Type X dual left anterior descending (LAD) artery masquerading as type 1 LAD \u2014 a case report

Anish Bhargav,Manphool K Singhal,Parminder S Otaal

doi:10.1186/s43162-021-00053-0

Abstract

BackgroundDual left anterior descending (LAD) coronary artery is a rare congenital anomaly. To date, eleven variants of dual LAD have been described with three published reports of type X dual LAD. Here, we describe a new variant of type X dual LAD with a short LAD artery masquerading as type 1 LAD.Case presentationA 42-year hypertensive female presented with recent onset angina with a treadmill test positive for inducible ischemia. Coronary angiography showed a normal right coronary artery (RCA). The left main coronary artery (LMCA) originated from the left sinus of Valsalva (SOV), giving rise to a LAD and the left circumflex artery (LCX). Appearing a normal angiogram with type 1 LAD based on its length, the presence of a large bare area in LAD territory (especially at the apex) and lack of septal branches prompted a search for an additional vessel. Right SOV injection showed a vessel originating separately from RCA, which was confirmed to be a long LAD on selective injection, with a pre-pulmonic course and giving rise to septal branches exclusively before wrapping around the apex. Computed tomography coronary angiography (CTCA) confirmed the pre-pulmonic course of long LAD, defined its entry to the distal interventricular septum to the right of short LAD, and ruled out other coronary artery anomalies. In the absence of a stenotic lesion in the epicardial coronaries, angina in our case was presumed to be due to microvascular dysfunction. She was discharged on beta-blocker therapy for co-existing hypertension and is asymptomatic on follow-up at one year.ConclusionsA short LAD artery of type X Dual LAD could be potentially misdiagnosed as type 1 LAD based on its length. However, an active search for a long LAD could properly diagnose the case as a variant of type X dual LAD, which has important clinical implications. Its awareness is critical for cardiologists and cardiac surgeons to correctly interpret the coronary angiogram and plan proper management.

Highlights

Dual left anterior descending (LAD) coronary artery is a rare congenital anomaly
Our immediate angiographic reassessment and search for long LAD correctly classified it as a new variant of published cases of type X Dual LAD
Appearing as a normal angiogram with type 1 LAD based on its length, a review prompted a search for anomalous segment due to the presence of a large bare area in LAD territory and lack of septal branches

Summary

Conclusions

Our report shows that the short LAD artery of type X dual LAD may be misinterpreted as type 1 LAD based on its length. A high index of suspicion and an active search for long LAD is the key to properly diagnose type X dual LAD, especially in the presence of a bare area. Delineation of anomalously arising vessel and knowledge of existing patterns of dual LAD is indispensable for the cardiologists and cardiac surgeons for correctly interpreting the coronary angiogram and planning a proper management. Patient’s perspective I am a 42-year-old lady with a long history of high blood pressure for the last 10 years. For the last 2 months, I developed some chest discomfort and heaviness, which worsened with activity. After ignoring my symptoms initially, I consulted my doctor who advised me a treadmill test followed by coronary angiography. I underwent angiography, which did not reveal any blockage of my heart vessels, as was thought earlier.

Background

Discussion