Noninvasive diagnosis of pulmonary hypertension: a World Health Organization study.

In the detection of pulmonary hypertension, especially that of only moderate extent usually associated with chronic obstructive lung disease, noninvasive methods, applied individually, are usually of insufficient accuracy. Accordingly, the World Health Organization undertook a prospective study in which several noninvasive methods were employed together in order to improve the diagnostic accuracy. The examinations analyzed encompassed chest roentgenography, electrocardiography, vectorcardiography, mechanocardiography, echocardiography, myocardial scintigraphy and ventriculography and pulmonary scintigraphy. From the chest X-ray, the size of the main pulmonary artery, the transpulmonary artery distance and the size of the right descending pulmonary artery were analyzed; correct identification of patients with or without pulmonary hypertension was achieved in only 40%. With respect to the electrocardiogram, the number of false negative and false positive findings renders this method of negligible usefulness. Mechanocardiography proved technically difficult and incurred inconsistencies in interpretation such that this method was only rarely useful in the diagnosis of pulmonary hypertension. The same held true for the use of echocardiography since it is technically difficult to obtain adequate imaging in patients with overinflated lungs and the pulmonic valve can only be visualized in about 50% of the patients. Right ventricular systolic time intervals would be interest but their measurement can only be accomplished in a small number of patients. Myocardial scintigraphy with thallium-201 may render indirect evidence of pulmonary hypertension if the right ventricular wall can be visualized; this is the case in 80% of patients in whom mean pulmonary artery pressure exceeds 30 mm Hg but only in 56% of those with mean pulmonary artery pressures between 21 and 30 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)