deck 8

Question 1

What’s the diagnosis?

Answer 1

blocked APC

blocked APC may manifest as:

• delayed R-R interval
• tall T wave in between

Question 2

History of chronic Afib with the following rhythm strip.

Answer 2

think of dig toxicity

• rhythm strip shows junctional tachycardia
• in the setting of digoxin usage, this may be CHB w/ junctional escape (“regularized Afib”)

Question 3

Pt with chief complaint of worsening DOE has below EKG. Most striking feature of this EKG?

Answer 3

electrical alternans

Question 4

45M p/w worsening chest pain and recent viral illness. EKG shown below. Likely diagnosis?

Answer 4

pericarditis, stage 1 (early)

pertinent EKG findings:

• diffuse concave-up STEs
• PR depression inferiorally
• PR elevation aVR

Question 5

What stage pericarditis is shown below?

Answer 5

pericarditis, stage 3

characterized by:

• isoelectric ST and PR segments
• diffuse T wave inversions

Question 6

EKG stage of pericarditis?

Answer 6

pericarditis, stage 2 (days later)

characterized by:

• diffuse T-wave flattening
• isoelectric ST segment

Question 7

Most likely cause of LAD in EKG shown below?

Answer 7

probably LAFB

• LAD + POSITVE QRS amplitude in aVR → axis is between -60 and -90 -> usually happens with left anterior hemiblock
• *note: by definition LAFB has profound left axis deviation (-45 to -60)

Question 8

48M who doesn’t take any medications has EKG shown below. What EP intervention will he likely need if you restore sinus rhythm?

Answer 8

dual chamber PPM

• EKG shows Aflutter with 6:1 AVB
• > 4:1 AV conduction ⇒ AVN pathology

Question 9

Most likely rhythm in strip shown below?

Answer 9

ectopic low-atrial rhythm

• pertinent EKG findings: regular AV conduction w/ negative P-wave in II
• since PR interval = ~0.12, rhythm is likely low atrial (PR > 0.11 goes w/ atrial source)

Question 10

35M with syncope while playing tennis has this EKG.

Answer 10

think of HOCM

EKG shows:

• large-amplitude QRS
• pseudoinfarct pattern in precordium
• hypertrophy-related ST changes (HSTs)

Question 11

Young pt with pleuritic chest pain after being punched in chest has EKG shown below. Biomarkers are negative. Most likely diagnosis?

Answer 11

early repolarization

to better characterize etiology of concave-up STEs, look at V6 ST segment:

• STE:TWH > 25% → goes w/ pericarditis
• STE:TWH

EKG shows

• concave-up STEs in precordial leads
• STE:TWH (v6) ≈ 10% ⇒ early repol more likely

Question 12

Female with EKG shown below has syncopal episode.

Answer 12

think of apical HCM

• typical apical HCM findings: deep asymmetric TWIs in V3-V6

Question 13

Brugada criteria for Vtach? (4)

Answer 13

VT diagnosed when ANY of the following present:

1. Absence of RS in all precordial leads
2. RS interval is > 100 ms in 1+ precordial leads
3. AV dissociation
4. morphologic criteria in both V1/V2 AND V6

Question 14

Definition of “RS interval” used in the Brugada criteria for VT?

Answer 14

RS interval = start of R wave to nadir of S wave

Question 15

Definition of precordial transition lead (PTL)?

Answer 15

PTL = precordial lead where R/S amplitude is 1

Question 16

Pt with Stage 4 CKD is found with K of 7.2. EKG does not display any ST changes. Why no hyperacute ST changes?

Answer 16

• Peaked T waves usually only occur in ACUTE hyperkalemia
• This pt likely has chronic hyperkalemia from CKD

Question 17

Differential diagnosis of group beating on EKG? (4)

Answer 17

• sinoatrial dz: 2nd degree SAE block, Blocked APCs
• AVN dz: 2nd degree AVB
• HPS dz: Concealed His-bundle depolarizations

Question 18

Criteria for pathologic Q wave in Rt precordial leads?

Answer 18

essentially, q of any type in V1-V3

technical definition for Q in Rt precordial leads→ either of the following in V1-V3:

• qR w/ q > 20 ms
• QS

Question 19

How can you distinguish between the two types of 2nd degree sinus exit block (SEB)?

Answer 19

• 2nd degree SEB, type 1: PP’ is LESS THAN TWICE the normal PP interval
• 2nd degree SEB, type 2: PP’ is a multiple of normal PP interval

*where PP’ = p to p interval that contains pause

Question 20

What is the diagnosis indicated by the arrows?

Answer 20

aberrantly-conducted APCs

EKG shows:

• APCs
• extra-systolic QRSs that conduct with RBBB pattern

Question 21

Name 3 features of Ashman’s phenomenon that help distinguish it from PVCs.

Answer 21

1. initial QRS forces are same direction as normal sinus beat (and terminal forces are RBBB pattern)
2. presence of other normally-conducted APCs
3. SAN is reset (should see non-compensatory pause)

Question 22

What should you think of when pt in question stem has “heart failure” or “Afib?”

Answer 22

digoxin-related EKG findings

Question 23

EKG presentation of hypothermia? (8)

Answer 23

• atrial arrhythmias: : sinus brady, Afib
• PAN-prolongation of conduction: prolonged PR, widened QRS
• repolarization anomalies: prolonged QTc, Osbourne waves
• pause-dependent escape rhythms: AV junctional escape, VT/VF

Question 24

What percentage of patients with low body temperature will have hypothermia-induced AFib?

Answer 24

incidence of hypothermia-induced Afib = 50-60%

Question 25

Pt found down on floor by EMS has EKG shown. Most important thing to code on EKG?

Answer 25

hypothermia!

• massive osbourne waves are shown
• it is unclear whether underlying rhythm is Afib vs. sinus arrhythmia (no apparent p waves, but phasic variation in R-R interval)