Left Atrial Appendage Ejection Flow Waves in Differentiation of Atrial Flutter from Atrial Fibrillation

Background: Atrial Flutter (AFL) and Atrial Fibrillation (AF) are among the most common supraventricular tachyarrhythmias. Sometimes, differentiation of the two arrhythmias using surface electrocardiography becomes difficult. Objectives: This study aimed to compare the Left Atrial Appendage (LAA) ejection flow waves of AFL and AF to determine whether it can serve as a method for differentiating the two arrhythmias. Methods: This cross-sectional study was conducted on 20 patients with AF and 20 ones with AFL selected via simple sampling method. During Trans-Esophageal Echocardiography (TEE), pulsed Doppler sampling was laid 1 cm inside the LAA and pattern of LAA ejection flow waves was recorded in terms of rate (number per minute), velocity (centimeter per second), and regularity. The two groups were compared using Mann-Whitney U-test. P ≤ 0.05 was considered to be statistically significant. Results: The rate of LAA ejection flow waves was 493.75 ± 50.57 in the AF group and 303.50 ± 16.31 in the AFL group (P < 0.001). Besides, the mean velocity was 0.172 ± 0.069 m/s in the AF group and 0.302 ± 0.106 m/s in the AFL group (P < 0.001). Velocity more than 0.17 m/s had a sensitivity of 95.0% (95% CI, 75.1 - 99.2%), specificity of 70.0% (95% CI, 45.7 - 88.0%), positive predictive value of 76.0%, and negative predictive value of 93.03% for diagnosing AFL. All patients in the AF group had irregular patterns, but all those in the AFL group had regular patterns. Conclusion: Since TEE is a usual part for evaluation of patients suspected to have AF or AFL, it may be helpful for differentiating AFL from AF by examining LAA ejection flow waves.