1. EKG Analysis Ventricular Arrhythmias

2. Ventricular arrhythmias conduct more slowly so the QRS is wide (greater than.12 seconds) They are usually caused by an ectopic focus in the ventricles that has become “irritable” due to ischemia. They may also originate from complete pacemaker failure

3. Premature Ventricular Contractions (PVCs)  Irritable focus causes ventricles to depolarize before the SA node fires  Premature beat that has a wide QRS –QRS and T wave of a PVC usually point in opposite direction from one another  “Bad PVCs” – more than 6/minute, coupled, multifocal, and on or near the T wave of the previous sinus beat  Suppressed by lidocaine.

4. Coupled PVCs

5. Multifocal PVCs

6. R-on-T Phenomenon: May cause a run of PVCs or Vfib

7. Vtach: 3 or more PVCs in a row  Wide QRS with a regular pattern and a rate of 150-200  Patient will usually lose consciousness  Treated with lidocaine; may help to have patient cough if they are still conscious  May require DC shock

8. Vtach

9. Remember, 3 or more PVCs in a row is a run of Vtach

10. Vfib  Many ectopic foci firing at the same time  There is no regular pattern as in Vtach  No effective cardiac output!  Requires CPR and DC shock, ie, Defibrillation

11. Vfib This is “coarse” vfib

12. Vfib This is “fine” vfib

13. Idioventricular Rhythm  Ventricles depolarizing on their own because of no conduction from above –Rate will be between 20-40  A rate of 60-120 (all PVCs) is sometimes called “Slow Vtach”

14. Agonal Rhythm Leading to Ventricular Standstill (Asystole)

15. External Cardiac Pacing : Pacemakers  Electrodes most commonly placed in ventricles  Most pacemakers are “demand” type  Used for symptomatic bradycardia or heart blocks  EKG shows a “spike” when pacer fires

16. Demand Pacemaker

17. Artifact: 60 cycle interference

18. Laboratory Exercises # 6 Numbers 9-12 Laboratory Exercises #7 Numbers 1-8