Discussion
Bacterial infection of the pericardial space is an uncommon cause of pericardial effusion1. Infected coronary artery aneurysms are rare and they occur mostly after stent placement or in septic and immune-compromised patients. However, spontaneous ICAAs have been reported previously3, as in our case. The literature of ICAA is mainly based on case reports or case series4,5. The clinical course of coronary artery aneurysm remains largely unpredictable and without appropriate diagnosis and treatment the outcome is invariably poor with sepsis and aneurysmal rupture with resultant hemodynamic collapse and death4. Exceedingly high morbidity and mortality have been reported (mortality 43-53%)5. Surgical management was the treatment of choice for the most ICAAs. The most common surgical method is ICAA resection and distal bypass of the artery (mortality rate of 20.9%)5.
Our case is also uncommon in that the presentation involved purulent pericarditis. It is unknown whether the aneurysm or purulent pericarditis preceded. The impaired systolic function of the right ventricle can be attributed to the myocardial ischemia of the right ventricle due to the RCA aneurysm. Consequently, we can not determine if the ICAA was the cause of purulent pericarditis (ICAA leak into the pericardial sac) or the result of the purulent pericarditis (local injury of the CAA due to the artery’s wall inflammation and artery’s wall bacterial infection from pericardial fluid) . Therefore, safe conclusions about the onset of purulent pericarditis and the formation of the CAA can not be drawn.
In conclusion, this was a rare case of a spontaneous giant “mycotic” aneurysm of the RCA presented with purulent pericarditis. ICAAs present high mortality and surgical management is the treatment of choice in most cases. When purulent pericarditis and ICAA co-exist the riddle of the chicken and the egg becomes apparent.