ECGs Flashcards
Give the diagnosis:
Sinus rhythm followed by no p wave before a normal QRS, or one immediately before or after the normal QRS; the next p wave is late, followed by sinus rhythm
Junctional (nodal) extrasystole
When do you see -ve or +ve deflections of the QRS?
-ve in I, and +ve in III is R axis deviation
predominantly -ve in II and III is L axis deviation
What sort of pathology does LBBB indicate?
Heart disease, ~ on the L side Aortic stenosis Ischaemic disease Hypertension Cardiomyopathy Acute MI if also chest pain
What do hyperacute T waves indicate?
MI
How can you identify atrial flutter on an ECG?
Look at leads II, aVR and aVF
Narrow complex tachycardia
P waves at >250 bpm, and multiple p waves per QRS
No flat baseline between p waves (sawtoothed appearance)
If the R-R interval is 5, what is the heart rate?
300/5 is 60
Give the diagnosis:
No p waves, only an irregular baseline
Normal shaped QRS complexes, very irregular rate (may be abnormal shape if also a BBB)
V1 may look a bit sawtoothed
Atrial fibrillation
Give the diagnosis: No relationship between p and QRS Different rates for p and QRS Abnormally shaped or broad QRS Slow QRS rate
3rd degree (complete) heart block
What does a thick base line on the ECG reading indicate?
Electrical interference eg. from electric lights or electric motors on beds/mattresses
What ECG changes are seen in digoxin Tx?
Downward sloping ST segment
Give the diagnosis:
Sinus rhythm followed by an abnormal, early p wave, normal but early QRS; the next p wave is late, followed by sinus rhythm
Atrial extrasystole
What ECG changes are seen in R and L atrial hypertrophy? Give 2 causes of each
Right:
Peaked p waves
Tricuspid valve stenosis
Pulmonary hypertension
Left:
Broad and bifid p waves (p mitrale)
~ due to mitral stenosis
Also can be due to mitral regurg
What does an RSR1 pattern indicate in V1?
RBBB
Normal if <120 ms (partial RBBB)
Give the diagnosis:
Delay after a beat, followed by an abnormal p wave and normal QRS. Returns to sinus arrhythmia
Atrial escape
Which direction is the depolarisation wrt the sizes of the R and S waves?
R>S (overall upward) means depolarisation is moving towards that lead.
S>R (overall downward) means it’s moving away.
R=S means the depolarisation wave is moving at right angles to the lead.
How do you determine a normal 11 o clock - 5 o clock axis?
They will be a predominantly upward deflection in leads I, II and III, with a greater deflection in II
What ECG changes are seen in PE?
Can have a normal ECG with sinus tachycardia
RBBB
Peaked p waves
Increased height of the QRS (>35 mm) in V1
Q wave in III but no aVF + R axis deviation
Dominant R waves in V1 (R>S)
Deep S wave in V6
Transition point shifted to V5 or V6 (clockwise rotation)
T waves inversion in III, V1, V2 and possibly V3 and V4
What ECG changes are seen in L anterior hemiblock?
Marked L axis deviation
Deep S waves in leads II and III, ~ with a slightly wide QRS complex
When are p waves broad and bifid (p mitrale)?
L atrial hypertrophy, which is ~ due to mitral stenosis, or sometimes mitral regurg
How do you work out the position of an MI?
Anterior: V3-4 (often V2 and V5)
Inferior: III and aVF
Lateral: I, aVL, V5-6
True posterior: dominant R waves in V1
Give the diagnosis:
Slow QRS rate
No p waves in junctional beats, but normal QRS
Nodal (junctional) escape
How do you determine R axis deviation. What sort of conditions is this associated with?
I has negative deflection.
III has increased positive deflection of the QRS.
Caused by R ventricular hypertrophy, which is associated with pulmonary conditions that put a strain on the R heart (eg. PE), as well as congenital heart disorders.
Can also be normal in tall, thin people
What are the causes of sinus arrhythmia?
Changes in heart rate associated with respiration - ~ seen in young ppl
When are QRS complexes narrow?
Supraventricular rhythms (sinus, atrial, nodal)