Evaluation of Left Ventricular Systolic Function after Cardiac Resynchronization Therapy in Heart Failure Patients

Background : Cardiac resynchronization therapy (CRT) has introduced as new treatment strategy in heart failure (HF) patients and some of its effects have been investigated. The aim of this study was to study the effectiveness of CRT in the improvement of left ventricular systolic function indicated by left ventricular ejection fraction (LVEF) in HF patients.
Materials and Methods : In our prospective study 22 HF patients with NYHA class III and above, QRS duration>120 ms and EF (ejection fraction) ≤35% who were candidates for CRT enrolled. Patients were evaluated for NYHA class, QRS width, left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV) and LVEF before and two months after the CRT procedure. Paired-t test analysis used to compare the before and post-CRT data statistically.
Results : Initial evaluation showed that all of the patients were in NYHA class III before CRT. Two months after CRT, all of the patients improved their NYHA class in a way that 18 patients (82%) were in NYHA class I and the other 4 (18%) were in NYHA class II. The mean (SD) QRS width decreased significantly after biventricular (BiV) pacing (p<0.001). Also a significant decrease in LVESV, LVEDV and increase in LVEF was shown in HF patients after CRT (p<0.001).
Conclusion : The present study showed the efficacy of CRT in improvement of LVEF in HF patients with wide QRS after two months from CRT.