Loss of P wave

Electrocardiographic finding characterized by the absence of visible atrial depolarization (P waves), reflecting absent, obscured, or markedly abnormal atrial electrical activity.

Causes

• Cardiac rhythm disorders

  • Atrial fibrillation

  • Atrial flutter

  • Sinus arrest

  • Sinoatrial exit block

  • Sick sinus syndrome

  • Junctional rhythm

  • Junctional tachycardia

  • Atrioventricular nodal re-entrant tachycardia (AVNRT)

  • Other supraventricular tachycardias with P waves buried within the QRS complex

• Hyperkalemia

• Medications: Antiarrhythmic drugs, Digoxin toxicity

• Technical causes

  • Loose ECG electrodes

  • Incorrect lead placement

  • Poor skin-electrode contact

  • Motion artifact

  • Equipment malfunction