[Right ventricular visualization by Tl-201 myocardial scintigraphy in chronic obstructive pulmonary disease]

Tl-201 myocardial scintigraphy was performed in 130 patients with chronic obstructive pulmonary disease (COPD) to evaluate right ventricular hypertrophy, and the clinical significance of this method was studied. Tl-201 uptake ratio of the right ventricle, which represents the ratio of total counts of the right ventricle to counts of the administered dose of Tl-201, was higher in COPD, especially in pulmonary emphysema and B type COPD by Burrows classification than in controls. The grade of visualization of the right ventricle by visual assessment (RVV) was marked (+3) in only a few cases and moderate (+2) in many cases (more than 80%) in all diseases except bronchial asthma. The incidences of right ventricular hypertrophy by electrocardiogram, right-sided heart failure and marked dyspnea (Hugh-Jones 4.5) were very low in cases with RVV grade +2 and very high in cases with +3. The grade of RVV was related to the severity of pulmonary perfusion impairment, although in diffuse panbronchiolitis the RVV was relatively slight compared with the impairment of perfusion. May parameters of pulmonary function such as %VC, FEV1.0%, RV/TLC, V25, %DLCO, Raw, delta N2 and PaO2 showed abnormal values in patients with RVV grade of (+2) or (+3) in all diseases except bronchial asthma. In COPD, Tl-201 myocardial scintigraphy seems to be useful for assessment of right ventricular overloading, and for follow-up observation and differentiation between cor pulmonale and right ventricular hypertrophy secondary to cardiac diseases by observing Tl-201 uptake of the lung and left ventricle.