Rhythms Flashcards
Sinus Rhythm HR
60-100
Sinus Rhythm Regularity
Regular
Sinus Rhythm Measurements
PRI: 0.12-0.20 sec
QRS: 0.04-0.10 sec
QT: <0.5 sec
Sinus Rhythm P: QRS ratio
1:1
Sinus rhythm Treatment
None
Sinus Bradycardia Hear rate
<60
Sinus Bradycardia Regularity
Normal
Sinus Bradycardia Measurements
Normal
Sinus Bradycardia P:QRS ratio
Normal
Sinus Bradycardia Treatment
Increase CO so give Atropine (0.5-1.0 mg IV q 3-5 minutes: 3 mg max) and then transcutaneous pacing, dopamine, or epinephrine if ineffective. Avoid Atropine if hypothermic.
Sinus Bradycardia Cause
digoxin, Beta/Ca blockers, vasovagal, MI, athletes, SA node disease, increased ICP, hypoxemia, hypothermia
Sinus Tachycardia Heart Rate
> 100
Sinus Tachycardia Regularity
Normal
Sinus Tachycardia Measurements
P wave maybe hidden at higher rates
QT may be shortened
Sinus Tachycardia P:QRS ratio/Shape
Normal
Sinus Tachycardia Treatment
Treat underlying cause: hyperthyroidism, hypovolemia, heart failure, pain, fever, exercise, stimulants, anxiety.
Sinus Tachycardia May cause
decrease in CO b/c of shorter ventricular filling time.
SVT (Atrial Tachycardia) Heart rate
150-250
SVT (Atrial Tachycardia) Regularity
Normal
SVT (Atrial Tachycardia) Measurements
PRI: <0.12 or not measurable
QRS: <0.04
SVT (Atrial Tachycardia) Shape
P wave: maybe hidden in QRS or behind T wave
SVT (Atrial Tachycardia) Treatment
Assess, vasovagal maneuver. If that fails or unstable give Adenosine 6mg. If does not convert, give 12mg IV. Then try electrical cardioversion (sync) if Adenosine is ineffective or emergency. May also give Beta/Ca blockers or Amiodarone.
SVT (Atrial Tachycardia) Causes
Digoxin tox, electrolyte imbalance, lung disease, ischemic heart disease
Premature Atrial Contractions (PACs) Heart rate
Determined by underlying rhythm
Premature Atrial Contractions (PACs) Regularity
Interrupts regularity of underlying rhythm for a single beat followed by a short pause
Premature Atrial Contractions (PACs) Measurements
PRI: <0.12
Premature Atrial Contractions (PACs) Shape
P wave: different than NSR
T wave: can be distorted
Premature Atrial Contractions (PACs) Treatment
None
Premature Atrial Contractions (PACs) Cause
caffeine, tobacco, ischemia, hypokalemia, hypomagnesemia, lung disease
A-Flutter (saw tooth) Heart rate
Atrial: 240-320
Ventricular: varies- normally >100
(rapid ventricular repolarization)
A-Flutter (saw tooth) Regularity
P wave: flutter consistent
QRS and T wave maybe irregular
A-Flutter (saw tooth) Measurement
PRI: None
A-Flutter (saw tooth) Shape
P wave: sawtooth
QRS can be altered from P wave
A-Flutter (saw tooth) Treatment
chronic anticoag therapy, elective cardioversion performed after taking anticoag for 3 weeks before and 4 weeks after. Ablation may be done (remove piece of myocardium causing irregular beat). AV blocking medications
A-Flutter (saw tooth) Cause
lung disease, heart failure, alcoholism
A-Fibrillation Heart rate
Atrial: uncountable
Ventricular: varies
A-Fibrillation Measurement
PRI: None
QRS, QT: normal if not bundle branch block
Usually will not see a T wave
A-Fibrillation Shape
No discernable P wave. Irregular waves are referred to as fibrillatory or F waves
QRS: <0.04 or >0.10
A-Fibrillation Treatment
Chronic antioag, AV blocking medications- Amiodarone, elective cardioversion, ablation. Emergency cardioversion considered if tachy is associated with hemodynamic instability
A-Fibrillation Cause
Ischemia, heart disease, valvular heart disease, hyperthyroidism, heart failure, lung disease, elderly.