Use of GATED-SPECT for Ventricular Desynchronization Evaluation in Patients with Heart Failure Submitted to Cardiac Resynchronization Therapy

Abstract Background: Approximately 20 to 40% of patients with heart failure do not respond to cardiac resynchronization therapy (CRT). To improve patient selection, phase analysis by myocardial perfusion scintigraphy (GSPECT) was developed. Objectives: To evaluate the clinical and scintigraphic response of patients with heart failure (HF) submitted to CRT using GSPECT. Method: This was an interventional study that included consecutive patients assessed by GSPECT four weeks prior to CRT implantation and six months after it for comparison. These patients also answered the Minnesota Living with Heart Failure Questionnaire (MLHFQ). The categorical variables were compared using Fisher's exact test and chi-square test, whereas Student's t-test was used for numerical variables. The level of statistical significance was set at 5%. The scintigraphic variables analyzed were left ventricular ejection fraction, end-systolic volume, end-diastolic volume, left ventricular mass, standard deviation and bandwidth, as well as QRS duration and the Minnesota Quality of Life Questionnaire score. The presence of mechanical dyssynchrony was defined as standard deviation > 43º. Results: Nine patients were included in the study. After the cardiac resynchronization therapy, there was a significant improvement (p