EKG basics

• related: Cardiology, bundle branch blocks, ECG samples

EKG leads

• Chest leads aka precordial leads:
• V1-V2: anteroseptal
• V3-V4: anteroapical
• V5-V6: anterolateral
• Limb leads:
• LA: left arm
• RA: right arm
• LL: left leg
• RL/N: right leg

QRS Complex

• Left bundle branch block produces a dominant S wave in V1 with broad, notched R waves and absent Q waves in the lateral leads.
• Hyperkalaemia is associated with a range of abnormalities including peaked T waves
• Tricyclic poisoning is associated with sinus tachycardia and tall R’ wave in aVR
• Wolff-Parkinson White syndrome is characterised by a short PR interval and delta waves
• Ventricular pacing will usually have visible pacing spikes
• Hypothermia is associated with bradycardia, long QT, Osborn waves and shivering artefact