[Intravascular ultrasound in recurrent myocardial ischemia and unremarkable coronary angiogram]. / Intravaskulärer Ultraschall bei rezidivierender Myokardischämie und unauffälligem Koronarangiogramm.

ABSTRACT

HISTORY AND CLINICAL FINDINGS: 3 months after sustaining an intramural anterior wall myocardial infarction (AWMI) a 57-year-old man was again admitted with the clinical and electrocardiographic (ECG) signs of an acute AWMI. As the activities of creatinine kinase (841 U/l) and of the myocardial isoenzyme (CKMB 143 U/l) were markedly elevated, thrombolysis with streptokinase was instituted. Subsequent left heart catheterization demonstrated discrete wall irregularity in the proximal branch of the anterior interventricular artery (PAIVA) and the right coronary artery, but no evidence of stenosing coronary heart disease. TREATMENT AND COURSE Because of the discrepancy in the findings, intravascular ultrasound imaging (IVUI) was performed. It revealed an eccentric unstable plaque in the PAIVA with a minimal cross-sectional stenosis of 3.3 mm2 (50% luminal narrowing). After stent implantation under IVUI a good primary result was achieved (stent cross-sectional area 6.2 mm2). CONCLUSION: The usual cause of acute MI is rupture of an unstable, not flow-limiting and thus angiographically possibly "silent" plaque. IVUI can provide immediate assessment of atheromatous wall changes and can thus help to decide on further specific interventional measures.