Giant coronary artery aneurysms, though exceedingly rare, presentunique diagnostic and therapeutic challenges. The prevalence of giant coronary arteryaneurysms >50mm is 0.02%. While a universally accepted definition for giantcoronary artery aneurysms does not exist, commonly used definitions in theliterature include a diameter > 4 times the reference vessel diameter or ananeurysmal sac diameter of >20mm. Patients with giant coronary arteryaneurysms are often asymptomatic but may present with angina like symptoms,pericardial tamponade and sudden death. We present a case of one of the largestgiant coronary aneurysms ever recorded in medical literature.

An 82 year old woman presented to hospitalwith a three day history of worsening left sided pleuritic chest pain andepigastric pain. Her past medical history was significant for Crohn’s diseasewhich was well controlled. Her regular medications included Ustekinumab 90mgsubcutaneously every two months and mesalazine 800mg twice daily. ECG showedsinus tachycardia at 97 beats per minute with less than one millimeter of STelevation in II, III and aVF. Large P waves were noted in the inferior leads.Initial troponin was elevated at 597ng/L (normal range 0 to 14ng/L) and D dimerwas elevated at 902ng/mL (normal range 0 to 200ng/mL).

CTpulmonary angiogram showed a massive cardiac mass compressing the right atriumand ventricle which was 67mmm x 72mm x 97mm in size (see images 1 and 2). Itwas initially interpreted as a solid homogenous mass. Transthoracicechocardiogram was performed which showed normal systolic function with anejection fraction of 65% and what was initially interpreted as severe rightatrial dilatation. Right ventricular function was moderately to severelyreduced. A coronary angiogram was performed which showed that the cardiac masswas in fact a massive coronary aneurysm, originating from the right coronaryartery. Right sided collateralization from the left circumflex artery wasnoted. The patient then underwent CT coronary angiogram with the right coronaryaneurysm measuring 103mm x 83mm x 74mm. A distance between the arterial inflowand outflow of approximately 91mm was noted. The right coronary artery aneurysmwas further visualized with 3D reconstruction (see image 3). Followingdiscussion at the Heart Team Meeting, the patient underwent single coronaryartery bypass, with median sternotomy, subtotal resection of the aneurysm walland utilization of a saphenous vein graft. Transthoracic echocardiogrampost-operatively showed an improvement in right ventricular function with residualmild to moderate impairment.

Giantcoronary aneurysms are an exceptionally rare cause of presentation to hospitalwith a prevalence of 0.02% of aneurysms >50mm. Transthoracic echocardiogram,as an initial investigation, may not reliably identify these masses as coronaryartery aneurysms. CT coronary angiogram is a useful tool for coronary arteryaneurysm diagnosis as well as for aneurysm visualization with 3D reconstructionand operative planning.