Ventricular Fibrillation in Emergency Medicine Clinical Presentation

Updated: Jan 12, 2021
  • Author: Keith A Marill, MD, MS; Chief Editor: Erik D Schraga, MD  more...
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Ventricular fibrillation (VF) often occurs without forewarning. The following symptoms, while not necessarily specific for sudden cardiac death or VF, may develop before any major cardiac event:

  • Chest pain and other angina equivalents

  • Dyspnea

  • Easy fatigue

  • Palpitations

  • Immediately preceding acute cardiac arrest, possible increase in heart rate, presence of premature ventricular contractions (PVCs), or period of VT


Physical Examination

Physical examination findings may include no pulse or respiration as well as wide and chaotic QRS complexes on cardiac monitors.

Patients in cardiac arrest have no pulse. However, both lay rescuers and healthcare providers may have difficulty determining pulselessness. Current AHA guidelines do not recommend that lay rescuers check for a pulse. Healthcare providers should take no more than 10 seconds to check for a pulse. If no pulse is found, the provider should proceed with chest compressions.

Patients in cardiac arrest have absent or abnormal (gasping) respirations. Adults who are unresponsive or have been witnessed to collapse, and have absent or abnormal respirations are likely to be in cardiac arrest. AHA guidelines recommend activating the emergency response system (call 911) and initiating CPR.

Patients in cardiac arrest become unconscious.