Hypoplastic right coronary artery

A hypoplastic right coronary artery refers to an underdeveloped or small-sized right coronary artery (RCA) with a narrowed lumen or a short course.  

Epidemiology

Associations

Clinical conditions associated with a hypoplastic right coronary artery include ^1,2:

• left coronary arterial dominance
• other congenital coronary artery anomalies e.g. absent left main coronary artery
• sudden cardiac death

Clinical presentation

A hypoplastic right coronary artery can be an incidental finding on invasive coronary angiography,  cardiac CT or cardiac MRI, there have been also reports of syncope or sudden cardiac death as an initial presentation ¹.

Complications

A hypoplastic right coronary artery can lead to the following conditions ^1,2:

• arrhythmia
• myocardial ischemia
• sudden cardiac death

Radiographic features

Usually, the term hypoplastic right coronary artery is used in case of a short course that does not reach the crux cordis,  a further feature is a narrow vessel lumen ^1-4.

Radiology report

The radiological report should include a description of the following features:

• right coronary artery origin, course, segments
• left main coronary artery origin and variant anatomy
  • left anterior descending artery with course branches and segments
  • circumflex artery with its course, branches and segments
• coronary artery stenoses with location based on the AHA coronary artery segment model

Treatment and prognosis

There seems to be no clear management strategy. Due to an increased risk of arrhythmia, the implantation of an implantable cardioverter-defibrillator (ICD) has been recommended ¹.

History and etymology

A right rudimentary coronary artery has been first described by Walter B.Whiting  in 1937 ⁵. The term hypoplastic coronary artery has been used by JA Ogden in 1970 ⁶.

Differential diagnosis

The differential diagnosis of hypoplastic right coronary artery includes the following:

• right coronary artery stenosis
• right coronary artery occlusion