Thromboembolic Pulmonary Hypertension Induced Myocardial Ischemia in a Patient With Anomalous Right Coronary Artery

Patients with pulmonary hypertension (PH) occasionally develop angina pectoris due to compression of the left coronary artery ostium between the enlarged pulmonary artery and aorta. We describe a case of anomalous right coronary artery (RCA) presenting as transient myocardial ischemia induced by thromboembolic PH.

A 61-year-old man with an anomalous RCA was referred for the treatment of angina pectoris. Coronary angiography depicted severe stenosis of the ostium of the anomalous RCA (Figure A, Supplementary Movie). Adenosine-stressed myocardial perfusion single photon emission computed tomography (SPECT) demonstrated reversible myocardial ischemia of the inferior left ventricle with right ventricular loading (Figure B). Because negative T-wave inversions were newly observed on SPECT (Figure C), we performed coronary computed tomography angiography, which revealed a submassive pulmonary embolism (Figure D–G). Anticoagulant therapy (rivaroxaban) improved pulmonary embolism and exertional symptoms¹ (Figure H). Follow-up exercise-stressed SPECT did not detect ischemia (Figure I).

Figure.

(A) Severe stenosis of the right coronary artery (RCA) ostium on right anterior oblique view (arrow). (B) Reversible ischemia in the inferior region of the left ventricle (Upper: under stress, Lower: at rest). (C) New-onset negative T waves. (D) RCA taking-off at the left coronary cusp. (E) Anomalous RCA being compressed by the pulmonary artery (green). (F) Bilateral pulmonary emboli (arrows). (G) D-shaped intraventricular septum (*) suggesting pulmonary hypertension (pulmonary artery pressure: 63 mmHg). (H) Absence of pulmonary emboli after treatment. (I) No induction of myocardial ischemia. (A) Before referral; (B–G) diagnosis of pulmonary thromboembolism; (H,I) at follow-up.

PH could cause myocardial ischemia in the territory of the RCA, as a result of the compression of the RCA ostium and right ventricular overload. New symptom onset in patients with an anomalous RCA may signal concurrent PH.

This article was written in accordance with the Declaration of Helsinki.

Acknowledgments

We thank all those involved in the treatment of the patient.

Conflicts of Interest

None.

Supplementary Files

Supplementary Movie. Right coronary artery (RCA) angiography showing its narrowed ostium.

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-22-0115

Reference

• 1.   Yamashita Y, Morimoto T, Kimura T. Venous thromboembolism: Recent advancement and future perspective. J Cardiol 2022; 79: 79–89.