Introduction
Previously published studies showed differences regarding the prevalence of intraventricular thrombi in patients with acute myocardial infarction (MI) (4–56%). Until now there are no exact results about the occurrence of left ventricular thrombi in acute STEMI. Recognition of LV thrombus is important because the related risk of systemic embolization is high.
Methods
To investigate the extent of myocardial infarction we examined 225 consecutive patients undergoing primary percutaneous coronar intervention (PCI) in acute STEMI within 12 h after symptom onset by cardiac magnetic resonance imaging within 2– 4 days. Routinely all patients were examined with transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). All images were analyzed for the presence of intraventricular thrombi.
Results
In 18 patients (8.0%) we detected left ventricular thrombi, but none of these were seen in TTE or TEE. In two cases an intraventricular thrombus was detected by TEE and TTE, but in the subsequently performed MRI no thrombus was found. In all cases the left ventricular thrombi could be detected in the late enhancement sequence, 8 (44.4%) of them were missed in the cine SSFP sequences. Left ventricular thrombi were more frequently diagnosed in patients with moderate to severe impairment of the left ventricular systolic function (13/18 [72,2%]). Remarkable was also that 14 (77.8%) of the 18 patients with left ventricular thrombus in MRI had an anterior MI, whereas only 2 (11.1%) had an inferior MI, 1 (5,6%) a septal MI and 1 patient (5,6%) a lateral MI.
Conclusion
In our study TEE and TTE missed left ventricular thrombi in all 18 patients as compared to MRI. There were two false-positive results in TEE and TTE as compared to MRI. Patients with impaired left ventricular function and acute anterior MI have a higher risk of developing left ventricular thrombi than in other infarct-locations. Therefore it could be potentially important to screen in particular high-risk patients (with anterior MI and impaired left ventricular function) with cardiac magnetic resonance imaging to exclude left ventricular thrombi and to lower the risk of embolic events. In particular late enhancement sequences are suitable to detect intraventricular thrombi.
Prognostic impact of unrecognized myocardial scar in the non-culprit territories by cardiac magnetic resonance imaging in patients with acute myocardial infarction