04 - Arrhythmias of Sinus Origin Flashcards
Clinical manifestations of arrhythmias
Palpitations - patients are aware
Decreased CO - light headed/syncope
Arrhythmias with underlying cardiac disorder - CHF, can lead to angina
Anything other than a normal sinus rhythm
Dysrhythmia
Not every one is a problem
Sometimes, the first clinical manifestation of arrhythmias is
Sudden death
Why do arrhythmias happen?
HIS DEBS Hypoxia Ischemia, infarction, irritability Sympathetic stimulation DRUGS!! Electrolyte disturbances Brady - brady-tachy syndrome, sick sinus syndrome Stretch - hypertrophy, valvular probs
How do we find arrhythmias?
ECG rhythm strip
12 lead ECG
Event monitor
Holter monitors
What triggers an event monitor?
The patient when symptoms of arrhythmias are felt
Portable ECG for 24-48 hours
Holter monitor
The first component when evaluating and EKG is
Rate
Five types of arrhythmias?
Arrhythmias of sinus origin Ectopic rhythms Reentrant arrhythmias Conduction blocks Pre excitation syndromes
Arrhythmias of sinus origin
Tachy Brady Sinus arrhythmia Sinus arrest Asystole Escape beats
Rate > 100 bpm
Normal P wave
Narrow QRS
1:1 P:QRS ratio
Sinus tachycardia
If heart rate is above ____, P wave may be difficult to distinguish from previous T wave
140 bpm
Causes of sinus tachycardia
Pain Fear, anxiety Exercise Hyperthyroid Anemia Hypovolemia Malignant hyperthermia Sepsis
What can resolve tachycardia?
Resolution of underlying causes
Vagal maneuvers - carotid massage, valsalva, gagging
AV blocking agents - adenosine, verapamil
Beta blockers - Esmolol, metoprolol
Rate: 40-59 bpm
Normal P wave
Normal QRS
Regular rhythm
Sinus bradycardia
Causes of sinus bradycardia?
Vagal maneuver Athleticism Sleep Sever hypertension Beta blockers Hypothyroid
Severe bradycardia can drop CO so low that the reduced blood flow causes
Syncope (fainting)
Treatment of chronic bradycardia?
Pacemaker
Thyroid therapy
Treatment of acute bradycardia?
Cease stimulation
Atropine
Glycopyrrolate
Treatment of bradycardia is ______ unless pt in concurrently hypotensive or symptomatic
Not usually indicated
Rate: 45-100 bpm (varies with RR)
Normal P wave
Normal QRS
Irregularly regular rhythm WHAT??
Sinus arrhythmia
Not a true arrhythmia
Spontaneous breathing causes sinus arrhythmias due to fluctuations in
Parasympathetic vagal tone
The hearts fail safe pacing mechanism proving three levels of back up pacing is known as?
Overdrive suppression
What are the three levels of back up pacing in overdrive suppression?
Automaticity foci in atria
The ventricles
AV junction
Conditions that increase automaticity?
Sympathetic nervous system stimulation
Hypoxia
What are the automaticity foci and their rates?
SA node: 60-100 bpm
Atrium: 60-80 bpm
Junction: 40-60 bpm
Ventricle: 20-40 bpm
Sinus arrest occurs when SA node and other pacemaker cells
Stop firing
The rescuing beats originating from outside the sinus node are called
Escape beats
Which pacemaker cells rescue the heart most frequently?
AV junction
If alternative pacemaker cells beat for an extended period of time into a regular rhythm, this is
Junctional escape rhythm
A junctional escape rhythm can have P waves that are not seen or appear retrograde because
There is an abnormal pattern of atrial depolarization
