Clinical ECG Practice

Question 1

Which specialty lead is used to capture special waves in ARVD, and what are the special waves?

Answer 1

A Fontaine lead is used to highlight epsilon waves, which are found at the beginning of the ST segment in 50% of ARVD sufferers.

Question 2

How do you do a Lewis Lead?

Answer 2

• no precords or RL
• may want to 2x sensitivity if possible
• RA –> 2nd ICS, either sternal border
• LL –> 4th ICS, either sternal border
• LA in usual place
• rhythm strips of I, II, III, noted as a Lewis lead, labelled with side that the leads were placed on, and distance from sternal border

Question 3

What is the purpose of a Lewis lead?

Answer 3

This specialty lead amplifies atrial activity that may be hard to find on a regular 12-lead ECG.

Question 4

Why would you ask the patient to do deep inspiration/expiration?

Answer 4

If Q-waves are seen in inferior leads on a 12-lead, doing another ECG while the patient is breathing in deeply can help determine if there is an old inferior MI. If the Q-waves go away or shrink when the patient breathes in, it’s likely to not be an old inferior MI.

Question 5

What is the purpose of an MCL1/MCL6?

Answer 5

Modified chest leads will help you better distinguish between origin of tachyarrhythmias. MCL1 magnifies atrial activity, MCL6 magnifies ventricular activity.

Question 6

How do you do an MCL1?

Answer 6

• LL –> V1

- rhythm strip of lead III

Question 7

How do you do an MCL6?

Answer 7

• LL –> V4

Question 8

What are four ECG abnormalities that you might see in the ECG of someone with ARVD?

Answer 8

1. Epsilon waves (little dips or bumps at the J-point/beginning of the ST segment)
2. Wide QRS in V1-V3 (right-sided leads)
3. ST-T waves abnormalities in the same leads
4. Bursts of vTach with LBBB morphology

Question 9

How do you do a Fontaine lead?

Answer 9

RA –> manubrium
LA –> xiphoid process
LL –> V4
- rhythm strips of I, II, III (labeled FI, FII, FIII in red ink on ECG printout)