1. VENTRICULAR
TACHYARRHYTHMIA
S
DR.SIDRA QAZI
(HO,MU-I)

2. May
manifest in following forms:
Ventricular
extrasystoles
 ventricular tachycardia
 ventricular flutter
 ventricular fibrillation
 ventricular parasystole

3. • PREMATURE VENTRICULAR
CONTRACTIONS(extrasystoles)
Due
to premature discharge of an
ectopic ventricular focus
Arises in diastolic period of preceding
sinus beat
 recorded earlier than next anticipated
sinus beat

4. • ECG SHOWS
QRS COMPLEX:
 bizarre
 widened (more than 2 small squares)
 slurred/notched

as impulse travels through ordinary
muscle tissue which is relatively poor
conductor


5. • ST SEGMENT AND T WAVE
ST
segment depressed, T wave inverted
when QRS upright
ST segment elevated, T wave upright
when QRS downward


6. Unifocal
Multifocal
(diff. coupling interval)
Multiformed (same coupling interval, but
diff. shapes)
Coupling
interval : interval b/w ectopic
beat and preceding sinus beat

9. PVC’s
can be
Isolated
 Couplets
 Triplets
 Salvos i.e 4 or 6 PVC’s in a row (brief
ventricular tachycardia)


12. • COMPENSATORY PAUSE
Sum
of pre- and post ectopic intervals is
exactly equal to two consecutive sinus
cycles
PVC’s followed by complete pause,
PAC’s followed by incomplete

14. • SIGNIFICANCE OF PVC’s
Always
significant when associated with
myocardial disease
Unifocal PVC’s significant if they occur
frequently,occur in person over 40 yrs of
age or they are precipated by exercise
Frequent PVC’s esp. couplets often
herald V-tac or V-fib

15. • VENTRICULAR TACHYCARDIA
“Series
of three or more consecutive
ventricular ectopic beats, recorded in
rapid succession”
It is due to rapid discharge of an ectopic
ventricular pacemaking focus

16. Bizarre
QRS complexes recorded in
rapid succession
Can be monomorphic or polymorphic
 There is AV dissociation , P wave has no
relationship to QRS complexes
 Retrograde AV conduction, bizarre QRS
complexes followed by P` waves

19. CAPTURE
BEAT:
 occasionally during relatively slow
ventricular tachycardia, a sinus impulse
may reach AV node during nonrefractory phase
Sinus impulse can then be conducted to
ventricles
This conducted beat during ectopic
ventricular rhythm is called Captured
beat

20. QRS
complex of captured beat is
recognized because it resembles sinus
beat
 more reliable diagnostic pointers to
ventricular origin of basic tachycardia

22. FUSION BEAT:
 capturing sinus impulse may invade the
ventricles concomitantly with ectopic
ventricular impulse
 QRS complex will have shape in b/w
sinus beat and ectopic beat
 VFB is most reliable diagnostic pointer of
ventricular origin of basic tachycardia


24. • VENTICULAR FLUTTER
Very
rapid and REGULAR ectopic
ventricular discharge
MECHANISM:
mostly caused by re-entry
with a frequency of 300 bpm
ventricles depolarize in a circular pattern,
which prevents good function resulting in
minimal CO

25. • ECG SHOWS:
Grossly
abnormal intraventricular
conduction: QRS and deflexions are very
wide and bizarre, one merging with the
other
 difficult to define QRS complex, ST
segment and T wave
This results in appearance of a
continuous sine-like waveform

27. Atrial
frequency 60-100 bpm
Ventricular frequency 150-300 bpm
Regularity regular
Origin ventricles
P-wave AV-dissociation

29. • TORSADES DE POINTES (twisting of
points)
QRS
bizarre and multiform
Have sharply pointed apices
 QRS form and axis undulate
 sharp points of QRS, for a short period,
be directed upwards followed by QRS
contours directing downwards for a
short period
Multiform ventricular flutter

31. Multiform
ventricular flutter
 complicate advanced and third degree
AV block

33. • VENTRICULAR FIBRILLATION
Expression
of chaotic, uncoordinated,
ventricular depolarization
MECHANISM:
 Advanced physiological asymmetry of
biventricular chamber such as in MI
Premature or rapid stimulation of
asymmetrical chamber i.e PVC’s,VT or
V.flutter


34. • ECG SHOWS
Completely
irregular, chaotic and
deformed deflexions of varying height,
width and shape
P waves, QRS complexes, ST segments
and T waves cant be identified

36. • SIGNIFICANCE
Is
a terminal event
 associated with IHD, esp. acute MI
 quinidine and digitalis intoxication esp.
with hypokalemia
 hypothemia <28 C

38. DIFFERENCE B/W V.FLUTTER AND
V.FIB:
 V.flutter deflexions are uniform ,
constant, regular and are of relatively
large amplitude
V.fib deflexions are small,completely
chaotic and irregular


41. THANK YOU!