Unipolar and Bipolar pacing

Question 1

Unipolar pacing

Answer 1

Extracardiac Anode (Can) and and electrode in contact with myocardium (Tip)

Question 2

Bipolar pacing

Answer 2

Anode is the ring on the lead; cathode is tip to myocardium

Question 3

Bipolar vs unipolar pacing impedance

Answer 3

Higher in Bipolar because it has 2 conducting wires

Question 4

Disadvantage of unipolar pacing

Answer 4

Pectoral myopotentials can be sensed during unipolar sensing.

Question 5

Effect of myopotenial signals

Answer 5

They can lead to inappropriate pacing inhibition during muscle contraction

Question 6

Effect of Unipolar at higher outputs

Answer 6

pectoral muscle stimulation

Question 7

Advantage of unipolar pacing

Answer 7

Larger pacing spike on surface ECG which aids in assessing pacemaker function

Question 8

Bipolar pacing in ICDs is preferred due to auto-gain sensing. Why?

Answer 8

Unipolar pacing creates large pacing spike that can cause under-detection of low amplitude signals.

Question 9

Rate adaptive sensors and Bipolar leads

Answer 9

The ring electrode is used to sense myocardial capture