Pacemakers and pacing

Question 1

pacemaker

Answer 1

battery powered device whose primary purpose is to stimulate the heart electrically

Question 2

types of pacemakers

Answer 2

fixed rate - designed to fire constantly at a present rate without regard to the hearts own electrical activity
demand - can be temporarily converted to fixed rate mode by placing a special magnet to the chest wall
single chamber - pace either the ventricles or atria
duel chambered - pace both the atria and ventricles

Question 3

Codes

Answer 3

first letter indicates which chamber paced (A atria, V ventricles, D both)
second letter indicates which chamber is sensed
third letter indicates the mode of sensing or the response of the pacemaker to a P wave or QRS (I output inhibited by the P wave or QRS, D inhibited by QRS and triggered by P wave
fourth letter inidcates the programmabiilty of the pacemaker
fifth letter indicates whether it has cardioversion/defib capability

Question 4

Atrial Demand Pacemaker (AAI)

Answer 4

pacemakers that senses spontaneously occurring P waves and paces the atria when they do not appear

Question 5

Atrial Synchronous Ventricular Pacemaker (VDD)

Answer 5

senses spontaneously occurring P waves and QRS complexes and paces the ventricles with QRS complexes fail to apear following spontaneously occuring P waves

Question 6

Atrial Sequential Pacemaker (DDI)

Answer 6

senses spontaneously occuring QRS complexes and paces both the atria and ventricles when QRS complexes do not appear

Question 7

Optimal Sequential Pacemaker (DDD)

Answer 7

senses spontaneously ocurring P waves and QRS complexes and paces the atria when P waves fail to appear and paces the ventricles when QRS complexes fail to appear following spontaneously occuring or paced P waves