Prevents the heart rate from becoming to slow and overdrive supression of tachydysrhythmias.
Indications for a pacemaker
Symptomatic sinus bradycardia
Junctional Rhythms
Idioventricular rhythm
Dying Heart
Permanent Pacemaker
-Pulse generator(battery pack) inserted surgically into a pocket made for under the RT clavicle
-Pacing catheter is inserted via the subclavian vein into the superior vena cava and down into the Rt atruim or ventricle
Temporary Pacemakers
-Transvenous pacing catheter inserted into a large vein and threaded into the RT atruim and down into the RT ventricle.
-Transcutaneous large pacing electrodes attached to the chest and back that pace the heart through the chest wall.
Pacemaker terminology
*Firing-pacemaker generations of an electrical stimulus.(Noted on ekg presence by a pacemaker spike)
*Capture-is the presence of a P wave or QRS (or both) after the pacemaker spike. Tissue in the chamber is depolarized QRS complexes are wide and bizarre.
*Sensing-pacemakers ability to recognize the patients own intrinsic rhythm or beats to decide its on fire.
*Demand Node-they fire only when needed (only on demand)
3-letter pacemaker code
*The first letter is reffered to chamber paced.
*The 2nd letter refers to the chamber sensed.
V=ventricle
A=atruim
D=dual(atruim & ventricle)
O=none
*the 3rd letter refers to the responsed to sense events.
I=inhibited(pacemaker watches and waits, does not pace until needed)
T=triggered(pacemaker sends out a signal in responsed to a sensed event)
D=dual(inhibited & triggered)
O=none
VVI Pacemaker aka ventricular demand pacer
consists of a catheter w/both pacing & sensing capabilities & is inserted into the RT ventricle
What does a VVI pacemaker do to the RT ventricle?
Paces the ventricle so it looks intrinsic QRS complexes to determine if it needs to fire.
DDD Pacemaker aka AV universal pacemaker
Is the most modern and physiologic. Now the most commonoly inserted pacemaker and rate responsive meanning they will provide a paced QRS.
What does the DDD pacemaker do?
Senses intrinsic atrial activity & takes advantage of the patients P wave if it is given within its preset rate and will not need to give another P wave.