Rhythm Disturbances Flashcards
76 yo Pt with mechanical mitral valve presents with new onset palpitations.
EKG shows irregular R-R intervals without a distinct P wave, along with fibrillatory waves
Atrial Fibrillation: irregularly irregular
Tx Goal: decrease progression, tachy-mediated cardiomyopathy
Tx:
- Beta Blockers,
- Aspirin, Warfarin or novel anticoags like Dabigitran;
- Antiarrhythmics (amiotarone) to prevent cardiomyopathy in younger patients.
- Chemical or electrical cardioversion
- Catheter ablation
30 yo man with new onset palpitations
ECHO: normal
EKG: irregularly irregular tachycardia with wide, variable QRS with Delta Wave
Atrial Fibrillation with Pre-Excitation
(due to accessory pathway)
Caution: can give rise to Vtach or Vfib
Tx:
- Stable: procainamide
- Unstable: electric or chemical (abutalide) cardioversion (60% success) and catheter ablation (95% success)
37 yo man with presyncope/fainting
EKG: PP interval is greater than 1.6 - 2 seconds and pause is not a multiple of PP interval
Sinus Pause (aka Sinus Arrest):
SA failure of automaticity followed by SA note impulse or escape rhythm
Note: can lead to tachy brady syndrome
ETX: genetic if younger, or aging to fibrosis to pause
TX: pacemaker
71 yo man with intermittent lightheadedness, syncope and palpitations
EKG: combination of bradyarrhythmia, tachyarrhythmia, sinus pauses, exit blocks and/or junctional escape rhythm
Sick Sinus Syndrome aka Tachy Brady Syndrome
ETX: SA node dysfunction seen in elderly
TX: monitoring if Sx (Holter, Zeopatch), pacemaker if syncope
76 y o woman with lightheadedness and weakness
EKG: regular RR interval, P waves are all over the place (before, during and after QRS), HR 40-60 bpm, QRS is narrow
Juncional Escape Rhythm
Rhythmn originating from the AV junction
Risk Factors/ETX: athletes with increased vagal tone, sick sinus, acute rheumatic fever, Lyme, digitalis, poast cardiac or valve surgery, isoproterenol IV, during MI
Note: Junctional rhythms can be brady <40, accelerated 60-100, tachy >60
55 y o man with prior A-fib ablation in hospital with palpitations
EKG: narrow complex tachycardia with P waves that all look different, isoelectric baseline, long R-P intervals, atrial rate of 100-240
(multifocal) Atrial Tachycardia
SVT originating in atria but outside SA node
ETX:
- Unifocal: Digitalis
- Multifocal: COPD, asthma due to hypoxia and irritation of SA node
57 yo man with new onset tachycardia
EKG: narrow and wide QRS,
long RR interval followed by short RR interval
Atrial Tachycardia with Aberrancy
Atrial Tach w wide QRS due to depolarization during long refractory period (refractory period influenced by rate and preceding cycle length)
Ashman Phenomenon: long R-R, then short R-R, then aberrant QRS waves
NOTE: can tell it is not Vtach because some of the QRS are narrow.
46 yo woman who drinks lots of coffee presents with sudden onset palpiations
EKG: Narrow complex tachycardia at 150 bpm with short RP interval (less than 1/2 R-R)
AV Nodal Re-Entry Tachycardia AVNRT
aka Supraventricular Tachy SVT
ETX: genetic abnormality having dual node pluse exposure + coffee/stress –> PACs or PVCs –> AV node loop
Tx:
- Acute: vagal maneuver + IV adenosine or diltiazam pill to stop AV node
- Recurrent: catheter ablation of slow pathway of dual node
50 yo woman with palpitations
EKG: narrow complex tachycardia
with inverted P wave in aVF, long R-P interval.
AV Re-Entry Tachycardia AVRT
Re-entrant tachicardia involving the AV node and an accessory pathway
- Orthodromic: narrow QRS with anterograde conduction via VA node and His-Perkinje system to ventricle
- Antridromic: wide QRS with anterograde conduction via a bypass tract and retrograde vis AV node
TX: interrupt AV nodal conduction to end tachy (diltiazem CCB or beta blocker) but with crashcart nearby bc can lead to Vfib via accessory pathway in 3/100.
48 yo woman with episodes of sustained tachycardia
EKG: normal P wave axis and morphology, short PR interval (
Wolff-Parkinson-White pattern
pre-excitation of ventricles by bypassing AV node
via Bundle of Kent accessory pathway
Tx: catheter ablation if Sx due to risk of sudden death
Can locate accessory tract based upon
where delta waves are seen on EKG
53 yo man with aortic stenosis
EKG: narrow complex tachycardia with regular R-R intervals and uniform sawtooth P waves (4:1 rato of P:R)
Atrial Flutter
Macro-re-entrant atrial tachycardia originating in the rightr atrium aroung the cavo-tricuspid isthmus
- Typical/ Counterclockwise (90%): Inverted F waves in inferior leads, everted in V1
- Atypical/Clockwise (10%): Everted F waves in inferior leads, inverted in V1
Tx: rate control and anticoags; Catheter ablatio in typical
Ratio of P:R tends to be 2:1 or 4:1
53 yo woman with non-ischemic cardiomyopathy
EKG: broad complex tachycardia >100 bpm
Ventricular Tachycardia
Sustained (.30 sec) vs Non-sustained (3+ beats, <30 secs)
Tx:
- Stable (re pulse, BP, Sx): amiodarone to control arrhythmia or lidocaine if CAD or cannot take amiodarone
- Unstable: defibrillation
57 yo ma with recent MI
EKG: polymorphic ventricular tachycardia with characteristic twisting beat-by-beat QRS changes
Torsades de Pointes
ETX: long QT (often caused by medications) + PVS (prolonged repolarization leads to early after depolarization EADs)
Tx:
- Avoid provocative agents (meds, ETOH, electrolytes)
- Suppress long QT using magnesium sulfate
- Emergency: defibrillation
598 yo alcoholic woman with hypocalcemia and hypomagnesemia
EKG: QTc interval > 460 ms
Long QT Interval
QTc>440 in men, 460 in women
ETX: genetic +/- hypocalcemia, hypothyroid, meducations (mathodone, haloperidol, etc)
TX:
- Low Risk of sudden death: avoid provocative agents
- Sx/Med risk: BB, Na+ channel blockers
- Hi risk: implanted cardio defibrillator (ICD)
66 yo man with CAD presents with syncope and collapse, BP = 0, unresponsive, no previous heart disease
EKG: chaotic, irregular waves without identifiable P, QRS or T
Amplitude decreases with duration (course to fine)
Ventricular Fibrillation
ETX: R on T PVC (at vulnerable period), baseball to the chest during T wave, often preceded by Vtach
TX: chest compressions and defribrillation with antiarrhythmics (amiodarone, lidocaine)
