Acute coronary syndrome

Question 1

In an MI setting what are the different cardiac serum markers used to confirm MI, and which one is the most accurate?

Answer 1

You can use troponin I, troponin T, and CK-MB (creatinine kinase muscle/brain)

Troponin I is shown to be most accurate marker of MI in literature.

NOTE: troponin I should be measured 3 hours later after initial measurement as it rises.

Question 2

What are the coronary arteries of the heart, and their branches (briefly)?

NOT their areas of supply.

Answer 2

Right coronary artery and left coronary arteries.

Right coronary arteries divide into right marginal artery, SA nodal artery (60%), AV nodal artery and posterior interventricular branch.

Left coronary arteries divide into left circumflex artery and left marginal artery, left anterior descending artery (anterior interventricular artery), SA nodal artery (40%).

Question 3

What areas do arteries of right coronary arteries supply?

Answer 3

RCA arises from right aortic sinus of the ascending aorta and runs along atrioventricular groove.

• SA nodal artery supplies SA node
• Right marginal artery supplies apex and part of right ventricle
• Right anterior ventricular arteries supply RV
• AV nodal artery supplies AV node
• Posterior interventricular branch runs along inferior surface to the base of the heart to apex

Question 4

What areas do arteries of left coronary arteries supply?

Answer 4

LCA arises from aortic sinus between left auricle and infundibulum of right ventricle.

• Left circumflex artery can produce SA nodal artery, anastomoses with RCA
• Left anterior descending artery gives large anterior ventricular branches, anastamoses with posterior interventricular artery at apex, and supplies LA, LV, interventricular septum and AV bundle

Question 5

What are the different types of coronary veins?

Answer 5

1. Great cardiac vein
2. Small cardiac vein
3. Middle cardiac vein
4. Posterior vein of left ventricle
5. Oblique vein of left atrium

Question 6

What is the course and drainage of great cardiac vein?

Answer 6

Great cardiac vein begin at apex, ascends in anterior interventricular groove next to LAD, and continues along circumflex artery into left end of the coronary sinus.

Question 7

What is the course and drainage of small cardiac vein?

Answer 7

It accompanies the right marginal artery. It drains into coronary sinus and/or right atrium directly.

Question 8

What is the course and drainage of middle cardiac vein?

Answer 8

It begins at apex and ascends in the posterior interventricular groove alongside posterior interventricular artery to fuse with coronary sinus.

Question 9

What is the course of posterior vein of left ventricle?

Answer 9

Joins to the left of middle cardiac vein.

Question 10

what is the course of oblique vein of left atrium?

Answer 10

Runs downwards into the left end of the coronary sinus?

Question 11

What is the common site of stenosis and atherosclerosis formation in the coronary circulation?

Answer 11

1. LAD
2. RCA
3. LCA

Question 12

What is the blood supply of SA node?

Answer 12

60% RCA

40% Left circumflex artery

Question 13

How do you identify AV node?

Answer 13

Look for triangle of Koch:

bordered by tendon of Todaro, coronary sinus and tricuspid valve cusp.

Question 14

As a complication of MI where is it most likely to rupture in the heart?

Answer 14

Interventricular septum
Papillary muscles (lead to mitral regurgitation)
Left ventricular free wall (leading to cardiac tamponade)

Question 15

List three causes of pansystolic murmur.

Answer 15

1. Mitral regurgitation
2. Tricuspid regurgitation
3. Ventricular septal defect