EKG-Class 2

Question 1

causes first degree AV block:

Answer 1

conduction system dz, drugs (BB, CCB, amiodarone), MI (lost tissue in AV node/bundle of his)

Question 2

EKG findings for first degree AV block:

Answer 2

widened PR interval (>200msec)

no dropped beats

Question 3

EKG findings for Wenckebach TII heart block

Answer 3

*progressive PR interval prolongation
grouped beating until
QRS drops
ratio P:Q is 4:3 or 3:2

Question 4

Sxs of TII heart block

Answer 4

usually asxmatic, can have irregular HR, “skipped beat” and rarely dizzy/syncope (more common in Mobitz)

Question 5

EKG findings Mobitz TII heart block

Answer 5

*fixed PR interval

QRS drops

Question 6

Difference in location of heart block in Wenckebach and Mobitz

Answer 6

Wenckebach: AV node
Mobitz: His bundle or lower (more dangerous )

Question 7

Tx for Mobitz

Answer 7

temporary pacing; then permanent pacemaker

Question 8

EKG findings third degree heart block

Answer 8

atria and ventricles “march out independently”
not grouped
P-P and R-R intervals are different and w/o pattern

Question 9

Causes of third degree heart block

Answer 9

drug toxicity (digitalis, BB, CCBs), MI, stroke/TIA, post cardiac surgery, idiopathic

Question 10

Tx for complete heart block

Answer 10

cardio consult
drugs to increase cardiac output
temp pacing wire/external pacing pads
permanent pacemaker

Question 11

Which two types of heart block require permanent pacemaker for tx?

Answer 11

mobitz and complete

Question 12

Bundle branch blocks can be a/w:

Answer 12

pulmonary emboli
cardiomyopathy
COPD
HCM
HTN
AV disease
ASD, VSD

Question 13

EKG findings for RBBB:

Answer 13

wide QRS >120
Rabbit ears or RSR’ pattern: V1/2
V1: positive, upright QRS (should be negative)
wide, slurred S wave in lateral leads (I, aVL, V5-6)

Question 14

which BBB is more common?

Answer 14

left BBB

Question 15

RBBB can be a/w:

Answer 15

normal individuals
conditions affecting R side of heart/lungs (pulm dz, PE, R HF)
fixed split S2

Question 16

EKG findings with LBBB:

Answer 16

wide QRS >120
deep/broad QR or RS in V1
QRS: negative in V1 (unlike RBBB)
J point elevated
RSR' in V6

Question 17

LBBB can be a/w:

Answer 17

chronic heart dz (more serious than RBBB)

AS, dilated CMP, acute MI, CAD, aortic root dilation, paced rhythm

Question 18

EKG findings with intraventricular conduction delay (IVCD)

Answer 18

QRS > 110

morphology not like L/RBBB

Question 19

Causes of IVCD:

Answer 19

conduction system dz, antiarrythmic drug toxicity, hyperkalemia, WPW syndrome, hypothermia