deck 9

Question 1

What is the rhythm?

Answer 1

bradycardia-dependent LBBB

• pertinent EKG findings:
  
  • ​LBBB pattern at slower HR
  • instantaneous reversion to normal HPS conduction at slightly faster HR

Question 2

EKG features of HCM? (4)

Answer 2

mnemonic: Ladies Love Hunky Persists

1. LAD (20% of cases)
2. LVH (50-60% of cases)
3. pseudoinfarct pattern (Q waves in I, aVL, V4, V5)HSTs
4. HSTs (hypertrophy-related ST changes)

Question 3

Which 2 syndromes can mimic MAT? How can you distinguish MAT from these syndromes?

Answer 3

MAT can resemble:

1. Sinus tachycardia w/ frequent APCs (MAT will have absence of one dominant atrial pacemaker)
2. Coarse AFib (MAT will have isoelectric baseline between p waves unlike AFib)

Question 4

What does the term “pseudo-RVH” refer to?

Answer 4

large R wave w/ TWI in V1 (seen in HOCM)

Question 5

Describe 4 EKG changes that are typical of digitalis EFFECT.

Answer 5

dig effect changes are similar to those of hyperkalemia:

1. Salvador dali mustache (sagging ST segment)
2. decreased QT interval (due to shortened phase 2 of action potential)
3. prominent U Waves
4. increased PR interval

Question 6

What are the characteristics of anti-arrhythmic drug toxicity? (6)

Answer 6

• slowing of ventricular repolarization: marked prolongation of QTc → torsades de pointes
• slowing of conduction in His-Perkinje system: QRS widening and AVB
• slowing of automaticity of PM cells: sinus bradycarda → sinus arrest

Question 7

Miller (Varecki) algorithm for VT diagnosis? (4)

Answer 7

mnemonic: Ivana Wants New Dick

ANY of the following present in aVR is diagnostic of VT:

1. Initial R-wave
2. Width of r or q wave > 40 ms
3. Notch on descending limb of neg QRS
4. dvi/dvt

**velocity ratio = dvi/dvt Where dvi is change in voltage over initial 40 ms and dvt is change in voltage over terminal 40 ms

Question 8

Which type of VT will respond to verapamil?

Answer 8

fascicular VT

Question 9

Most common cause of ST elevation on resting EKG?

Answer 9

normal-variant early repolarization

Question 10

ER resident calls you for cath consult but says he thinks this is early repol. He tells you there are 3-4 mm concave-down ST elevations in V2 & V3.

What to tell him?

Answer 10

this is likely NOT early repolarization because STEs are TOO HIGH AMPLITUDE & are CONCAVE DOWN

• STE characteristics in early repolarization:
  
  • up to 3 mm in precordial leads (V2-V4) & up to 1 mm in limb and lateral leads
  • concave up

Question 11

Differential diagnosis of prolonged JT segment? (2)

Answer 11

1. hypocalcemia
2. LQTS (type III)

Question 12

Which electrolyte abnormalities can prolong the QT interval? (3)

Answer 12

1. hypocalcemia
2. hypomagnesemia
3. hypokalemia

note that the above electrolyte deficiencies prolong different regions of the QT interval

Question 13

Criteria for coding accelerated idioventricular rhythm? (4)

Answer 13

1. QRS morphology similar to PVCs
2. AV dissociation
3. +/- capture/fusion beats
4. rate = 60-110 bpm

Question 14

Name 2 characteristics of AV dissociation.

Answer 14

1. atria & ventricles depolarize independently from one another
2. ventricular rate is usually greater than atrial rate

Question 15

distinguishing EKG characteristics of AVNRT? (3)

Answer 15

1. usually starts w/ APC (no warm up period)
2. short RP tachycardia
   
   • pseudo R’ in V1 - P wave buried in V1 that was not present in NSR
   • RP interval usually

Question 16

EKG diagnosis of left atrial abnormality? (3 different criteria)

Answer 16

code for LAA if ANY of the following are present:

1. V1 criterion: terminal P > 1.5 mm deep x 0.04 ms wide
2. II criterion: p > 0.12 ms wide
3. p-mitrale: II has BIFID p-wave AND peak-to-peak interval > 0.03 s

Question 17

criteria for diagnosis of acute posterior wall MI (2)

Answer 17

ALL of the following must be present in V1 AND V2:

1. pathologic R waves (R>S AND R > 40 ms wide)
2. ST depression > 1-2mm

Question 18

How to distinguish blocked APC from 2nd degree AVB?

Answer 18

• blocked APCs: shortened PP interval followed by absent QRS
• 2nd degree AVB: constant PP followed by absent QRS

Question 19

DDx of prominent upright U waves? (6)

Answer 19

mnemonic: CHAD Loves Urine (Urine stands for u wave)

1. CAD
2. Hypothermia/Hypokalemia
3. ARD effect
4. Digoxin effect
5. LVH

Question 20

DDx of prominent inverted U waves? (2)

Answer 20

1. LVH
2. CAD

Question 21

Criteria for interventricular conduction delay? (2)

Answer 21

either of the following:

1. QRS ≥ 0.11 s AND pattern not c/w RBBB/LBBB
2. abnormal notching of QRS (with or without prolongation)

Question 22

Conditions that can cause IVCD pattern on EKG? (5)

Answer 22

Slowed HPS conduction

• due to electrolyte disturbance → hyperkalemia
• Slowed conduction due to low body temp → hypothermia
• Increased amount of myocardium to depolarize* → LVH/RVH
• Bypass tract with Abnormal ventricular activation* → WPW
• abberent intraV conduction* → prior infarct (Fractionated QRS)

Question 23

Criteria for diagnosis of complete LBBB? (3)

Answer 23

All of the following must be met:

1. QS or rS in Rt precordial leads (V1 & V2)
2. broad R in lateral leads (I, V5, V6)
3. General Criteria for complete BBB met**

**all complete BBBs must have:

• QRS > 120 ms
• Delayed intrinsicoid deflection (> 50 ms)
• Appropriate Secondary ST changes

Question 24

Criteria for diagnosis of complete RBBB? (3)

Answer 24

All of the following must be met:

1. qR or rSR’ in Rt precordial leads (V1 & V2)
2. wide slurred S in lateral leads (I, V5, V6)
3. General criteria for complete BBB met**

**all complete BBBs must have:

• QRS > 120 ms
• Delayed intrinsicoid (> 50 ms)
• Appropriate Secondary ST changes

Question 25

RBBB morphologic criteria for diagnosing VT using Brugada method? (4)

Answer 25

RBBB-morphology with ANY of the following features suggests VT:

1. monophasic R (V1 or V6)
2. qR (V1 or V6)
3. notched QS (V1 or V6)
4. R/S ratio > 1 (V6 only)