ECG BASICs ventricular arrhythmias PVCS TRIGEMINY BIGEMINY ventricular escape beat tachycardia fibrillation

1. ECG BASICSECG BASICS
66thth
LectureLecture
Ventricular arrhythmias
By
Salah Mabruok Khalaf
South Egypt Cancer Institute
2017
Course of Medical Oncology
Medical Oncology department

2. 1. Premature ventricular complexes (PVCs)
2. Ventricular Escape Beat
3. Ventricular Parasystole
4. Ventricular tachycardia
5. Ventricular fibrillation
6. Ventricular flutter
7. Idioventricular rhythm
8. Accelerated ventricular rhythm
9. Ventricular asystole
Ventricular arrhythmias
o N.B. expected rate of Ventricular cells is 20 - 45 bpm.N.B. expected rate of Ventricular cells is 20 - 45 bpm.

3. 1.Premature Ventricular Complexes
(PVCs(

4. Compensatory pause
Usually
• PVC is followed by a complete pause
• PAC is followed by an incomplete pause

7. Premature Ventricular Complexes (PVCs)
•Causes:
Cyclic Antidepressants
Caffeine, Alcohol, Nicotine
Acidosis
Acute MI
Stress
Serum Electrolyte Imbalance
Heart Disease
Hypoxia

8. Types of PVCs
A- According to number of ectopic focus
1.Unifocal: one site, fixed coupling intervals, same
shape
2.Multifocal: different sites of origin, different coupling
intervals, various shapes
3.Multiformed: originate in the same ectopic site with
fixed coupling intervals but their conduction through the
ventricles differ, various shapes .
•Coupling interval
It is the length of time between an ectopic beat and the
sinus beat preceding it

11. B- according to its frequency:
1.Isolated single
2.Couplets
3.Triplets
4.Salvos (4-6 PVCs in a row), also called
brief ventricular tachycardias.

12. SalvosSalvos

13. C- According to Pattern
1. Every other = Bigeminy
2. Every third = Trigeminy
Ventricular trigeminy

14. D. According to relation to previous cycleD. According to relation to previous cycle
1.Early in the cycle (R-on-T phenomenon),
2.After the T wave, or
3.Late in the cycle - often fusing with the next QRS
(fusion beat).

15. R-on-T PVCs may be especially dangerous in an acute
ischemic situation, because the ventricles may be
more vulnerable to ventricular tachycardia or fibrillation.

16. • Interpolated PVC
•

17. 2-Ventricular Escape Beats
• Ventricular Escaped beats must have the following
qualities:
1. They must occur at the end of a pause.
2. Wide QRS complex
• 3. No 'P' wave will precede the ventricular beat.

18. 3. Ventricular Parasystole
• Non-fixed coupled PVCs where the inter-ectopic intervals
(i.e., timing between PVCs) are some multiple (i.e., 1x,
2x, 3x, . . . etc.) of the basic rate of the parasystolic focus
• PVCs have uniform morphology unless fusion beats
occur

19. 4. Ventricular Tachycardia
1.Sustained (lasting >30 sec) vs. nonsustained
2.Monomorphic (uniform morphology) vs.
polymorphic (Torsade-de-pointes)
3.Presence of AV dissociation (independent atrial
activity) vs. retrograde atrial capture.
4.Presence of fusion QRS complexes (Dressler
beats).

20. Ventricular Tachycardia: Nonsustained

21. Ventricular Tachycardia:Ventricular Tachycardia:
SustainedSustained

22. Polymorphous ventricular tachycardia (Torsade
de pointes).
• Tachcardia
• Wide QRS complexes with multiple morphologies
• Changing R - R intervals
• The axis seems to twist about the isoelectric line
• it is important to recognise this pattern as there are a number of
reversible causes
– Heart block
– Hypokalaemia or hypomagnesaemia
– Drugs (e.g. tricyclic antidepressant overdose)
– IHD

23. 5- Ventricular fibrillation
• Bizarre, irregular, random waveform
• No clearly identifiable QRS complexes or P waves
• Wandering baseline

24. 6- Ventricular flutter
•Ventricular 'flutter' is a bizarre sine-wave like
rhythm, and usually degerates into ventricular
fibrillation. You won't see it often (or for long).

25. • 7. Idioventricular Rhythm
• A "passive" escape rhythm that occurs by
default whenever higher-lever pacemakers in AV
junction or sinus node fail to control ventricular
activation. Escape rate is usually 30-50 bpm
(i.e., slower than a junctional escape rhythm).
• Seen most often in complete AV block with AV
dissociation or in other bradycardic conditions.

26. 8. Accelerated Ventricular Rhythms8. Accelerated Ventricular Rhythms

27. • Ventricular Asystole
Causes:
• Extensive myocardial damage
• Acute respiratory failure
• Ischemia or Infarction
• Traumatic cardiac arrest
• Ventricular aneurysm
• Countershock
• Hypoxia, Hypothermia
• Hyperkalemia,
• Hypokalemia
• Preexisting acidosis
• Drug overdose
 Rate: Ventricular rate = 0
 Rhythm: unless Ps are∅
present, then regular or
irregular
 P waves: may be present
 qRs: ∅
 P:qRs ∅