Early reversal of right ventricular dysfunction in patients with acute pulmonary embolism after treatment with intravenous tissue plasminogen activator

To assess abnormalities of right heart function and their reversal with thrombolysis in pulmonary embolism, serial imaging and Doppler echocardiographic studies were performed before and after a 6 hour intravenous infusion of 80 to 90 mg of recombinant tissue-type plasminogen activator (rt-PA) in seven patients with segmental or lobar acute pulmonary embolism. None of the five men and two women had known prior pulmonary hypertension. Substantial clot lysis and improvement in pulmonary blood flow, as determined by serial pulmonary angiography and perfusion lung scanning, were achieved in all. Coincident with clot lysis, pulmonary artery systolic pressure decreased (from 42 ± 11 to 26 ± 7 mm Hg, p < 0.005), right ventricular diameter decreased (from 3.9 ± 1.0 to 2.0 ± 0.5 cm, p < 0.005) and left ventricular diameter increased (from 3.7 ± 0.9 to 4.4 ± 0.6 cm, p < 0.01). Right ventricular wall movement, initially mildly, moderately or severely hypokinetic in one, two and four patients, respectively, normalized in five and improved to mild hypokinesia in two. Tricuspid regurgitation was present before lytic therapy in six patients. In five, flow velocity in the tricuspid regurgitant jets indicated a peak systolic right ventricular minus right atrial pressure gradient of 25 to 52 mm Hg. Tricuspid regurgitation was detected early after lytic therapy in only two patients. Systolic septal flattening was noted before but not after lysis. These findings confirm that pulmonary emboli may result in appreciable right ventricular dysfunction and dilation, resultant tricuspid regurgitation, abnormal septal position and decreased left ventricular size. Their early reversal after rt-PA suggests that this therapy might be efficacious in the management of patients with pulmonary embolism presenting with more serious hemodynamic compromise. The potential of rt-PA in this regard merits further investigation.