ECG Interpretation Flashcards
Normal Interpretation
Rate - count no. of squares between R, divide 300 by that number = heart rate
Rhythm - is there equal spaces between the QRS complexes?
P wave - consistent shape? do they precede a QRS complex? <0.12 secs
PR Interval - 0.12-0.2 secs
QRS complex - normal shape, 1:1 with p wave, <0.12 secs
ST segment - consistent with isoelectric line?
Interpretation?
ST Depression
Indicative of myocardial ischaemia Appearance - ST line horizontal downwards sloping upwards sloping from downwards position
Causes -
- myocardial ischaemia
- ventricular hypertrophy
- right and left bundle branch block
- digoxin toxicity
Course of Action
- monitor pulse and BP, stay with teh patient
- stop treatment
- report to medical stagg
- consider emergency response
ST Elevation
Indicative of myocardial infarction Early Acute MI - no Q waves - ST elevation sloping upwards - tall, widened T waves
Established MI
- prominent Q waves
- elevated ST segments
- inverted T wave
ST line may be horizontal, convex or coved
Causes - - MI myocardial ischaemia myocardial injury myocardial infection coronary vasospasm pericarditis
Course of Action
- stop treatment
- seek medical assistance
- prep emergency equipment
- monitor the patient
- prep for CPR
Sinus Tachycardia
- increased rate in atrial contraction originating from the
SA node - 100bpm +
- normal shapes and ratios just increased rate
- not pathological if during increased activity
- source for concern if at rest
Atrial Fibrillation (tachycardia)
a disorganised electrical signal from abnormal ectopic foci in the atria
Appearance -
- bag of worms
- no distinct p waves
- irregular RR interval
Causes - any disease process that changes the structure of atrial tissue
Course of Action - Chronic - look at current symptoms, changes in BP, pulse or pallor - is the rate controlled? - would they be able to tolerate functional rehab? Acute - if new onset - cease intervention - refer on medical assessment
Atrial Flutter (tachycardia)
flutter occurs when automaticity foci fire when they shouldn’t
rate is normally 250bpm
due to AV node refractory period, AV depolarisation doesn’t occur with each flutter
Appearance
- multiple, saw tooth p waves
- occasional QR complex
- regular RR interval
Course of Action - Chronic - look at current symptoms, changes in BP, pulse or pallor - is the rate controlled? - would they be able to tolerate functional rehab? Acute - if new onset - cease intervention - refer on medical assessment
Premature Atrial Contraction
premature beat arising from the atria Appearance - - abnormal p wave - followed by a normal QRS complex - occurs in pairs, groups or threes
Course of Action - Chronic - look at current symptoms, changes in BP, pulse or pallor - is the rate controlled? - would they be able to tolerate functional rehab? Acute - if new onset - cease intervention - refer on medical assessment
Premature Ventricular Contraction
premature discharge of an ectopic focus in the ventricles
Appearance
- can occur as a single beat, every second beat or in pairs
- abnormal QRS complex
- no preceding p wave
Causes -
- anxiety
- excessive caffeine/alcohol
- drugs
- congestive heart failure
- myocardial infarction
- valvular heart disease
Not life threatening
Issue if have other heart condition or if occurs very frequently
Ventricular Fibrillation
chaotic electrical discharge from multiple foci in the ventricles
- lose cardiac output - ventricles aren’t working properly
Appearance -
- extremely disorganised
- no rate
- no wave or QRS complex
- series of random peaks, no regular shape or rate
Causes -
- may be spontaneous
- electrolyte disturbance
- reperfusion of the myocardium after thrombolysis
- mechanical stimulation
- myocardial infarction
Course of Action
- medical emergency
- stop treatment
- seek medical assistance
- need to commence CPR
Ventricular Tachycardia
originates from a ventricular ectopic focus
- between 140-250bpm
Appearance
- regular QRS complexes, wide, abnormal shape, just look like wide peaks
- no p wave
Causes -
- digoxin toxicity
- electrolyte disturbances
- myocardial infarction
- cardiomyopathy
- congestive heart failure
- medications
Course of Action
- medical emergency
- stop treatment
- seek medical assistance
- need to commence CPR
Pulseless Electrical Activity
form of cardiac arrest
no pulse but still have electrical impulse
severe cardiac/circulatory dysfunction means that despite electrical impulse there is no contraction of the heart
can’t use defib
Asystole
absence of all electrical activity
- flat line
Causes - ischaemia degeneration of the conducting system electrocution can't use defib
