ECG

Key anatomy

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LBB has 2 branches, RBB has one branch

P wave

Start of to start of q

PR interval: 1.2s-2s

QRS

0.12 s

T wave - potassium. Don't give bolus

Einthoven's triangle (red, yellow and green): if an impulse goes from negative to a positive then you will get a positive deflection

Questions to ask: is ther any electrical activity? ventricular rate? qrs regular or irregular (coming from one or more places)? QRS normal or prolonged (atria or not)? Atrial activity present? atrial activity related to ventricular activity?

special situation: if there is wide QRS but there is a p wave present then think bundle branch block

Over 160/200 - 300 bpm is a true SVT - ata higher point in the atria

example: junctional rythm

Leads

Augmented: AVR (right arm), AVF (left arm), AVF (unipolar leads)

Chest leads: unipolar - put on in order V1,2,4,3,5,6. This is because the landmark for v4 is midclavicular line 5th intercostal and v3 will be between this and V2 (left sternal edge 3rd ICS). Note V1 sits over SAN and so is negative.

Limb - bipolar

12 lead ECG

Inferior: ll, lll, AVF

Right lateral: AVR - everything in here should be negative

Left lateral: l, AVR, V4-6

V1,2,3: anterior

Look for reciprocal changes (ST depression)

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