Sinus Tachycardia

Sinus Tachycardia

David Ray Velez, MD

A Rapid Regular Heart Rate Originating in the Sinoatrial (SA) Node

EKG Pattern

  • Heart Rate > 100 bpm
  • Normal P Waves Preceding Every QRS Complex
    • *With Significant Tachycardia, the P Waves Can Be “Hidden” in the Preceding T Wave (“Camel Hump” Appearance)

Compared to SVT

  • Most Likely Secondary to Underlying Cause (Pain/Stressor)
  • Progressively Increases Rate
  • Heart Rate is Usually Not Very High (< 150 bpm)
  • Typically See Separate P and T Waves
  • Generally Asymptomatic
  • May See Moderate Rate Variability

Sinus Tachycardia

Inappropriate Sinus Tachycardia

  • Sinus Tachycardia is Most Often Secondary to an Identifiable Etiology
  • Inappropriate Sinus Tachycardia (IST): A Primary Condition with No Identifiable Explanation
  • IST is Generally Benign but Can Cause Symptoms (Palpitation, Dizziness, and Dyspnea)

Secondary Causes

  • Pain and Anxiety
  • Hypovolemia
  • Hypoxia or Hypercarbia
  • Acidemia
  • Sepsis
  • Anemia
  • Pulmonary Embolism
  • Cardiac Tamponade
  • Alcohol Withdrawal
  • Drug Abuse (Tobacco, Methamphetamine, Cocaine)
  • Caffeine
  • Medications

Treatment

  • Primarily Managed Conservatively
  • Treat Any Underlying Cause
  • Potential Indications for β-Blocker Treatment:
    • Acute Coronary Syndrome (If Primarily Due to ACS and Not Due to Fear, Anxiety, etc.)
    • Symptomatic Inappropriate Sinus Tachycardia (May Also Consider Treatment with Ivabradine)
    • *See Antiarrhythmic Pharmacology