Arrhythmias Flashcards
Sinus tachycardia characteristics
Regular
100-150 bpm
Normal intervals
Sinus tachy causes
Fever Activity Hemorrhage Stimulants Anxiety Injury Hypoxia Anemia Low BP COPD Meds MI
S/S hypoperfusion
Dizziness Weakness Syncope Disorientation Chest pain SOB Diaphoresis Pallor Hypotension Weak pulses Palpitations
Sinus tachy tx
Treat cause (anxiolytics, bolus fluids, digoxin, beta blockers, calcium channel blockers)
Sinus brady characteristics
Regular
<60 bpm
Normal intervals
Sinus brady d/t
hypothermia
hypoxia
Digoxin, beta blockers/calcium channel blockers
Acute MI
Vagal stimulation (vomiting/suction/rectal exam)
Athletes
Sinus brady tx
Atropine
Epinephrine
Pacemaker (rare)
Normal sinus rhythm
Regular
60 bpm
Normal intervals
Rhythm strip interpretation
1) Regularity
2) Rate
3) P wave : QRS complex ratio
4) PR interval
5) QRS complex
6) QT interval
7) INTERPRETATION :)
Normal values
PR: 0.12-0.20 s
QRS: 0.06-0.12 s
QT interval: 0.36-0.44 s
Sinus arrhythmia
Irregular HR
60-100 bpm
Normal intervals
Sinus arrhythmia d/t s/s tx
Normal pressure changes in chest cavity during breathing
No s/s
No tx
Sinus pause
Regular except for pauses 60-100 bpm Normal intervals Calculate pause (b/t QRS complexes)
Sinus pause d/t
Ischemic, inflammatory or degenerative disease of SA node
Sleep apnea
Cardiac meds
Excessive vagal tone
Sinus pause s/s tx
Longer, more frequent pauses –> decreased CO –> s/s hypoperfusion
Atropine, epi, dopamine if symptomatic
SVT
Regular or irregular
150-250 bpm
Undefined P/T waves
Narrow QRS
SVT causes
Sinus tachy, a fib, a flutter, junctional tachy
Severe anxiety
Stimulants (coke, caffeine, amphetamines)
Alcohol, narcotics
SVT treatments
Stable: adenosine, vagal maneuvers
Unstable: Synchronized cardioversion
A fib
Irregular
60-180 bpm
Undefined P/T waves - multiple P waves
QRS complex narrow
Slow <60 bpm
Fast >100 bpm
State rate as a range
A fib causes s/s
MI, longstanding CAD, COPD, atrial septal defects
Cardiac insufficiency, valve regurgitation, hypertrophy
S/S possible: hypoperfusion
A fib tx
New onset: IV heparin, IV amiodarone
Stable, fast: amiodarone, beta blockers, calcium channel blockers
Unstable (>180 bpm, hypotension, chest pain): synchronized cardioversion
A flutter
Regular or irregular Saw-toothed appearance: similar F-waves (one or two ectopic pacemakers bombard AV node) Undefined PR interval Undefined QT interval Narrow QRS complex
A flutter causes
Antiarrhythmic drugs (to suppress a fib) Obesity Obstructive sleep apnea Sick sinus syndrome Pericarditis Pulmonary disease PE Cardiomyopathy Thyrotoxicosis
PAC
Irregular overall (regular other than PAC)
P wave for premature beat different than regular P waves
Normal QRS complex
Normal QT interval
PAC causes
Possible cardiac history Food or meds Anxiety Caffeine Exercise Tobacco ETOH Electrolyte
PAC s/s
Often no symptoms
Might feel palpation or skipped beat if frequent
PAC treatments
Not usually treated
Eliminate ingested causes if d/t toxicity
Correct electrolyte imbalances
Junctional rhythm
Regular
40-60 bpm
P wave: inverted (superior AV node), absent (mid AV node), after QRS complex (inf AV node)
QRS complex narrow
Accelerated junctional rhythm
Regular rhythm
60-100 bpm
P wave: inverted, absent or after QRS complex
QRS complex narrow
Accelerated junctional rhythm causes, s/s, tx
D/T: digoxin toxicity, electrolyte imbalances, ischemia
S/S: None or hypoperfusion
TX: Remove cause of SA node suppression (adjust meds)
Junctional tachycardia
Regular 100-180 bpm P wave: inverted, absent, after QRS complex QRS complex narrow Basically could also be SVT
Junctional tachy causes, s/s, tx
D/T: anxiety, exercise, heart disease, caffeine, CNS stimulants
S/S: depends on rate - hypoperfusion
TX: stable: vagal maneuvers, calcium channel blockers, digoxin
Unstable: Synchronized cardioversion
1st degree AV block
Regular 60-100 bpm but may be brady/tachy PR interval > 0.2 s + constant QRS complex narrow QT interval normal
1st degree AV block causes s/s tx
D/T: aging, cardiomyopathies, myocarditis, congenital defects, ischemic heart disease, meds (digoxin, beta blocks, calcium channel blocks)
S/S: none
TX: reduce/eliminate meds if d/t intox
2nd degree AV block type I (Wenkenbach)
Regular P waves
PR intervals get progressively longer until QRS complex is dropped
QRS complex narrow
QT interval normal
2nd degree AV block type II
Regular P waves
PR interval regular and constant
QRS complex narrow and periodically absent
2nd degree AV block type I causes
Cardiomyopathies Myocarditis Congenital defects Ischemic heart disease Meds (dig, beta, calcium)
2nd degree AV block type II causes
Cardiomyopathies
Myocarditis
Ischemic heart disease
Meds
2nd degree AV block s/s, tx
S/S: none or hypoperfusion
TX: IV atropine, epinephrine and dopamine, pacemaker
3rd degree AV block
20-60 bpm
P waves regular amongst themselves or hidden
QRS complexes regular amongst themselves
P waves and QRS complexes not in sync
Atrial rate > ventricular rate
3rd degree AV block causes
Cardiomyopathies Myocarditis Ischemic heart disease Long term degenerative heart disease CHF Meds
3rd degree AV block s/s
None or hypoperfusion Cheyne-Stokes breathing Seizures Apnea Death
3rd degree block tx
IV atropine, epi or dopamine
Pacemaker (transvenous)
Bundle branch block
Reg or irregular depending on underlying rhythm (sinus rhythm with BBB, a fib with BBB)
Wide, irregular QRS complex (V1 = right, V6 = left)
PVC
Irregular overall, regular other than PVCs
QRS complex wide and weird
P wave may be absent with premature beat
Run of 5 or more = v tach
PVC causes
MI, CHF, CAD Anxiety, exercise Caffeine, tobacco, etoh, drugs, meds Electrolyte imbalance (potassium) Hypoxia (COPD) Normal following angio (reperfusion)
PVC s/s, tx
S/S: often none, palpitations
TX: may not be treated
Treat cause
Antiarrhythmic meds
Ideoventricular rhythm
Regular or irregular
20-40 bpm
Wide QRS complex
Often no P-wave - undefined PR interval
Ideoventricular rhythm causes
Vagal stimulation
Cardiac depressant meds
MI, rheumatic heart disease, septal defects
Large dose of CNS depressants
Ideoventricular rhythm s/s, tx
S/S: May be asymptomatic, or s/s hypoperfusion
TX: Atropine, epi drip
Ventricular tachycardia
Regular 110-250 bpm Wide weird QRS complex With/out pulse Sustained >30 seconds
Vtach causes
Heart disease, ischemia, MI, CAD, congenital defects
Ventricular aneurysm, PVC on T wave , defib on T wave
Epi, thyroid meds, amphetamines, cocain, cardiac meds
Electrical shock
Vtach s/s
Short runs = asymptomatic
Longer runs = s/s hypoperfusion –> changes in LOC, seizure, pupil dilation, no BP, no HR
Vtach tx
VT with pulse: amiodarone, synchronized cardioversion
VT without pulse: CPR, defib
Ventricular fibrillation
No CO = arrest
No rate
No QRS complex
V fib causes, s/s, tx
D/T: Electric shock, PVC on T wave, defib on T wave, massive MI
S/S: No pulse, no BP, no RR
TX: CPR defib
Torsades de pointes
Type of v tach with polymorphous QRS complexes
150-250 bpm
D/T: long QT syndrome (congenital or acquired)
Drug induced, eating disorders, electrolyte imbalance
S/S: short term palpitations
long term no pulse, no BP, no RR
Tx: IV Mg
Artifact
What to do:
Go to bedside: verify replace reposition electrodes, wires
Ask patient to minimize movements
Ensure chest is shaved