Resynchronizing Implantable Cardioverter-Defibrillator (CRT-D) for Left Ventricular Dysfunction in Patients with Chronic Heart Failure

Abstract

A cardiacresynchronization therapy defibrillator (CRT-D) corrects intracardiac mechanical dyssynchrony by pacing the right and left ventricles synchronized with the atrial rhythm. The CRT-D implantable cardioverter defibrillator is used in chronic heart failure (CHF) because patients with heart failure have a poor prognosis, with mortality rates averaging 15–60% per year. Implantable cardioverter defibrillator CRT-D improves the functional state of the heart and increases left ventricular systolic dysfunction.The purpose of the study wasto evaluate the effect of the implantable cardioverterdefibrillator CRT-D device on left ventricular function in patients with CHF.We selected patients with NYHA class III or IV heart failure, left ventricular ejection fraction (LVEF) less than 35%, and internal QRS complex duration of more than 150 ms for CRTD implantation among patients hospitalized in the cardiology department of Aktobe Medical Center (AMC) in Aktobe, Kazakhstan, from 2022 to 2023. Total 60 patients were monitored for 48 weeks with an assessment of left ventricular function after CRT-D implantation. At 48 weeks after implantation of the ventricular assist device, significant treatment outcomes were observed (p=0.001): physical tolerance increased from 268 m to 326 m within 6 minutes of the test and LV ejection fraction (EF,%) from 33 to 37% and decrease in QRSms duration from 154 to 128ms .Also, EDV/EDS (ml/cm) decreased from 249 to 160 mL/174 to 110cm. There was a correlation between EDS (cm) and 6MWD (m) levels (r=0.376; p=0.001). Thus, patients with CHF who were implanted with the CRT-D device showed improvement in left ventricular function.

Keywords

• implantable cardioverter/defibrillator (CRT-D)
• chronic heart failure (CHF)
• LV dyssynchrony
• left ventricular ejection fraction (LVEF)
• QRS duration