Ventricular tachycardia sustained

Ventricular tachycardia is a series of three or more consecutive VPDs at a rate of greater than 100 bpm. Ventricular tachycardia is defined as non-sustained if it lasts less than 30 seconds and terminates spontaneously sustained VT lasts greater than 30 seconds and does not terminate spontaneously, but rather requires therapeutic intervention for termination. 

Treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia, that are judged to be life-threatening. Because of the proarrhythmic effects, use with lesser arrhythmias is generally not recommended. 

Treatment of documented ventricular arrhythmias (eg, sustained ventricular tachycardia) considered to be life-threatening. 

Treatment of documented life-threatening ventricular arrhythmias, such as sustained ventricular tachycardia. 

Proarrhythmia Mexiletine can worsen arrhythmias it is uncommon in patients with less serious arrhythmias (freguent premature beats or nonsustained ventricular tachycardia) but is of greater concern in patients with life-threatening arrhythmias, such as sustained ventricular tachycardia. 

For patients with sustained ventricular tachycardia, initiate therapy in the hospital and monitor rhythm. 

Proarrhythmia Like other antiarrhythmic agents, sotalol can provoke new or worsened ventricular arrhythmias in some patients, including sustained ventricular tachycardia or ventricular fibrillation, with potentially fatal consequences. Because of its effect on cardiac repolarization, is the most common form of proarrhythmia associated with sotalol, occurring in approximately 4% of high-risk patients. 

Gomes JA, Winters SL, Stewart D, Horowitz S, Milner M, Barreca P. A new noninvasive index to predict sustained ventricular tachycardia and sudden death in the first year after myocardial infarction based on signal-averaged electrocardiogram, radionuclide ejection fraction and Holter monitoring. J. Am. Coll. Cardiol. 1987 10 349-57. 

Moricizine is indicated for the treatment of documented ventricular arrhythmias, particularly sustained ventricular tachycardia. Moricizine was evaluated in the CAST II clinical trial for the prevention of postinfarction ventricular premature complexes. It was ineffective and found to be proarrhythmic. Patients in the moricizine arm of the trial exhibited a greater incidence of sudden cardiac death than did controls. 

Life-threatening ventricular arrhythmias, sustained ventricular tachycardia PO Initially, 100 mg q 12h, increased by 100 mg (50 mg twice a day) every 4 days until effective dose or maximum of 400 mg/day is attained. 

Supraventricular and ventricular arrhythmias (12%), nonsustained ventricular tachycardia (2%), and sustained ventricular tachycardia (1%) may occur. 

Documented, life-threatening ventricular arrhythmias, such as sustained ventricular tachycardia PO Initially, 150 mg q8h may increase at 3-to 4-day intervals to 225 mg q8h, then to 300 mg q8h. Maximum 900 mg/day PO (Extended-Release) Initially, 225mgql2h, May increase at 5-day intervals. Maximum 425 mg ql2h. 

Side effects include ventricular arrhythmias, sustained ventricular tachycardia, angina, ventricular fibrillation, headache and hypokalemia. 

These are class IC drugs with similar pharmacological profiles and with the same indication range and adverse effects. They are mainly used for the treatment of severe, lifethreatening ventricular tachyarrhythmias, and non-sustained ventricular tachycardia or high-frequency premature ventricular beats. The main adverse effects are cardiovascular, including proarrhythmic actions and severe negative inotropic effects, especially in patients with impaired cardiac function. Both flecainide and encainide increase the risk of sudden death in patients with myocardial infarction and asymptomatic unsustained ventricular arrhythmias. 

Supraventricular tachycardia is the major arrhythmia indication for verapamil. Adenosine or verapamil are preferred over older treatments (propranolol, digoxin, edrophonium, vasoconstrictor agents, and cardioversion) for termination. Verapamil can also reduce the ventricular rate in atrial fibrillation and flutter. It only rarely converts atrial flutter and fibrillation to sinus rhythm. Verapamil is occasionally useful in ventricular arrhythmias. However, intravenous verapamil in a patient with sustained ventricular tachycardia can cause hemodynamic collapse. 

In addition to sinus tachycardia and tremor, vomiting is common after overdose. Hypotension, tachycardia, hypokalemia, and hyperglycemia may occur, probably due to -adrenergic activation. The cause of this activation is not fully understood, but the effects can be ameliorated by the use of B-blockers (see below). Cardiac arrhythmias include atrial tachycardias, premature ventricular contractions, and ventricular tachycardia. In severe poisoning (eg, acute overdose with serum level > 100 mg/L), seizures often occur and are usually resistant to common anticonvulsants. Toxicity may be delayed in onset for many hours after ingestion of sustained-release tablet formulations. 

A child presented at 12 months of age with status epilepticus, sustained ventricular tachycardia, and a positive urine screen for cocaine. At 22 months he returned with a cardiac arrest, a history of a fall, a head injury, and a positive test for cocaine in the urine. He died soon after. 

Adverse reactions are similar to those of flecainide and are commoner in poor metabolisers. In addition, conduction block may occur, cardiac failure may worsen and ventricular arrhythmias may be exacerbated, and it should not be used in patients with sustained ventricular tachycardia and poor left ventricular fimction. 

Broad complex tachycardia (treat as sustained ventricular tachycardia) ... 

A 64-year-old woman with atrial fibrillation was given adenosine 12 mg she developed a non-sustained polymorphous ventricular tachycardia followed by sustained ventricular fibrillation requiring DC shock. 

An 86-year-old woman was given adenosine 12 mg intravenously for sustained supraventricular tachycardia, which terminated but was followed by atrial fibrillation and paroxysmal ventricular tachycardia (24). Cardioversion was unsuccessful, but normal sinus rhythm was obtained with procainamide. This followed an anteroseptal myocardial infarction. 

In a prospective study of 187 episodes of tachycardia in 127 unselected patients adenosine was given in an average dose of 9.7 mg (28). In 108 cases, adenosine induced transient ventricular extra beats or non-sustained ventricular tachycardia after successful termination of supraventricular tachycardia more than half had a right bundle branch block morphology that suggested that the dysrhythmias had originated from the inferior left ventricular septum. 

Pinar Bermudez E, Garcia-Alberola A, Martinez Sanchez J, Sanchez Munoz JJ, Valdes Chavarri M. Spontaneous sustained monomorphic ventricular tachycardia after administration of ajmaline in a patient with Brugada syndrome. Pacing Clin Electrophysiol 2000 23(3) 407-9. 

An isolated report (2) suggests that amiloride may have prodysrhythmic potential in a small proportion of patients with inducible sustained ventricular tachycardia. 

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