EOM: CARDIO

Question 1

The heart is supplied by:

Answer 1

Left and right coronary arteries

Question 2

The left coronary artery divides into:

Answer 2

Left anterior descending, left marginal and circumflex arteries

Question 3

Compared to other veins (35%), O2 saturation in coronary venous blood is very low. Why?

Answer 3

Oxygen extraction by cardiac muscle is much higher compared to other cells.

Question 4

What does the right coronary artery supply?

Answer 4

The inferior surface of the heart - right ventricle, right atrium, SAN and AVN

Question 5

The right coronary artery divides into:

Answer 5

Right marginal and posterior interventricular (80/85%) arteries

Question 6

What does the left coronary artery supply?

Answer 6

Left atrium and left ventricle

Question 7

When does blood flow to the myocardium occur?

Answer 7

Mainly during diastole

Question 8

What organ is responsible for the synthesis of coagulation factors and fibrinogen?

Answer 8

Liver

Question 9

What is the precursor for an enzymes that lyses clots?

Answer 9

Plasminogen ( –> plasmin, which breaks down fibrin into fibrin degradation products)

Question 10

What makes up the coagulation cascade?

Answer 10

A series of proteolytic enzymes that circulate in plasma in an inactive form, and generate thrombin when activated.
- Thrombin then catalyses the conversion of fibrinogen I (soluble) to fibrin (insoluble)

Question 11

What is the role of platelet dense granules?

Answer 11

Released upon cell activation, contain a high concentration of a molecule which acts as an agonist at the platelet P2Y12 receptor i.e. binds to it and activates it.

Question 12

What is responsible for the apex beat and where is it palpated?

Answer 12

Left ventricle - normally palpated in the left 5th intercostal space and midclavicular line.

Question 13

What prevents backflow of blood into the left atrium during ventricular systole?

Answer 13

Mitral valve

Question 14

What is the function of the aortic valve?

Answer 14

Maintains systemic diastolic blood pressure by preventing backflow of blood into the heart during diastole.

Question 15

What represents ventricular repolarisation?

Answer 15

T wave

Question 16

What is the normal duration for the PR interval?

Answer 16

0. 12 - 0.2 milliseconds
   - Period that extends from the beginning of the P wave (=onset of atrial depolarisation) to the beginning of the QRS complex

Question 17

What assesses the electrical activity within the lateral myocardial territory?

Answer 17

Leads I, aVL, V5 and V6

Question 18

Which lead yields complexes normally inverted compared to anterior and inferior leads?

Answer 18

aVR

Question 19

What happens to the ST segment during acute injury/infarction of a substantial myocardial territory?

Answer 19

Abnormal elevation (the larger the elevation, the more severe the problem)

Question 20

What does the QRS complex represent?

Answer 20

Ventricular depolarisaion

- Should last less than 0.12 milliseconds