ECGs are frequently presented to candidates sitting the OSCE element of the exam, a systematic approach is essential.

  • Name, date, calibration (1mv=1cm, 0.2s=1cm [small square 40 msec])
  • Rate = 300/number of big squares between Q-Q
  • Rhythm AF, tachy (>100), brady (<60), sinus, heart block
  • Axis normal = -30° to +110°

P              peaked, tall Dright atrial hypertrophy

notched, broad Dleft atrial hypertrophy

P-R          >5 small squares

I degree block: prolonged PR interval

                II degree block:

                                Wekeneback: sequential ­ of PR interval

Mobitz typ II: fixed PR, dropped QRS (2:1, 3:1…)

                III degree block: disassociation of P and QRS

QRS        wide (<2.5 small squares)

MarroW Dright bundle branch block

WilliM Dleft bundle branch block

Q             1mm wide, 2mm/25% of R-wave

D old MI

Normal in lead I, aVL V6

ST           raised: 1mm 2xconsangious limb-leads, 2mm chest-leads

Depression: myocardial ischemia

Reverse tick: digoxin effect

Saddle shaped elevation: acute constrictive pericarditis

T              peaked hyperkalaemia

Flat, prolonged, hypokalaemia

Ischemia, infarction

Normal in III, V1-2 (and V3 in Negroes)

U             Normal/Hypokalaemia


MI: Hyperacute T-waves, ST-elevation T-wave inversion, Q-waves. Inf. (II, III, aVF) Ant. (V1-4), Lat. (I, aVL,V5-6) Post. look at V1-2. New LBBB.

PE: S-I (deep S-waves in I), Q-III (Q-waves in III), T-III (inverted T-waves in III). More generally a sign of R-heart strain.

Hyperkalaemia: tall tented T, wide QRS

Hypokalaemia: flattened T, prominent U, (muscle weakness, cramps, tetany)



On the webECG Wave-Maven – is a resource with many “barn-door” ECGs, presented in a quiz format; large database, expert explanations.


Bedside Critical care Echo (POCUS – Point of Care UltraSound) deserves it’s own page, while not featured prominently on the exam, it is becoming a standard of care on most units. There are lots of pages out there, here are a few I’ve found helpful


guideline Joint Statement: Appropriate Use Criteria for Echocardiography (2011) – this statement considers the evidence and utility of performing echo in specific situations.

On the webVirtual Transthoracic Echocardiography – this page shows high quality, interactive 3D images which will help you understand what your seeing on echo and also gives a few tips.

podcastMatt and Mike are constantly putting new podcasts out, they carry several lectures on the physics of ultrasound alongside the use of ultrasound of other parts of the body.



  • Serum sodium concentration <135 mmol/L.

Classification (biochemical)

  • Mild – between 130 and 135 mmol/L
  • Moderate – between 125 and 129 mmol/L
  • Profound – less than 125 mmol/L

Classification (temporal)

  • Acute – less than 48 h
  • Chronic – greater than 48 h



guideline Clinical practice guideline on diagnosis and treatment of hyponatraemia. Intensive Care Med (2014) 40:320–331