ECG

Question 1

What are the pre-excitation syndromes?

Answer 1

Pre-excitations syndromes occur when at least one extra conductive pathway exists between the atria and the ventricles

The three most common types of pre-excitations syndromes are

1) wolf parkinson white
2) Lown-ganong-levine syndrome
3) Mahaim-type

Question 2

What are the features of Wolf-Parkinson-White Syndrome?

How do you differentiate it from other pre-excitations syndromes?

Answer 2

1) PR interval is short < 120 ms
2) QRS interval long > 110
3) Presence of a delta wave (sluring slow rise of QRS)
4) ST segment and T wave discordant changes-
5) pseudo infarction pattern- negatively deflected delta waves in inferior/ anterior leads

Wolf Parkinson White has Bundle of Kent

Wolf Parkinson White has a small risk of sudden cardiac death

Often has the history of palpitations where they valsalva to get it under control

Question 3

What are the features of atrial flutter?

Answer 3

Regular tachycardia with QRS < 120ms at a rate of 240-340/min

Flutter waves in lead II, III, AVF are typically inverted and without an isoelectric baseline

Flutter waves in V1 are small positive deflections with a distinct isoelectric baseline

AV conduction ratio is usually fixed

Question 4

What is the diagnostic pathway for an arrhythmia?

Answer 4

Question 5

What are the differences between a junctional and a ventricular escape rhythm?

Answer 5

Junctional rhythm

• rate 40-60 bpm
• QRS typically narrow (< 120 ms)
• no relationship between QRS complexes and any preceeding atrial activity

Ventricular escape rhythm

• ventricular rhythm of 20-40
• QRS complexes are broad (> 120 ms) and may have a LBBB or RBBB morphology

Question 6

What are the rates of the ectopic rhythms?

Answer 6

SA node ( 60-100 BPM)

Atria (< 60)

AV node ( 40-60)

Ventricles (20-40)

Question 7

What are the differences between first, second and third degree heart blocks, and what is their respective treatment
?

Answer 7

Type 1

-lengthened pr interval > 200ms

all p waves are conducted

Type 2

a) mobitz type 1
- pr interval increases until a beat is dropped
- resulting p wave of a dropped beat is not followed by a qrs
b) mobitz type 2
- dropped beats without pr interval increasing
- THIS INDICATES A BLOCK WITHIN THE BUNDLE OF HISS
- Mobitz type 2 can progress to third degree heart block–>therefore it is an indication for pacemaker

Third degree heart block

SA node and AV

Question 8

What is the treatment for the different types of heart blocks?

Answer 8

Type 1

atropine

Type 2

a) atropine
b) Pacemaker

Type 3

pacemaker

Question 9

What are the