Presentation
Palpitations investigated with echocardiogram found coronary sinus dilation prompting MRI and CT investigation for a left sided SVC or unroofed sinus.
Patient Data
- ECG gated, axial CTA shows a small connection between the distal left circumflex artery and the coronary sinus which is grossly dilated, with small regions of eccentric calcification, but separate to the left atrium, draining into the right atrium.
- Adjacent pulmonary subsegmental left lower lobe atelectasis.
- Profound dilation and tortuosity of the left coronary system with relatively small caliber of the mid to distal LAD.
- Eccentric, calcified atherosclerosis within the mid LAD and mid circumflex.
- The right coronary artery is not involved.
- Dilation of the pulmonary trunk relative to the aorta.
Case Discussion
The coronary artery to sinus connection effectively creates a sizable left to right shunt, with the high pressure left coronary artery circulation preferentially flowing into the low pressure venous sinus, with vastly increased flow as a result, leading to profound dilation and tortuosity of the left coronary system. The relatively small caliber of the mid to distal LAD is due to steal phenomenon, which can cause diffuse subendocardial ischemia within the left ventricle.
Dilation of the pulmonary trunk relative to the aorta is due to the established left to right shunt.
ECG gated post cardiac CT with left and right heart contrast is the optimal test to accurately assess coronary artery and venous anatomy in multiple planes, to facilitate planning and workup of these cases.
Follow up cardiac MRI with contrast may be helpful to quantify the shunt, assess right heart dilation and function and detect the volume of chronic myocardial ischemia caused by steal.
Unable to process the form. Check for errors and try again.