Miscellaneous EKG Rhythms
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1. What EKG 1. Brugada syndrome
changes can re- 2. Wellens syndrome
sult in sudden 3. Long QT syndrome
cardiac death? 4. Hypertrophic cardiomyopathy (HOCM)
(*Can cause sudden death in young otherwise healthy pts*)
2. Brugada Syn- - *Autosomal dominant inheritance* in 50%
drome - May be seen on a "routine" EKG
- PE is usually normal
- Characterized by *RBBB pattern associated with ST segment elevation in leads V1
or V2*
-> Wide QRS complexes + P waves -> upright QRS back from T wave in V1 -> RBBB
-> ST elevation in V1 or V2
- Prone to develop ventricular dysrhythmias that lead to syncope and sudden
death
-> May be responsible for up to 4% of sudden deaths
- No pharmacologic tx is effective
- *The only effective tx is implantation of an AICD*
(*Uncommon but deadly*)
3. Wellens Syn- - Aka the *widow maker*
drome - Result of *critical stenosis of the LAD*
-> Progression leads to anterior wall MI
- May present with "symptoms" of unstable angina
- PE often unrevealing
- EKG shows *deeply inverted symmetric T waves or "biphasic" T waves in leads
V2-V4 without any significant ST segment abnormalities*
-> Inverted or upward/downward component T waves (biphasic)
- Should not undergo stress testing
, Miscellaneous EKG Rhythms
Miscellaneous EKG Rhythms
Study online at https://quizlet.com/_jrm2hn
- *Requires emergent cardiac cath!*
-> Tx like a STEMI!
4. Long QT Syn- - QT interval is measured from the beginning of the QRS to the end of the T wave
drome -> Count the blocks!
- This represents the duration of activation and recovery of the ventricular my-
ocardium
- A *QT interval (corrected for HR - QTc) should be < 0.44 secs in males and < 0.46
secs in females*
- *Predisposes to Torsades de Pointes*
-> Increased risk of R on T phenomenon with a longer QT interval
- *A normal QT should be less than 1/2 of the preceding RR interval*
- May be seen on a "routine" EKG
- Causes:
-> *Congenital*
-> *Med-induced* - macrolides, fluoroquinolones, antipsychotics, etc.
-> *Electrolyte-induced*
- Typical EKG change seen with *hypocalcemia*
- Risk factors for Torsades in pts with underlying prolonged QT include:
-> *Hypocalcemia*
-> *Hypokalemia*
-> *Hypomagnesemia*
-> *Multiple meds*
- PE is usually normal
- *Propensity to develop ventricular tachydysrhythmias* which may lead to syncope
or sudden death
- *Treated with beta blockers or AICD implantation*
- Avoid strenuous exercise and certain meds
, Miscellaneous EKG Rhythms
Miscellaneous EKG Rhythms
Study online at https://quizlet.com/_jrm2hn
5. What are the 2 1. Count number of blocks from beginning of QRS to end of T wave
ways in which 2. Should be 1/2 the preceding RR interval
you can deter-
mine the length
of a QT interval?
6. What medica- - *Antipsychotics*:
tions should be -> Chlorpromazine
avoided in pts -> Haloperidol
with long QT syn- -> Droperidol
drome? -> Quetiapine
-> Olanzapine
-> Thioridazine
- *Antidysrhythmics*:
-> Quinidine
-> Procainamide
-> disopyramide (IA)
-> Flecainide
-> Encainide (IC)
-> Sotalol
-> Amiodarone (IIIC)
- *SSRIs, SNRIs, TCAS and atypical antidepressants*
- *Antihistamines and anticholinergics*
- *Macrolides and quinolones*
- *Chloroquine*