Atrial arrhythmias fibrillation

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. 

Unlabeled Uses Control of hemodynamicallystableventriculartachycardia, control of rapid ventricular rate due to accessory pathway conduction in preexcited atrial arrhythmias, conversion of atrial fibrillation to normal sinus rhythm, in cardiac arrest with persistent ventricular tachycardia or ventricular fibrillation, paroxysmal supraventricular tachycardia, polymorphic ventricular tachycardia or wide complex tachycardia of uncertain origin, prevention of postoperative atrial fibrillation... 

Vascular disease, MI, angina pectoris, atrial fibrillation, heart failure, arrhythmia, atrial arrhythmia, and pulmonary embolism have been reported. 

It is indicated in prevention of atrial arrhythmia, atrial fibrillation or flutter, paroxysmal supraventricular tachycardia, ventricular premature beats and ventricular tachycardia. 

Digitalis is useful in the management of atrial arrhythmias because of its cardioselective parasympathomimetic effects. In atrial flutter and fibrillation, the depressant effect of the drug on atrioventricular conduction helps to control an excessively high ventricular rate. Digitalis has also been used in the control of paroxysmal atrial and atrioventricular nodal tachycardia. At present, calcium channel blockers and adenosine... 

Adenosine is the treatment of choice for PSVT. It slows the conduction and interrupts the re-entry pathways through the atrioventricular node, restoring dysrhythmia to NSR. Adenosine is not effective in treating other atrial arrhythmias such as atrial flutter or atrial fibrillation or in treating ventricular arrhythmias. Adenosine is rapidly degraded... 

Most side effects of /3-blockers are an extension of their ability to antagonize /3-adrenoceptors. /3-Blockade in the myocardium can be associated with bradycardia, atrioventricular conduction abnormalities (e.g., second- or third-degree heart block), and the development of acute heart failure. The decreases in heart rate actually may benefit certain patients with atrial arrhythmias (e.g., atrial fibrillation and atrial flutter) and hypertension by both providing rate control and lowering BP. /3-Blockers usually only produce heart failure if... 

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. 

Adenosine is most useful in the therapy of supraventricular tachycardias such as Wolff-Parkinson-White syndrome. It is not effective against normal atrial arrhythmias such as atrial flutter and atrial fibrillation. 

Supraventricular arrhythmias arise from atrial or accessory pathways. They are not life threatening unless the arrhythmia is communicated to ventricular pathways. Atrial arrhythmias include atrial flutter and atrial fibrillation. 

Arrhythmias Atrial tachycardia, fibrillation AV nodal tachycardia AV blockade Premature ventricular contractions, ventricular tachycardia, ventricular fibrillation... 

There are several important consequences of programming a PVARP that is unnecessarily long. As indicated in the following, the PVARP has important effects on the behavior of the pacing system at high atrial rates. In addition, the occurrence of atrial pacing after an intrinsic P wave may result in the induction of paroxysmal atrial arrhythmias such as atrial fibrillation. 

The range of therapies includes antitachycardia and antibradycardia pacing, cardioversion, and defibrillation. The ICD can also pace both the right atrium and right ventricle. Some can perform biventricular pacing. ICDs that provide therapy for atrial arrhythmias, such as atrial fibrillation, are also available. 

Implantable tachyrhythmia devices, available for some years, address far less dangerous atrial tachyarrhythmias and fibrillation. The technical barriers to counteracting ventricular tachyarrhythmias and fibrillation using massive shocks have been formidable and are compounded by the possibiUty of causing the very problem the shock is designed to overcome. Newer tachyrhythmia devices are being readied that can safely regulate arrhythmias across the hiU spectmm. 

QuinidJne. Quinidine, an alkaloid obtained from cinchona bark (Sinchona sp.), is the dextrorotatory stereoisomer of quinine [130-95-0] (see Alkaloids). The first use of quinidine for the treatment of atrial fibrillation was reported in 1918 (12). The sulfate, gluconate, and polygalacturonate salts are used in clinical practice. The dmg is given mainly by the oral (po) route, rarely by the intravenous (iv) route of adniinistration. It is the most frequentiy prescribed po antiarrhythmic agent in the United States. The clinical uses of quinidine include suppression of atrial and ventricular extrasystoles and serious ventricular arrhythmias (1 3). 

Verapamil. Verapamil hydrochloride (see Table 1) is a synthetic papaverine [58-74-2] C2qH2 N04, derivative that was originally studied as a smooth muscle relaxant. It was later found to have properties of a new class of dmgs that inhibited transmembrane calcium movements. It is a (+),(—) racemic mixture. The (+)-isomer has local anesthetic properties and may exert effects on the fast sodium channel and slow phase 0 depolarization of the action potential. The (—)-isomer affects the slow calcium channel. Verapamil is an effective antiarrhythmic agent for supraventricular AV nodal reentrant arrhythmias (V1-2) and for controlling the ventricular response to atrial fibrillation (1,2,71—73). 

Newly developed class III drugs comprise dofetilide, a specific Ik, blocker, and ibutilide, which blocks IKl and activates the slow iNa- Both drugs lack hemodynamic side effects. These drugs are scheduled for the treatment of atrial fibrillation and atrial flutter. As with class HI drugs, they can induce torsade de pointes arrhythmia. 

The most common arrhythmia in humans is atrial fibrillation. Because of the lack of rhythmic atrial activation, irregular ventricular rhythms and thromboembolism result. There are two possible therapeutic goals ... 

Cardiac arrhythmia with a rapid and irregular activity in different areas within the upper chambers (atria) of the heart is also known as atrial fibrillation. 

The cardiotonics are used to treat HF and atrial fibrillation. Atrial fibrillation is a cardiac arrhythmia characterized by rapid contractions of the atrial myocardium, resulting in an irregular and often rapid ventricular rate. See Chapter 40 for more information on various arrhythmias and treatment. 

The uses of the antiarrhythmic drug are given in the Summaiy Drug Table Antiarrhythmic Drug3. In general these drugp are used to prevent and treat cardiac arrhythmias, such as premature ventricular contractions (PVCs), ventricular tachycardia (VT), premature atrial contractions (PACs), paroxysmal atrial tachycardia (PAT), atrial fibrillation, and atrial flutter. Some of the antiarrhythmic dru are used for other... 

Systemic anaphylaxis in man is frequently accompanied by electrocardiographic alterations ischemic ST waves, arrhythmias and atrial fibrillation [6-11]. Anaphylactic reactions after insect stings can lead to coronary spasm or acute myocardial infarction [12, 13]. Myocardial infarction can also occur as a consequence of idiopathic... 

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. It is important for clinicians to understand AF, because it is associated with substantial morbidity and mortality and because many strategies for drug therapy are available. Drugs used to treat AF often have a narrow therapeutic index and a broad adverse effect profile. 

Common supraventricular tachycardias requiring drug treatment are atrial fibrillation (AF) or atrial flutter, paroxysmal supraventricular tachycardia (PSVT), and automatic atrial tachycardias. Other common supraventricular arrhythmias that usually do not require drug therapy are not discussed in this chapter (e.g., premature atrial complexes, wandering atrial pacemaker, sinus arrhythmia, sinus tachycardia). 

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