EP Flashcards
WPW without symptoms risk stratification
Exercise stress test
Procainamide challenge
Long RP interval regular, narrow complex tachycardia
Sinus tachycardia
Atrial tachycardia
Short RP narrow complex tachycardia
AVNRT
Accessory pathway
Typical atrial flutter EKG
Negative II, III, aVF
Positive V1
Does reduction dabigatran CKD
CrCl 15-30, reduce to 75 mg BID
Not recommended CrCl < 15
Does reduction rivaroxaban CKD
CrCl 15-30, reduce to 15 mg daily
Not recommended CrCl < 15
Does reduction apixaban CKD
2.5 mg BID if 2/3 factors present
CrCl < 15 / HD, 5 mg BID (2.5 mg BID if age >= 80 or weight <= 60)
Does reduction edoxaban CKD
CrCl 15-30, reduce to 30 mg daily
Not recommended CrCl < 15
AF AAD if no structural heart disease
Flecainide Propafenone Sotalol Dronaderone Dofetilide Amiodarone second line
AF AAD if CAD, MI hx
Sotalol
Dofetilide
Dronedarone
Amiodarone second line
AF AAD if LV dysfunction
Dofetilide
Amiodarone
Acute AF ablation complications
Tamponade
Phrenic nerve palsy
Volume overload
Recurrent arrhythmia
Subacute / Delayed AF ablation complications
PV stenosis
Recurrent arrhythmia
Stiff LA syndrome
AF ablation atrial esophageal fistula features
1-4 weeks after Fever, chills Esophageal symptoms Stroke GIB Dx - CT chest contrast Tx - surgery
WCT LBBB morphology
Terminal QRS negative V1
WCT RBBB morphology
Terminal QRS positive V1
Features of VT vs SVT with aberrancy
AV dissociation Capture beats Fusion beats Right superior axis Precordial concordance Abnormal septal activation Slow initial slope, fast terminal slope
Idiopathic VT types
Outflow tract, papillary muscle, perivenous areas
RVOT VT EKG
LBBB
Inferior axis
Outflow tract tachycardia features
Normal structural heart
Rare sudden death
Exercise, hormonal triggers
Suppressed by AVN blockers
Fascicular tachycardia EKG
RBBB + left axis / LAFB
Fascicular tachycardia features
Young patient, relatively narrow QRS
Reenetry
Verapamil works, adenosine doesn’t
AADs for scar based VT
Class III
Amiodarone, sotalol, dofetilide
ARVC EKG
LBBB morphology
TWI V1-V3
Epsiolon wave
Bundle branch reentry arrhythmia features
NICM / DCM
Reenetry
VT may look like sinus rhythm
Ablation, ICD
Brugada type I EKG pattern
Coved STE in at least one of V1-V3
Brugada Syndrome
Type 1 EKG Type 2 or 3 if they convert to Type 1 Syncope Sudden death Present in >= 1 relative \+ Genetic test
Genetic test for Brugada Syndrome
BrS1
Loss of function in sodium channels
Indications for ICD in Brugada
Aborted cardiac arrest
Syncope + spontaneous EKG
?asymptomatic / positive EP study
Medication for Brugada
Quinidine
Triggers for Brugada
Meds
Alcohol, marijuana, cocaine
Fever
Catecholinorgic Polymorphic Ventricular Tachycardia (CPVT) EKG
Normal rest EKG
Bidirectional VT -> VF with exercise
Similar to digoxin toxicity
Features of CPVT
Exertion induced syncope / SCD
No structural heart defect
Mimics long QT
Normal rest EKG
Pathophysiology of CPVT
RyR2 gene, ryanidine receptor
Leaky calcium channels, diastolic Ca overload, arrhythmias
Treatment of CPVT
Nadolol + flecainide
Left cardiac sympathetic denervation
Possibly ICD for aborted cardiac arrest
Features of congenital long QT syndrome
Syncope
Seizures
SCD
Suspicion with exertional, auditory, postpartum syncope / seizures
Where to measure QT interval
Lead II and V5, not V2/V3
Measure from where downward slope of t hits baseline
QT less than half RR interval =
QTc < 460
Measuring QT interval in sinus arrhythmia or AF
Take average of QT and RR intervals
Wide QRS adjustment for QTc
Adjusted QTc = QTc - [QRS - 120]
Guidelines for abnormal QTc
450 men
460 women
Risk rises with QTc of
500 ms
Congenital long QT path
Defective ion channels
17 genes
LQT1, LQT2, LQT3 make up majority
LQT1
Loss of function in potassium channel
Broad based T wave
Adrenergic trigger - swimming
Tx - BB
LQT2
Loss of function in potassium channel
Notched T
Auditory, postpartum trigger
Tx - BB
LQT3
Loss of function in sodium channel
Normal T after long isoelectric segment
Arousal, non-adrenergic trigger
Tx - BB
LQTS treatment
BB - nadolol or propranolol
Denervation therapy
ICD
Avoid meds
ICD indications for LQTS
Aborted cardiac arrest
LQT2 women with QTc > 500
QTC > 550 and not LQT1
Class I AAD mechanism of action
Block sodium channels
Slow conduction
Broaden QRS
Class Ia AADs
Quinidine Procainamide Disopyramide Amiodarone Increase QRS and QT, also block K channels
Class Ib AADs
Lidocaine
Mexiletine
Drug of choice in ischemic myocardium
Decrease QT, less proarrhythmia
Class Ic AADs
Flecainide
Propafenone
Increase QRS
Class III AADs
Dofetilide
Sotalol
Prolong depolarization, QT
Mechanisms of AAD proarrhythmia
Slow conduction - reentry
Prolong repolarization - EADs
Calcium overload - DADs
AADs with proarrhythmia through slowed conduction
Class Ic agents - black box warning for scar
Monomprhic VT
AADs with proarrhythmia through prolonged repolarization
Class III agents
Polymorphic VT / torsades
Pause dependent
AADs with proarrhythmia through calcium overload
Digoxin / CPVT
Bidirectional VT
Not pause dependent
Class Ic AADs use dependence
Use dependent Greater effect at faster HR Pill in pocket Potential for wide complex SVT QRS widening
Class III AADs use dependence
Reverse use dependence
Slower HR, more effect
Maintenance of sinus rhythm
QT prolongation
Class Ib AADs use dependence
Ischemia
Amiodarone use dependence
Rate independence
Treatment for polymorphic VT from class III AADs
Increase HR
Propafenone / flecainide toxicity
Bradycardia, broad QRS
7% of population slow CYP 2D6 metabolizers
Amiodarone warfarin interaction
Increases INR
Amiodarone digoxin interaction
Increased digoxin effect
Amiodarone cyclosporine, tacrolimus interaction
Increases levels
Class Ic drug monitoring
Rule out ischemia
Baseline QRS
QRS at 14 days +/- stress test
Dofetilide drug monitoring
Baseline electrolytes, EKG for QTc < 440
Telemetry and serial EKGs for 5 doses
EKG q3 months
Sotalol drug monitoring
Baseline electrolytes, EKG for QTc < 450
Telemetry and serial EKGs for 5 doses
Periodic QTc assessment
RFs for prosthetic valve thrombosis
AF
Previous thromboembolism
Hypercoagulability
EF < 30%
Reflex syncope / neural mediated / neurocardiogenic
Due to reflex that causes vasodilation / bradycardia
Hypotension + bradycardia
Vasovagal, carotid sinus syndrome
Treatment of vasovagal syncope
Counter pressure maneuvers
Salt and fluid intake
Midodrine, fludrocrotisone, BB, PPM for recurrent
Cardioinhibitory response carotid sinus syndrome
3+ sec pause or AV block
PPM, anticholinergics
Vasodepressor response carotid sinus syndrome
> 50 mm fall in BP
Midodrine, florinef, SSRI
PPM 1st letter
Chamber paced
PPM 2nd letter
Chamber sensed
PPM 3rd letter
Response to sensed event
PPM 4th letter
R (sensor driven pacing)
ICD for ToF
- LV systolic dysfunction
- NSVT
- QRS >= 180 ms
- Extensive RV scarring
- Inducible sustained VT
Scar-mediated VT mechanism
Re-entry
VT DADs ->
Idiopathic outflow tract VT
VT EADs ->
Torsades
VT abnormal automaticity ->
Fascicular VT
Lamin mutation
conduction system disease / AV block, ventricular arrhythmias, cardiomyopathy