EKGs: atrial and ventricular arrhythmias

CO=SV x HR; explain how SV and HR are changes with brady-arrhythmias and tachy-arrhythmias

brady: decreased HR and increased SV

tachy: increased HR and decreased SV

What is artifact with an EKG?

this is when something causes a disruption in monitoring; it is clinically insignificant;

ex: muscle contractions and tremors

true or false: artifact can hide an arrythmia

true

automaticity think about

pacemaker activity

What is: when an impulse travels back and re-excites the site of origin

reentry

what is: generation of spontaneous electrical action potentials

automaticity

What are the 4 major things that should be included on an EKG report?

orientation, rhythm, rate, and interval

how do we know if something is “sinus”

if a normal p wave precedes every QRS complex

What can be caused by sick sinus syndrome, common in athletes and during sleep, physiological response to a vagal maneuver

sinus bradycardia

how do we treat sinus bradycardia?

usually self-limiting

atropine if vitals are unstable

pacemaker if recurrent

when do we see a narrow QRS vs wide QRS?

narrow (normal): supraventricular (originating above the ventricles— like atria and nodes)

wide: originating in the ventricles

What is a normal physiologic response to pain, exercise, stress, infection, anemia, dehydration, PE, etc.?

sinus tachycardia

how do we treat sinus tachycardia?

identify and treat the underlying cause

What arrythmia?

premature activation of the atria form an atrial site other than the sinus node

premature atrial contractions

What arrythmia?

irregular rhythm

abnormal p-wave (could be embedded in the T wave or not isolated form the t wave)

premature atrial contractions

What arrythmia?

regular atrial rhythm originating outside of the SA node with rate >100 bmp

focal atrial tachycardia

What arrythmia?

rhythm regular; p waves almost hidden in T waves; adenosine can reveal underlying atrial activity

focal atrial tachycardia

What arrythmia?

the most common type of paroxysmal supraventricular tachycardia

AV nodal reentrant tachycardia (AVNRT)

What arrythmia?

results from a reentrant circuit at the site of the AV node → depolarizes the atrium and ventricle simultaneously

AV nodal reentrant tachycardia (AVNRT)

What arrythmia?

rhythm is regular; p waves may be retrograde or buried

AV nodal reentrant tachycardia (AVNRT)

How do we treat AV nodal reentrant tachycardia (AVNRT)?

ablation

What arrythmia?

retrograde p wave

WPW syndrome (accessory pathway)

AV reentrant tachycardia (AVRT)

What is a form of AVRT; has a bundle of Kent; pre-excitation refers to early activation of the ventricles due to impulses bypassing the AV node via an accessory pathway

WPW syndrome

note: bundle of Kent is the accessory pathway

What arrythmia?

shortened PR interval, delta wave, and widened QRS

WPW syndrome → type of AVRT

even though its a supraventricular tachycardia, it still has a widened QRS (exception to the rule)

How do we treat WPW syndrome?

ablation of the accessory pathway

vagal maneuvers

what should be avoided with WPW syndrome?

AV-nodal supressing agents

What arrythmia?

firing of multiple impulses from numerous ectopic pacemakers in the atria → chaotic asynchronous activity in atrial tissue

atrial fibrillation

What arrythmia?

rhythm is irregularly irregular, no p waves

most common cause is HTN

atrial fibrillation 

how do we treat A-fib?

rate control: beta-blockers, CCBs. digoxin

rhythm control: amiodarone, sotalol, flecainide

anticoagulation

What ablation can we do for atrial fibrillation?

pulmonary vein isolation

With the CHADS2-VASc score, what are the scores and what do they say about treatment?

0: doesn’t say anything (low risk)

1: low-mod risk → antiplatelet or anticoagulation

2: mod-high risk → anticoagulation 

What arrythmia?

reentry circuit within the right atrium that transverses the cavo-tricuspid isthmus

atrial flutter

with atrial flutter what is the most common ratio of AV?

atria contracts twice for every one ventricular contraction

atria around 300 bmp while ventricles around 150 bmp

What arrythmia?

narrow complex tachycardia; saw-tooth pattern

atrial flutter

How do we treat/manage atrial flutter?

anticoagulation, cardioversion if unstable; ablation of cavo-tricuspid isthmus

What arrythmia?

irregular rhythm; 3+ different p-wave shapes

multifocal atrial tachycardia

how do we treat multifocal atrial tachycardia?

verapamil and tx underlying cause

What arrythmia?

ectopic beats that originate below the branching point of the bundle of His

generated below AV node so wide QRS usually without a preceding p wave

premature ventricular contractions

When do we treat a premature ventricular contraction?

if also acute MI, couplets, bigeminy, or trigeminy, multifocal, are frequent, or symptomatic 

What arrythmia?

p waves are usually obscured/not present, are unrelated to the QRS complex

uniform wide QRS complex

monomorphic ventricular tachycardia

how do we treat monomorphic ventricular tachycardia?

amiodarone

What arrythmia?

chaotic electrical activity from the ventricles that causes the absence of cardia output

ventricular fibrillation (very bad)

What is the treatment for ventricular fibrillation?

immediate defibrillation and ACLS protocols

What arrythmia?

causes: drugs that prolong QT interval, MI, electrolyte imbalances (mostly: hypo-Mg, hypo-K, and hypo-Ca)

torsades de pointes

how do we treat torsades de pointes?

synchronized cardioversion

IV MG or IV K

first line is IV Mg