RESUMO
OBJECTIVES: The goal of this study was to determine whether right ventricular (RV) ischemia is a contributory factor in the development of RV dysfunction in patients with primary pulmonary hypertension (PPH). BACKGROUND: Patients with advanced PPH develop RV dysfunction, characterized by a decreased cardiac output, increased right atrial pressure (RAP) and/or elevated RV end-diastolic pressure, which progresses to heart failure and death. The cause of this dysfunction is unknown. Right ventricular ischemia may play a role in its development. METHODS: From 1992 to 1999, a prospective study involving 23 patients with PPH at the Instituto Nacional de Cardiologia "Ignacio Chavez" (Mexico City, Mexico) was undertaken. These patients were evaluated clinically and further studied by echocardiography, right heart catheterization and stress myocardial scintigraphy using technetium 99m sestamibi. RESULTS: Nine patients of 23 were found to have scintigraphic images consistent with RV ischemia. Significant correlation was found between RV ischemia obtained through myocardial perfusion scintigraphy and elevation of RV end-diastolic pressure (p < 0.001), elevation of RAP (p < 0.037) and a decrease in mixed venous oxygen saturation (p < 0.0001). No other clinical or hemodynamic variables showed a significant correlation with RV ischemia. CONCLUSIONS: A direct correlation exists between RV ischemia, as determined by myocardial scintigraphy, and hemodynamic alterations suggestive of RV dysfunction in patients with PPH.
Assuntos
Hipertensão Pulmonar/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Disfunção Ventricular Direita/fisiopatologia , Adulto , Feminino , Coração/diagnóstico por imagem , Hemodinâmica , Humanos , Hipertensão Pulmonar/complicações , Masculino , Isquemia Miocárdica/complicações , Isquemia Miocárdica/diagnóstico por imagem , Estudos Prospectivos , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton Único , Disfunção Ventricular Direita/etiologiaRESUMO
Fifty nine boys and 41 girls underwent exercise stress testing (ETT), utilizing the Bruce protocol. Their mean age was 10 years. They were grouped by sex, age and body surface area. Blood pressure (BP), heart rate (HR) at rest, during exercise and after were monitored as well as the duration of the test and the energy cost. The HR and-BP had a similar linear relationship in both groups during the different stages of the test. The duration of the test expressed in minutes was 11.8 +/- 1.2 in boys and 10.7 +/- 1.2 in girls (P = 0.001). The oxygen consumption (ML/kg/min) was 45.2 +/- 4.9 and 41.9 +/- 4.5 that is equivalent to 12.9 +/- 1.4 and 11.9 +/- 1.2 mets for each group respectively. The group of boys of 6 (9.8) and 14 years of age (13.6) (P = 0.002) and in the girls in the 7 (9.5) and 10 years age group (11.8) P = 0.05. We conclude that 1) The ETT can be done in children safely but was have to take in consideration their age, sex, and body surface area in evaluating the results. 2) This study gives a reference to evaluate children with an without heart disease.
Assuntos
Teste de Esforço , Adolescente , Fatores Etários , Pressão Sanguínea , Criança , Pré-Escolar , Feminino , Frequência Cardíaca , Humanos , Masculino , México , Oxigênio/metabolismo , Valores de Referência , Fatores SexuaisRESUMO
The present article summarises statistical information about the problem of hypertension in this country making reference to international and national epidemiological works, with the purpose of evaluating the problem in community. Includes information about the clino-pathologic experience acheived at the National Institute of Cardiology of Mexico. The data is analyzed and commented from the point of view of how worth might be to study hypertension in Mexico.