Intercoronary communication (ICC) is an extremely rare congenital anomaly where a direct connection exists between two coronary arteries. Physicians generally consider this condition benign because it often serves as a "safety valve" during obstructive events. However, a recent case report highlights a paradoxical scenario where intercoronary communication vasospasm directly induced myocardial stunning and ischemia.

Consequently, a 79-year-old woman presented with rest angina, which prompted immediate clinical investigation. Furthermore, initial transthoracic echocardiography revealed hypokinesia in the posterolateral left ventricular wall. Subsequently, coronary angiography identified an ICC between the left circumflex artery and the right coronary artery. During an acetylcholine-induced provocation test, focal coronary vasospasm occurred exclusively within the ICC itself. Importantly, this spasm was relieved after administering intracoronary isosorbide dinitrate, confirming the functional nature of the obstruction.

Clinical Significance of Intercoronary Communication Vasospasm

The case illustrates that ICC is not always a protective feature. Specifically, the localized vasospastic activity within the communication channel led to significant myocardial ischemia. This finding challenges the traditional view of ICC as purely beneficial. Following the diagnosis, the patient received oral vasodilators. Fortunately, she remained symptom-free during the follow-up period, and echocardiography showed a complete recovery of wall motion. Therefore, clinicians should consider vasospasm within anomalous connections when evaluating patients with ischemia but no obstructive coronary disease.

Frequently Asked Questions

What is intercoronary communication (ICC)?

ICC is a rare congenital coronary anomaly where two coronary arteries are connected by a vessel with open-ended circulation, distinct from collateral vessels found in obstructive disease.

Can ICC cause myocardial ischemia?

While often benign, ICC can lead to ischemia through mechanisms like coronary steal or localized vasospasm within the communicating vessel.

Disclaimer: This content is for informational and educational purposes only. It does not constitute professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

1. Mizokami G et al. Myocardial Stunning Induced by Vasospasm Within an Intercoronary Communication. JACC Case Rep. 2026 Mar 10. doi: undefined. PMID: 41805276.

2. Medscape. Coronary Artery Vasospasm: Background, Etiopathophysiology, Epidemiology. Available at: https://www.medscape.com

3. National Institutes of Health. Intercoronary Communication between the Circumflex and Right Coronary Arteries Coexisted with Coronary Vasospasm. Available at: https://www.ncbi.nlm.nih.gov