure of left atrial function

Left atrial end-diastolic volume index (LAEDVI), the smallest achieved diastolic volume, strongly predicts cardiovascular events. We hypothesize that echocardiographic left atrial reservoir strain (LASr) parallels LAEDVI, providing an additional measurement of LA function.

We analyzed 133 subjects from the BEAT-AFib study. All subjects were in sinus rhythm when studied and were either deemed at risk for atrial fibrillation (Afib) (At-risk, n = 73) or had a history of Afib (Afib, n = 60). The at-risk group had two or more of the following: age > 65 years, hypertension, diabetes, sleep apnea, BMI ≥ 30 kg/m², stable heart failure, and chronic kidney disease without dialysis. We included 83 normal subjects from our laboratory database. LA volumes were measured from 3-dimensional images. LASr was obtained by 2-dimensional speckle tracking R-R gating method from apical 4- and 2- chamber views.

LASr was 38 % in normal, 31 % in at-risk, and 23 % in Afib, (p < 0.01). LAEDVI was 11 mL/m² in normal, 15 mL/m² in at-risk, and 21 mL/m² in Afib (p < 0.01). LASr was associated with LAEDVI (r = -0.684), LAESVI (r = -0.528), LA ejection fraction (r = 0.661), E/e' ratio medial (r = -0.571) (all p < 0.01).

LAEDVI are significantly different among normal subjects, those at-risk for Afib development and sinus rhythm with Afib history. LASr paralleled with LAEDVI in its ability to distinguish among these groups indicating that LASr is an additional useful component in evaluating LA function.