Evaluation of left atrial longitudinal function in patients with hypertrophic cardiomyopathy: a tissue Doppler imaging and two-dimensional strain study

Objective: We sought to quantify left atrial longitudinal function by tissue Doppler (TDI) and two-dimensional (2D) strain in patients with hypertrophic cardiomyopathy (HCM). Design: Case-control study. Setting: Tertiary university hospital. Patients: 43 consecutive patients with familial HCM, aged 49 (SD 18) years, along with 21 patients with non-HCM left ventricular hypertrophy (LVH, aged 52 (12) years) and 27 healthy volunteers (aged 42 (13) years). Interventions: Subjects were studied by both TDI and 2D left atrial strain during all three atrial phases (reservoir, conduit, contractile), as well as by left ventricular systolic strain; total atrial deformation (TAD) was defined as the sum of maximum positive and maximum negative strain during a cardiac cycle. Main outcome measures: Left atrial longitudinal function. Results: Both TDI and 2D atrial strain and TAD were significantly reduced in HCM, compared to the other two groups in all atrial phases (p<0.001 in most cases); left ventricular systolic strain was also significantly reduced in HCM (p < 0.001). Adding 2D contractile atrial strain to a model of conventional echo measurements (including left atrial diameter and volume index, interventricular septal thickness and E/A ratio and E/e' ratios) increased its prognostic value in differentiating HCM from non-HCM LVH (p value of the change < 0.001), while addition of TDI atrial strain or left ventricular strain did not. A cut- off for 2D contractile strain of -10.82% discriminated HCM from non-HCM LVH with a sensitivity of 82% and a specificity of 81%. Intra-observer and inter-observer variabilities for atrial strain in HCM were 16% and 17.5% for TDI and 8% and 9.5% for 2D, respectively. Processing time per case in HCM was 12.5 (2.6) minutes for TDI versus 3.8 (1.2) minutes for 2D strain (p<0.001). Conclusion: Left atrial longitudinal function is reduced in HCM compared to non-HCM LVH and healthy controls. In addition, 2D atrial strain has an additive value in differentiating HCM from non-HCM LVH and it is more reproducible and less time consuming than TDI strain.