Dysrhythmias II + III - Exam 3 Flashcards
What are premature atrial contractions?
Defined as an ectopic focus in the atria that fires before the next sinus node impulse
beat occurs earlier than the next beat
What does the P wave look like? How do you document them?
different P wave morphology
Atrial bigeminy (every other)
Atrial trigeminy (every 3rd)
Atrial quadrigeminy (every 4th)
What do you call PAC that occur less freqently than every 4th beat?
“Sinus rhythm with multiple/frequent PACs”
______ May also be precursor to atrial tachycardia, atrial fibrillation/flutter. What will the pt complain of?
PACs
asymptomatic or palpitations
What is the tx for asymptomatic PAC and symptomatic PAC?
asymptomatic: nothing!
symptomatic:
1st -> BB or CCB
2nd -> Class IC or III antiarrhythmic
What is the result of ectopical atrial arrhythmias? What is the MC atrial rate?
Results from an ectopic atrial focus creates an action potential at a rate faster than the sinus rate, therefore becoming the pacemaker
Atrial rate can range between 50 and 180 bpm
What is the typical HR associated with paroxysmal atrial tachycardia? May not see _____ if buried in ____
Typical HR of 100 to 200 bpm (other sources say 150 to 250)
P wave
T wave
What are the key EKG findings of multifocal atrial tachycardia? What is it called with HR is greater than 100 bpm? Less than 100 bpm?
P waves of different morphology
Varying PR segments
QRS will be narrow
When HR > 100 bpm = MAT
When HR < 100 bpm = WAP
What does structural heart disease when combined with Multifocal Atrial Tachycardia result in?
sustained atrial tachycardia
Electrolyte disturbances (especially hypokalemia), chronic lung disease or pulmonary infection, acutealcoholingestion, hypoxia, and use of cardiac stimulants (theophylline,cocaine) can all cause _____
Multifocal Atrial Tachycardia
What is the tx for ectopic atrial rhythms? MAT specifically? 2nd line?
Beta blockers and non-dihydropyridine CCBs are good first-line option
MAT: diltiazem and verapamil
2nd line: Class IC or III antiarrhythmic
What is the tx for refractory atrial rhythms?
Class IC or III antiarrhythmic
**_____ is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally
Atrial fibrillation (AF)
What is atrial fibrillation?
AF is a chaotic, rapid (300-500 bpm), and irregular atrial rhythm
A supraventricular tachyarrhythmia with uncoordinated atrial activation and ineffective atrial contraction
What is the pathophys behind atrial fibrillation?
Often stems from waves of electrical activity originating from ectopic action potentials most commonly generated in the pulmonary veins (PVs) of the left atrium (LA), or in response to reentrant activity promoted by heterogeneous conduction due to interstitial fibrosis.
What are the 6 reasons behind afib?
HTN
Valve dz
coronary artery dz
obesity
alcohol abuse
sleep-disordered breathing
_____ is a systemic dz that presents as an electrical problem also very common to see after _____
afib
cardiac sx
What are some EKG characteristics that are commonly found with afib? What is the nickname?
irregular R-R intervals (when atrioventricular conduction is present)
absence of distinct P waves
irregular atrial activity also known as fibrillatory waves
“Irregularly irregular rhythm”
What are the 4 classifications of atrial fibrillation?
paroxysmal: less than 48 hours
persistent: greater than 7 days or requires CV
long-standing persistent: greater than 1 year
permanent: fully accepted
maybe consider looking at this slide again??
maybe look at it
What is the clinical presentation of afib?
Palpitations, heart racing sensation, SOB, chest pain, fatigue, dizziness, near syncope – all possible
may cause hypotension
What needs to be included as part of the diagnostic evaluation for afib?
echo
stress test: to eval for ischemic eval
BMP
TSH
CBC
What is the 3 fold management strategies for afib?
- Risk Factor Modification / Lifestyle Modification
- Rate/Rhythm control - Assesses symptoms of AF and its complications
- Thromboembolic event prevention
What are the lifestyle/risk factor modifications needed for afib?
What is the pharm management for afib? Give first line? acute setting?
Non-DHP CCBs - 1st line (contraindicated in HFrEF patients)
Beta blockers - 1st line
Digoxin
Amiodarone - used for hypotension in acute setting with hemodynamic instability
Atrioventricular node ablation and permanent pacemaker implantation
What is the tx for hemodynamically unstable afib?
immediately cardioverted
What is the tx for non-emergent afib cardioversion? What qualifies as elective cardioversion? Once a person is electively cardioverted, ______ needs to be initiated for the following 4 weeks
Mechanical (Electricity) or Chemical (Ibutilide)
< 48 hrs duration, or
confirmed no thrombus with TEE, or
3 weeks of therapeutic anticoagulation
anticoag is needed for 4 weeks
What afib pts need to be on an anticoag?
Based on overall risk of thromboembolic event / stroke:
Low (∼<1%/y)
Intermediate (∼1 to ∼2%/y)
High (∼>2%/y)
**What is the CHADS2- VASC chart? Need to know the entire chart
**What is considered an intermediate risk for CHADS- VASC scoring? What is considered high risk? What is an important note to remember?
1= intermediate risk
2= high risk
female #1 doesnt count as intermediate risk
**What are the anticoag recommendations based on low, intermediate, high risk CHADSVASC score?
What is considered valvular atrial fib?
moderate/severe mitral stenosis or mechanical valve
can consider ______ in afib management while determining long-term tx options
Low-molecular weight heparin (Lovenox) (1 mg/kg subQ Q12 hours)
Heparin (full dose sliding scale protocol)
What are the anticoag options used in afib? What is important to note about the dosing?
Dabigatran (Pradaxa)
Rivaroxaban (Xarelto)- QD
Apixaban (Eliquis)- BID
Edoxaban (Savasya)
______ is the standard of care for afib patients for stroke prevention. Use ______ if anticoag are CI. What class of recommendation?
oral anticoag
Surgical and percutaneous techniques to occlude the left atrial appendage (LAA): Watchman and Amplatzer implants in the left atrial appendage
class 2a recommendation
When is surgical left atrial appendage exclusion indicated? What class of recommendation?
In patients with AF at moderate to high risk of stroke undergoing cardiac surgery, surgical exclusion of the LAA, in addition to continued anticoagulation, is indicated to reduce stroke risk
class I recommendation
What is the maintenance/long term management and pt education for afib pts?
pts may go between rate and rhythm control
NO CURE for afib only management
will need to monitoring to eval tx response
pt education:
avoid alcohol
control underlying risk factors
monitor for signs of bleeding
What is atrial flutter?
Commonly referred to as “organized atrial fibrillation
Typical atrial flutter involves a macroreentrant circuit around the tricuspid annulus traversing the cavotricuspid isthmus (CTI)
May involve a different circuit than tricuspid valve/isthmus - then it is called “atypical” AFL
aka think its a circuit and need to ablate the circuit, flutter is considered “more curable” than afib
What is the atrial rate in atrial flutter? What is the classic description on EKG?
P waves (atrial rate) usually 250 to 350 bpm (most common is 300 bpm)
classic “sawtooth” pattern
What is the tx for aflutter?
Higher rate of cure with catheter-based radiofrequency ablation, so should consider first-line - Refer to EP
Antiarrhythmics, Cardioversion, and rate control options same as AF
A/C same as AF
What is the common HR associated with junctional arrhythmias? What is the typical EKG finding? Will it be narrow or wide QRS?
HR commonly between 70 and 120 bpm
Retrograde P waves either immediately preceding QRS, immediately following QRS, or buried in the QRS and not visible
narrow QRS complex
____ is the normal rate of juncitonal pacemaker cells. ____ is considered accelerated. ______ is considered junctional tachycardia
40-60bpm
60-100bpm
greater than 100 is junctional tachycardia
**What are the 2 big causes of junctional arrhythmias?
Digoxin toxicity
Electrolyte abnormalities (especially hyper K)
What is the tx for junctional arrhythmias?
Treat underlying cause: FIX the reversible cause
Usually no need for pacemaker or other management
What is a premature ventricular contraction? What doe the QRS complex look like? What follows it?
Occurs earlier than the next beat should
Occurs earlier than the next beat should
followed by a long compensatory pause
How do you describe PVCs? If less frequent than every 4th beat, what is it called?
Ventricular bigeminy
Ventricular trigeminy
Ventricular quadrigeminy
Sinus rhythm with multiple/frequent PVCs”
What are frequent common causes of PVCs?
Caffeine, stress, alcohol
Structural heart disease – CAD, Valvular disease, LVH
Electrolyte abnormalities
Thyroid disease
What suppressed PVCs?
Normally diminish in frequency with exercise (suppressed by increased heart rate)
What are you thinking if PVCs increase with exercise?
Associated with higher risk of CV mortality
What is the associated work-up for a pt with PVCs?
Ambulatory monitoring to assess burden
Echocardiogram if concerns for structural heart disease
BMP, TSH
Referral to cardiology only necessary if associated with heart disease
____ is a very common complaint for pt with PVCs. What is happening?
Palpitations: “skipped beats”
functionally the ventricles squeeze but no blood gets ejected
What is the tx for PVCs? What is pt is asymptomatic?
first-line therapy is beta-blocker therapy (Lopressor)
asymptomatic: just reassurance, no meds
What is the tx for PVCs if BB fail?
If beta-blocker therapy fails, may consider Class IC or III AAD
Catheter ablation is also an option, especially with significant ectopy burden
What is accelerated idioventricular rhythm?
Regular wide complex rhythm with a rate of 60–120 beats/min
What are the 2 different mechanisms of accelerated idioventricular rhythm?
1) an escape rhythm due to suppression of higher pacemakers resulting from sinoatrial and AV block or from depressed sinus node function
(2) slow ventricular tachycardia due to increased automaticity
What are the causes of accelerated idioventricular rhythm?
In acute MI and following reperfusion with angioplasty or thrombolytics
Also common with digoxin toxicity
When is tx indicated in accelerated idioventricular rhythm?
Treatment is not indicated unless there is hemodynamic compromise or more serious arrhythmias
aka does usually require tx
define ventricular tachycardia. **What is considered non-sustained? **What is considered sustained?
Defined as three or more consecutive ventricular premature beats.
**Nonsustained – less than 30 seconds, terminates spontaneously
**Sustained – greater than 30 seconds
What are the causes of vent tachy?
Acute myocardial infarction, CAD
Cardiomyopathy, valvular disease, myocarditis
May occur in structurally normal hearts
What causes Torsades de pointes?
severe hypokalemia, hypomagnesemia, or after administration of a drug that prolongs the QT interval
What are the characteristics of congenital long QT syndromes?
Characterized by recurrent syncope, a long QT interval (usually 0.5–0.7 second), documented ventricular arrhythmias, and sudden death
______ may occur in the presence (Jervell-Lange-Nielsen syndrome) or absence (Romano-Ward syndrome) of congenital deafness.
Congenital Long QT Syndromes
Congenital Long QT Syndromes specific genetic mutations affecting membrane _____ and _____ channels have been identified
potassium
sodium
Congenital Long QT Syndromes is mainly characterized by episodes of ______ that are often triggered by ______ which can be brought about by physical exertion or mental or emotional stress.
torsades de pointes
adrenergic stimulation,
The most common forms of congenital LQTS are caused by _____ defects. LQT1and LQT2are ____ channel abnormalities. LQT3is an ____ channel mutation
ion channel
K+
Na+
When do Congenital Long QT Syndromes pts typically have their first episode? Which types account for 80% of the cases? _____ is only seen in 10% of the cases but it accounts for most of the lethal cases of LQTS
9 to 12 years of age
LQT1and LQT2
LQT3
What is Brugada syndrome characterized by?
Characterized by sudden death associated with one of several ECG patterns characterized by incomplete right bundle-branch block and ST-segment elevations in the anterior precordial leads
How is Brugada syndrome inherited? What gene is it associated with?
Autosomal dominant pattern of transmission in about 50% of familial cases
SCN5Agene
What is the EKG pattern seen with Brugada syndrome?
incomplete right bundle-branch block and ST-segment elevations in the anterior precordial leads
What is the management for Brugada and congenital long QT syndromes?
Refer to Cardiology or EP as soon as possible if suspected
Propranolol and Nadolol are preferred
ICD implantation to prevent sudden death from VT/VF
need to avoid medications that may further prolong the QT interval
What is the management for hemodynamically unstable Vent Tachy?
direct current cardioversion
aka shock them
What is the tx for vent tachy if the pt is stable? What is pt is refractory?
IV amiodarone likely will convert to sinus
IV lidocaine
Iv magnesium
What is the long term management strategy for sustained vent tachy?
ICD
Beta blockers
Amiodarone, Sotalol (Class III AAD)
Catheter ablation
What is the tx for nonsustained VT for individuals without heart disease? What is due to structural heart disease?
treat with beta blocker if symptoms only
treat with beta blockers, even if the patient has no sx’s, due to increased risk of sustained VT and sudden death
What is the tx for vent fibrillation?
SHOCK THEM
NOT a sustainable rhythm
consider ICD if indicated
_____ is the leading cause of sudden death
vent fibrillation
_____ most often occurs in patients with underlying heart disease and may be associated with progressive conducting system disease. Can it been seen in structurally normal hearts?
LBBB
can be seen in structurally normal hearts
The ______ provides the primary blood supply for the LBB
left anterior descending artery
LBBB is ____ usually the result of a single clinical entity, except in _____
not, usually the result of several chronic conditions that contribute to LBBB
acute MIs.
What is the tx for asymptomatic LBBB pts? What is the tx for Symptomatic patients with LBBB and low EF (<40%) ?
For asymptomatic patients with an isolated LBBB and no other evidence of cardiac disease, no specific therapy is required
CRT (cardiac resynchronization therapy / biventricular pacing)
What artery do RBBB receive most of its blood supply from?
septal branches of the left anterior descending coronary artery
What is the tx for isolated chronic RBBB? should think _____ pts
generally asymptomatic and do not require further diagnostic evaluation or tx
lung pts because increased RIGHT sided pressures
What is the tx for fascicular blocks?
For asymptomatic patients with fascicular block, no further diagnostic evaluation or therapy is required
For patients who present with presyncope or syncope and have ______ on EKG. What needs to happen next?
bifascicular block
continuous EKG monitoring for 24-48 hours, usually in an INPATIENT setting
need echo
If complete heart block is identified, _____ needs to happen next
permanent pacemaker should be implanted
If no symptoms and no underlying ischemia with bifascicular block, what is the tx?
no tx is necessary
