RESUMEN
BACKGROUND: Patients with congestive heart failure (CHF) have increased ventilatory equivalent for carbon dioxide (Ve/VCO(2)), which may contribute to the symptom of exercise-induced hyperpnea. We have developed a technique in which simultaneous blood volume single photon emission computed tomography imaging and transmission tomography are used to measure extravascular lung density (ELD). We investigated the correlation between Ve/VCO(2) and ELD in patients with CHF. METHODS AND RESULTS: Thirteen patients with stable CHF and eleven control subjects were studied. Attenuation-corrected blood volume emission tomography was acquired with simultaneous transmission tomography to measure pulmonary blood volume and total lung density, respectively. Seven CHF patients underwent maximal exercise treadmill testing with online respiratory gas analysis. ELD was calculated as total lung density minus pulmonary blood volume. SPECT and transmission tomography were repeated immediately after exercise. CHF patients had significantly higher total lung density and ELD compared with normal subjects. No differences in pulmonary blood volume were observed. There was a significant inverse correlation between ELD and left ventricular ejection fraction at rest in CHF patients (r = -0.77, P <.001). A strong correlation was also found between post-exercise ELD and Ve/VCO(2) at peak exercise (r = 0.74, P =.008) and at anaerobic threshold (r = 0.67, P =.024). CONCLUSION: Patients with chronic CHF have increased ELD. The correlation between ELD and Ve/VCO(2) suggests that increased lung water may contribute to the ventilatory abnormalities seen in patients with CHF.
Asunto(s)
Absorciometría de Fotón/métodos , Insuficiencia Cardíaca/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Trastornos Respiratorios/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único/métodos , Adulto , Anciano , Prueba de Esfuerzo , Femenino , Imagen de Acumulación Sanguínea de Compuerta/métodos , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/diagnóstico , Humanos , Hiperventilación/diagnóstico , Hiperventilación/diagnóstico por imagen , Hiperventilación/etiología , Pulmón/irrigación sanguínea , Masculino , Persona de Mediana Edad , Circulación Pulmonar , Reproducibilidad de los Resultados , Trastornos Respiratorios/diagnóstico , Trastornos Respiratorios/etiología , Sensibilidad y Especificidad , Estadística como Asunto , Técnica de SustracciónRESUMEN
Operative cardiac interventions have been performed on pregnant women with varying degrees of success since the late 1950s. Currently, reported maternal mortality for cardiac operations is similar to the mortality rate for nonpregnant female patients. However, fetal mortality remains high, at approximately 20%. Aortic root replacement with an aortic homograft in a 34-year-old pregnant woman with bacterial endocarditis at 18 weeks gestation is presented. Fetal echocardiography during and after bypass was employed.