Ventricular mural thrombi - An occult occurrence?

Background: Ventricular mural thrombi are rare occurrences and form one of the common mechanical complications of myocardial infarctions. They also occur in patients with nonischemic myocardial disorders and even in those devoid of cardiac diseases. Clinical detection often depends on the size of the thrombi.

Aim: This study was aimed at ascertaining the etiopathogenesis of mural thrombi with a clinicopathologic correlation.

Materials and methods: This was a 12-year retrospective observational study reviewing the autopsy records of all cases showing ventricular mural thrombi. The location, size, morphology, and histologic appearances of the thrombi were noted. The cases, depending on the etiology, were categorized into myocardial ischemic (Group 1), myocardial nonischemic (Group 2), and non-myocardial (Group 3) causes. These features were correlated with the clinical settings.

Results: There were 93 cases of mural thrombi with an almost equal sex distribution and a mean age of 45.9 years. The cause was ischemic heart disease in most of the patients (Group 1, 46.2%), while 21.5% and 32.3% of patients belonged to Group 2 and Group 3, respectively. Unlike the large and dominantly left ventricular thrombi seen in Group 1, the other two groups frequently had biventricular involvement, location in the intertrabecular spaces, and a high microscopic detection. Clinical diagnosis had been made in only 3.2% of patients. Thromboembolism was noted in other organs in 34.4% of the total cases.

Conclusion: Ventricular thrombi should be ruled out in patients with evidence of systemic and/or pulmonary thromboembolism, even in those without any cardiac disorders.