A patient has drug resistant ventricular tachycardia

Discussion in 'Plab 1 and 2 forum' started by Neha Gupta, May 28, 2013.

  1. Neha Gupta

    Neha Gupta Active Member

    A patient has drug resistant ventricular tachycardia . Treatment with a membrane active antiarrhythmic agent is required , which does not depress conduction velocity or automaticity.

    a) Atropine

    b) bretylium

    c) Calcium gluconate

    d) Dopamine infusion

    e) Epinephrine IV infusion

    f) transcutaneous cardiac pacing

    g) norepinephrine

    h) amiodarone intravenously

    i) Lidocaine IV infusion

    j) Sodium bicarbonate
  2. Neha Gupta

    Neha Gupta Active Member

    Bretylium tosylate (Bretylol) has recently been approved for parenteral use against resistant ventricular arrhythmias. The pharmacological action of beryllium is complex, and its antiarrhythmic action differs significantly from other drugs. Bretylium is an adrenergic neuronal blocking agent taken up selectively at peripheral adrenergic nerve terminals, where it initially releases norepinephrine (sympathomimetic effect) and then produces adrenergic neuronal blockade. It has a direct cardiac membrane effect to prolong action potential duration and effective refractory period but, unlike other membrane active antiarrhythmic agents, does not depress conduction velocity or automaticity. Bretylium increases the ventricular fibrillation threshold and prevents the decrease in ventricular fibrillation threshold associated with myocardial ischemia. It does not depress myocardial contractility. Clinical studies have shown parenteral bretylium to be effective in suppressing ventricular arrhythmias, particularly recurrent, drug resistant ventricular tachycardia or ventricular fibrillation.

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