ECG

Question 1

Blood flow through the heart.

Valves of the heart in order.

Answer 1

“Try Pulling My Aorta”

Try - Tricuspid,
Pulling - Pulmonary,
My - Mitral,
Aorta - Aortic.

Question 2

Electrical conduction of the heart.

Describe

Answer 2

“Sweet Apples Have Big Price”

Sweet - SA Node,
Apples - AV Node,
Have - HIS Bundle,
Big - Bundle branches,
Price - Purkinje fibres.

Question 3

“Try Pulling My Aorta”

Explain

Answer 3

Blood flow, and valves of the heart.

Try - Tricuspid,
Pulling - Pulmonary,
My - Mitral,
Aorta - Aortic.

Question 4

What is the defining feature of 1st Deg Heart Block?

How will this present on an ECG?

Answer 4

Slowed AV conduction.

A prolonged PR interval (>0.20 sec) that is constant throughout.

Question 5

What is the defining feature of 2nd Degree Type I Heart Block?

What will you see on an ECG?

Answer 5

An increasing delay of AV nodal conduction that continues until the atrial impulse fails to conduct.

An increasingly prolonged PR interval until a QRS complex is dropped.

Question 6

Another name for 2nd Degree Type I Heart Block.

Answer 6

Mobitz Type I,
or Wenckebach.

Question 7

Another name for 2nd Degree Type II
Heart Block.

Answer 7

Mobitz Type II.

Question 8

2nd Degree Type II (Mobitz type II)
Heart Block.

Describe the mechanism.

Answer 8

Mobitz II is usually due to failure of conduction at the level of the His-Purkinje system (i.e. below the AV node).

Question 9

What can be observed on an ECG with 2nd Degree Type II Heart Block.

Answer 9

The PR Interval is constant through out.
It may be normal or prolonged.
Suddenly, a QRS will be dropped.

Question 10

Second Degree Type II Characteristics:

QRS Complex

Answer 10

Depending on where the blocked electrical signal occurs, the QRS may be wide or narrow.

Question 11

1st degree AV block is not technically a block.

Explain.

Answer 11

It is a delay,
not an interruption,
in the conduction of atrial impulses to the ventricles, which results in a prolonged PR interval.

Question 12

Third degree (Complete) heart block.

Are the atria
(P waves) and ventricles (QRS) working together?

Answer 12

No. They operating independently.

The atrial rhythm is regular and the rate normal.

The ventricular rhythm is regular but the rate is typically much slower (Can be as slow as 40p/m).

• Likely to get variable PR Intervals.