1. Heart Blocks and Pacing
PDN Julie Allen
SN Solon Avanzado
The Queen Elizabeth Hospital
King’s Lynn

2. PQRST in Normal Sinus Rhythm
Explanation of NSR, ask group to come up with what is happening at each point – useful to draw diagram with conduction system

3. Conduction system

4. FIRST Look at the patient!
Convey the importance of the patients condition and troubleshooting ie not assuming asystole when leads are off!

5. Arrhythmias – at a glance!
Patient? – poorly or well
Rate? – Too fast or too slow
Complexes? – Narrow or Wide
Treatments? Drugs or electricity
Simplified assessment process

6. Heart Blocks Block in normal conduction
Could be at any part of the conduction system
Ranging in severity
Transient or permanent
Can deteriorate
May require pacing
Introduction to heart blocks

7. 1st Degree Block
Ask the students what they see. Explain characteristics, possible causes, effects on the patient, appropriate management

8. 2nd Degree Block Mobitz Type 1: Wenckebach
Ask the students what they see. Explain characteristics, possible causes, effects on the patient, appropriate management

9. 2nd Degree Block Mobitz Type II

10. Complete Heart Block
Ask the students what they see. Explain characteristics, possible causes, effects on the patient, appropriate management

11. Pacing Temporary – Permanent – Implanted device
Transcutaneous (Emergency use with external pacing/defib unit, precordial thump!!!!!)
Transvenous (Emergency use with external pacemaker)
Permanent – Implanted device

12. Indications for Temporary
Bradycardia with unstable haemodynamics unresponsive to Atropine.
Bradycardia with symptomatic escape rhythms unresponsive to medication.
PEA - overdose, electrolyte abnormalities, acidosis
Over ride pacing – refractory tachycardias (failed cardioversion or medication)
Inferior MI with Heart Block

14. Contraindications to temporary pacing
Severe hypothermia
Prolonged bradyasystolic arrest

15. Types of pacing box
Single Chamber Dual Chamber

16. Indications for permanent
• Symptomatic CHB
CHB that does not recover following:
- MI after 2 weeks
- Valve replacement after 1 week
- CABG after 2 weeks
Bifascicular block, BBB or CHB post anterior infarct
Symptomatic sinus arrest or AV block not related to drugs

17. Permanent Pacing Single/Dual chamber Pacing and defibrillate
Magnets and MRI scanners

18. Atrial pacing Indications : • Sinus bradycardia
• Supression of ventricular ectopics
• Slow junctional rhythms
• Overdrive pacing of supra-ventricular tachycardias
NB – atrial pacing is ineffective in atrial fibrillation and fluter

19. Atrio-ventricular pacing (Sequential pacing)
Indications :
• Complete block
• Second degree block to achieve 1:1 conduction
• First degree block if PR interval too long
AV pacing is always preferable to single chamber pacing.

20. Ventricular pacing Indications :
• Slow ventricular response to atrial fibrillation/flutter
• Failure of atrial pacing to maintain heart rate
NB – ventricular pacing is the least effective mode for optimising haemodynamics.

21. Pacing Modes Fixed rate:
Pacing Mode stimulates the heart at a pre-set interval
Does not respond to intrinsic heart activity
!!Fixed ventricular pacing
can trigger VT/VF!!

22. Pacing Modes
Demand:
Pacemaker initiates an impulse only when a pre-set R-R interval has elapsed without spontaneous cardiac activity
The escape interval is determined by the rate the pacemaker is set
The pacemaker is inhibited by intrinsic cardiac activity

23. Complications
Permanent
Temporary
Pneumothorax
Pericardial effusion
Infection – endocarditis
Hematoma
Wire displacement
Avoid placing defibrillator pads directly over permanent pacing devices
Transvenous – All the same as Permanent with increased risk of wire displacement
Transcutaneous –
Poor contact resulting in non-pacing
Skin burns (abrasions, prolonged usage without changing pads regularly)

24. Other issues with permanent
MRI scanning – myth that unable to go in MRI
Travel – Pacemaker cards are carried for travelling through security.
Driving – 1 week after implantation for ordinary (Group1)
6 weeks for vocational (Group 2)
Batteries years depending upon usage.
MRI 1.5% of 438pts & 500 scans resulted in heart device to reverting to default settings . Circulation 2006; 114 (12):

25. Analysis of Pacing Problem
Need to obtain rhythm strip or 12 lead ECG
Establish pacemaker settings (if possible)
If there are pacing spikes with no corresponding P-QRS = pacing/capture problem
If there are no pacing spikes where you would expect them = sensing problem

26. Atrial pacing, Ventricular pacing, failure to capture, failure to sense

27. Nursing Care Transcutaneous Transvenous Explain to patient
Skin prep – trim hair, dry skin
Good skin contact – avoid electrodes & transdermal patches
Avoid carotid pulse check use femoral
Pain relief & sedation
Monitor & record Hr rate & rhythm
Monitor & record pacing (rate, current output, mode)
Monitor & record Hr, B/P & rhythm to assess response
Observe sensing of intrinsic beats & appropriate device pacing
Secure wire and device – extreme care with confused patients
Immobility - bedrest