Sinus Arrhythmias Flashcards
how many leads on EASI lead ECG?
5-lead ECG
positions of the 5-lead ECG
BROWN= lower sternum (5th ICS) RED= left mix-axillary line (5th ICS) BLACK= upper sternum (just below sternal angle) WHITE= right mid-axillary line (5th ICS) GREEN= anywhere
ECG paper small square time
0.04 seconds
ECG paper large square time
0.20 seconds
five step approach to ECG rhythm strip
- heart rate
- rhythm
- P waves
- PR interval
- QRS complex
what can cause artefacts on an ECG?
patient movement
defective electrodes (fuzzy baseline)
improper grounding
faulty apparatus
what does a U wave on ECG indicate?
hypokalaemia
how to calculate HR on ECG
300/ number of small squares between R-R
number of QRS in 30 large squares x 6 ?
what is the atrial count?
number of P waves in 1 minute
what is the ventricular rate?
count number of QRS in 1 minute
normal PR interval
0.12-0.2 seconds
normal QRS interval
0.06-0.12 seconds (1.5-3 small boxes)
five common variations in sinus rhythm
- normal sinus rhythm (60-100bpm)
- sinus bradycardia (<60bpm)
- sinus tachycardia (>100bpm)
- sinus arrhythmia
- sinus pause/ arrest
define bradycardia
PR interval and QRS are normal, there is just a longer pause between beats
causes of bradycardia
normal in athletes sleep vagal manoeuvre hypoglycaemia hypothermia hypothyroid previous cardiac history medications toxic exposure MI (right coronary artery, inferior wall)
management of bradycardia
atropine or pacing if haemodynamically compromised
define sinus tachycardia
heart rhythm over 100bpm at rest
causes of sinus tachycardia
damage to heart tissues hypertension fever stress excess alcohol caffeine nicotine cocaine medication response to pain imbalance of electrolytes hyperthyroidism
what is the risk in tachycardia?
risk of falling CO due to inadequate ventricular filling time and myocardial demand is increased so can precipitate ischaemia and infarction
management of narrow QRS tachycardia
vagal manoeuvres adenosine beta blockers CCBs synchronised cardioversion
management of broad QRS tachycardia
procainamide
amiodarone
sotalol
define sinus arrhythmia
rate increases with inspiration
causes of sinus arrhythmia
can be normal heart disease stress caffeine nicotine alcohol
management of sinus arrhythmias
reduced CO but only treat if symptomatic
define sinus pause/ arrest
transient absence of P waves that lasts 2 seconds to several minutes
causes of sinus pause/ arrest
healthy hearts during sleep myocarditis cardiomyopathy MI digoxin toxicity elderly vagal stimulation
risks of sinus pause/ arrest
sudden cardiac death falls VTE events CHF AF
management of sinus arrest/ pause
atropine
pacemaker
