[Parameters of perfusion pulmonoscintigraphy and radionuclide tomoventriculography in non-massive thromboembolism of pulmonary-artery branches].

OBJECTIVE: The present work was aimed at identifying the most informative parameters of perfusion pulmonoscintigraphy and radionuclide tomoventriculography in non-massive thromboembolism of the pulmonary-artery branches. MATERIALS AND METHODS: We examined a total of fifty-five patients. The Study Group was composed of 40 subjects (mean age 60.3 +/- 10.4 years) presenting with non-massive pulmonary artery thromboembolism (PATE). The Comparison Group comprised 15 patients with coronary heart disease (CAD) (average age 59.0 +/- 9.0 years, NYHA functional class I-IT circulatory insufficiency). All patients were subjected to perfusion-ventilatory pulmonoscintigraphy and radionuclide equilibrium tomoventriculography. The basic systolic and diastolic parameters of the right ventricle (RV) were determined using the obtained RESULTS: The Group of patients with non-massive PATE (i. e., damage to the pulmonary vascular bed up to 50%) turned out hypertension. quite heterogeneous by the severity degree of the RV contractility dysfunction. This Group included the patients with and without signs of RV contractility dysfunction. Taking into consideration small extension of the lesion, normal values of functional capability of the right portions of the heart may be interpreted as a sign of acute PATE, whereas the presence of pronounced systolicdiastolic dysfunction of the right ventricle should be regarded as apathognomonic sign of chronicpost-thromboembolic pulmonary hypertension. CONCLUSIONS: The most informative scintigraphic signs of right-ventricular dysfunction in thromboembolism of the pulmonary-artery branches are as follows: a decrease in the RV stroke volume, peak ejection rate and filling rate which are revealed even in insignificant embolisation of the lesser-circulation vessels. The preserved functional ability of the right portions of the heart in patients with a small scope of damage to the vascular bed of the lungs may be regarded as a sign of acute thromboembolism, while systolic-diastolic dysfunction of the right ventricle as one of the indices of chronic post-thromboembolic pulmonary hypertension.