ECG interpretation Flashcards
What two things can always be said about rhythms which originate in the ventricles? (2)
Always patholgical; always have a broad QRS (greater than 0.12 seconds, or three small squares)
Why is ventricular tachycardia an emergency?
Can impair cardiac output (haemodynamically unstbale), thus depriving the myocardium of oxygen and causing to degenerate into ventricular fibrillation -> asystole
What is the commonest mechanism of ventricular tachycardia?
Re-entry mechanism due to cardiac wall damage e.g. previous infarction
Distinguighing between LBBB and RBBB?
Left = WilliaM (W in v1, M in v6)
Right- MorroW
Cardiac axis:
leads I and II +ve
Normal axis
Cardiax axis:
lead I negative
Right axis deviation
Cardiac axis:
Lead I positive, leads II and III negative
Left axis deviation
Serial ECG changes in infarction? (4)
Peaked T waves
ST elevation
“Pathological” q waves
T wave inversion
New onset LBBB is a sign of…?
myocardial infarction
ST-elevation which is more slanting and occurs in younger people?
Pericarditis
ST-depression in V1-V3?
Posterior infarction
ECG changes in COPD? (4)
RAD
Low voltage QRS complexes particularly in V5-V6
Peaked P-waves in the inferior leads
Right ventricular strain pattern
Features of right ventricular strain pattern?
ST depression and and T-wave inversion in inferior leads (II, III and aVF) and V1-V4
ECG signs of hypothyroidism? (3)
Bradycardia
Low QRS voltage
Widespread T wave inversion
Prolonged QT indicates which metabolic disturbance?
Hypocalcaemia
ECG changes in hypercalcaemia? (2)
Short QT
J-waves- notching of the terminal QRS complex
Metabolic disturbance causing reduced myocardial excitability –> depressed pacemaking and conduction
Hyperkalaemia
ECG signs of hyperkalaemia? (5)
Peaked T waves (earliest sign)
Wide flat P waves
Conduction abnormalities ( lengthened PR interval, QRS duration)
Concave ST elevation, PR depression and sinus tachycardia can be signs of?
Pericarditis
ECG changes in pulmonary embolism? (5)
Sinus tachy RBBB Right ventricular strain pattern Right axis deviation S1 Q3 T3
ECG changes in left ventricular hypertrophy?
Increased QRS amplitude in leftsided ECG leads (I, avL and V4-V6)
Left axis deviation
Left ventricular strain pattern
What is the left ventricular strain pattern?
ST depression and T wave inversion in the left sided leads
Left-sided ECG leads?
I, avl and V4-V6
Right-sided ECG leads?
II, III and avF (the inferior leads)
V1-V4
ECG features of hypokalaemia? (5)
U waves Small or absent T waves Long QT ST depression Prolonged PR
Normal QRS?
<0.12 seconds (three small boxes)
Normal PR interval?
Between 0.12 and 0.20 (three-five small boxes)
