Lecture 1 - Intro

Question 1

What is an EKG?

Answer 1

graphic representation of the heart’s electrical activity

Question 2

What are the two components of EKG interpretation?

Answer 2

descriptive analysis, clinical impression

Question 3

Which part of heart dominates anterior view?

Answer 3

Right ventricle

Question 4

Which part of heart dominates electrical view?

Answer 4

Levt ventricle

Question 5

What is automaticity?

Answer 5

ability to create action potentials/pacemaking capability

Question 6

What is the main function of the electrical conduction system?

Answer 6

create an electrical impulse and transmit it to the rest of the myocardium

Question 7

Where is the conduction system in relation to the myocardium?

Answer 7

inside the myocardium

Question 8

How are atrial myocytes innervated?

Answer 8

direct contact from one cell to another

Question 9

What do the internodal pathways do?

Answer 9

transmit the impulse from the SA node to the AV node

Question 10

What is the final component of the conduction system and what does it do?

Answer 10

purkinje system - innervates myocardial cells in ventricles

Question 11

What is overdrive suppression?

Answer 11

pacemaker with highest rate sets the pace of all other cells that will follow

Question 12

What creates the effective pumping action of the heart?

Answer 12

overdrive suppression - creates an organized beating of all cardiac cells in a specialized sequence

Question 13

What is the order of pacemaker settings and backup system? (7)

Answer 13

SA node, atrial cells, AV node, Bundle of His, Bundle branch, Purkinje cells, Myocardial cells

Question 14

What is the primary pacemaker?

Answer 14

SA (sinoatrial) node

Question 15

What is the normal rate of the SA node? What is the rhythm originating from here called?

Answer 15

60-100 bpm. sinus rhythm

Question 16

What is the SA node’s blood supply?

Answer 16

right coronary artery (sometime left)

Question 17

What is the purpose of the internodal pathways?

Answer 17

transmit the impulse from SA node to the AV node

Question 18

How many internodal pathways are there?

Answer 18

3: anterior, middle, posterior

Question 19

What does the AV node?

Answer 19

responsible for slowing down conduction for atrial contraction-maximizes cardiac output

Question 20

What is the AV node’s blood supply?

Answer 20

right coronary artery (always)

Question 21

What is the only route of electrical communication between the atria and ventricles?

Answer 21

Bundle of His

Question 22

Where does the left bundle branch begin and end?

Answer 22

begins at Bundle of His, ends at beginning of left anterior and left posterior fascicles (LAF, LPF)

Question 23

What does the left anterior fascicle innervate? Where does it end and how many strands is it?

Answer 23

innervates anterior and superior left ventricle. terminates in purkinje fibers. single-stranded.

Question 24

What does the left posterior fascicle innervate? Where does it end and what is its structure like?

Answer 24

Innervates inferior and posterior left ventricle. terminates in purkinje fibers. Fan-like structure.

Question 25

Which is more easily blocked: left anterior fascicle or left posterior fascicle, and why?

Answer 25

The left anterior fascicle is more easily blocked because it is single-stranded. The left posterior fascicle is thicker, more difficult to block, and more difficult to interpret on EKG.