Dysrhythmias
What are the normal ranges for heart rate, PR interval, QRS, and QT interval?
Heart rate: 60-100 bpm
PR interval: 0.12- 0.20 sec
QRS complex: ≤ 0.12 sec
QT interval: 0.32- 0.40 sec
How do you identify the following rhythms: sinus rhythm (SR), sinus bradycardia (SB),
sinus tachycardia (ST), atrial flutter, atrial fibrillation, ventricular tachycardia (VT),
ventricular fibrillation (VF), asystole.
Sinus Rhythm
Heart rate, PR interval, QRS complex, and QT interval is within normal range
Indicative of good cardiac health
o A resting heart rate of 80+ increases the risk of cardiovascular disease
Sinus Bradycardia
Heart rate is > 60 bpm
Causes
o Vagus nerve stimulation
o Medications- beta- blockers
Assessment
o Hemodynamic stability
o Asymptomatic vs symptomatic
Hypotension
Dyspnea
Alteration in mental status
Angina
Management/Treatment
o Atropine
o Transcutaneous pacing
o Dopamine & epinephrine
, Sinus Tachycardia
Heart rate is < 100 bpm
Causes
o Physiologic or psychological stress
o Medications- atropine, amphetamines ; illicit drugs
o Autonomic dysfuction = POTS
Tachycardia without hypotension (check hydration status)
Management/Treatment
o Vagal maneuvers
o Synchronized cardioversion
o Adenosine
Atrial Fibrillation
Most common arrythmia
Caused by structural or electrophysiologic abnormalities
Increased risk for heart failure, myocardial ischemia, mitral valve dysfunction, and stroke
Characteristics
o Rapid atrial rate 300-600 bpm
o Irregular rhythm
o No discernible p wave
o Can not measure PR interval
Can be paroxysmal (occurs periodically), persistent (lasts > 7 days), or permanent (lasts <
12 months)
Assessment
o History & physical
o 12 lead EKG
o Labs
Thyroid function
Renal function
Hepatic function
Management/Treatment
o Anticoagulants & antiplatelets
o Beta-blockers
o Amiodarone
o Electrical cardioversion
Only for patients who are hemodynamically unstable and not responding
to medications
o Catheter ablation, maze procedure, or pacemaker
What are the normal ranges for heart rate, PR interval, QRS, and QT interval?
Heart rate: 60-100 bpm
PR interval: 0.12- 0.20 sec
QRS complex: ≤ 0.12 sec
QT interval: 0.32- 0.40 sec
How do you identify the following rhythms: sinus rhythm (SR), sinus bradycardia (SB),
sinus tachycardia (ST), atrial flutter, atrial fibrillation, ventricular tachycardia (VT),
ventricular fibrillation (VF), asystole.
Sinus Rhythm
Heart rate, PR interval, QRS complex, and QT interval is within normal range
Indicative of good cardiac health
o A resting heart rate of 80+ increases the risk of cardiovascular disease
Sinus Bradycardia
Heart rate is > 60 bpm
Causes
o Vagus nerve stimulation
o Medications- beta- blockers
Assessment
o Hemodynamic stability
o Asymptomatic vs symptomatic
Hypotension
Dyspnea
Alteration in mental status
Angina
Management/Treatment
o Atropine
o Transcutaneous pacing
o Dopamine & epinephrine
, Sinus Tachycardia
Heart rate is < 100 bpm
Causes
o Physiologic or psychological stress
o Medications- atropine, amphetamines ; illicit drugs
o Autonomic dysfuction = POTS
Tachycardia without hypotension (check hydration status)
Management/Treatment
o Vagal maneuvers
o Synchronized cardioversion
o Adenosine
Atrial Fibrillation
Most common arrythmia
Caused by structural or electrophysiologic abnormalities
Increased risk for heart failure, myocardial ischemia, mitral valve dysfunction, and stroke
Characteristics
o Rapid atrial rate 300-600 bpm
o Irregular rhythm
o No discernible p wave
o Can not measure PR interval
Can be paroxysmal (occurs periodically), persistent (lasts > 7 days), or permanent (lasts <
12 months)
Assessment
o History & physical
o 12 lead EKG
o Labs
Thyroid function
Renal function
Hepatic function
Management/Treatment
o Anticoagulants & antiplatelets
o Beta-blockers
o Amiodarone
o Electrical cardioversion
Only for patients who are hemodynamically unstable and not responding
to medications
o Catheter ablation, maze procedure, or pacemaker
