*Note that this tip is mostly for interest-only: Paramedic scope of practice is to recognize and treat the patient and underlying rhythm – these pearls are also included in this #SWORBHPTip series 

What Causes V-Tach​

• In our last SWORBHPTips, we explored what V-Tach is and how to describe some different types​
• In this tip, we will look at some causes of V-Tach​
• There are MANY causes!​
• Most common cause for both monomorphic and polymorphic V-Tach =  Cardiac ischemia​
  • Due to ischemic and dead myocardium that causes:​
    • Re-entry phenomenon due to surrounding necrotic myocardium unable to properly conduct the electrical impulses via the usual "proper" synchronized conduction pathway ​
    • The myocardium that does function, does not function WELL  due to itself being ischemic
• A single ectopic foci causes monomorphic V-Tach (often due to myocardial scar)​​
• Multiple ectopic foci cause polymorphic V-Tach (often due to acute injury)​​
• Re-perfusion in acute ischemia can also cause monomorphic V-tach
• Other causes (aside from Cardiac Ischemia):​
  • Electrolyte disorders​
    • Ex. HypoK, HypoMg, HypoCa​
  • Structural heart disorders​
    • Congenital heart disorders​
    • Infiltrative disorder (ex. Sarcoidosis)​
  • Inherited conduction disorders ​
    • Ex. Prolonged QT syndrome, Brugada syndrome​
  • Acute drug toxicity​
    • Ex cocaine, methamphetamines​
    • QT prolonging medications

For the Non-ischemic causes, there is generally an underlying condition that CAN cause V-Tach if there is a trigger​

• Example: Inherited long QT Syndromes with the trigger of administration of a medication that can prolong the QT​
• • Recall: This is why Ondansetron is contraindicated in patients with known "Prolonged Long QT Syndrome"

Summary ​

• There are multiple causes of ventricular tachycardia​
• The most common is cardiac ischemia, which acutely can present as polymorphic or monomorphic tachycardia​​
• The causes of VT are much less important to paramedic practice than the recognition and treatment of this arrythmia 

No additional resources available for this #SWORBHPTip.