IJCS | Volume 31, Nº3, May/ June 2018

DOI: 10.5935/2359-4802.20180022 264 ORIGINAL ARTICLE International Journal of Cardiovascular Sciences. 2018;31(3)264-273 Mailing Address: Christiane CigagnaWiefels Pós-graduação em Ciências Cardiovasculares - Rua Marques do Paraná 303. Postal Code: 24033-900, Centro, 3º andar, Prédio Anexo, Niterói, RJ - Brazil. E-mail: chriswreis@gmail.com, cwiefels@yahoo.com.br Use of GATED-SPECT for Ventricular Desynchronization Evaluation in Patients with Heart Failure Submitted to Cardiac Resynchronization Therapy Christiane Cigagna Wiefels 1 , Erivelton Alessandro do Nascimento 2 , Christiane Rodrigues Alves 1 , Fernanda Baptista Ribeiro 1 , Fernando de Amorim Fernandes 1 , Mario Luiz Ribeiro 1 , Claudio Tinoco Mesquita 1 Hospital Universitário Antônio Pedro, Universidade Federal Fluminense 1 , Niterói, RJ - Brazil Instituto Estadual de Cardiologia Aloysio de Castro 2 , Rio de Janeiro, RJ - Brazil Manuscript received Abril 24, 2017, revised manuscript August 24. 2017, accepted October 15, 2017. Abstract Background: Approximately 20 to 40%of patientswith 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 < 0.05) in the end-systolic volume (206 ± 80 mL vs. 158 ± 108 mL), QRS (180 ± 18 ms vs. 120 ± 9 ms), left ventricular mass (248 ± 65 g vs. 193 ± 52 g) and Minnesota Quality of Life Questionnaire score (63 ± 16 vs. 34 ± 20). All patients with scintigraphic criteria of mechanical dyssynchrony showed clinical improvement. Two patients had only electrical dyssynchrony and did not achieve significant clinical improvement, although they showed QRS duration reduction. Conclusion: GSPECT was able to differentiate patients with isolated electrical dyssynchrony from those with associated mechanical dyssynchrony, through the intraventricular dyssynchrony parameters. The cardiac resynchronization therapy is associated with the improvement of both mechanical and electrical dyssynchrony. Pre- implantation GSPECT showed that patients with associated electrical and mechanical dyssynchrony had a better response to cardiac resynchronization therapy than those with isolated electrical dyssynchrony. (International Journal of Cardiovascular Sciences. 2018;31(3)264-273) Keywords: Heart Failure; Cardiac Resynchronization Therapy; Myocardial Perfusion Imaging / scintigraphy; Stroke Volume; Artery Coronary Disease / physiopathology; Myocardial Infarction. Introduction In the United States, approximately 550,000 new cases of Heart Failure (HF) are diagnosed each year, totaling 5 million Americans with the disease. Therefore, decompensated HF is responsible for more than 1 million hospitalizations per year. 1 The estimated direct and indirect costs for HF in 2011, in the United States, were US$ 215 billion, and this figure is expected to reach US$ 804 billion in 2020. 2 The Brazilian Registry of Heart