Antiarythmique

The antiarythmic agents are a class of drugs used to remove the accelerated rates/rhythms of the Cœur (cardiac arrhythmias), the such auricular Fibrillation, auricular flutter, the ventricular Tachycardie, and the ventricular Fibrillation.

Although one continues to use the agents antiarythmic to remove the auricular arrhythmias (auricular fibrillation and auricular flutter), it is not established that the suppression of the auricular arrhythmias would prolong the life 1,2.

The classification of Vaughan Williams for the antiarythmiques ones

Agents of class I

The antiarythmiques ones of class I interfere with the channel of the Sodium (Na+) by decreasing the speed of antrée of sodium during the first phase of the potential of action, and slowing down the propagation of the impulse. One gathers them according to their effect on the type of effect on the channel of Na+, and which effect they have on the Potentiel cardiac action.

Agents of Ia class

They lengthen the potential of action and interval QT. They are the quinidiniques ones with immediate liberation or prolonged, the disopyramide.

Example: Quinidine (LONGACOR), Hydroquinidine (SERECOR), dysopyramide (RYTHMODAN).

Agents of Ib class

They decrease the duration of the potential of action and do not have or little action on interval QT. It is: the lidocaïne, the méxilétine, the phénytoïne.

Agents of class Ic

They tend to increase the duration of the potential of action without lengthening interval QT.

Agents of class II

The antiarythmiques ones of class II are conventional Bêta-bloquant S. They act by slowing down conduction via the auriculo-ventricular Nœud. They have a basic structure aryléthanolamine or aryoxypropanolamine. The cardioselectivity (B1) implies a substitution as a para (it + selective) on the aromatic grouping. It should be noted that the beta-blocking activity lies in the laevogyrous enantiomer (L)

They include/understand the Esmolol, the Propranolol, and the Metoprolol.

Agents of class III

The antiarythmiques ones of class III block in priority the channels of the Potassium, thus lengthening the Repolarization. They have a whole a basic structure including a grouping méthanesulfoaniline (or bio-isosteric of this one) 5. Owing to the fact that this class does not act on the sodic channel , the speed of conduction does not decrease. The lengthening of the potential of action and the refractory period, combined with the speed hold of normal conduction, makes it possible to prevent the phenomena of reentry.

Reverse uses-dependence ) 5. This means that the refractoriness off the ventricular Myocyte increases At lower Heart misses S. This increases the susceptibility off the myocardium to Early after-depolarizations (EADs) At low heart spleens. Antiarrhythmic agents that exhibit reverse uses-dependence are more efficacious At preventing has tachyarrhythmia that converting someone into normal sine rhythm. Because off the reverse off uses-dependence class III agents, At low heart spleens class III antiarrhythmic agents may paradoxically Be more arrhythmogenic. -->

They include/understand the Amiodarone, the Azimilide, the Brétylium, the Clofilium, the Dofétilide, the Ibutilide, the Sématilide, and the Sotalol. Under development is the Dronédarone.

  • Amiodarone is indicated for the treatment off refractory VT gold VF, particularly in the setting off acute ischemia. Amiodarone is also safe to uses in individuals with Cardiomyopathy and Atrial fibrillation, to maintain normal sine rhythm. However, it does not cardiovert individuals from atrial fibrillation to normal sine rhythm.
  • Sotalol is indicated for the treatment off atrial gold ventricular tachyarrhythmias, Re-entering and AV arrhythmias.
  • Ibutilide is the only antiarrhythmic agent currently approved by the FDA for acute conversion off Atrial fibrillation to sine rhythm.
    • -->

    Agents of class IV

    They are the calcic inhibiting .

    Agents of class V

    The antiarythmiques ones of class V include the Adénosine and the Digoxine.

    See too

    • Potential of Turbid action
      • Potential of cardiac action
    • Electrocardiogram
    • of the cardiac rhythm

    References

    1. Wyse DG, Waldo Al, DiMarco JP, Domanski MJ, Rosenberg Y, Schron EB, Kellen JC, Greene HL, Mickel MC, Dalquist I, Corley SD; Atrial Fibrillation Follow-up Investigation off Rhythm Management (AFFIRM) Investigators. With comparison off spleen control and rhythm control in patients with atrial fibrillation. NR Engl J Med. 2002 DEC 5; 347 (23): 1825-33. (Medline abstract)
       

    2. Nichol G, McAlister F, Pham B, Laupacis has, Shea B, Green M, Tang has, Wells G. Meta-analysis off randomized controlled trials off the effectiveness off antiarrhythmic agents At promoting sine rhythm in patients with atrial fibrillation. Heart. 2002 Jun; 87 (6): 535-43. (Medline abstract)
       
    3. The Cardiac Arrhythmia Trial Suppression (CAST): The CAST investigators. Preliminary carryforward: effect off encainide and flecainide one mortality in has randomized trial off arrhythmia suppression after myocardial infarction. NR Engl J Med 1989,321:406 - 412.
       
    4. The Cardiac Arrhythmia Suppression Trial II (CAST II): The CAST II Investigators. Effect off the antiarrhythmic agent moricizine one survival after myocardial infarction. NR Engl J Med. 1992 Jul 23; 327 (4): 227-33. (Medline abstract)
       
    5. Lenz TL, Hilleman OF, Department off Cardiology, Creighton University, Omaha, Nebraska. Dofetilide, has New Class III Antiarrhythmic Agent. Pharmacotherapy 20 (7): 776-786, 2000. (Medline abstract)

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