Eustachian valve endocarditis caused by Streptococcus viridans.

A 76-year-old man was admitted for ethanol detoxification. He was found to be in atrial fibrillation with a rapid ventricular response that was refractory to electrical and chemical cardioversion attempts. The patient subsequently developed respiratory distress. A transesophageal echocardiogram revealed a vegetation attached to the eustachian valve and blood cultures grew Streptococcus viridans. After treatment with appropriate antibiotics, the patient converted to sinus rhythm with sotalol hydrochloride, and the eustachian valve vegetation resolved. This is the first reported case of eustachian valve endocarditis caused by S viridans.     

A wide, complex look at cardiac dysrhythmias

The diagnosis and treatment of cardiac dysrhythmias answers the following four questions: Is the patient stable? Is the rate fast or slow? Are the ventricular complexes wide or narrow? Is the rhythm regular or irregular? The most common narrow complex regular tachycardias are sinus tachycardia, atrial flutter, atrial tachycardia that blocks, and paroxysmal supraventricular tachycardia. Carotid sinus massage is useful in differentiation. Irregular narrow-complex tachycardias are usually atrial fibrillation. An ultra-rapid wide-complex or polymorphous irregular tachycardia is likely to be atrial fibrillation with ventricular preexcitation.

Wide-complex regular tachycardias present a special challenge, since wide beats may result from supraventricular or ventricular impulse formation. Ventricular tachycardia is more likely than supraventricular tachycardia in the presence of underlying ischemic heart disease, atrioventricular dissociation, fusion or capture beats, or a very broad (greater than .14 seconds) QRS complex. Still, misdiagnosis is common; the most costly mistake is over-diagnosis of SVT.

In emergencies, where vital organ hypoperfusion is present, the origin of the impulse and the name of the dysrhythmia are unimportant. With the exception of sinus tachycardia, all life-threatening, rapid tachycardias should be terminated by electrical cardioversion.     

血清C反应蛋白水平与孤立性心房颤动复律后复发的关系

目的 探讨C反应蛋白(CRP)水平对孤立性心房颤动患者转复窦性心律后复发的预测作用.方法 选取孤立性持续性房颤经药物复律或电复律患者,按其1个月内复发情况分为复发组(15例)和窦律组(18例),复律前抽取静脉血检测其CRP水平,并取18名正常人作对照.结果 两组房颤患者年龄、性别、房颤持续时间、电复律的比例及左室射血分数差异均无统计学意义,但复发组左房内径明显大于窦性心律者(P＜0.05).复发组CRP水平较窦性组明显升高(P＜0.05),两组CRP均比正常组显著升高(P＜0.01).结论 孤立性房颤患者复律前CRP水平可作为复律后复发的预测指标.     

伊布利特治疗预激综合征合并房颤患者的临床疗效观察

[目的]探讨伊布利特治疗预激综合征合并房颤的临床疗效.[方法]回顾性分析2017年2月至2019年6月本院收治的7例预激综合征合并房颤患者,所有患者均给予富马酸依布利特注射液治疗,所有患者在用药后均行预激旁道和(或)房颤射频消融术治疗.观察记录所有患者用药后窦性心律转复情况及手术情况.[结果]7例患者静脉注射伊布利特后...     

Pharmacological management of atrial fibrillation: an update

Therapy of atrial fibrillation remains difficult in many patients. There is increasing awareness that antiarrhythmic drug therapy instituted to maintain sinus rhythm after successful cardioversion of atrial fibrillation may pose a substantial risk to the patient. Therefore, results of prospective randomized trials are needed to allow a more evidence-based approach to the treatment of this common arrhythmia. Two recently published studies have shown superiority of amiodarone over conventional antiarrhythmic drugs in maintaining sinus rhythm. The largest such study published today, the Canadian Trial in Atrial Fibrillation (CTAF), has randomized 403 patients to amiodarone or to sotalol or propafenone. At the end of the observation period, amiodarone-treated patients were significantly more likely to remain in sinus rhythm than conventionally treated patients. A number of new antiarrhythmic drugs, mainly class III substances, are currently developed for the treatment of atrial fibrillation or atrial flutter. Ibutilide has recently been released for intravenous administration, attempting pharmacological cardioversion of atrial fibrillation/atrial flutter. It has been evaluated in a number of prospective trials, which showed a higher conversion rate in patients with atrial flutter. Dofetilide is another new compound developed mainly for maintenance of sinus rhythm after restoration of sinus rhythm. It has been evaluated in two prospective, randomized, placebo-controlled trials; moreover, analysis of the DIAMOND trials showed effectiveness of dofetilide in maintaining sinus rhythm in patients with depressed left ventricular function without increased mortality when compared with placebo. Finally, several ongoing studies compare the therapeutic strategy of controlling ventricular rate in atrial fibrillation compared with the strategy of maintaining sinus rhythm. These trials will help to optimize therapy in atrial fibrillation, the most commonly encountered arrhythmia.     

Cardioversion of pre-excited atrial fibrillation leading to ventricular fibrillation- case report and review of literature

Pre-excited, fast conducting atrial fibrillation (AF) is a serious life-threatening arrhythmia that requires urgent pharmacological or electrical cardioversion. When anti-arrhythmic medications fail to restore sinus rhythm, biphasic, direct current (DC) cardioversion is required. Appropriate synchronization of the DC shock with the QRS is crucial, however not easily achieved. Since the QRS-T complexes in pre-excited AF are severely distorted, the diagnosis of inaccurate synchronization may be overlooked. Here, we report a unique case where during electrical cardioversion of pre-excited AF with inappropriate synchronization on the T wave inadvertently resulted in ventricular fibrillation (VF), and review the literature.     

Classification of atrial fibrillation as a model of decisional analysis for the treatment of patients with current atrial fibrillation observed in the emergency department.

Atrial fibrillation (AF) is the most common cardiac arrhythmia observed in the emergency room (ER). We propose a new classification of AF which is useful for the standardization of terms to be used for future clinical trials and for clinical management of this arrhythmia in the ER. We recognized three categories: (1) atrial fibrillation lasting less than 72 hours (AF < 72 h); (2) persistent atrial fibrillation and (3) permanent atrial fibrillation. Atrial fibrillation lasting less than 72 hours can be reconverted to sinus rhythm spontaneously or with pharmacological or electrical cardioversion. If AF < 72 h is not treated and the arrhythmia persists for more than 72 hours we recognize persistent AF. In persistent AF the systemic thrombo-embolism is a significant risk and therapeutic anticoagulation must be associated to pharmacological or electrical cardioversion even though transoesophageal echocardiography does not visualize thrombi or spontaneous echocontrast in the cardiac chambers. These treatments can reconvert the persistent AF to sinus rhythm, but, in the absence of treatment, or if treatment fails, the arrhythmia goes into the permanent category. In permanent AF ventricular rate control and anticoagulation, if suitable, are the first choice for stroke prevention.     

Discordant regulation of CRP and NT-proBNP plasma levels after electrical cardioversion of persistent atrial fibrillation

BACKGROUND: B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been suggested to be prognostically relevant markers in patients with cardiovascular disease. Additionally, BNP and CRP plasma levels seem to be independently elevated in patients with atrial fibrillation (AF). However, there are only sparse data about the significance and temporal course of these plasma markers after restoration of sinus rhythm (SR). METHODS: We performed a prospective study in consecutive patients with symptomatic atrial fibrillation. NT-proBNP and CRP plasma levels were measured before and one month after electrical cardioversion (CV). Patients with infections, an acute coronary syndrome, or surgery 4 weeks prior to CV, were excluded. RESULT: Twenty-five patients (men 84%, age 66 +/- 8 years, duration of AF 90 +/- 75 days, left ventricular ejection fraction 0.57 +/- 0.11) were analyzed. At follow-up (33 +/- 6 days after CV) 14 patients (56%) were in SR and 11 patients (44%) in AF. In patients with SR there was a significant reduction of NT-proBNP levels (baseline 1647 +/- 1272 pg/mL, follow-up 772 +/- 866 pg/mL, P < 0.05), even in a subgroup of patients (n = 10) with normal left ventricular ejection fraction (1262 +/- 538 vs 413 +/- 344 pg/mL, P < 0.001). CRP levels in patients with SR were similar at baseline and at follow-up (3.5 +/- 3.6 vs 3.2 +/- 2.5 mg/L, P = 0.8). CONCLUSION: We conclude that even in patients with normal left ventricular ejection fraction restoration of sinus rhythm leads to a significant reduction of NT-proBNP plasma levels. In contrast, CRP plasma levels seem not to be influenced during the first 4 weeks after electrical cardioversion.     

The relation between ejection fraction and mitral annulus motion before and after direct‐current electrical cardioversion

Mitral annulus motion (MAM) and the relation between left ventricular ejection fraction (EF) and MAM has been shown to differ between patients with sinus rhythm and patients with atrial fibrillation. However, it has not been investigated how the relation between EF and MAM changes on direct‐current (DC) electrical cardioversion to sinus rhythm. Therefore, 31 consecutive patients on the waiting list for DC electrical cardioversion were examined by echocardiography before DC electrical cardioversion, and those who maintained sinus rhythm (13 patients) were examined again 4–8 weeks after cardioversion. The conversion factor (CF) (ratio EF/MAM) decreased from 8·4 ± 1·7 before to 5·8 ± 0·8 SD after cardioversion (P<0·001). The EF increased slightly (P<0·05) but the MAM had a much greater increase (P<0·001), resulting in the decrease in CF. There was no significant difference in CF between patients after cardioversion and age‐ and gender‐matched control patients with sinus rhythm, indicating that CF is normalized or almost normalized 4–8 weeks after cardioversion. This indicates that when MAM is used for investigation of the left ventricular function, and the function is expressed as EF, the same CF as in other patients with sinus rhythm can be used 4–8 weeks after DC electrical cardioversion.     

Postoperative atrial fibrillation

Atrial fibrillation is a common arrhythmia after cardiac surgery. It is associated with an increase in morbidity, length of hospital stay, and mortality. Patients who are at higher risk of postoperative atrial fibrillation should receive prophylactic treatment. Atrial fibrillation usually resolves spontaneously after heart rate is controlled; however, if patients are highly symptomatic or hemodynamically unstable, sinus rhythm should be restored by electrical or pharmacologic cardioversion. Patients with atrial fibrillation of more than 48 hours should receive antithrombotic therapy for thromboembolism prevention.     

Efficacy of Dronedarone Versus Propafenone in the Maintenance of Sinus Rhythm in Patients With Atrial Fibrillation After Electrical Cardioversion

Purpose

Our objective was to compare the efficacy of dronedarone and propafenone in maintaining sinus rhythm in patients with atrial fibrillation (AF) after electrical cardioversion.

Methods

In this single-center, open-label, randomized trial, we randomly assigned patients with AF after electrical cardioversion to receive dronedarone 400 mg BID or propafenone 150 mg TID.Follow-up clinical evaluations were conducted at 1, 2, 3, and 6 months of treatment. The primary end point was the time to the first recurrence of AF.

Findings

A total of 98 patients were enrolled (79 men; mean age, 59.2 years; n = 49 per group). The median times to first recurrence of AF were 31 days in the dronedarone group and 32 days in the propafenone group (P = 0.715). The median (interquartile range) ventricular rates at first recurrence of AF were 76.5 (67.3–86.5) beats/min in the dronedarone group and 83.0 (71.0–96.0) beats/min in the propafenone group (P = 0.059).

Implications

Dronedarone and propafenone had similar efficacies in maintaining sinus rhythm in patients with AF after electrical cardioversion. The ventricular rate at the first recurrence of AF was numerically but not statistically significantly lower in the dronedarone group than in the propafenone group. ClinicalTrials.gov identifier: NCT01991119.     

Atrial fibrillation: current therapeutic approaches.

Atrial fibrillation is associated with potentially life-threatening strokes. Anticoagulation with warfarin or aspirin reduces the risk of embolic events in patients with chronic atrial fibrillation and mitral valve stenosis or other underlying heart disease. In patients with acute onset of atrial fibrillation, anticoagulation is not necessary before cardioversion. However, in patients with chronic atrial fibrillation, anticoagulation should be started three weeks before cardioversion and continued for four weeks after the return of normal sinus rhythm. Quinidine remains the agent most commonly used for medical cardioversion in patients who are hemodynamically stable. If a patient is hemodynamically unstable or the atrial fibrillation is not corrected with drug therapy, direct-current electrical cardioversion has a high success rate. Antiarrhythmic (quinidine) therapy is often continued indefinitely to help maintain sinus rhythm.     

CGMP Levels Following ANF Challenge are Markers of Subsequent Successful Reversion of Lone Atrial Fibrillation to Sinus Rhythm

The aim of the present study was to assess whether cGMP release to ANP stimulation can be a biochemical marker of subsequent successful electrical cardioversion of lone atrial fibrillation to sinus rhythm. For this purpose, we studied 13 patients with chronic, lone atrial fibrillation of less than one year's duration who presented to our laboratory for electrical therapy of their arrhythmia. Prior to electrical cardioversion, peripheral venous cGMP levels were assessed at baseline and following an tntravenous challenge of 50 Ug human ANP. Venous blood samples for cGMP assessment were taken a) at baseline, b) 5 and 10 mins after the end of ANP infusion. ANOVA of repeated measures was used for statistical analysis. Eight of the study patients were successfully cardioverted to sinus rhythm, while the remaining 5 were not. Although no difference was noted between the two groups regarding the mean time of arrhythmia duration as well as left atrial and ventricular dimensions, ANP stimulation provoked significantly greater cGMP release in patients whose arrhythmia reverted to sinus rhythm, when compared with that of patients whose arrhythmia persisted (p<0.001). Therefore, cGMP levels following ANP challenge might discriminate between patients with chronic AF who are going to be successfully cardioverted and those who are not. These findings imply that the underlying atrial disease might be different in extent/nature between patients with lone AF responsive to cardioversion and those with resistant arrhythmia.     

预激综合征合并房颤20例急诊治疗临床分析

目的 分析预激综合征合并房颤的急诊治疗效果.方法 回顾性分析20例预激综合征合并房颤病例的电复律、药物复律疗效.结果 盐酸普罗帕酮使用11例次,转复7例,好转4例;利多卡因使用5例次,转复3例;急诊血流动力学障碍3例和药物复律无效2例,经直流电复律一次性转复为窦性心律.结论 普罗帕酮和利多卡因是急诊治疗预激综合征合并房颤常规使用的有效复律药物,血流动力学障碍或药物复律无效者宜采取电复律.     

Unusual Cause of Recurrent Syncope in a Child

A 5‐year‐old boy with an unremarkable past medical and family history presented with recurrent syncope precipitated by physical activity. Electrocardiogram performed in the emergency room after one of his episodes revealed atrial flutter. He had a structurally normal heart. Exercise stress test revealed atrial fibrillation with rapid ventricular response immediately on commencement of running. Atrial fibrillation subsequently organized into atrial flutter with variable ventricular response followed by spontaneous conversion to sinus rhythm. This case highlights the use of exercise stress test in a preschool child to elicit an unusual cause of syncope.     

Electrical cardioversion for persistent atrial fibrillation or atrial flutter in clinical practice: predictors of long-term outcome

Despite the results of Atrial Fibrillation Follow-up Investigation of Rhythm Management and Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation trials, which favour a general shift in atrial fibrillation (AF) therapeutic approach towards control of ventricular rate, a strategy based on restoration of sinus rhythm could still play a role in selected patients at lower risk of AF recurrence. We explored possible predictors of relapses after external electrical cardioversion among patients with persistent AF or atrial flutter (AFL). We analysed the clinical characteristics and conventional echocardiographic parameters of patients with persistent AF/AFL enrolled in an institutional electrical cardioversion programme. Among 242 patients (AF/AFL, 195/47; mean age 62+/-13 years), sinus rhythm was restored in 215 (89%) and maintained in 73 (34%) at a follow-up of 930 days (median). No baseline clinical/echocardiographic variables predicted acute efficacy of cardioversion at logistic regression analysis. However, two variables predicted long-term AF/AFL recurrence among patients with successful cardioversion at multivariate Cox's proportional hazards analysis: (i) duration of arrhythmia>or=1 year (HR, 2.07; 95% CI, 1.29-3.33) and (ii) presence of previous cardioversion (HR, 1.67; 95% CI, 1.17-2.38). These variables also presented high-positive predictive values (72% and 80% respectively). Whereas the high acute efficacy of electrical cardioversion (approximately 90%) does not appear to be predictable, two simple clinical variables could help identify patients at higher risk of long-term AF/AFL recurrence after successful electrical cardioversion. We think there could be a case for initially attempting external electrical cardioversion to patients who have had AF/AFL for <1 year. In such patients, the chance of long-term success appears to be relatively high.     

房颤电复律相关影响因素分析

目的探讨影响房颤电复律成功的因素。方法试验组房颤患者62例，对照组门诊查体窦性心律者60例。将试验组分为复律成功组（A组）和复律失败组（B组），比较试验组、对照组以及试验组各组间左心房内径、左心室舒张末期内径、左心室射血分数、c反应蛋白（CRP）水平的差异。所有患者于入院后或入组后第2天常规空腹抽血，采用免疫比浊法测定高敏感CRP（hs—CRP）。结果①A、B组与对照组相比，左心房内径大于对照组（P〈0．05），CRP高于对照组（P〈0．05）；②B组左心房内径更大（P〈0．05），多合并瓣膜性病变（P〈0．05），房颤持续时间长于复律成功组（P〈0．05），CRP更高（P〈0．05）。经多因素分析，CRP水平OR为2．1（95％CI 1．4～3．2，P=0．004），左房直径OR为1．8（95％CI 1．2～2．2，P=0．006），房颤持续时间OR为2．8（95％CI 1．6～4．0，P=0.007）。结论高敏感CRP、左房直径及房颤持续时间是影响房颤电复律成功的独立预测因素。     

Intravenous amiodarone bolus for treatment of atrial fibrillation in patients with advanced congestive heart failure or cardiogenic shock

BACKGROUND: The clinical course of patients with advanced organic heart disease is often complicated by the occurrence of atrial fibrillation. Slowing the ventricular rate and, if possible, restoration of normal sinus rhythm is crucial but difficult in the state of decreased ventricular function. METHODS: We included 78 consecutive patients with atrial fibrillation and heart rate above 135 beats min(-1) in an observational, uncontrolled study in the coronary care unit of a tertiary care center. Thirty-nine patients suffered from advanced congestive heart failure, 26 patients had pulmonary edema, and 13 patients were in cardiogenic shock. All patients were treated with 450 mg amiodarone given as a single intravenous bolus through a peripheral venous access without further infusion. Ventricular heart rate and cardiac rhythm were measured within 30 minutes after drug administration. Cardiac rhythm was monitored for 24 hours. The site of venous access was examined 30 minutes after drug administration and every 6 hours until the needle was removed after a maximum of 48 hours. RESULTS: Twenty-five patients (32%) converted to normal sinus rhythm within 30 minutes. Another 15 (19%) reverted into sinus rhythm during the following 24 hours. Within 30 minutes after amiodarone administration, ventricular heart rate decreased significantly from 152 +/- 12 to 88 +/- 17 (p < 0.0001) beats min(-1) in patients who converted to sinus rhythm and from 157 +/- 14 to 98 +/- 16 beats min(-1) in patients who did not. The degree of reduction in heart rate was similar among patients presenting with exacerbated congestive heart failure, pulmonary edema, or cardiogenic shock. Systolic blood pressure decreased in two patients, from 115 to 80 mmHg and from 130 to 100 mmHg, but was reversible after 10 and 90 minutes respectively without specific intervention. No proarrhythmia or clinical relevant bradycardia was observed, and no inflammation detected at the site of venous access. CONCLUSIONS: Amiodarone, given as a single intravenous bolus through a peripheral vein rapidly reduced ventricular rate and was well tolerated in patients with atrial fibrillation, even in the presence of congestive heart failure and cardiogenic shock.     

Acute management of atrial fibrillation: Part I. Rate and rhythm control

Atrial fibrillation is the arrhythmia most commonly encountered in family practice. Serious complications can include congestive heart failure, myocardial infarction, and thromboembolism. Initial treatment is directed at controlling the ventricular rate, most often with a calcium channel blocker, a beta blocker, or digoxin. Medical or electrical cardioversion to restore sinus rhythm is the next step in patients who remain in atrial fibrillation. Heparin should be administered to hospitalized patients undergoing medical or electrical cardioversion. Anticoagulation with warfarin should be used for three weeks before elective cardioversion and continued for four weeks after cardioversion. The recommendations provided in this two-part article are consistent with guidelines published by the American Heart Association and the Agency for Healthcare Research and Quality.     

Atrial Fibrillation in the Intact Unanesthetized Dog: Hemodynamic Effects during Rest, Exercise, and Beta-Adrenergic Blockade

The effects of atrial fibrillation were studied in 12 healthy unanesthetized dogs, 9 to 49 days after surgical implantation of transducers for measurement of aortic flow and left ventricular diameter. Atrial fibrillation and pacing at comparable ventricular rates were induced by electrical stimulation of the right atrial appendage, and their effects were compared with observations made during sinus rhythm in each dog. At rest, cardiac output and mean arterial pressure were not significantly different during sinus rhythm, atrial fibrillation, and atrial pacing. After beta-adrenergic blockade with propranolol, cardiac output during fibrillation was significantly less than that during pacing at comparable ventricular rates. Arterial pressure was not detectably altered. During moderately severe treadmill exercise by six dogs, cardiac output fell significantly upon induction of fibrillation. After pentobarbital anesthesia fibrillation caused decrements in cardiac output and arterial pressure that were accentuated after thoracotomy.These observations suggest the existence of compensatory mechanisms that maintain an essentially constant cardiac output when atrial fibrillation is induced in healthy unanesthetized dogs at rest. These mechanisms appear to fail during moderately severe exercise, beta-adrenergic blockade, and pentobarbital anesthesia.