Quinidine atrial flutter

The risk of atrial flutter is a 2 1 transmission to the ventricles generating a high ventricular rate. The therapeutic goal is to reduce transmission to 3 1 or 4 1 by administration of either (3-adrenoceptor antagonists, Ca2+ channel blockers or amiodarone. Quinidine must not be used in this arrhythmia, since it accelerates AV-conduction due to its vagolytic effect. 

Primary indications for the use of quinidine include (1) abolition of premature complexes that have an atrial, A-V junctional, or ventricular origin (2) restoration of normal sinus rhythm in atrial flutter and atrial fibrillation after controlling the ventricular rate with digitahs (3) maintenance of normal sinus rhythm after electrical conversion of atrial arrhythmias (4) prophylaxis against arrhythmias associated with electrical countershock (5) termination of ventricular tachycardia and (6) suppression of repetitive tachycardia associated with Wolff-Parkinson-White (WPW) syndrome. 

Although quinidine often is successful in producing normal sinus rhythm, its administration in the presence of a rapid atrial rate (flutter and possibly atrial fibrillation) can lead to a further and dangerous increase in the ventricular rate secondary to inhibition of basal vagal tone upon the A-V node. For this reason, digitalis should be used before quinidine when one is attempting to convert atrial flutter or atrial fibrillation to normal sinus rhythm... 

The indications for use of disopyramide are similar to those for quinidine, except that it is not approved for use in the prophylaxis of atrial flutter or atrial hbrUla-tion after DC conversion. The indications are as follows unifocal premature (ectopic) ventricular contractions, premature (ectopic) ventricular contractions of multifocal origin, paired premature ventricular contractions (couplets), and episodes of ventricular tachycardia. Persistent ventricular tachycardia is usually treated with DC conversion. 

The effects of disopyramide are very similar to those of procainamide and quinidine. Its cardiac antimuscarinic effects are even more marked than those of quinidine. Therefore, a drug that slows atrioventricular conduction should be administered with disopyramide when treating atrial flutter or fibrillation. 

Quinidine is used for the maintenance of normal sinus rhythm in patients with atrial flutter or fibrillation. It is also used occasionally to treat patients with ventricular tachycardia. Because of its cardiac and extracardiac side effects, its use has decreased considerably in recent years and is now largely restricted to patients with normal (but arrhythmic) hearts. In randomized, controlled clinical trials, quinidine-treated patients are twice as likely to remain in normal sinus rhythm compared with controls. However, drug treatment was associated with a twofold to threefold increase in mortality. 

ATRIAL FLUTTER Quinidine Propranolol Verapamil IH Digoxln... 

Therapeutic uses Quinidine is used in the treatment of a wide variety of arrhythmias, including atrial, AV junctional, and ventricular tachyarrhythmias. Quinidine is used to maintain sinus rhythm after direct current cardioversion of atrial flutter or fibrillation and to prevent frequent ventricular tachycardia. 

Quinidine is used to treat and control atrial fibrillation and atrial flutter. Quinidine is also approved to treat premature ventricular contractions and to treat paroxysmal atrial tachycardia or paroxysmal atrioventricular junctional rhythm. It may also be used to treat malaria, although quinine is preferred. 

Disopyramide, proprietary name Norpace, is used for maintenance of sinus rhythm in patients with atrial flutter and atrial fibrillation and for prevention of ventricular tachycardia and fibrillation. The mechanism of action of disopyramide is similar to that of quinidine, and the drug can be used as replacement therapy for quinidine when quinidine side effects are intolerable. 

Disopyramide (Norpace, others) exerts electrophysiologi-cal effects very similar to those of quinidine, but the drugs have different adverse effect profiles. Disopyramide is used to maintain sinus rhythm in patients with atrial flutter or atrial... 

Quinidine (200 to 600 mg t.i.d.), a cinchona alkaloid with antiarrhythmic properties, is indicated in premature atrial, AV junctional, and ventricular contractions paroxysmal atrial (supraventricular) tachycardia paroxysmal AV junctional rhythm atrial flutter paroxysmal and chronic atrial fibrillation established atrial fibrillation when therapy is appropriate paroxysmal ventricular tachycardia not associated with complete heart block and maintenance therapy after electrical conversion of atrial fibrillation or flutter (see Figure 103). 

Quinidine is used in the therapy of atrial arrhythmias, particularly atrial flutter and atrial fibrillation. It is also useful in other types of arrhythmias (e.g., v-tac), and is also useful in the treatment of malaria, when given intravenously. 

Quinidine also produces a adrenergic receptor blockade and vagal inhibition. Thus, the intravenous use of quinidine is associated with marked hypotension and sinus tachycardia. Quinidine s vagolytic effects tend to inhibit its direct depressant effect on AV nodal conduction, so its effect on the PR interval is variable. Moreover, quinidine s vagolytic effect can increase AV nodal transmission of atrial tachycardias such as atrial flutter (Table 34-1). 

Procainamide (e.g., Pronestyl) II If Premature atnal depolarization, atrial fibrillation, Wolff-Parkinson-White, ventricular tachycardia, atrial flutter, premature ventricular depolarization. Fewer Gl effects and weaker anticholinergic effects than quinidine, but similar cardiac toxicity. Lupus-like syndrome and other hypersensitivity reactions. 

Quinidine is a medical drug—indicated for cardiac complications, namely arrhythmias, atrial flutter and fibrillation. It depresses myocardial excitability, conduction, velocity and contractility. It is used in the form of quinidine sulfate. 

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