Arrhythmias

Question 1

what are cardiac arrhythmias?

Answer 1

disorders of the heart rate

Question 2

what is a tachyarrhythmia?

Answer 2

fast
impair cardiac function by reducing diastolic filling time
atrial fibrillation
ventricular tachycardia

Question 3

what is brady arrhythmia?

Answer 3

slow
heart block
drug induced (b blocker, digoxin)

Question 4

what is a heart block?

Answer 4

slow/no conduction thru the AV node to ventricles impulse from SA node
prolonged p-q interval on ECG
levels classified by length of signal delay
1,2,3
3 complete heart block only intrinsic rate

Question 5

what are atrial tachyarrhythmias?

Answer 5

narrow QRS on ECG
atrial fibrillation- rapid impulses conducted to ventricles giving high HR
no p waves as disorganised atrial activity
irregular pace

Question 6

what are ventricular tachyarrhythmias?

Answer 6

broad QRS on ECG

dangerous as it can lead to ventricular fibrillation and death

Question 7

what are cardiac pacemakers used to treat?

Answer 7

bradyarrhythmias

Question 8

what do pacemakers do?

Answer 8

keep heart at minimum level

• no effect if HR above certain level
• sensing and pacing circuits
• box fitted in chest wall, wires passed thru b.v. into ventricle

Question 9

what is a risk with pacemakers?

Answer 9

electrical interference cause sensing to shut down

• electrical fields
• dental induction scalers generate strong EM field

Question 10

what do the waves mean in sinus rhythm?

Answer 10

P- atrial depolarisation
QRS- ventricular depolarisation
T-ventricular repolarisation

Question 11

what is ventricular fibrillation?

Answer 11

unstable heart electrical activity
-heart attack
-electrocution
-long QT syndrome
-wolf-parkinson-white syndrome
no cardiac output=death
disorganised electrical activity
muscle fibres contracting at random
defib

Question 12

what is asystole?

Answer 12

no cardiac output
no electrical activity
-do no defib
low chance survival
adrenaline may produce electrical activity-> defib