Adenosine for paroxysmal supraventricular tachycardia

Adenosine is the most recent drug approved for the treatment of paroxysmal supraventricular tachycardia. Its advantage is that it is just as effective as verapamil and is far less toxic. The lack of toxicity is due to the extremely short half-life (one to seven seconds). The mechanism of action of adenosine is different from that of other antiarrhythmic agents. For the specific purpose of ameliorating paroxysmal supraventricular tachycardia, adenosine appears to be an ideal antiarrhythmic drug.     

Adenosine: novel antiarrhythmic therapy for supraventricular tachycardia.

Adenosine (Adenocard) is a unique new agent for the acute treatment of paroxysmal supraventricular tachycardia (PSVT). Administered by intravenous bolus, it has an onset and duration measured in seconds and greater than 90% efficacy. Its primary effect is to slow atrioventricular nodal conduction, thus converting reentrant forms of PSVT to normal sinus rhythm. Side effects quickly dissipate without treatment because of the short duration of action. Other uses include diagnosis of broad or wide QRS complex tachycardias and controlled intraoperative hypotension. Its short duration and high efficacy in converting select forms of PSVT make adenosine an excellent alternative to verapamil in patients with compromised hemodynamics. This article will review the clinical use and anesthetic implications for the administration of this drug.     

Adenosine in the treatment of supraventricular tachycardia: 5 years of experience (2002-2006)

We report a retrospective analysis of 5 years of adenosine use in our emergency department (2002-2006). We treated 454 patients with an intravenous bolus of adenosine. The cohort was made up of 40.7% men and 59.3% women, with mean age of 47.32 years, mean heart rate of 162.48 beats per minute. Among them, 73% responded immediately to the 6-mg dose, 15% responded after the second 12-mg dose, and 11% responded to a further 12-mg dose, whereas 11% were unresponsive. We observed minor side effects in a high percentage of patients (ie, chest tightness 83%, flushing 39.4%, sense of impending death 7%). Only 1 major adverse effect was recorded, that is, administering 12 mg of adenosine induced a marked acceleration in the ventricular rate of a patient with an undiagnosed atrial flutter, caused by induction of atrioventricular conduction (1:1). Our results confirm that when patients are appropriately selected, adenosine is probably the best available drug to treat paroxysmal supraventricular tachycardias, especially in emergency situations.     

Adenosine conversion of supraventricular tachycardia associated with high-dose epinephrine therapy for cardiac arrest

Adenosine has received wide acceptance as the drug of choice for initial treatment of supraventricular tachycardias (SVT), and as a diagnostic adjunct in hemodynamically stable, wide-complex tachycardias. This report describes the successful use of adenosine for the treatment of SVT occurring after successful initial resuscitation from ventricular fibrillation, in which a high dose of the epinephrine protocol was used.     

Verapamil or adenosine for the immediate treatment of supraventricular tachycardia

A comparison of verapamil with adenosine for the immediate treatment of supraventricular tachycardia was made from a retrospective review of 164 spontaneous episodes of paroxysmal tachycardia in 43 patients. Verapamil administered to 33 patients restored sinus rhythm in 91 of 112 episodes (81 per cent). Hypotension occurred in 9 per cent of episodes. Adenosine terminated 94 per cent of episodes of supraventricular tachycardia in 25 patients. The arrhythmia recurred shortly after adenosine restored sinus rhythm in 20 episodes. Transient side effects were common. Fifteen patients were treated with both agents. Adenosine was successful in all, but verapamil failed to restore sinus rhythm at least once in seven of the 15 patients. Early recurrence of tachycardia occurred in five of these after adenosine, but in only one after verapamil. Verapamil and adenosine are both effective in the treatment of supraventricular tachycardia; adenosine has the higher success rate and is safer, but transient symptoms are common and arrhythmias may recur.     

High-dose adenosine for treatment of refractory paroxysmal supraventricular tachycardia

Paroxysmal supraventricular tachycardia (PSVT) is one of the more common arrhythmias requiring treatment in the emergency department. Intravenous adenosine is recommended as the initial medication of choice for treatment of PSVT, given in escalating doses up to a maximum of 12 mg. With a serum half-life of less than 10 s, adenosine must be given rapidly to allow for adequate time for it to reach the heart via venous return. In over 10% of adult patients, PSVT will not be terminated with maximum doses of adenosine. We report a case of a patient requiring a higher-than recommended dose of adenosine for termination of PSVT. The patient had a history of pulmonary hypertension with resultant right heart failure at the time of presentation. We believe the higher dose of adenosine was necessary in this patient because of the impaired venous return to her right heart. This case indicates that patients with impaired venous return to the right heart may require higher-than-recommended doses of adenosine for effective termination of PSVT.     

Use of constant-infusion verapamil for the treatment of postoperative supraventricular tachycardia

The effects of constant-infusion verapamil were studied in ten postoperative ICU patients who developed supraventricular tachycardia (atrial fibrillation) with rapid ventricular response rates. A 5-mg iv bolus dose of verapamil was followed by a 5-mg/h infusion that continued for 8 h. Ventricular rates were significantly (p less than .005) reduced from a pretreatment mean of 156 +/- 14 (SD) to 104 +/- 9 beat/min on constant-infusion therapy. This therapy was well tolerated without observed side-effects. Moreover, constant-infusion verapamil might avoid the hypotension and wide range of ventricular rates frequently encountered with repeated bolus doses of verapamil.     

Serum troponin testing in patients with paroxysmal supraventricular tachycardia: outcome after ED care

Paroxysmal supraventricular tachycardia (PSVT), a common dysrhythmia seen in the emergency department (ED), is usually managed without difficulty and with a favorable prognosis. Serum cardiac troponin I (cTnI) testing provides important risk stratification information in certain patients; its use in PSVT patients, however, has not been explored. A retrospective review of consecutive adult ED PSVT patients seen for 21 months was performed. Fifty-four PSVT patients were identified on the basis of International Classification of Disease, Ninth Edition codes and the ED patient log at a university hospital. Three patients were excluded for incorrect rhythm, leaving 51 who were included in data analysis. Thirty-eight patients had at least one serum cTnI value measured. Of those, 11 had a positive result, defined as serum cTnI of more than 0.02 ng/dL. Thirty-day outcomes for these patients were evaluated and showed one ED return, no PSVT recurrences, and no deaths at our regional hospital. In this sample, serum cTnI testing did not identify PSVT patients at risk for poor outcome. Further consideration of the use of this testing modality in the PSVT patient population is recommended.     

Flecainide in the intrauterine treatment of fetal supraventricular tachycardia.

OBJECTIVES: To assess the efficacy of flecainide in the intrauterine treatment of fetal supraventricular tachycardia (SVT) with 1 : 1 atrioventricular conduction. DESIGN: Twenty fetuses (21-35 weeks of gestation) with SVT ranging between 215 and 280 bpm were analyzed retrospectively. Fetuses received flecainide and digoxin as either first, second or third line therapy. Intracardiac blood flow, venous Doppler waveforms and cardiotocograms were evaluated before and after drug induced conversion to sinus rhythm. RESULTS: After initiation of combined flecainide and digoxin therapy, the median time interval until final conversion to sinus rhythm was 5 days (range, 0-14 days). The majority of fetuses (n = 15; 75%) converted to sinus rhythm within 7 days of treatment, whereas the remaining five (25%) showed initial reduction of the heart rate to 160-215 bpm over several days, with restoration of a triphasic venous blood flow pattern before late conversion within 7-14 days after initiation of flecainide treatment. One of these fetuses showed a decrease in fetal heart rate to 160-190 bpm without conversion to sinus rhythm but with resolution of hydrops. All fetuses survived. CONCLUSIONS: Flecainide is safe and highly effective in the intrauterine treatment of hydropic fetuses with supraventricular tachycardia. Conversion into sinus rhythm can be expected 72 h after initiation of therapy but may take up to 14 days. Therefore therapy should be continued beyond 72 h, especially when an initial decrease of fetal heart rate is observed which may represent an early therapeutic response.     

Clinical effectiveness of ethacizine in the treatment of supraventricular paroxysmal tachycardia

I. v. administration of ethacizine was used in 2 cases of spontaneous and 15 cases of induced SV arrhythmic paroxysm. Induction was based on rapid left atrial transesophageal pacing. In addition to external leads esophageal leads were also recorded. The drug was injected at a dose of 50-100 mg. The effect was achieved in 18 (94.7%) and lasted 3-10 min. AV recurrent tachycardia was stopped as a result of blockade in the AV node in anterograde or retrograde direction, in orthodromic tachycardia--as a result of impulse conduction blockade via accessory conductive tract, and in cases of antidromic--as a result of retrograde blockade in the AV node. Among the most serious side-effects was ventricular tachycardia.     

胺碘酮治疗室上性心动过速的观察与护理

<正>胺碘酮是一种强有力的广谱抗心律失常药物,广泛应用于临床治疗各种室上速及室性心律失常,但若使用不当,亦可发生严重心律失常、低血压、静脉炎、甲状腺功能异常、肺纤维化等不良反应,增加病人的烦恼和痛苦。因此,在临床工作中观察和护理极为重要。现就我院急诊科采用胺碘酮治疗室上性心动过速48例的护理措施和体会报告如下。     

Neonatal refractory supraventricular tachycardia: successful treatment with amiodarone

A 3-week-old neonate with supraventricular tachycardia unresponsive to traditional therapy was treated successfully with amiodarone. An electrophysiologic study suggested the presence of a concealed left-sided accessory atrioventricular pathway. Because of its significant side effects, amiodarone should be used only as a last resort in the treatment of neonatal supraventricular tachycardia.     

普罗帕酮终止阵发性室上性心动过速疗效观察

目的观察普罗帕酮(心律平)终止阵发性室上性心动过速(PSVT)的即时疗效及安全性.方法37例PSVT,静脉注射普罗帕酮70mg,于5分钟完成,观察20分钟;未终止者重复用70mg,再观察30分钟,仍未终止者再用70mg.用药前、后和PSVT终止时,记录血压、心率及12导联心电图.结果显效75.7%(28/37),有效21.6%(8/37),总有效率97.3%.起效时间1～55(7.1±2.8)分钟.普罗帕酮平均累积量105mg.部分患者可出现轻度血压下降,P-R间期、QRS时限及QTc间期延长,一过性Ⅱ度Ⅰ型窦房阻滞及头晕、恶心等副作用,未经处理逐渐消失.结论普罗帕酮静脉注射终止PSVT有效、快速、安全.