Arrhythmias Flashcards
abnormalities of the electric rhythm
arrhythmias
why do arrhythmias happen? (7)
Hypoxia
Ischemia
Sympathetic stimulation
Bradycardia
Electrolyte disturbance
Drugs
Stretch
what does an abnormal number of P waves for every QRS complex suggest?
AV nodal block
what does it mean if P waves are not identical?
another pacemaker cell is firing
what does a narrow QRS complex mean?
impulse came from supraventricular rhtyhm
what does a wide QRS complex indicate?
impulses transmitted by direct cell to cell contact
what slows rate by stimulating the vagus nerve and can end arrhythmias?
carotid massage
arrhythmias in which electrical activity follows the usual conduction pathway
arrhythmias of sinus origin
arrhythmia in which electrical activity originates from a focus other than the sinus node
ectopic rhythm
arrhythmia in which electrical activity is trapped within an electrical racetrack whose shape and boundaries are determined by various anatomic or electrical myocardial configurations. These can occur anywhere in the heart.
reentrant arrhythmias
arrhythmia in which electrical activity originates in the sinus node and follows the usual pathways but encounters unexpected blocks and delays
conduction blocks
arrhythmia in which electrical activity follows anomalous accessory conduction pathways that bypass the normal ones
preexcitation syndromes
what speeds up and slows down the heart rate in a sinus arrhythmia, respectively?
inspiration
expiration
SA node discharge rate greater than 100 bpm that most often results from increased sympathetic and/or decreased vagal tone
sinus tachycardia
SA node discharge less than 60 bmp that can result from enhanced vagal tone and cause fainting
sinus bradycardia
what medications cause sinus bradycardia? (3)
beta blocker
CCBs
opioids
what is the most common rhythm disturbance seen in the early stages of an AMI?
sinus bradycardia
variation in heart rate that accompanies inspiration and expiration
sinus arrhythmia
a delay in the SA node that leads to delayed depolarization and contraction
atrial escape beat
how could a P wave in atrial escape beat look? (2)
flattened
notched
P wave of ectopic beat that occurs early and can be flatted or notched, and may be lost in the preceding T wave
premature atrial contractions
a contraction where the P wave could be buried in the QRS or show up after the QRS
junctional premature beat
what is frequently the inciting event to paroxysmal supraventricular tachycardia and will reset the SA node?
premature atrial contractions
pre-atrial contractions that can last a few seconds to days, in which the SA node gives up and another place in the atria picks up the slack by pacing the heart
ectopic atrial rhythm
what would be seen in an ectopic atrial rhythm?
P wave may be negative in 1, 2, and aVF
what does an upside down P wave tell us?
depolarization started at the bottom of the atria
formation of a reentry circuit, or dual electrical pathways confined to the AV node
atrioventricular nodal reentrant tachycardia (AVNRT)
what kind of depolarization / refractory period would a slow pathway in AVNRT produce?
slow depolarization / short refractory period
what kind of depolarization / refractory period would a fast pathway in AVNRT produce?
fast depolarization / long refractory period
what is the most common symptom of AVNRT?
palpitations
what is the usual rate of AVNRT?
120-220 bpm
a finding on ECG of buried or upside down P wave, depressed ST segment, and T wave inversion indicates what?
AVNRT
what is suspected in a patient with abrupt onset and offset of rapid sustained palpitations?
AVNRT
what could terminate an episode of AVNRT?
carotid massage (vagal maneuver)
what medication can be used to manage AVNRT?
adenosine
a reentrant circuit that runs along the tricuspid valve at an atrial rate of 180-350 bpm
atrial flutter
in atrial flutter, the atrial impulse cannot repolarize, so will not get to the ventricle to produce a QRS. what is this caused by?
AV block
what kind of P waves will be seen in atrial flutter?
saw toothed P waves
what is the typical relationship between P waves and QRS complexes in atrial flutter?
2:1
what are 2 ways to get rhythm control in atrial flutter?
synchronized cardioversion
chemical cardioversion
what is the drug of choice for atrial flutter?
ibutillide
what are 3 medications to help rate control in atrial flutter?
CCB
beta blocker
digoxin
what is the best treatment for rate control in atrial flutter?
radiofrequency catheter ablation
why wouldn’t carotid massage terminate atrial flutter?
originates above the AV node
multiple tiny reentrant circuits whirling around in totally unpredictable fashion
atrial fibrillation
what are the etiologies of atrial fibrillation?
Pulmonary embolism
Iatrogenic
Rhematic heart disease
Acute coronary syndrome
Thyroid (hyperthyroidism)
ETOH
Sleep (obstructive sleep apnea) or Sick heart
what causes changes in depolarization pattern in atrial fibrillation?
atrial remodeling / fibrosis
in atrial fibrillation, what does chronic remodeling lead to?
irreversible atrial enlargement
what are 2 symptoms of atrial fibrillation?
palpitations
tachycardia
what would a patient present with when coming in for atrial fibrillation?
embolism
what will be seen on JVP or monitoring of atrial fibrillation?
absent A waves
how is atrial fibrillation rhythm described?
irregularly irregular
what is the usual atrial rate in atrial fibrillation?
more than 350 bpm
a patient with unremarkable hx, somewhat normal physical, and incidental finding of atrial fibrillation on ECG would be considered what?
stable
a patient with hypotension, ongoing ischemia, severe heart failure, stroke, and atrial fibrillation on ECG would be considered what?
unstable
how should a stable patient with atrial fibrillation be treated?
treat underlying etiology
how should an unstable patient with atrial fibrillation be treated?
cardioversion
an electrical discharge that is synchronized to occur at the time of the QRS complex to terminate supraventricular tachycardias or ventricular tachycardias
cardioversion
would would cardioversion during the T wave lead to?
reentry leading to ventricular fibrillation
what is used to terminate ventricular fibrillation and is not timed with QRS since there is not a QRS complex on which to synchronize it
defibrillation
in a patient with atrial fibrillation, how should oral anticoagulants be initiated?
bridging - initially use heparin with another anticoagulant
what management is the initial approach for most old patients in atrial fibrillation?
rate control with drugs
what management is pursued in younger patients in atrial fibrillation?
rhythm control via cardioversion and arrhythmic drugs
what 2 types of medications are used in atrial fibrillation for rate control?
beta blocker
CCB
what medication is used in patients with atrial fibrillation and systolic heart failure?
digoxin
what medication is useful in acute ischemia, MI, LV dysfunction, or atrial flutter and atrial fibrillation?
amiodarone
rhythm with at least 3 different visible shapes in the P wave with a rate that is normal
wandering atrial pacemaker
irregular rhythm with at least 3 different shapes in the P waves with an atrial rate over 100 bpm
multifocal atrial tachycardia (MAT)
what 2 conditions is multifocal atrial tachycardia most common in?
severe pulmonary disease
hypoxemia
what medication can slow the ventricular rate in multifocal atrial tachycardia?
CCB verapamil
what does not work to treat multifocal atrial tachycardia?
carotid massage
displayed by a warm-up period when it starts, followed by a somewhat irregular rhythm, and a cool-down period when it terminates
paroxysmal atrial tachycardia
what can cause paroxysmal atrial tachycardia?
digitalis toxicity
what is the typical rate in paroxysmal atrial tachycardia?
100-180 bpm
paroxysmal atrial tachycardia (PAT) and AVNRT look similar. How can I tell the difference?
PAT will not respond to carotid massage