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Source: Sanoski CA, Bauman JL. The arrhythmias. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861§ionid=146057036. Accessed March 28, 2017.
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Acute myocardial infarction (MI)
Cardiomyopathy.
Heart failure.
Electrolyte abnormalities (hypokalemia, hypomagnesemia)
Hypoxia.
Drug toxicity (eg, digoxin)
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Defined by ≥3 repetitive premature ventricular complexes (PVCs) occurring at rate of >100 beats/min.
Nonsustained VT self-terminates after brief duration (usually <30 s).
Sustained VT lasts >30 s.
Monomorphic VT has consistent QRS configuration, whereas polymorphic VT has varying QRS complexes.
Torsades de pointes (TdP) is polymorphic VT in which QRS complexes appear to undulate around central axis.
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Incidence not known precisely because clinical findings overlap with ventricular fibrillation (VF).
Approximately 300,000 deaths per year in the United States are caused by VT or VF.
Incidence of sudden cardiac death is 53 per 100,000 population.
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CLINICAL PRESENTATION
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MEANS OF CONFIRMATION AND DIAGNOSIS
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DIAGNOSTIC PROCEDURES
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DIFFERENTIAL DIAGNOSIS
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TREATMENT: NONPHARMACOLOGIC THERAPY
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If severe symptoms present, perform synchronized direct current cardioversion (DCC) immediately to restore sinus rhythm.
Correct precipitating factors if possible.
If VT isolated event with transient initiating factor (eg, acute MI, digitalis toxicity), long-term antiarrhythmic therapy not needed after correction of precipitating factors.
Most patients with acute TdP require and respond to DCC, but TdP tends to be paroxysmal and often recurs rapidly after DCC.
Automatic implantable cardioverter-defibrillator ...