RESUMO
Objetivo: Avaliar o significado da evidência da isquemia miocárdica e a ocorrência de eventos cardiovasculares na Síndrome Cardíca X (SCX), comparando com doença coronária obstrutiva inicial (DAC <- 50 por cento). Métodos: Estudo observacional de coorte, em, amostra de 605 pacientes (população fonte de 5.137 indivíduos), com ecocardiografia sob estresse físico (EEF) positiva para isquemia miocárdica, os quais foram submetidos à cineangiocoronariografia, e divididos, posteriormente, em 2 grupos: G1 (SCX, n=64) e G2 (DAC<- 50 por cento, n=84). Os pacientes foram comparados quanto às características clínicas, parâmetros ergométricos e ecocardiográficos, e seguidos po +- 43,8 meses (mínimo de 12 meses e máximo de 85 meses), quanto ao surgimento de ngina típica, infarto agudo do miocárdico...
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Angina Microvascular/complicações , Angina Microvascular/diagnóstico , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico , Ecocardiografia sob Estresse/métodos , Ecocardiografia sob Estresse , Isquemia Miocárdica/diagnóstico , Fatores de RiscoRESUMO
OBJECTIVE: Although chronotropic incompetence (CI) represents an independent predictor of mortality and incidence of coronary artery disease, its pathophysiological mechanisms remain unknown. The purpose of this investigation was to evaluate wall motion abnormalities of the left ventricle and location of coronary arterial lesions in patients with and without CI. METHODS: After exclusion of confounding factors, 610 patients (mean age of 58.4 +/- 11 years; 275 men) with ischaemia who underwent exercise echocardiography were studied. Based on heart rate (HR) reached in treadmill testing, patients were divided into two groups: Chl (97 patients who did not reach 85% of maximum HR recommended for age) and ChC (513 patients who achieved 85% of the maximum age-predicted HR). RESULTS: There was a higher frequency of dyspnoea (5.2% vs. 0.6%, P = 0.003), systemic hypertension (69.1% vs. 57.3%, P = 0.031) and obesity (38.1% vs. 22.6%, P = 0.001), and a lower tolerance to effort (dyspnoea as limitation of physical effort: 36.1% vs. 8.0%, P < 0.0001; duration of treadmill test: 4.4 +/- 2.2 vs. 7.2 +/- 2.8, P < 0.0001; METs: 6.0 +/- 2.6 vs. 8.4 +/- 2.9, P = 0.002) in Chl compared to ChC. The wall motion score index (WMSI) was higher in Chl than in ChC, both at rest (1.15 +/- 0.29 vs. 1.07 +/- 0.19, P = 0.011) and after exercise (1.24 +/- 0.29 vs. 1.15 +/- 0.19, P = 0.002). Systolic function, which was evaluated in peak exercise through WMSI, was significantly more altered in the Chl group. The presence of severe injuries in right coronary was independently associated with CI (adjusted OR = 3.57, CI 95%: 1.86-6.87). CONCLUSION: Chronotropic incompetence is associated with ventricular dysfunction in peak exercise and critical right coronary artery lesions.
