Left Atrial Dysfunction as Marker of Arrhythmic Events in Patients with Hypertrophic Cardiomyopathy

Background: In this study, we investigated whether left atrial functions evaluated by speckle tracking echocardiography, classic echocardiographic and clinic parameters predict appropriate Implantable Cardioverter Defibrillator (ICD) shock in patients who underwent ICD implantation for hypertrophic cardiomyopathy.

Methods: Totally 87 patients who received ICD implantation for primary or secondary prevention were included in the study. Patients’ clinical, elect rocardiographic, 2 dimension classic, and speckle tracking echocardiographic data were collected. Left atrial functions were assessed by speckle tracking echocardiography. Left atrial strain just before mitral valve opening was taken as peak atrial longitudinal strain. Appropriate ICD therapy was defined as cardioversion or defibrillation due to ventricular tachycardia or fibrillation. Patients were divided into 2 groups as occurrence or absence of appropriate ICD therapy during follow-up (mean, 50.2 ± 9.3 months). Patients with an European Society of Cardiology (ESC) risk score >6% were considered high-risk patients.

Results: A total of 24 (27.5 %) patients were observed to have an appropriate ICD therapy. In patients on whom appropriate ICD therapy was performed, a higher Sudden Cardiac Death risk Score and decreased peak atrial longitudinal strain and global longitudinal
peak strain were observed. In patients with high ESC risk score (> 6%), in Cox regression analysis, peak atrial longitudinal strain (odds ratio: 0.806, P =.008), Sudden Cardiac Death risk score (odds ratio: 1.114, P =.03) and global longitudinal peak strain (odds ratio: 1.263, P =.02) were found to be independent predictors of occurrence of appropriate ICD therapy.

Conclusion: Easily measurable peak atrial longitudinal strain may provide additional information in predicting ventricular arrhythmias or deciding on prophylactic medical treatment to prevent ventricular arrhythmias or reduce the frequency of appropriate shock in high-risk patients with ICD implanted.