Pacemaker Malfunctions Even less amusing!

Pacemaker Codes (NASPE/BPEG) Position I IIIII Category Chamber(s) Chamber(s) Response to paced sensed sensing O=None O=None O=None A=Atrium A=Atrium T=triggered V=Ventricle V=Ventricle I=Inhibited D=Dual (A+V) D=Dual(A+V) D=Dual (T+I)

Triggered l Means different things n If an intrinsic event is sensed, the pacemaker will trigger pacing to that chamber OR to another chamber –P wave will trigger an AV interval –R wave will trigger pacing to the ventricle

Triggered? Atrial paced spike triggers AV interval Triggered ventricular pacing spike is in refractory period of ventricular cycle

A O O Chamber Paced Chamber Sensed Action or Response to a Sensed Event AOO Pacing Asynchronous mode Not sensing so can’t react

V V I Chamber Paced Chamber Sensed Action or Response to a Sensed Event VVI Pacing

Even more! l Fourth letter- Programmable Functions n R = rate modulation n C = Communicating n M = Multiprogrammable n S = simple programmable n O = None l Fifth letter – antitachycardic functions n O = none n P = paced n S = shock

Rate Modulation l Atrium or Ventricle is pacing or tracking above the set upper limit (permanent pacemaker) n Used to help compensate for increased demands –Sensor can be: l Change in temperature l Change in movement or body position l Change in pH l Change in minute ventilation

D D D R Chamber Paced Chamber Sensed Response to a Sensed Event DDDR Pacing Rate modulated

Pacing Malfunctions l Often a two person job n One person supports the patient n One person troubleshoots the pacemaker

Failure to pace (not tryin’ to tickle) l No pacing spikes or not enough coupled with the intrinsic rhythm to ensure good CO l Pacing energy not being transmitted from generator to patient

Failure to pace ( not trying to tickle)

How do you fix this? l Pacing spikes not visible (often an equipment problem) n Pacer on? n Rate set correctly? n Battery fresh ? n Connections tight? n Get another cable n Get another generator n Often an equipment problem-no energy thrown

Failure to capture (target is not ticklish/not ticklin’ hard enough) l Pacing Arm is throwing out energy-target is not responding

Loss of Capture (target is not ticklish) Nothing happens in response to arm throwing out impulse

How do you fix this? l Myocardium is not responding to stimulation n Battery fresh? n Connections tight? –Make sure lead is in contact with myocardium n mA high enough? n Assess electrolytes, oxygenation, acid base balance n Ischemic tissue? Fibrin sleeve? n Reposition patient or patient’s arm on side of pacemaker if subclavian entry

Undersensing (ticklin’ too much) l Intrinsic rhythm not seen so pacing arm throws out energy

Undersensing (ticklin’ at the wrong time) Pacer eyeball is set too high! Can’t see target moving so the arm throws out a stimulus

The danger of “not seeing”... Pacer arm throws out stimulus during vulnerable portion of cardiac cycle

How do you fix this l Pacermaker not seeing correctly n Battery fresh n Connections tight –Leads in contact with myocardium –Lead fracture n Do a sensitivity threshold to get eyes at proper level

Oversensing ( not ticklin’ enough) l Pacemaker misinterprets noncardiac events as intrinsic activity

Oversensing (not ticklin’ enough) Pacer eyeball thinks it sees cardiac activity so the arm does not throw out an stimulus

How do you fix this l Pacermaker not seeing correctly n Battery fresh n Connections tight –Leads in contact with myocardium –Lead fracture n Do a sensitivity threshold to get eyes at proper level

Let’s practice

Other Complications l Infection l Pulmonary embolus l Venous Thrombus l Myocardial perforation l Endocarditis

Nursing Care l Assess heart rate and rhythm l Protect patient from injury l Troubleshoot malfunctions l Evaluate pacemaker function l Keep patient informed

Sample documentation l Temporary pacemaker (0800) n Epicardial wires ( 2 ventricular) n Pacing threshold 3; mA set at 6 n Sensitivity threshold 4 mV; mV set at 2 mV n Rate set at 60; patient’s intrinsic rate 30 n Patient pacing about 50% of time. 100% capture when paced. l Temporary pacemaker (1400) n Pacemaker off. Pacing wires grounded and taped to chest wall. Site care with betadine.

Flippin’ a switch l What’s the deal with the magnet?

No Magnet

With Magnet

Rapid Atrial Pacing

l Used only in the atrium l Pace at rates from n Need to get higher than patient’s ATRIAL rate l Physician must be present when in use n Nurse may only connect l Always have defibrillator available

What are the possibilities? l Single chamber pacemaker l Dual chamber pacemaker l Free standing RAP machine n Think Frankenstein

Rapid Atrial Pacing (single chamber) l Flip open top of pacemaker n Press enable to begin l Set rate according to physician instruction or let MD set rate n Rate will be higher than patient’s atrial rate l Press hold to deliver until instructed to stop n Will be done in bursts n Pacing light will flash

Rapid Atrial Pacing (dual chamber) l Found on bottom half of pacer l Must hit menu screen and scroll to menu 3 l Set rate by turning round knob l Press select to deliver and HOLD until instructed to release Menu Select 3 DDD RAP 320 SELECT Press toDeliver Rapid Atrial Pacing

Permanent pacemakers

Differences l You cannot access pacing generator l You cannot see leads l Helps interpretation of strip if you know how pacemaker is set up n Should have card n Old records n Request info from cardiologist

You are in trouble! What can you try if you have a malfunction with a permanent pacemaker that is compromising your patient?

Biventricular pacemakers? l Pacing leads in the RV and into the coronary sinus l Allow both ventricles to pace synchronously l Improves heart function for patients with CHF l EKG will not look different from single ventricular pacing

The END