A chaotic, disorganized pattern of electrical impulses from multiple ectopic pacemakers in the ventricles
No effective ventricular mechanical activity or contractions
No cardiac output and no pulse
On the line
Identifying VF
The following rhythm strips illustrate coarse ventricular fibrillation (first strip) and fine ventricular fibrillation (second strip). Look for these distinguishing characteristics:
Rhythm
Chaotic
Rate
Undetermined
P wave
Absent
PR interval
Unmeasurable
QRS complex
Indiscernible
T wave
Indiscernible
QT interval
Not applicable
Other
Waveform is a wavy line
What Causes It⬆⬇
Acid–base imbalance
CAD
Drug toxicity, such as from digoxin, procainamide, or quinidine
Electric shock
Electrolyte imbalances, such as hypercalcemia, hyperkalemia, and hypokalemia
MI
Myocardial ischemia
Severe hypothermia
Underlying heart disease such as dilated cardiomyopathy
Untreated VT
What to Look for⬆⬇
Full cardiac arrest
Unresponsive patient with no detectable blood pressure or central pulses
How It's Treated⬆
Start prompt treatment following healthcare facility and emergency medical system protocols.
Assess the patient to determine if the rhythm is VF.
Start CPR. To preserve the oxygen supply to the patient's brain and other vital organs, CPR must be performed until the defibrillator arrives and is fully charged.
Defibrillate the patient immediately with 360 joules (monophasic defibrillator) or 120 to 200 joules (biphasic defibrillator). (See appendices ACLS algorithm: Pulseless arrest.)
Administer epinephrine or vasopressin.
Establish an airway and ventilate the patient.
Follow ACLS protocol for giving an antiarrhythmic, such as amiodarone or lidocaine. Consider magnesium for torsades de pointes.
Teach the patient and his family how to contact the emergency medical system and use an automated external defibrillator, if appropriate, after discharge from the facility.
Instruct the patient's family how to perform CPR, if necessary.
Teach the patient and his family about long-term therapies that help prevent recurrent episodes of VF, including antiarrhythmic therapy and ICDs.
