Atrial fibrillation, treatment

Rapid loading dose for the management and treatment of CHF control ofventricular rate In patients with atrial fibrillation-, treatment and prevention of recurrent paroxysmal atrial tachycardia PO Initially, 0.5-0.75 mg, additional doses of 0.125-0.375 mg at 6-to8-hr intervals. Range 0.75-1.25 mg. IV 0.6-1 mg. 

Maintenance dosage for CHF control of ventricular rate in patients with atrial fibrillation treatment and prevention of recurrent paroxysmal atrial tachycardia PO, IV... 

Mant J, Hobbs FD, Fletcher K et al. (2007) Midland Research Practices Network (MidReC). Warfarin versus aspirin for stroke prevention in an elderly community population with atrial fibrillation (the Birmingham Atrial Fibrillation Treatment... 

Interventional approaches have an established role in the treatment of symptomatic patients with drug-refractory AF. Randomized trials will assess catheter ablation as first line therapy as an alternative to anti-arrhythmic drug therapy, with emphases on efficacy, safety, and survival (Table 6.1). The Radiofrequency Ablation versus Antiarrhythmic Drugs for Atrial Fibrillation Treatment (RAAFT) study is a multicenter, randomized trial designed to assess the efficacy and... 

Abbreviations A4, atrial fibrillation ablation versus antiarrhythmic drugs AAD, antiarrhythmic drug APAF, ablation for paroxysmal atrial fibrillation CACAF, catheter ablation for the cure of atrial fibrillation CPVA, circumferential pulmonary vein ablation PVI, pulmonary vein isolation RAAFT, radiofrequency ablation versus antiarrhythmic drugs for atrial fibrillation treatment. 

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). 

Dlgltoxin. Digitoxin is a cardiac glycoside obtained from Digitalis purpurea. Digitoxin is indicated in the treatment of atrial flutter, atrial fibrillation, and supraventricular tachycardia. Its electrophysiologic and adverse effects are similar to those described for digoxin (87). 

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. 

Kvl.5 In human atria, the Kvl.5 presents the ultrarapid delayed rectifier that contributes to the repolarization in the early phase of cardiac action potential. Selective blockers of Kvl.5 channels could be potentially beneficial in the treatment of atrial fibrillation because blocking Kvl. 5 could delay repolarization and prolong refractoriness selectively in cardiac myocytes. Examples for Kvl.5 blockers include AVE0118, S9947, and analogs of diphenyl phosphine oxide (DPO). 

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. 

Prevention and treatment of atrial fibrillation with embolization... 

Expert opinion is a source, frequently elicited by survey, that is used to obtain information where no or few data are available. For example, in our experience with a multicountry evaluation of health care resource utilization in atrial fibrillation, very few country-specific published data were available on this subject. Thus the decision-analytic model was supplemented with data from a physician expert panel survey to determine initial management approach (rate control vs. cardioversion) first-, second-, and third-line agents doses and durations of therapy type and frequency of studies that would be performed to initiate and monitor therapy type and frequency of adverse events, by body system and the resources used to manage them place of treatment and adverse consequences of lack of atrial fibrillation control and cost of these consequences, for example, stroke, congestive heart failure. This method may also be used in testing the robustness of the analysis [30]. 

The Heparin in Acute Embolic Stroke Trial (HAEST) was a multicenter, randomized trial of the effect of LMWH (dalteparin 100 lU/kg sc twice daily) or aspirin (160 mg once daily) for the acute treatment of 449 patients with ischemic stroke and atrial fibrillation (AF). The primary outcome was the rate of recurrent stroke within 14 days. No difference in rates of early recurrence (8.5% dalteparin treated vs. 7.5% aspirin treated) or good 3-month functional outcome was found. The frequency of early slCH was 2.7% on dalteparin versus 1.8% on aspirin. 

Warfarin has been the primary oral anticoagulant used in the United States for the past 60 years. Warfarin is the anticoagulant of choice when long-term or extended anticoagulation is required. Warfarin is FDA-approved for the prevention and treatment of VTE, as well as the prevention of thromboembolic complications in patients with myocardial infarction, atrial fibrillation, and heart valve replacement. While very effective, warfarin has a narrow therapeutic index, requiring frequent dose adjustments and careful patient monitoring.15,29... 

A 59-year-old male with a history of rheumatic heart disease is found to have atrial fibrillation (AF for which he is treated with digoxin. Treatment with digoxin converts his AF to a normal sinus rhythm and most likely results in a decrease in which of the following ... 

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). 

FIGURE 6-2. Algorithm for the treatment of acute (top portion) paroxysmal supraventricular tachycardia and chronic prevention of recurrences (bottom portion). Note For empiric bridge therapy prior to radiofrequency ablation procedures, calcium channel blockers (or other atrioventricular [AV] nodal blockers) should not be used if the patient has AV reentry with an accessory pathway. (AAD, antiarrhythmic drugs AF, atrial fibrillation AP, accessory pathway AVN, atrioventricular nodal AVNRT, atrioventricular nodal reentrant tachycardia AVRT, atrioventricular reentrant tachycardia DCC, direct-current cardioversion ECG, electrocardiographic monitoring EPS, electrophysiologic studies PRN, as needed VT, ventricular tachycardia.)... 

Prophylaxis and treatment Prophylaxis and treatment of venous thrombosis and its extension pulmonary embolism peripheral arterial embolism atrial fibrillation with embolization. 

Prophylaxis and/or treatment of the thromboembolic complications associated with atrial fibrillation and/or cardiac valve replacement. 

Atrial fibrillation Peak digoxin body stores larger than the 8 to 12 mcg/kg required for most patients with heart failure and normal sinus rhythm have been used for control of ventricular rate in patients with atrial fibrillation. Titrate doses of digoxin used for the treatment of chronic atrial fibrillation to the minimum dose that achieves the desired ventricular rate control without causing undesirable side effects. Data are not available to establish the appropriate resting or exercise target rates that should be achieved. 

Tachy-arrhythmias may be treated with a /3i-selective blocker. Sotalol may be used in the treatment of postoperative atrial fibrillation, which is observed frequently following cardiac surgery. 

Digoxin, prototype of the cardiac glycosides, is frequently used postoperatively for the management of atrial fibrillation. This effect is based on the impairment of AV conduction and unrelated to digoxin s positive inotropic activity. In the treatment of post-operative atrial fibrillation digoxin may be... 

Inappropriate sinus bradycardia, sinoatrial block, and bradycardia-tachycardia syndrome (bradycardia followed by supraventricular tachyarrhythmias such as atrial fibrillation) are included in this syndrome. Treatment of sick sinus syndrome is generally based upon the patients symptoms. In general, bradycardia... 

Management of hypothyroidism consists of identifying the underlying cause and then providing thyroid hormone replacement to normalize thyroid sta-ms. The goal of treatment is to reduce semm TSH levels to normal, which for most assays is roughly between 0.5 and 3 mU/1. Oversuppression of TSH levels is probably not advisable, as overtreatment may predispose to cardiac arrhythmias (particularly atrial fibrillation), and may have subtle effects on bone mineral density. 

Procainamide is an effective antiarrhythmic agent when given in sufficient doses at relatively short (3-4 hours) dosage intervals. Procainamide is useful in the treatment of premature atrial contractions, paroxysmal atrial tachycardia, and atrial fibrillation of recent onset. Procainamide is only moderately effective in converting atrial flutter or chronic atrial fibrillation to sinus rhythm, although it has... 

Dofetilide is approved for the treatment of atrial fibrillation and atrial flutter. Because of the lack of significant hemodynamic effects, dofetilide may be useful in patients with CHF who are in need of therapy for supraventricular tachyarrhythmias. Dofetilide is not indicated for use in the setting of ventricular arrhythmias. 

Reiffel JA. Drug choices in the treatment of atrial fibrillation. Am J Cardiol 2000 85(10A) 12D-19D. 

Treatment of venous thrombosis, pulmonary embolism, peripheral arterial embolism, atrial fibrillation with embolism Intermittently Initially, 10,000 units, then 50-70 units/kg (5000-10,000 units) q4 6h. IV Infusion Loading dose 80 units/kg, then 18 units/kg/hr, with adjustments based on aPTT. Range 10-30 units/kg/hr. 

Patients with chronic atrial fibrillation have a strongtendency to revert after conversion to sinus rhythm. Treatment to maintain sinus rhythms carries risks. Patients should be carefully selected for ibutilide therapy. 

Paradoxical, extremely rapid ventricular rate may occur during treatment of atrial fibrillation or flutter. 

It is indicated in the prophylaxis and treatment of deep vein thrombosis in major surgery and pulmonary embolism, treatment of atrial fibrillation with embolisation, prophylaxis and treatment of peripheral arterial embolism. 

Paroxysmal supraventricular tachycardia, atrial fibrillation and flutter. Not of benefit in treatment of ventricular arrhythmias Miscellaneous... 

This agent also has some class lA and class II effects. It is effective for the treatment of ventricular and supraventricular tachycardias (AV nodal and accessory pathway re-entry, atrial flutter and fibrillation). Propafenone is useful in converting recent-onset atrial fibrillation or flutter to sinus rhythm, and for terminating paroxysmal supraventricular tachycardia. Its pro-ariythmic and myocardial depressant effects limit its use, especially in patients with poor ventricular function. 

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