arryhthmias

Question 1

what is an arrhythmia?

Answer 1

abnormal generation or conduction

• abnormal HR and or rhythm
• abnormality in specialized CARDIAC muscle cells
• ALTERS cardiac cycle (CO and perfusion is affected!)

Question 2

etiology of arrhythmias?

Answer 2

• congenital heart defects: opening in septum (foramen ovale) usually closed before birth- hole in septum prevents electrical impulses from being transported
• myocardial ischemia (reversible)
• MI (form scar tissue–> irreversible)
• stimulant drugs (especially recreational drugs)
• fluid-electrolyte imbalance

Question 3

4 common types of arrhythmias?

Answer 3

1. atrial flutter
2. atrial fibrillation
3. heart block
4. ventricular fibrillation

Question 4

what is atrial flutter?

Answer 4

• RAPID, REGULAR rhythm
• atrial tachycardia (up to 300bpm)
• ventricular tachycardia (about 150bpm)
• ventricles must wait a certain amount of time to contract while they wait for transmission of electrical impulse (AV nodal delay), so if atria begin to beat faster, this will not increase rate of ventricular contractions BUT increase ratio of A:V

Question 5

what is atrial fibrillation?

Answer 5

-SPONTANEOUS contraction, IRREGULAR
-chaotic and uncoordinated
-atrial contraction NOT effective, lack rhythm
-atrial rate of 300-600bpm
-no time for atria to fill w blood
-ECG changes: longer space between QRS complex
also irregular rapid ventricle rate ~80-180bpm

Question 6

what is heart block?

Answer 6

SA node FIRES, but PASSAGE of electrical impulse from atria—> ventricles blocked
NOT a blockage of flow—> either no conduction or abnormal conduction!

Question 7

1st degree heart block

Answer 7

delayed conduction, regular rhythm, increased PR interval

Question 8

2nd degree heart block

Answer 8

some AP goes to ventricle, some doesnt (intermittent failure of conduction)

Question 9

3rd degree heart block

Answer 9

no AP passes, no conduct

safety net activated (ventricle sets pace)

Question 10

what is ventricular fibrillation?

Answer 10

worst case scenario
Heart QUIVERS
NO contraction of ventricles
NO filling or emptying of chambers= no CO 
ECG goes flat
DEATH in minutes
need a defibrillator!

Question 11

treatment of arrhythmias

Answer 11

NON invasive
may not be treated if minor
-anti-arrhythmic drugs (class 1 to 4)
-defibrillation (pads to chest to deliver shock and -distinguish electrical activity)
-pacemakers (temporary or permanent)
-ablation (remove part of muscle causing arrhythmia)