Coronary angiogram levophase
Coronary angiogram levophase showing the catheter engaged in the left main coronary artery (artery not visible as it is the levophase). Levophase angiogram is a delayed recording after contrast injection into the coronary artery. After filling the coronary arteries, the contrast drains into the coronary venous system, finally opacifying the coronary sinus, which drains into the right atrium. The unmarked vein seen in the middle of the image is the middle cardiac vein and that in the left cardiac border the posterolateral vein. A small inconspicuous vein seen behind the coronary sinus label is the small cardiac vein. Distal region of the coronary sinus is joined by the great cardiac vein. Another distal vein not seen in the image is the oblique vein of Marshall (oblique vein of left atrium).
To get better visualization of the coronary sinus and its tributaries, a balloon occlusion angiography of the coronary sinus is done by cannulating it retrogradely from the right atrium. Visualization of coronary sinus and its tributaries are needed for placing the left ventricular lead in cardiac resynchronization therapy. A posterolateral vein is selected for left ventricular pacing in cardiac resynchronization therapy (CRT) for heart failure with wide QRS suggesting dyssynchrony.