Physio basis of arrhythmias n injury Flashcards
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What is an Arrhythmia
Abnormal formation of action potential
Name 3 causes of Arrhythmias:
Electrolyte imbalance
Drugs
Anatomical Problems
Degenerative changes
What is the range for contraction rates for a flutter
250-350 mins
What occurs in Atrial Fibrillation
Depolarization currents arise from many sites within the atria and is not via the SA node.
What happens when ventricular rate is greater than 200?
Decrease in cardiac output as ventricles do not have enough time to fill.
Features of Ventricular Fibrillation
No discernable wavs
No cardiac output
No ventricular filing
Features of atrial fibrillation
Uncoordinated, low voltage, high frequency depolarizations
No discernable P wave
Ventricular rate irregular and rapid
Name the 4 AV Node Blocks
1st degree AV Block
2nd degree block, Mobitz Type 1 (Wenkebach)
2nd Degree block, Mobitz Type 2
3rd degree AV Block
What is the effect of each AV nodal block
1st degree block - PR interval fixed
2nd Mob 1- PR gradually lengthen, then drop QRS
2ns Mob 2- PR fixed, but drop QRS randomly
Type 3- PR and QRS dissociated
Which impulse fails to make it through the AV node in 2nd degree AV block Wenkebach
3rd or 4th
Which AV block is represents a complete block of conduction in the AV junction
3rd Degree AV block
In the 3rd degree block atria and ventricles form impulses independently of each other. True or false?
True
When does the ventricles own intrinsic pacemaker kicks in?
30-45 beats/min
1 small box on the x-axis of the graph represents what
0.04 seconds
Name 2 heart conditions that are a result of absent P waves
Atrial fibrillation and Atrial flutter
Fewer P waves than QRS complexes can be an indication that the patient has tachycardia; True of False
True
What are the 3 classifications of Arrhythmia
- Life threatening vs Non-life threatening
- Bradyarrhythmia vs Tachyarrhythmia
- Supraventricular vs Ventricular
What classification does Wolff-Parkinson-White syndrome fall under
Tachyarrhythmias specifically supraventricular
Define sinus pause and arrest
Sinus pause and sinus arrest are characterized by the failure of the SA node to form an impulse.
Define ventricular escape rhythm
Junctional and ventricular escape rhythms arise when the rate of supraventricular impulses arriving at the AV node or ventricle is less than the intrinsic rate of the ectopic pacemaker
Wolff Parkinson White Syndrome
Wolff-Parkinson-White (WPW) syndrome is a condition that causes the heart to beat abnormally fast for periods of time.
WPW syndrome occurs due to the presence at birth of an extra pathway in the heart that allows additional electrical signals to pass from the upper and lower heart chambers.
Where on the body are the chest leads placed
V1-
V2-
V3-
V4- Mid clavicular line, 5th intercostal space
V5-
V6-
What happens to the P wave in sinus arrest
Before each QRS identical. New rhythm begins after a pause. The P to P interval is disturbed
Appearance of P wave in Atrial Flutter graph
Sawtoothed Appearance
