Arrhythmias

Question 1

What is an arrhythmia?

Answer 1

abnormal heart rate and/or rhythm, it can occur in a normal heart or a diseased heart

Question 2

Why can an arrhythmia be problematic?

Answer 2

arrhythmias can alter the cardiac cycle and effect the filling and/or emptying of the heart (this then affects cardiac output and perfusion)

Question 3

What causes an arrhythmia?

Answer 3

• heart defects (congenital)
• myocardial ischemia (metabolic acidosis)
• myocardial infarction
• drugs (usually cause reversible arrhythmias, usually stimulants)
• fluid electrolyte imbalances (affects resting potential and thus electrical activity)

Question 4

What are the four types of arrhythmia?

Answer 4

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

Question 5

What is atrial flutter?

Answer 5

• ineffective contraction
• regular rhythm
• atrial tachycardia (~300 bpm)
• ventricles follow suit, regular rhythm and tachycardia (~150 bpm)

Question 6

What is atrial fibrillation?

Answer 6

• spontaneous, uncoordinated muscle contraction (shivering or shaking)
• irregular, chaotic contractions (~400-600 bpm)
• irregular rapid ventricular rate (~80-180 bpm)

Question 7

What is heart block?

Answer 7

• problem with conduction of electrical activity from atria to ventricles (abnormal or no impulse)

Question 8

What is ventricular fibrillation?

Answer 8

• shaking, quivering of ventricles, no contraction

- can cause death in minutes

Question 9

What are the three types of heart block?

Answer 9

1) 1st degree - delayed conduction, regular rhythms
2) 2nd degree - intermittent failure of conduction
3) 3rd degree - no conduction, non pacer cells take up pacing function but then there is problem of synchronicity

Question 10

How is arrhythmia treated?

Answer 10

• may not need treatment
• drugs (beta blockers, calcium channel blockers) but not for ventricular fib
• defibrillation
• pacemaker
• surgical ablation