EKG: heart blocks, electrolyte imbalances, etc.

where is the block with 1st degree, Mobitz 1, mobitz 2, and 3rd degree?

1st degree and Mobitz 1: AV node

• less severe

mobitz 2 and 3rd degree: His-Purkinje system

• more severe

What is the heart block poem?

if the R is far from the P, then you have a 1st degree

PR gets longer, longer, longer, drop, its a case of Wenckebach (mobitz 1)

if some Rs don’t get through, prepare to Pace that mobitz 2

if the Rs and Ps don’t agree, prepare to Pace that 3rd degree

What is this?

delayed conduction from atrium to ventricle

you see: prolonged PR interval

usually asymptomatic and no treatment required

1st degree heart block

how do you treat a 1st degree heart block?

no treatment 

What is this?

the PR interval progressively increases until a QRS complex is dropped

cycle starts over after that drop  (regularly irregular)

Mobitz type 1 (second degree; Wenckebach)

How do you treat a Mobitz type 1 (Wenckebach)?

no treatment (usually asymptomatic)

What is this?

dropped QRS complex that is not preceded by a lengthening of the PR interval (PR interval is consistent)

symptoms may be present like: presyncope, syncope, fatigue, SOB

Mobitz type II (second degree block)

How do we treat mobitz type 2 (second degree)?

pacemaker

What is this?

when the atria and ventricles beat independently of eachother

3rd degree heart block

What is this?

p-waves not associated with QRS complexes

atrial pacing is greater than ventricular pacing

equal RR intervals and PP intervals, but no association

3rd degree heart block

What type if heart block is associated with Lyme disease?

3rd degree heart block

How do we treat a 3rd degree heart block?

pacemaker

what is this?

ventricular septal depolarization is reversed

you see V1: W shape

left bundle branch block (LBBB)

What is this?

V1-V2 shows a rSR’ pattern (M)

right bundle branch block

How can we decide if a bundle branch block is right or left?

look at lead I; use the “turn signal” thingy

go backwards on the EKG and see which way your “car” would turn to go from the T wave towards the QRS complex

with electrolyte disturbances, 90% of the time how do e (electrolyte), QT, and QRS change?

decreased e → decreased QRS and increased QT

• aka hypo

increased e → increased QRS and decreased QT

• aka hyper

What do we suspect with a tall peaked narrow based t wave and QRS widening?

hyperkalemia

What do we suspect with:

depression of the ST segment, decreased amplitude of the T wave, and increased amplitude of U waves

u waves usually seen V4-V6

hypokalemia (hypUkalemia → for the U waves)

What do we suspect with:

QT interval shortening with little to no effect on p, QRS, or t wave

hyercalcemia

What do we suspect with: 

prolonged QT interval and no change in the duration of the t wave

hypocalcemia

What do we suspect with: 

Osborne (“J”) waves (“camel hump” sign)

hypothermia