Chapter 11-Pacemaker Rhythms

Question 1

define an electronic pacemaker

Answer 1

man-made source of electrical current causing depolarization of myocardium, artificial pacemakers are electronic

Question 2

define ventricular pacing

Answer 2

electrical stimulation is delivered to ventricle(s) to stimulate ventricular depolarization ad result in ventricular contraction

Question 3

define atrial pacing

Answer 3

electrical stimulation delivered to atria to cause conduction from AV node throughout ventricles resulting in ventricular contraction

Question 4

define atrioventricular sequential pacing

Answer 4

stimulation of atria and then lower part of right ventricle in a sequence that mimics normal cardiac conduction system and allows for atrial kick

Question 5

define atriobiventricular pacing

Answer 5

sequential pacemaker stimulation of atria and then both ventricles, rather than just the lower right ventricle

Question 6

describe the three parts of the heart a pace maker can control

Answer 6

-atria
-ventricles
-both chambers

Question 7

how does a pace maker affect the heart rate

Answer 7

speed up slow rhythm, control abnormal or fast heart rhythm, coordinate electrical signalling within the heart

Question 8

define electrical capture

Answer 8

evidence of heart’s activity on ECG tracing, including spacing of spikes and waveforms

Question 9

define mechanical capture

Answer 9

heart’s ability to respond to electrical impulses delivered by natural or electronic pacemaker

Question 10

define the appearance of a normal pacing spike

Answer 10

current is a quick delivery and reflected as a thin spike , after pacing spike a tracing of a P wave or wide QRS complex or both will appear depending on chamber placement

Question 11

describe the resulting ECG of a ventricular pacemaker

Answer 11

pacing spike(s) will be followed by a wide QRS complex, typically looks similar to left bundle branch block (LBBB) pattern with a ventricular pacemaker or right bundle branch block (RBBB) with biventricular pacemaker. Ventricles are stimulated low, causing myocardium to depolarize slowly. Complex is wide and shaped differently from a natural QRS complex.

Question 12

describe the resulting ECG of an AV sequential pacemaker

Answer 12

has atrioventricular delay, similar to measurement of PR interval on normal rhythm tracing, programmed time frame somewhere between 0.12-0.20 similar to normal PR interval

Question 13

identify three causes of pacemaker complications

Answer 13

-malfunctioning (failure to pace)
-malsensing (failure to sense)
-loss of capture (failure to depolarize)
-oversensing
-undersensing