Identification of Candidates for Implantable Cardioverter Defibrillator Insertion as Primary Prevention: Global Longitudinal Strain Helps

Background: Heart failure is a life-threatening event that could lead to sudden cardiac death. It is primarily prevented by the use of implantable cardioverter defibrillators. Applying this therapy is mainly determined by left ventricular ejection fraction. However, this criterion results in considerable pitfalls. Improving the discrimination strategies in order to select eligible patients can help avoid unnecessary insertions. Objectives: This study aimed to compare global longitudinal myocardial strain and left ventricular ejection fraction in predicting sustained ventricular tachyarrhythmia in heart failure patients. Methods: This study was performed on 70 ischemic or dilated cardiomyopathic patients randomly selected from Imam Reza clinic. Patients with left ventricular ejection fraction ≤ 40% who had undergone implantable cardioverter defibrillator implantation were recruited into the research. Left ventricular ejection fraction and global longitudinal strain were measured by 3D echocardiography. Independent sample t-test was used for analysis and statistical significance was set at < 0.05. Results: The data were expressed as mean ± SD. The study subjects in the ischemic and dilated cardiomyopathic groups were categorized according to the occurrence of ventricular tachyarrhythmia. The results showed a significant difference between arrhythmic and non-arrhythmic cases only in the ischemic group regarding the amount of left ventricular ejection fraction. Meanwhile, a significant difference was observed between arrhythmic subjects and their counterparts in both ischemic and dilated cardiomyopathic groups concerning global longitudinal strain parameters. Conclusion: Global longitudinal strain could be considered as a valuable predictor of ventricular tachyarrhythmia occurrence beside left ventricular ejection fraction. This helps selection of appropriate patients for implantable cardioverter defibrillator therapy.