To determine the relation between right ventricular hypertrophy and right ventricular myocardial infarction in patients with chronic lung disease, the records of 28 patients with chronic lung disease, inferior myocardial infarction and significant coronary artery disease (group I) and 20 patients with right ventricular hypertrophy, chronic lung disease without inferior myocardial infarction or significant coronary artery disease (group II) were reviewed. Chronic lung disease was diagnosed by clinical criteria, chest radiographs and pulmonary function tests. All patients had postmortem examinations. Patients in group I were classified into two subgroups: group Ia (without right ventricular hypertrophy) and group Ib (with right ventricular hypertrophy). Right ventricular wall thickness was 3.3 mm +/- 0.5 in group Ia, 6.0 mm +/- 1.1 in group Ib and 8.8 mm +/- 2.4 in group II (group Ia versus Ib, p less than 0.001; group Ia versus II, p less than 0.001; group Ib versus II, p less than 0.001). Eleven patients (78.6%) in group Ib (chronic lung disease with both right ventricular hypertrophy and inferior myocardial infarction) had right ventricular myocardial infarction compared with only 3 patients (21.9%) in group Ia (chronic lung disease without right ventricular hypertrophy and with inferior myocardial infarction) (p less than 0.008). Isolated right ventricular myocardial infarction occurred in four patients (20%) in group II (chronic lung disease with right ventricular hypertrophy, but without evidence of infarction of the left ventricle or significant coronary artery disease). There was no significant difference in the extent of anatomic coronary disease in groups Ia and Ib.(ABSTRACT TRUNCATED AT 250 WORDS)