Right ventricular myocardial infarction in patients with chronic lung disease: Possible role of right ventricular hypertrophy

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 la, 6.0 mm ± 1.1 in group Ib and 8.8 mm ± 2.4 in group II (group Ia versus Ib, p < 0.001; group la versus II, p < 0.001; group Ib versus II, p < 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 la (chronic lung disease without right ventricular hypertrophy and with inferior myocardial infarction) (p < 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 la and Ib. The cause of death was believed to be directly related to right ventricular myocardial infarction in 6 (33%) of 18 patients; 4 patients were from group Ib and 2 from group II.Patients with right ventricular hypertrophy as a result of chronic lung disease are prone to right ventricular myocardial infarction in the setting of inferior myocardial infarction. Isolated right ventricular myocardial infarction may occur in patients with chronic lung disease, right ventricular hypertrophy and insignificant coronary artery disease. Both increased myocardial oxygen demand and a decreased supply may play a role in this relation