Electric and Clinical Predictors Related to the Outcomes of Cardiac Resynchronization Therapy and their Association with Changes in Left Ventricular Ejection Fraction over Time

Abstract Background Cardiac resynchronization therapy represents a well established treatment for heart failure patients, recommended for those with severely depressed left ventricular systolic function and left bundle branch block. The aim of this study was to determine the correlation between electrocardiographic changes, clinical, functional, and demographic parameters with the improvement in left ventricular ejection fraction after resynchronization therapy. Another focus of this study was to identify which parameters have predictive value for better patient selection and proper resynchronization strategy. Methods The study included 69 patients who underwent cardiac resynchronization therapy in our center. The parameters were monitored at 4 different key moments: before the procedure and at 6, 9 and 12 months after procedure. Results There was a significant improvement in the ejection fraction, which reached a peak at the 12-month follow-up. The value of atrial natriuretic factor precursor was negatively associated with the evolution of ejection fraction. QRS duration and left ventricular enddiastolic volume correlate with improvement in ejection fraction. Newer variables, such as the QRS area, the R wave amplitude in the right precordial leads, the QS duration, the percentage of biventricular pacing, and the intraprocedural blood pressure, were examined for their potential association with cardiac resynchronization therapy outcomes. However, the presence or absence of significant correlations with ejection fraction improvement requires further analysis. Conclusion Cardiac resynchronization induces cardiac remodeling, leading to echocardiographic and quality of life improvements. It also provides electrical improvements and correct ventricular dyssynchrony. Patients with narrower QRS durations after CRT experienced a rise in the ejection fraction based on higher rates of reverse remodeling.