Electrocardiogram

Question 1

P-wave?

Answer 1

Atrial depolarization

Question 2

What happens to the atrial repolarization?

Answer 2

It is masked by the QRS complex

Question 3

PR interval?

Answer 3

Conduction delay through AV node

Question 4

How long is the PR interval?

Answer 4

<200 msec

Question 5

QRS complex?

Answer 5

Ventricular depolarization

Question 6

How long is the QRS complex?

Answer 6

<120 msec

Question 7

QT interval?

Answer 7

Mechanical contraction of the ventricles

Question 8

T-wave?

Answer 8

Ventricular repolarization

Question 9

What would a T-wave inversion indicate?

Answer 9

Recent MI

Question 10

ST segment?

Answer 10

Isoelectric, ventricles depolarized

Question 11

U-wave?

Answer 11

• Hypokalemia

- Bradycardia

Question 12

What is the speed of conduction order?

Answer 12

Purkinje>Atria>Ventricles>AV Node

Question 13

What are the pacemakers speed of conduction?

Answer 13

SA>AV>Bundle of His/Purkinje/Ventricles

Question 14

What is the conduction pathway?

Answer 14

SA Node–>Atria–>AV node–>Common bundle–>Bundle branches–>Purkinje fibers–>Ventricles

Question 15

A prolongued QT interval can lead to ….

Answer 15

Torsades de pointes

Question 16

Torsades the pointes is a ventricular tachycardia that can progress to….

Answer 16

Ventricular fibrillation

Question 17

Congenital long QT syndromes are most often due to defects in…

Answer 17

Cardiac sodium or potassium channels

Question 18

Long QT syndrome in Jervell and Lange-nielsen syndrome can present with…

Answer 18

Sensorineural deafness

Question 19

ANP is released from ________ in response to _______ and _________.

Answer 19

Atrial myocytes, increased blood volume, atrial pressure

Question 20

ANP causes…

Answer 20

• Vascular relaxation
• Decreased Na resorption at medullary collecting tubule
• Constricts efferent renal arterioles
• Dilates afferent renal arterioles (cGMP)