RESUMO
BACKGROUND: Left ventricular (LV) dysfunction is the major reason for poor outcomes in patients with congenital complete atrioventricular block (CCAVB) and pacemaker. Long-term pacing has been associated with LV mechanical dyssynchrony. However, the relationship of dyssynchrony and LV dysfunction is not clear. OBJECTIVE: We sought to evaluate the prevalence of LV dyssynchrony by real time three-dimensional echocardiography (RT3DE) in patients with CCAVB and its association with LV dysfunction. In addition, we evaluated the agreement between RT3DE and tissue Doppler imaging (TDI) for detecting LV dyssynchrony. METHOD: We studied 50 patients [median age 20 years old (5 months to 62 years), 68% women] with CCAVB and pacemaker who underwent complete two-dimensional echocardiography and RT3DE. LV dyssynchrony was considered if the systolic dyssynchrony index (SDI) was ≥ 5%. Intraventricular mechanical delay was defined by TDI when differences in electromechanical activation between LV walls were > 65 msec. RESULTS: LV systolic dysfunction was present in 16 patients (32%) by two-dimensional and in 20 patients (40%) by RT3DE. There was a good correlation between LV ejection fraction by two-dimensional and RT3DE (r = 0.75; P < 0.001). Fourteen (28%) patients had intraventricular dyssynchrony by TDI, while 12 (24%) had intraventricular dyssynchrony by RT3DE. There was a good agreement between LV dyssynchrony by TDI and RT3DE (Kappa = 0.735; P < 0.001). There was a negative correlation between LV ejection fraction and SDI obtained by RT3DE (r = -0.58; P < 0.001) CONCLUSIONS: In patients with CCAVB and long-term pacing, LV dyssynchrony occurred in one-third of patients and was related to LV dysfunction. There was a good correlation between dyssynchrony obtained by RT3DE and TDI.
Assuntos
Bloqueio Atrioventricular/diagnóstico por imagem , Bloqueio Atrioventricular/terapia , Estimulação Cardíaca Artificial , Ecocardiografia Tridimensional , Bloqueio Cardíaco/congênito , Disfunção Ventricular Esquerda/diagnóstico por imagem , Adolescente , Adulto , Bloqueio Atrioventricular/complicações , Criança , Pré-Escolar , Comorbidade , Feminino , Bloqueio Cardíaco/complicações , Bloqueio Cardíaco/diagnóstico por imagem , Bloqueio Cardíaco/terapia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Disfunção Ventricular Esquerda/complicações , Adulto JovemRESUMO
BACKGROUND: Although several studies have demonstrated deleterious consequences of chronic right ventricular (RV) pacing on ventricular function and synchronicity, its effects on health-related quality of life (HRQoL) and functional exercise capacity remain uncertain. We aimed to evaluate the effect of RV pacing on HRQoL and functional capacity of children and young adults with congenital complete atrioventricular block (CCAVB). METHODS: We included 66 consecutive subjects with RV cardiac pacemaker due to CCAVB and under clinical follow-up for more than 1 year. Multidimensional HRQoL scores were evaluated by Short Form-36 Health Survey (SF-36) and Child Health Questionnaire-Parent Form 50 (CHQ-PF50). Functional capacity was tested by a 6-minute walk distance test (6MWDT). Association analysis was performed to examine if any demographic and clinical characteristics were associated with lower HRQoL scores and shorter distances at the 6MWDT. RESULTS: Domains presenting lower HRQoL scores were vitality (64.0 ± 17.3), mental health (67.3 ± 8.0), role emotional (69.7 ± 35.8) in the SF-36 questionnaire; general health perceptions (61.3 ± 8.3), general behavior (61.9 ± 15.6), parental impact-emotional (67.7 ± 28.7) in the CHQ-PF50. Female gender (P = 0.009), left ventricular ejection fraction lower than 55% (P = 0.013), cardiovascular drugs (P = 0.003) were significantly associated with lower HRQoL scores. Average distance traveled during the 6MWDT was 539.8 ± 82.9 m. The 6MWDT showed significant association with age (P = 0.006) and cardiovascular drugs (P = 0.024). CONCLUSIONS: Chronic RV pacing did not affect the HRQoL and physical capacity of pediatrics and young subjects. Female gender, ventricular function, and cardiovascular drugs were associated with lower HRQoL scores. Older subjects walked shorter distances in the 6MWDT, as well as subjects who were taking cardiovascular drugs.