Cardiology 3/8/20 Flashcards
(96 cards)
anatomical groups of ECG leads which leads are lateral?
precordial: V5 and V6 (low lateral) limb: I and aVL (high lateral)
anatomical groups of ECG leads which leads are inferior?
II, III and aVF
PR interval should be between…
120-200ms (3-5 small squares)
- long PR interval = 1st degree AV block
QRS complex should be…
- ≤120ms duration (<3 small squares)
RA enlargement shown on ECG by…
tall (>2.5mm), pointed P waves (P pulmonale)
- typically in chronic lung disease (eg. COPD)
LA enlargement shown on ECG by…
bifid/notched P wave (M shape - P mitrale) in limb leads
- mitral regurg/stenosis
causes of short PR interval
Wolff-Parkinson-White syndrome (delta wave)
causes of prolonged PR interval (1st degree heart block)
- idiopathic
- ischaemic heart disease
- hypokalaemia (hyperkalaemia rarely can cause prolonged PR)
- digoxin toxicity
- infection
> rheumatic fever
> endocarditis
> Lyme disease
normal cardiac axis
-30 to +90 degrees (shown by both leads I and II being positive)
left axis deviation
-30 to -90 degrees (shown by leads I and aVF/III LEAVING)
right axis deviation
+90 to +180 degrees (shown by lead I and aVF/III RETURNING)
north west axis
-90 to -180 degrees (lead I negative and aVF negative - very rare)
tachycardia with broad QRS can be…?
- atrial (supraventricular) tachycardia with BBB
- ventricular tachycardia
- in atrial tachycardia with BBB, each QRS complex is preceded by a P wave at a constant distance
- in ventricular tachycardia, atria and ventricles are beating independently of one another so QRS complexes are not preceded by P waves at a constant distance
acute inferior MI
- ST elevation in the inferior leads II, III and aVF
- reciprocal ST depression in the anterior leads
acute anterior MI
- ST elevation in the anterior leads V1 - 6, I and aVL (V3/V4 more pronounced)
- reciprocal ST depression in the inferior leads II, III, aVF
- hyperacute (tall) t waves
old MI shown by…
- pathological Q waves in anatomical distribution (eg. II, III and aVF for an inferior lesion)
broad QRS caused by:
- ventricular origin (eg VT)
- BBB
- hyperkalaemia
- pacemaker
causes of ST depression
- myocardial ischaemia
- digoxin toxicity
- hypokalaemia
- ventricular hypertrophy
QT interval should be….
- <440 for men
- <460 for women
ECG signs of LBBB
- broad QRS
- WiLLiaM (W in QRS of V1/2, M in V6)
- left axis deviation
ECG signs of RBBB
- broad QRS
- MaRRoW (M in QRS of V1/2, W in V6)
- wide S wave in lead I
first degree heart block
lengthened PR interval (>200ms)
second degree heart block
type 1 (Mobitz I)
- progressive prolongation of the PR interval until a dropped beat occurs
type 2 (Mobitz II)
- PR interval is constant but the P wave is often not followed by a QRS complex (intermittent dropped beats)
third (complete) degree heart block
- no association between the P waves and QRS complexes
- can be fatal and usually symptomatic








