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Pure right ventricular infarction
Katsuji Inoue1, Hiroshi Matsuoka, Hideo Kawakami
1Department of Cardiology, Ehime Prefectural Imabari Hospital, Japan. katsu2@dokidoki.ne.jp
Insights
This case study highlights pure right ventricular infarction, a condition mimicking anterior myocardial infarction due to right coronary artery occlusion. Early diagnosis is crucial for effective patient management.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Interventional Cardiology
Background:
- Acute myocardial infarction diagnosis typically relies on electrocardiography (ECG) and cardiac enzyme markers.
- Anterior myocardial infarction is characterized by ST-segment elevation in specific ECG leads.
- Right ventricular infarction can present with similar ECG findings, complicating diagnosis.
Observation:
- A 76-year-old man presented with chest pain and ECG findings suggestive of acute anterior myocardial infarction.
- Coronary angiography revealed ostial occlusion of a hypoplastic right coronary artery (RCA) with normal left coronary arteries.
- Nuclear imaging confirmed infarction limited to the right ventricular free wall, with normal left ventricular function.
Findings:
- The patient experienced ST-segment elevation in anterior and right precordial leads, mimicking anterior infarction.
- Despite ECG similarities, the infarction was isolated to the right ventricle due to ostial RCA occlusion.
- Conservative management led to favorable clinical outcomes and symptom resolution.
Implications:
- Pure right ventricular infarction should be considered in the differential diagnosis of ST-segment elevation myocardial infarction, especially with right precordial lead involvement.
- Accurate diagnosis requires a combination of ECG, coronary angiography, and nuclear imaging.
- Understanding this specific infarction pattern is vital for appropriate treatment strategies and prognosis.
Abstract:
A 76-year-old man with chest pain was admitted to hospital where electrocardiography (ECG) showed ST-segment elevation in leads V1-4, indicative of acute anterior myocardial infarction. ST-segment elevation was also present in the right precordial leads V4R-6R. Emergency coronary angiography revealed that the left coronary artery was dominant and did not have significant stenosis. Aortography showed ostial occlusion of the right coronary artery (RCA). Left ventriculography showed normal function and right ventriculography showed a dilated right ventricle and severe hypokinesis of the right ventricular free wall. Conservative treatment was selected because the patient's symptoms soon ameliorated and his hemodynamics was stable. 99mTc-pyrophosphate and 201Tl dual single-photon emission computed tomography showed uptake of 99mTc-pyrophosphate in only the right ventricular free wall, but no uptake of 99mTc-pyrophosphate and no perfusion defect of 201Tl in the left ventricle. The peak creatine kinase (CK) and CK-MB were 1,381 IU/L and 127 IU/L, respectively. His natural course was favorable and the chest pain disappeared under medication. Two months after the onset, the ECG showed poor R progression in leads V1-4 indicating an old anterior infarction. Coronary angiography confirmed the ostial stenosis of the hypoplastic RCA. This was a case of pure right ventricular free wall infarction because of the occlusion of the ostium of the hypoplastic RCA, but not of the right ventricular branch. Because the electrocardiographic findings resemble those of an acute anterior infarction, it is important to consider pure right ventricular infarction in the differential diagnosis.