Tachyarrhythmias & ACLS

Question 1

Ddx of irregular SVT?

Answer 1

AF or MAT is MC. Consider AFlutter.

Question 2

Ddx of regular SVT?

Answer 2

AVNRT.
AVRT (WPW).
AFlutter.
Consider ectopic atrial tachycardia.

Question 3

4 different types of AF based on timing?

Answer 3

-Paroxysmal terminates within 1 week with or without intervention.
-Persistent lasts longer than 1 week.
-Long-standing persistent lasts longer than 1 year.
-Permanent is sustained without further attempts at rhythm control.

Question 4

Treatment of unstable SVT? Be specific.

Answer 4

SYNCHRONIZED cardioversion. Biphasic, 120-200J.

Question 5

Treatment for AF-RVR with HF?

Answer 5

Amio, digoxin

Question 6

Treatment for AF-RVR with accessory pathway?

Answer 6

Ibutilide, procainamide. Do not use digoxin, amiodarone, CCBs.

Question 7

Options for pharmacologic cardioversion of AF?

Answer 7

-Ibutelide (4% risk of Torsades, avoid with HF)
-Amio (less effective)
-Procainamide (even less effective)

Question 8

Duration of AC after DCCV for AF?

Answer 8

4 weeks. Pretreat with either 3 weeks of DOAC, or with TEE to confirm no thrombus.

Question 9

Prognosis of post-cardiac surgery AF?

Answer 9

Excellent. 90% self-resolves in 6-8 weeks.

Question 10

Treatment for MAT (Multifocal Atrial Tachycardia)?

Answer 10

Rate control with BB, CCB, Dig. Rhythm control with procainamide, amio.
-Don’t use DCCV as it is ineffective.

Question 11

Pathophysiology of AVNRT?

Answer 11

Retrograde conduction pathway in the AV-Node that is faster than the anterograde pathway.

Question 12

EKG findings of AVNRT?

Answer 12

Short R-P interval and long P-R interval.

Question 13

Treatment of AVNRT or AVRT?

Answer 13

AV-Node blockers: Adenosine, CCBs, BB.
-Second line is Dig, amio, procainamide.
-Consider A or V Overdrive pacing.
-Vagal maneuvers and DCCV also options.

Question 14

EKG findings of AVRT?

Answer 14

Delta-wave: slurred up-slope of QRS. AVRT=WPW.

Question 15

Two types of AVNRT? Which type is more common?

Answer 15

Orthodromic Reciprocating Tachycardia (95%) vs Antidromic.

Question 16

Tx AVRT?

Answer 16

Avoid AVNodal blockers. Use Procainamide. Consider chemical cardioversion with ibutelide or DCCV.

Question 17

Definition of fusion / capture beat?

Answer 17

conduction of a sinus beat (usually unexpected sinus beat). Narrow QRS.

Question 18

QRS durations for LBBB and RBBB?

Answer 18

-LBBB > 160ms.
-RBBB > 140ms.

Question 19

Clues to diagnose SVT w/ abbarancy (4)?

Answer 19

-Termintes with vagal tone
-Critical rate at which QRS widens (i.e., rate-related BBB)
-Alternating BBB.
-Long-Short Syndrome (AKA Asherman’s Phenemenon) related to R-R distance.

Question 20

Tx of unstable VT w/ a pulse?

Answer 20

-Regular -> DCCV, 100J
-Irregular -> Defib, 200J

Question 21

Tx of stable VT w/ a pulse?
(Should this say SVT?)

Answer 21

-Adenosine if regular. Procainamide, amio. Ventricular overdrive pacing.