Paroxysmal Supraventricula Tachycardia (PSVT)  

What would happen if there was rapid bursts of irregular beats from ectopic focus?

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EKG Characteristics

Rhythm  

Regular with sudden onset and termination of rapid rate  
Rate   150 - 200  
P wave   May or may not be seen  
PR interval   If seen it is usually short  
QRS complex and T wave   normal configuration  
Clinical Findings
  • Symptoms are frequent and include palpitations, anxiety, lightheadedness

  • Angina may occur due to decrease coronary artery blood flow and increased myocardial oxygen consumption

  • Cardiac output may drop

Etiology
  • Can occur at any age and with no underlying heart disease. 

  • Can be due to hyperthyroidism, smoking, caffeine, amphetamines, dig toxicity.  

Interventions
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1. Vagal maneuvers
  • Methods to stimulate baroreceptors located in internal carotid arteries and the aortic arch.  Stimulation of these receptors results in reflex stimulation of vagus nerve and release of acetylcholine.  Acetylcholine slows conduction through the AV node, resulting in slowing of the heart rate.

  • coughing, bearing down, squatting, breath-holding, immersion of face in ice water, stimulation of gag reflex.

  • Carotid sinus message

2.  Medications
  • Adenosine - Drug of choice
    - Rapid action, half life is only a few seconds
    - 6 mg rapid IV Bolus- followed by 20 cc of NS
    - Head of bed slightly elevated
    - Will see pause - sometimes up to 6 seconds, tell pt to cough
    - Patient may complain of feeling hot.
  • Verpamil - not used very often
3. Synchronous Cardioversion - patient must be sedated
4. Over-drive suppression w temporary pacemaker

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