Echocardiographic observations of paradoxic pulse without pericardial disease.

Echocardiograms were obtained in 10 normal patients and in 11 patients with respiratory insufficiency due to chronic obstructive lung disease (8) and to thoracic poliomyelitis (3). Only the eight patients with obstructive lung disease had paradoxic pulse. No patient had pericardial disease. The left ventricular internal dimension, stroke volume, and the mitral valve E-F slope and D-E excursion were measured. The inspiratory to expiratory ratio of each measurement was significantly lower in patients with obstructive lung disease than in normal subjects. The patients with thoracic poliomyelitis demonstrated almost no respiratory change in these measurements. The magnitude of the change in the measured factors probably relates to the degree of negativity of intrathoracic pressure during respiration. The inspiratory reduction of mitral valve motion and left ventricular internal dimension is not specific to tamponade but may be seen in patients who exhibit paradoxic pulse due to other conditions.