ECG Flashcards
Inferior leads
Lead II, III and aVF
Lateral leads
V5, V6,
Lead I
aVR, aVL
Anterior leads
V3, V4
Leads giving septal view
V1, V2
Course of electrical activity in the heart
Begins at sinoatrial node Spreads to atrioventricular node Through Bundle of His To purkinje fibres Causing ventricular contraction
What deflection is produced when electrical activity moves in the direction of a lead?
Positive
If the R wave is bigger than the S wave in which direction is depolarisation heading relative to the lead?
Towards the lead
What term is used when Leads III and aVF are the most positive on ECG?
Right axis deviation
What causes right axis deviation?
Right ventricular hypertrophy
What conditions are associated with right axis deviation?
Pulmonary hypertension
May be normal in tall individuals
What term is used for negative deflection in leads III and II?
Left axis deviation
What leads to left axis deviation?
Conduction issues
What is the normal cardiac axis?
Between -30 degrees and
+90 degrees
What is a normal heart rate?
60-100bpm
What heart rate indicated tachycardia?
Greater than 100 bpm
What heart rate indicates bradycardia?
Less than 60 bpm
How do you calculate the heart rate using ECG in a patient with regular heart rhythm?
Count number of large squares within one R-R interval
Divide 300 by number of large sqaures
How do you calculate the heart rate on ECG in a patient with irregular heart rhythm?
Count number of complexes on rhythm strip and multiply by 6