Brief explanation of Junctional arrhythmia and Ventricular Arrhythmia. Slide 15, 16 and 18 are animations but cannot be viewed through the slide. Mail me if you need the animation or visit the website on the reference (number 7) and choose the animation according to your preference.
2. INTRODUCTION
Student should be able to understand what is
junctional and ventricular arrhythmias
Students should be able to identify these two
arrhythmias through electrocardiograph
Student should know the classification that
comes below these two arrhythmias
4. JUNCTIONAL ARRHYTHMIA
AV Nodal Reentrant Tachycardia
-A type of supraventricular tachycardia (SVT); above
the
bundle of His
-Reentry circuit forms within or just next to the AV node
-Slow pathway is located inferior and slightly posterior
to the
AV node, often following the anterior margin of
the coronary
sinus.
5. -common AVNRT; anterograde conduction is via the
slow pathway and the retrograde conduction is via the
fast pathway
-uncommon AVNRT; anterograde conduction is via the
fast pathway and the retrograde conduction is via the
slow pathway
7. Junctional Rhythm
-Abnormal heart rhythm resulting from impulses
coming from a locus of tissue in the area of
the AV node
-AV node as the pacemaker
-Retrograde conduction
ECG
-
Without a P wave or with an inverted P wave.
-
Retrograde P waves refers to the depolarization from the AV node
back towards the SA node
10. Normal person:
After electrical impulses reach the
ventricles, they die
off
Because all the ventricular muscle is in
refractory phase
11. Types of Ventricular
Arrhythmias
Premature Ventricular Contraction
Ventricular Tachycardia
Ventricular Flutter
Up to 200 bpm
200-350 bpm
Ventricular Fibrillation
350-500 bpm
12. Premature Ventricular Contraction
Heartbeat is initiated by Purkinje fibres in
the ventricles rather than by the SA node
Ventricles contract first and before the atria
have optimally filled the ventricles with
blood, which means that circulation is
inefficient
14. Ventricular
Tachycardia
-ventricular QRS
complexes are highly
polymorphic
analogous to the
ventricular extra
systoles
Ventricular Flutter
-ECG shows large
Ventricular
Fibrillation
ECG
-fast
oscillation; main and
-small potential
terminal deflections
fluctuations in rate
-rhythm
can no longer be
-Retrograde
conduction to the atria
differentiated
is almost always
blocked; thus,
undisturbed atrial
activity is scattered
with P waves without
any relation to QRS
complexes.
-amplitude
-appearance
*a fatal condition
15.
16.
17. CIRCUS MOVEMENTS AS THE
BASIS FOR VENTRICULAR
FIBRILLATION
Define circus movements:
‘Re-entry’ of the impulse into muscle that has already
been excited
Why?
Pathway around the circle is too long; dilated heart
Velocity of conduction becomes decreased; blockage of
Purkinje system, ischemia of the muscle or high blood
potassium levels
Refractory period of the muscle might become greatly
shortened; drugs (epinephrine) or after repetitive electrical
20. REFERENCES
1.
AK JAIN Medical Physiology, 3rd edition
2.
Davidson's Principles and Practice of Medicine, 21st Edition
3.
http://en.wikipedia.org/wiki/AV_nodal_reentrant_tachycardia
4.
http://en.wikipedia.org/wiki/Premature_ventricular_contraction
5.
American Heart Association. (2012, September 05).Ventricular fibrillation.
Retrieved from
http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/
Ventricular-Fibrillation_UCM_324063_Article.jsp
6.
Mayo Clinic Staff. (2011, November 01). Diseases and conditions
ventricular fibrillation. Retrieved from http://www.mayoclinic.org/diseasesconditions/ventricular-fibrillation/basics/definition/CON-20034473
7.
American Heart Association. (n.d.). Arrhythmias (ventricular fibrillation).
Retrieved from
http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=arrhyt
8.
http://www.drsegal.com/medstud/ecg/junction.htm
9.
http://en.wikipedia.org/wiki/Junctional_rhythm
