[The transpulmonary distance in the evaluation of the pulmonary arterial pressure: roentgenographic-hemodynamic relations in mitral valve disease].

A linear correlation between transpulmonary distance and pulmonary arterial mean pressure was found in 84 patients with pure mitral valve disease. Neither the sum of the horizontal distance from the midline to the first divisions of the right and left pulmonary arteries, nor the measurement obtained dividing the transpulmonary distance by the maximum transverse diameter of the thorax significantly increase the correlation. DIP greater than 9.64 and 10.72 have 80% and 90% of chances of being associated with an abnormally high mean arterial pressure but correlate poorly with the extent of hypertension. Greater usefulness of the index might be obtained correlating it with the mean pressure measured under exercise.