EKG Practice

Question 1

What do you see in first degree AV block?

Answer 1

• PR > 0.2 seconds (>5 small blocks) - prolonged PR

- P before every QRS and QRS after every P

Question 2

Do you need to treat first degree AV block?

Answer 2

No

Question 3

What do you see with a 2nd degree AV block type I?

Answer 3

• Mobitz 1 (wenckibach)
• Progressive prolongation of PR interval until QRS is dropped
• Narrow complex
• Site of injury inferior
• Rarely need treatment

Question 4

What do you see with a 2nd degree AV block type II (Mobitz II)?

Answer 4

-Regular PR interval but then you just drop QRS
-Some P are associated with QRS and some aren’t
-Site of injury anterior
-Progression to complete heart block (3rd degree)
-Common in acute MI - requires pacemaker
“on again off again”

Question 5

What do you see in third degree heart block?

Answer 5

-You don’t have any Ps in front of any QRSes
-No conducting through the AV node so atrial rate is completely separate from the ventricular rate!
-Complete heart block, requires pacemaker
“move to separate towns”
-QRSes may also be wide = clue that it is a block!

Question 6

What do you see in an EKG of Torsades de pointes?

Answer 6

“twisting of the points”

• Ventricular tachycardia
• See prolonged QR interval precedes the rhythm
• QRS complexes spiral around the baseline resembling like a twisted ribbon

Question 7

What sometimes helps treat torsades?

Answer 7

Magnesium!

Question 8

How do you use the isoelectric method to find the QRS axis?

Answer 8

• Pick Axis perpendicular to the most isoelectric lead
• Choose the perpendicular direction (-) or (+) that best fits the other EKG leads (are they mostly + or - with R waves?)