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[Intravascular ultrasound in recurrent myocardial ischemia and unremarkable coronary angiogram]
N Scheffold1, H Schöngart, N Kaag
1Medizinische Klinik I, Städtisches Krankenhaus Heilbronn.
Insights
A recurrent acute myocardial infarction (MI) was caused by a ruptured plaque not visible on angiography. Intravascular ultrasound imaging (IVUI) identified the unstable plaque, guiding successful stent implantation.
Area of Science:
- Cardiology
- Interventional Cardiology
- Medical Imaging
Background:
- Recurrent acute myocardial infarction (MI) can occur despite initial treatment.
- Coronary angiography may not always reveal the underlying cause of MI, particularly non-flow-limiting plaques.
Observation:
- A 57-year-old male presented with recurrent anterior wall MI symptoms and elevated cardiac enzymes.
- Left heart catheterization showed irregularities but no significant stenosis in the proximal anterior interventricular artery (PAIVA).
- Intravascular ultrasound imaging (IVUI) revealed an eccentric, unstable plaque in the PAIVA with 50% luminal narrowing.
Findings:
- The unstable plaque identified by IVUI was the cause of the recurrent MI.
- Successful stent implantation was performed under IVUI guidance.
- IVUI provided crucial information for interventional decision-making.
Implications:
- Rupture of angiographically 'silent' plaques is a common cause of acute MI.
- IVUI is valuable for assessing atheromatous changes and guiding interventions in complex MI cases.
- This case highlights the utility of IVUI in managing recurrent MI when conventional angiography is inconclusive.
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.