Chemical Cardioversion Of Atrial Fibrillation Research Articles

Lone atrial fibrillation: A case report on a rare complication of pregnancy

Atrial fibrillation (AF) is one of the most common arrhythmias and is a rare phenomenon seen in pregnant patients unless there is an underlying cardiopulmonary abnormality. Lone AF in pregnancy is a diagnosis of exclusion. A thorough workup including history, physical examination, imaging, and laboratory workup should be done diligently to exclude cardiopulmonary diseases (like hypertensive heart disease, congenital heart disease, valvular heart disease, asthma or chronic obstructive pulmonary disease, pulmonary embolism, rheumatic heart disease) and non-cardiac diseases (such as hyperthyroidism or electrolyte abnormalities or medications). There are very few case reports and studies published so far on this topic. This case report is on a pregnant patient without any significant past medical history who developed new-onset lone AF without any known cause and was managed with Diltiazem, which resulted in chemical cardioversion of atrial fibrillation with rapid ventricular rate to normal sinus rhythm.

A rare case of vernakalant-induced 1:1 atrial flutter during chemical cardioversion of atrial fibrillation requiring emergency direct current cardioversion

Vernakalant is an atrial-selective, multi-channel anti-arrhythmic that offers a safe alternative to traditional approaches to chemical cardioversion of recent-onset, non-valvular atrial fibrillation. This case report describes a very rare occurrence of unstable accelerated 1:1 atrial flutter during an attempted cardioversion of non-valvular atrial fibrillation using vernakalant hydrochloride that required emergent direct current cardioversion. This case report highlights the need for clinicians to remain vigilant and be prepared to treat rare consequences of vernakalant administration.

Ibutilide with magnesium for conversion of atrial fibrillation or flutter in rheumatic heart disease patients: Ibutilide with magnesium for chemical cardioversion of atrial fibrillation or flutter

BackgroundData on adjunctive use of magnesium with ibutilide for conversion of persistent rheumatic atrial fibrillation and flutter to sinus rhythm is lacking. AimWe aimed to study the efficacy of adjunctive supplementation of intravenous magnesium with ibutilide for conversion of persistent rheumatic atrial fibrillation and flutter to sinus rhythm and to define a definite level of serum magnesium which leads to significant increase in rates of such conversion. Methods and resultsThis was a prospective study including 33 Rheumatic heart disease patients (13 males and 20 females) with mean age of 49.27 ± 11.4 years and persistent AF or AFl. All patients received intravenous magnesium to raise serum magnesium level in range of 4 mg/dl to 4.5 mg/dl prior to administration of Ibutilide. 25 out of 33 (76%) patients converted to sinus rhythm. Upon univariate analysis, presence of background beta blocker therapy, serum potassium and magnesium at time of Ibutilide injection were found to have significant relation with conversion to sinus rhythm. Upon multivariate analysis serum magnesium level at the time of Ibutilide injection was found to have significant contribution on post injection rhythm reversal (p-value = 0.006).The level of magnesium at 3.8 mg/dl was found to have maximum sensitivity of 96% and specificity of 62.5% for conversion to sinus rhythm by ibutilide with magnesium (p-value< 0.05). ConclusionsIbutilide is highly effective in cardioversion of persistent rheumatic atrial fibrillation/flutter patients. Raising Serum Magnesium levels above 3.8 mg/dl significantly improves efficacy of ibutilide.

Qual o Diagnóstico?

Paciente do sexo feminino, 82 anos, branca, com história de fibrilação atrial paroxística (FA) há vários anos, com crises de palpitação com duração variável entre poucos minutos e várias horas, sem controle clínico, com uso de betabloqueadores e diltiazem. Apresentava queixas de cansaço aos esforços moderados, sem dor precordial ou síncope, com progressiva astenia e indisposição. Informou três internações prévias para cardioversão química de FA. Apresentava antecedente de hipertensão arterial sistêmica, hipotireoidismo e doença aterosclerótica do coração, tendo sido submetida a angioplastia coronariana em 2014 com colocação de stent não farmacológico, sem infarto prévio. Vinha em uso regular de irbesartana 300 mg, clopidogrel 75 mg e levotiroxina 75 mcg. Ao longo dos últimos oito meses, houve piora das crises de FA, passando a fazer uso de propafenona em doses crescentes, inicialmente 150 mg BID, sem melhora dos sintomas, passando para 300 mg BID e atualmente 750 mg/dia (300 – 150 – 300 mg, distribuídos de 8/8 horas), sem controle das palpitações e com sensação de mal-estar e fraqueza.

What is the Diagnosis?

A female 82-year-old Caucasian patient with a history of paroxysmal atrial fibrillation (AF) for several years, with palpitation crises of varying duration between a few minutes and several hours, without clinical control, using beta-blockers and diltiazem. The patient presented complaints of fatigue on moderate efforts, without precordial pain or syncope, with progressive asthenia and indisposition. She informed three previous hospitalizations for chemical cardioversion of AF.

Efficacy and Safety of Ibutilide for Chemical Cardioversion of Atrial Fibrillation and Atrial Flutter in Cancer Patients

BackgroundAtrial fibrillation and atrial flutter (AF/AFL) are the most common arrhythmias encountered in clinical practice. Rate versus rhythm control remains a difficult decision, especially in the acute setting. ibutilide is a class iii antiarrhythmic indicated for pharmacological cardioversion of recent-onset AF/AFL. At the University of Texas MD Anderson Cancer Center, restoration of sinus rhythm is desirable because many patients have contraindications to anticoagulation. In addition, most are on multiple medications that prolong the QT interval; therefore, the objective of this study was to establish the safety and efficacy of ibutilide. MethodsThis was a retrospective chart review of 81 patients who were identified via the pharmacy database as receiving ibutilide for AF/AFL from January 2002 to May 2006. Outcomes including cardioversion rates and effects on the QT interval were recorded. ResultsIbutilide use was associated with successful cardioversion in 75% of patients. Out of 81 patients, 68 patients (84%) were on at least 1 medication that prolonged the QT interval at the time of ibutilide administration. However, no significant changes in the corrected QT interval pre and post ibutilide cardioversion were noted in any group of patients. ConclusionsOverall, ibutilide is safe and effective in cancer patients when used for acute cardioversion of AF/AFL. Despite the use of multiple medications that can potentially prolong the QT interval, no patient experienced serious life-threatening rhythm disturbances or significant QT prolongation during ibutilide administration.

Accelerated AV Nodal Conduction with Use of Procainamide in Atrial Fibrillation

Background: Atrial fibrillation is a common dysrhythmia seen in the emergency department (ED). Chemical or electrical cardioversion may be performed on patients who have had atrial fibrillation for < 48 h duration and who are at low risk for thromboembolic events. Multiple studies suggest that intravenous procainamide is an appropriate agent in the treatment of acute atrial fibrillation due to its relatively low risk profile and high conversion rate. Objectives: A case is presented that demonstrates an adverse reaction to the use of intravenous procainamide for chemical cardioversion of atrial fibrillation in an otherwise hemodynamically stable patient. Case Report: We report a case of lone paroxysmal atrial fibrillation in a patient with a structurally normal heart who suffered paradoxical accelerated atrioventricular nodal conduction and secondary hypotension in response to procainamide administration. Conclusion: When administering procainamide for chemical cardioversion of atrial fibrillation, a low threshold should be maintained for administration of a complementary rate-controlling agent, and facilities for immediate electrical cardioversion always must be available.

Chemical cardioversion of atrial fibrillation or flutter with ibutilide in patients receiving amiodarone therapy.

Ibutilide is a class III drug that is used for the cardioversion of atrial arrhythmias, but it can cause torsade de pointes. Amiodarone also prolongs the QT interval but rarely causes torsade de pointes. There are no studies in which the concomitant use of the 2 agents was examined. The purpose of the present study was to assess the efficacy and safety of cardioversion with combination therapy in patients with atrial fibrillation or flutter. The study included 70 patients who were treated with long-term oral amiodarone and were referred for elective cardioversion of atrial fibrillation (57 of 70, 81%) or flutter (13 of 70, 19%). Patients were taking amiodarone (153+/-259 days, mean+/-SD) and were administered 2 mg intravenous ibutilide. Left ventricular ejection fraction was measured with echocardiography. The QT intervals were measured on 12-lead ECG. Fifty-five patients (79%) had structural heart disease. Patients were in arrhythmia for 196+/-508 days before cardioversion, with a left ventricular ejection fraction of 50+/-11%. In patients with atrial fibrillation, 22 (39%) of 57 and 7 (54%) of 13 patients with flutter converted within 30 minutes of infusion. Thirty-nine patients who did not convert after ibutilide were treated with electrical cardioversion, and 35 (90%) of 39 patients were successfully converted. The QT intervals were further prolonged after ibutilide for the group from 371+/-61 to 479+/-92 ms (P:<0.001). There was 1 episode of nonsustained torsade de pointes (1 of 70, 1.4%) after ibutilide. The use of ibutilide converted 54% of patients with atrial flutter and 39% of patients with atrial fibrillation who were treated with long-term amiodarone. Despite QT-interval prolongation after ibutilide, only 1 episode of torsade de pointes occurred. Our observations suggest that combination therapy may be a useful cardioversion method for chronic atrial fibrillation or flutter.

High-dose bolus lidocaine for chemical cardioversion of atrial fibrillation: A prospective, randomized, double-blind crossover trial

Background Most drugs used for chemical cardioversion of atrial fibrillation have significant proarrhythmia risk and require close monitoring after administration. Lidocaine has few of the proarrhythmic concerns of most antiarrhythmic drugs and, at high bolus doses, prolongs the atrial refractory period well enough to be effective in converting atrial fibrillation to sinus rhythm. This finding has been previously demonstrated in a dog model. We sought to confirm the animal findings in human beings with lidocaine doses of 1.5 to 2.5 mg/kg. Methods Twenty patients with atrial fibrillation scheduled for elective cardioversion were enrolled in this study. In a randomized, double-blind, crossover study design, each patient received intravenous bolus lidocaine or saline. Patients were observed for 10 minutes after the initial bolus to assess efficacy. The second test drug was then delivered if the first was unsuccessful at cardioversion. Results All 20 patients received both lidocaine and saline placebo therapy in a crossover manner. None of the 20 patients converted to sinus rhythm with either therapy. The 95% confidence interval for effectiveness of lidocaine in this population was 0% to 14%. Conclusion: In this population of patients referred for elective cardioversion of atrial fibrillation, high-dose bolus lidocaine was ineffective in converting patients to sinus rhythm. Although this study was not sufficiently powered to rule out a low efficacy of lidocaine (<15%) or a higher efficacy in certain subgroups of atrial fibrillation, routine use of lidocaine for this indication is not warranted. (Am Heart J 2000;139:e6.)

Bilateral Atrial Function After Chemical Cardioversion of Atrial Fibrillation with Amiodarone: An Echo-Doppler Study

Cardioversion of atrial fibrillation transiently increases the risk of embolism presumably by decreased atrial mechanical function. It has been suggested that a component of early dysfunction relates to the mode of cardioversion. Amiodarone is one of the drugs used to restore sinus rhythm in patients with atrial fibrillation. However, the effect of this drug on left and right atrial mechanical function after conversion to sinus rhythm is not well known. Thirty-one patients (group AF) cardioverted from atrial fibrillation with intravenous amiodarone (average dose 1 gm/day) were prospectively studied to examine the effect of this drug on recovery of left and right atrial mechanical function. These patients were compared with 17 consecutive individuals without evidence of cardiac disease who became our control group (group C). Transmitral flow velocities and echocardiographic parameters were recorded within 24 hours after cardioversion and on the seventh day in group AF and one time in group C. Left and right atrial ejection force to evaluate atrial mechanical function was defined as 0.5 × 1.06 × mitral (m) or tricuspid (t) orifice area × (m or t peak A velocity) 2. If this value in group AF was more than the mean minus 1 standard deviation of control group data, atrial ejection function after cardioversion was considered normal. The two groups were similar with respect to age, sex, arterial blood pressure, heart rate, left ventricular diameters, and left ventricular ejection fraction. Left and right atrial size was higher in group AF (left: group AF, 18.1 ± 3.9 cm 2; group C, 11.3 ± 2.5 cm 2, p < 0.01; right: group AF, 14.9 ± 3.2 cm 2; group C, 11.6 ± 2.3, p < 0.01). Measurements of right and left atrial ejection force measured within 24 hours and on day 7 in group AF were similar to that in group C (left: group C, 11.9 ± 5.3 kdyne; AF group, 24 hours, 19.4 ± 15.5 kdyne [NS]; AF group, day 7, 14.7 ± 13.6 kdyne [NS]; right: group C, 3.6 ± 1.99 kdyne; AF group, 24 hours, 4.3 ± 3.3 kdyne [NS]; AF group, day 7, 3.5 ± 2.9 kdyne [NS]). Therefore almost all patients undergoing cardioversion for atrial fibrillation with amiodarone recovered bilateral atrial mechanical function within 24 hours after cardioversion (26 of 31-84%-left atrial ejection force; 28 of 31-93.5%-right atrial ejection force), with normal left atrial function in 97% of patients and normal right atrial function in 100% of patients on day 7 after conversion to sinus rhythm. These findings may have significant implications on postcardioversion anticoagulation strategies. (J Am Soc Echocardiogr 1998;11:365-71.)

Chemical cardioversion of atrial fibrillation with intravenous dofetilide

We studied the effects of two active dose levels of dofetilide (8 and 12 μg/kg) and placebo in 16 patients with recent onset atrial fibrillation. The study was of a crossover design such that all patients received a theraputic agent, 15 patients completed the study. Cardioversion was achieved in 2 6 patients receiving 8 μg/kg dofetilide and in 2 9 patients receiving 12 μg/kg. No patients cardioverted as a result of the placebo infusion. Two patients who cardioverted suffered episodes of torsades de pointes following the active drug. Electrical cardioversion was attempted in eight patients who remained in atrial fibrillation and was successful in six. The average duration of atrial fibrillation was 35 days in those who cardioverted and 83 days in those who did not. The compound appears to have only limited effect in cardioversion of atrial fibrillation of moderate duration.