The American journal of cardiology
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This study reports the development of a micromultiplane 8.2-mm transesophageal echocardiographic probe. The probe is applicable to newborn infants and can deliver diagnostic images in adults.
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The pulmonary diffusing capacity for carbon monoxide (DLCO) is reduced in chronic heart failure and remains decreased after heart transplantation. This decrease in DLCO may depend on a permanent alteration after transplantation of one or the other of its components: diffusion of the alveolar capillary membrane or the pulmonary capillary blood volume (Vc). Therefore, we measured DLCO, the membrane conductance, and Vc before and after heart transplantation. ⋯ We conclude that the decrease in DLCO in patients with chronic heart failure is due to a restrictive ventilatory pattern because their DLCO/VA remains normal; the decrease in the membrane conductance is compensated by the increase in Vc. After transplantation, the decrease in Vc due to normalization of pulmonary hemodynamics is not completely compensated for by an increase in membrane conductance. Because the membrane conductances, measured before and after transplantation, are negatively correlated with duration of heart failure, its abnormal pulmonary hemodynamics may have irreversibly altered the alveolar capillary membrane.