Compare conditions

Put any two — or three — conditions side by side, adult or pediatric, to spot the look-alike differences fast, row by row.

Ventricular Tachycardia and Ventricular Fibrillation

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In one line

·The heart's lower chambers fire too fast (ventricular a fast heart rate (tachycardia)) or shake chaotically (ventricular fibrillation), stopping all blood flow. If the person has no pulse, shock immediately at 200 joules biphasic, do CPR, give epinephrine and amiodarone per ACLS.

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Normal physiology

·The heart's electrical system starts in the sinoatrial node (the natural pacemaker in the right atrium, one of the top chambers). That signal travels down through the atrioventricular node (the relay station between the top and bottom chambers) and then splits into the bundle of His and its branches, spreading across both ventricles so they squeeze together in one strong, coordinated push. This orderly flow keeps blood moving smoothly to the lungs and body.

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What goes wrong

·A patch of ventricle muscle starts firing its own chaotic or very fast electrical signal, ignoring the normal pacemaker. The ventricles either race too fast to fill (ventricular a fast heart rate (tachycardia)) or quiver uselessly without any real squeeze (ventricular fibrillation). Either way, blood flow drops or stops completely.

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Hallmark signs

·Fast, wide heartbeat pattern on the monitor (ventricular a fast heart rate (tachycardia)) or chaotic squiggly line (ventricular fibrillation)
·Sudden collapse or loss of consciousness
·No pulse or very weak pulse
·Chest pain or pressure
·Sudden shortness of breath or gasping
·Dizziness or lightheadedness
·Pounding or fluttering feeling in the chest (palpitations)
·Pale, cold, sweaty skin

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Red flags · escalate now

·No pulse and no breathing (cardiac arrest — start CPR and call for a defibrillator immediately)
·Sudden collapse or complete loss of consciousness
·Chest pain with a very fast heart rate and low blood pressure
·Ventricular fibrillation on the monitor (the heart is just quivering and must be shocked right away)

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Workup

·12-lead ECG
·Serum potassium (K+)
·Serum magnesium (Mg2+)
·Troponin (high-sensitivity cardiac troponin)
·Echocardiogram (echo)
·Toxicology screen and medication review
·Coronary angiography (heart catheterization)

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Treatment

·CPR (chest compressions 100–120 per minute, at least 2 inches deep) + defibrillation (one shock at 200 J biphasic) immediately
·Epinephrine 1 mg IV push every 3–5 minutes during CPR
·Amiodarone 300 mg IV push after the first shock, then 150 mg IV if the rhythm returns within 3–5 minutes
·Correct potassium to 4.0–4.5 mEq/L and magnesium to ≥ 2.0 mEq/L — give IV potassium chloride and magnesium sulfate 2 g over 5–10 minutes
·Stop any drug that prolongs the QT interval (antipsychotics, certain antibiotics like azithromycin or fluoroquinolones, tricyclic antidepressants)
·Emergency coronary angiography and stent or bypass if a heart attack (acute MI) triggered the rhythm
·Implantable cardioverter-defibrillator (ICD) if ejection fraction ≤ 35% after 40 days post-heart attack, or ≤ 35% despite 3+ months of optimal heart failure medications (ACE inhibitor or ARB, beta-blocker, aldosterone antagonist)

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NCLEX trap

·In ventricular fibrillation and pulseless ventricular a fast heart rate (tachycardia), the first action is CPR and shock — drugs come after. ACLS (the American Heart Association's rules for saving people in cardiac arrest) says shock first if VF or pulseless VT, then CPR, then drugs. The heart rhythm itself is the emergency; you must break it with electricity before medicine can help.
·If the monitor shows ventricular fibrillation or pulseless ventricular tachycargia, do not waste time checking a pulse. The rhythm is the proof. Start CPR and shock immediately. Time to defibrillation is the strongest predictor of survival in ventricular fibrillation — every minute you wait, the chance of survival drops by 7–10 %.
·Stable VT means the patient has a pulse and blood pressure — give amiodarone (a medicine that steadies heart rhythm) or procainamide (another rhythm-steadying drug) by IV drip to slow the rhythm. Pulseless VT means shock first, then CPR and drugs. Pulse changes everything.
·Only shock if you see ventricular fibrillation, pulseless ventricular a fast heart rate (tachycardia), or polymorphic VT (torsades — a twisting, unstable fast rhythm). A normal sinus rhythm or even a fast rhythm with a pulse does not get shocked. Match the rhythm to the clinical picture: no pulse plus chaotic rhythm equals shock.
·In ventricular fibrillation and pulseless ventricular a fast heart rate (tachycardia), keep chest compressions going for 2 minutes, then pause briefly to check the rhythm and shock if indicated. Compressions keep the brain and heart alive while the defibrillator and drugs work. Every pause in compressions means blood stops flowing.
·Ventricular fibrillation can be reversed if defibrillated fast and CPR is continued with drugs and good compressions. Do not give up early. Hypothermia (low body temperature), electrolyte problems (like too little potassium or magnesium), or medication overdose can mimic death but respond to prolonged ACLS. Keep going for at least 20–30 minutes or until reversible causes are ruled out.

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