Patients with hypertrophic cardiomyopathy (HCM) are prone to develop atrial fibrillation (AF) due to diastolic dysfunction and left atrial (LA) remodeling. According to guidelines, 48-hour ambulatory ECG is recommended every 12–24 months in stable patients and every 6–12months in case of LA dimension ≥45mm or if new palpitations.

The aim of this study is to investigate the predictive value of LA speckle tracking in detecting paroxysmal atrial fibrillation in HCM patients with enlarged left atrium.

We enrolled 62patients with HCM in sinus rhythm and LA diameter ≥45mm. All patients had previously underwent 24 or 48-hour ambulatory ECG in the last 12 months without detecting any paroxysmal AF. In this study, all our patients underwent standard echocardiographic with left ventricular (LV) and LA speckle tracking examination followed by 7-days long-term ambulatory ECG monitoring.

Among 62patients, 19patients (30.6%) were diagnosed with asymptomatic paroxysmal AF detected by 7-days long-term ambulatory ECG recorder (group1). In the same conditions, no paroxysmal FA was detected in the remaining 43 patients (group2). Group 1 patients showed no differences from group 2patients with regards to mean ages, BMI, LV dimensions and ejection fraction, E/e’ ratio and even in LA diameter. However, they had significantly impaired left atrial strain indices with significantly lower LA conduit strain 12.15±3.7% vs.17.34±4.08% (P<0.01), lower LA reservoir strain 24.78±4.49% vs. 32.18±5.6% (P<0.001) and lower LA contractile strain −12.02±3.91% vs. −15.16±4.12% (P<0.01).

Among HCM patients with enlarged LA, those with impaired LA strain indices were prone to higher risk for paroxysmal FA. Thus, LA strain may provide additional functional information for predicting AF susceptibility and may lead in case of impaired indices to propose prolonged ECG monitoring in order to enhance the detection of undiagnosed AF.