射频消融治疗儿童室上性心动过速的护理

目的总结50例室上性心动过速的患儿经皮射频消融术后的护理经验。方法术前做好家长及年长儿的心理支持工作,详细介绍射频消融手术及与疾病有关的治疗知识和手术方式,以解除家长忧虑,取得支持和配合。术前评估并记录患儿的情况,完善各项术前检查及术前常规准备工作。术后严密观察病情变化,进行全面全程的护理。护理配合及加强生命体征与穿刺部位的观察,防止术后并发症的发生。结果 50例均射频消融成功,5例术后出现并发症,其中2例Ⅰ度房室传导阻滞,2例穿刺口出血及皮下血肿,1例尿潴溜,经过针对性的治疗和护理,所有患儿术后恢复良好,全部治愈出院,患儿生长发育良好,生存质量显著提高。结论做好经皮射频消融术患儿术前、术后的护理工作是其手术治疗成功的重要保障。     

Refractory paroxysmal supraventricular tachycardia. Treatment with patient controlled permanent radio frequency atrial pacemaker

A patient with incapacitating recurrent supraventricular tachycardia, refractory to medical management, was evaluated for possible surgical intervention. Several types of competitive artificial pacemakers were considered, as was surgical section of the His bundle plus conventional pacing. The patient was treated with a competitive, radio-frequency-coupled atrial pacemaker, which she herself operates to break her supraventricular tachycardias. The device has operated successfully on numerous occasions for over 15 months. Several other aspects of this patient's arrhythmias were discussed.     

Paroxysmal supraventricular tachycardia as a major clinical presentation of the primary coronary sinus lymphoma: A case report

Rationale:Primary cardiac lymphoma is a rare tumor, especially a tumor located in coronary sinus (CS). The most common symptom of cardiac tumors is dyspnea, accounting for 64%, followed by chest pain, accounting for 26%. However, the cases with paroxysmal supraventricular tachycardia (SVT) as a major clinical presentation are extremely rare.Patient concerns:We report a 55-year-old female patient with primary CS lymphoma and paroxysmal SVT.Diagnoses:After the surgical resection, pathology revealed the evidence of diffuse large B-cell lymphoma.Interventions:The patient underwent chemotherapy after CS tumor resection.Outcomes:The patient was disease-free during the 6-month follow-up.Lessons:CS enlargement may be the cause of SVT. Echocardiography should focus on the CS section to arrive at the right diagnosis.     

The effects of carotid sinus pressure in re-entrant paroxysmal supraventricular tachycardia

The effect of carotid sinus pressure (CSP) on paroxysmal atrial tachycardia (PAT) was studied in eighteen patients. In twelve of the thirteen patients in whom CSP terminated the arrhythmia, gradual slowing occurred prior to conversion to sinus rhythm. With the use of His-bundle electrograms it could be demonstrated that this slowing was due to prolongation of conduction through the A-V nodal re-entrant pathway (increased A-H interval). Thus, slowing of a supraventricular tachycardia in response to CSP does not rule out the possibility that the arrhythmia is PAT. Further vagal maneuvers may, therefore, be indicated in the diagnosis and management of such an arrhythmia.     

Electrophysiology and long-term efficacy of pentisomide in patients with supraventricular tachycardia.

The electrophysiologic effects of pentisomide were investigated after intravenous (5 mg/kg) and oral (900-1200 mg three times a day) application in 9 patients with drug refractory atrioventricular nodal tachycardia and 6 patients with orthodromic atrioventricular re-entrant tachycardia. Pentisomide did not change sinus cycle length, effective refractory period of the right ventricle and the atrioventricular node. AH, HV interval, effective refractory period of the right atrium, QRS duration and QTc duration were (p less than or equal to 0.01) increased. Tachycardia cycle length was only increased after intravenous application of pentisomide, antegrade effective refractory periods of the accessory pathways and shortest fully pre-excited R-R intervals during atrial fibrillation were increased after the oral treatment phase (p = 0.054). Intravenous pentisomide prevented tachycardia in 6/9 patients with atrioventricular nodal tachycardia and in 2/6 patients with atrioventricular re-entrant tachycardia. If intravenous pentisomide did not prevent induction of the tachycardia, oral pentisomide was not effective either. During long-term follow-up 2/7 patients with atrioventricular nodal tachycardia and 1/4 patient with atrioventricular re-entrant tachycardia had a recurrence. Long-term treatment with pentisomide had to be discontinued because of possible side effects in 2 patients. It is concluded, that the electrophysiological effects of pentisomide are similar to those of flecainide and propafenone.     

冠状窦电极错误引导射频消融3例分析

本院曾在消融左前侧壁旁道2例和右侧希氏束旁旁道1例时因冠状窦电极错误引导而在左后间隔反复消融失败,最后在相应部位放电消融成功。报道如下。1临床资料3例中男1例,女2例,年龄42~48岁,阵发性室上性心动过速病程分别为1、5、10年,ECG示隐性旁道2例,显性旁道1例。3例均无其他器     

Paediatric use of flecainide in supraventricular tachycardia: clinical efficacy and pharmacokinetics.

Twenty three children with recurrent supraventricular tachycardia were treated with flecainide. Twenty one of these received intravenous treatment during an attack (2 mg/kg over 10 minutes). The tachycardia was terminated in 17. After an intravenous bolus of flecainide, blood samples were drawn at regular intervals for analysis of flecainide concentration over 48 hours. Pharmacokinetic variables were calculated--median terminal half life 7.5 hours, median volume of distribution 6.2 l/kg, and median plasma clearance 7.2 ml/min/kg. There was a significant correlation between half life and age. Twenty of the children received long term treatment with an oral preparation of flecainide to prevent further attacks. Twelve had no further attacks and 16 were considered to have good control. Two children suffered potentially serious arrhythmogenic effects soon after the start of oral treatment and flecainide had to be stopped. During oral treatment regular blood samples were drawn and plasma concentrations were analysed to assess the therapeutic range. This did not differ substantially from that proposed in adults (400-800 micrograms/l). Eight children were electively withdrawn from oral flecainide to see whether they really needed it. Blood samples for measurement of flecainide concentration were drawn after their last oral dose. Pharmacokinetic variables were calculated: time to maximum concentration 2 hours, median terminal half life 7.9 hours. For the combined data from patients receiving intravenous and oral treatment there was a significant correlation between elimination half life and age. An intravenous dose of 2 mg/kg over at least 10 minutes and an initial oral dose of 6 mg/kg/day in three divided doses is recommended. Treatment should be started in hospital so that children in whom the drug may be arrhythmogenic can be identified and plasma concentrations measured to identify patients in whom lack of efficacy is caused by underdosage.     

The radio frequency catheter ablation of inter-fascicular reentrant tachycardia: new insights into the electrophysiological and anatomical characteristics

Introduction

Macro-reentrant ventricular tachycardias (VT) utilizing the bundle branches and Purkinje fibers have been reported as verapamil sensitive VT (idiopathic left VT), bundle branch reentrant VT (BBRT) and inter-fascicular reentrant tachycardia (inter-fascicular VT). However, diagnostic confusion exists with these VTs due to the difficulty in differentiating between them with conventional electrophysiological (EP) studies. The aim of this study was to clarify the EP and anatomical entity of inter-fascicular VT, and provide successful methods for the radio frequency catheter ablation (RFCA) of inter-fascicular VT.

Methods and results

A total of nine patients were included in this study. All patients were diagnosed with idiopathic left VT in the first session, and underwent a second session after a failed RFCA. Detailed EP studies guided by a three-dimensional (3D) mapping system were performed to further analyze the VTs. All VTs were finally diagnosed as inter-fascicular VT. They were successfully cured with RFCA targeting the left anterior or posterior fascicle, which was regarded as a requisite part of the reentrant circuit of the inter-fascicular VT, using 3D and fluoroscopic images combined with a detailed EP investigation instead of the conventional RFCA method targeting Purkinje potentials for the RFCA of idiopathic left VT.

Conclusions

Inter-fascicular VT could be misdiagnosed as idiopathic left VT due to the limitations of the conventional EP study. Failed RFCA in presumptive idiopathic left VT cases has to be carefully investigated by further analysis, and a tailored RFCA strategy targeting the requisite portions of the left fascicles in the inter-fascicular VT reentrant circuit will be required for the successful elimination of the inter-fascicular VT.     

Adenosine and the treatment of supraventricular tachycardia.

Adenosine has recently become widely available for the treatment of paroxysmal supraventricular tachycardia. In order to evaluate its role in the management of arrhythmias, we have reviewed the literature on the cellular mechanisms, metabolism, potential for adverse effects, and clinical experience of the efficacy and safety of intravenous adenosine. Adenosine produces transient atrioventricular nodal block when injected as an intravenous bolus. This is of therapeutic value in the conversion to sinus rhythm of the majority of paroxysmal supraventricular tachycardias, which involve the atrioventricular node in a re-entrant circuit. The mean success rate was 93% from over 600 reported episodes. Compared with other antiarrhythmic agents, adenosine is remarkable for its rapid metabolism and brevity of action, with a half-life of a few seconds. It commonly produces subjective symptoms, particularly chest discomfort, dyspnea, and flushing, which are of short duration only. No serious adverse effect has been reported. Arrhythmias may recur within minutes in a minority of patients. Comparative studies have shown that adenosine is as effective as verapamil in the treatment of supraventricular tachycardia, and has less potential for adverse effects. Patients with supraventricular tachycardia should initially be treated using vagotonic physical maneuvers. Immediate electrical cardioversion is indicated if the arrhythmia is associated with hemodynamic collapse. Adenosine is the preferred drug in those patients in whom verapamil has failed or may cause adverse effects, such as those with heart failure or wide-complex tachycardia. The safety profile of adenosine suggests that it should be the drug of first choice for the treatment of supraventricular tachycardia, but only limited comparative data to support this view are available at present.     

Radiofrequency catheter ablation within the coronary sinus eliminates a macro-reentrant atrial tachycardia: Importance of mapping in the coronary sinus

We describe a patient who underwent radiofrequency (RF) catheter ablation of symptomatic atrial fibrillation. After left atrial (LA) catheter ablation and pulmonary vein isolation, a macro-reentrant atrial tachycardia (AT) with a critical isthmus at the mitral isthmus was induced by incremental atrial pacing from the coronary sinus. Extensive RF energy applications from endocardial sites using ablation catheters with 4 mm- and 8 mm- tips resulted in no discrete potentials being recorded from the endocardial sites of the isthmus, but the tachycardia could not be terminated. However, discrete potentials were recorded within the CS, and epicardial RF energy applications from the CS eliminated the tachycardia. Thus, mapping in the CS is useful for detecting residual conduction at epicardial sites along the mitral isthmus. RF catheter ablation within the CS should be considered when no distinct electrograms are recorded after extensive ablation from the endocardial sites and when distinct electrograms are recorded within the CS.     

Pacing techniques in the management of supraventricular tachycardias. Part 1. The use of high frequency stimulation (HFS) in the management of paroxysmal supraventricular tachycardia.

Using techniques for programmed electrical stimulation of the heart, seven patients with paroxysmal supraventricular tachycardia have been studied and shown to have a reciprocal mechanism as the most likely basis for the tachycardia. In four patients it was found that the tachycardia could be terminated by single right atrial premature beats and in three patients two right atrial premature beats were required. A variable zone for tachycardia termination was found when single or double stimuli were used and so a system for introducing high frequency stimuli at 100 or 1000 stimuli/sec for a given duration is described. Using this system a wider range of the cardiac cycle could be covered, thereby increasing the likelihood of producing correctly timed premature beats. The results of using this system are presented and its practical usage discussed.     

CARTO电解剖标测系统指导下射频消融室上速的临床研究

目的 评价CARTO电解剖标测系统对射频消融室上速的指导作用.方法 118例室上速患者分为CARTO组（69例）和常规组（49例）,比较两组标测与消融过程的X线曝光时间、手术时间、放电次数、放电时间、成功率及并发症发生情况.结果 118例均完成射频治疗,2例常规射频失败患者转为CARTO指导下成功完成治疗,两组成功率差异无统计学意义.CARTO组与常规组手术时间无差异[（118±36）min比（119±52）min,P＞0.05],但X线曝光时间明显缩短[（9±3）min比（17±6）min,P＜0.05],放电次数显著减少[（4±2）次比（9±3）次,P＜0.05],放电时间显著缩短[（196±73）s比（402±84）s,P＜0.05].两组患者均未发生并发症.结论 CARTO电解剖标测系统指导下射频消融室上速安全有效,可明显减少放电次数和时间,缩短X线曝光时间.     

Atypical ventricular tachycardia and syncope with left coronary artery origin from the right coronary sinus.

An 18 year old man suddenly lost consciousness while jogging. The ambulance crew documented atypical ventricular tachycardia and an episode of ventricular fibrillation. Coronary angiography showed the left main coronary artery arising from the right sinus of Valsalva. Subsequent surgical coronary revascularisation was successful.     

Focal atrial tachycardia originating from the musculature of the coronary sinus

Focal atrial tachycardias originate predominantly from the right atrium along the crista terminalis and less commonly from the left atrium. Successful catheter ablation usually can be performed via an endocardial approach. We report the case of a 34-year-old patient in whom a focal atrial tachycardia was successfully ablated 4 cm within the coronary sinus after extensive mapping of the left atrial endocardium and coronary sinus using the three-dimensional CARTO mapping system. Rarely, atrial tachycardia can originate from the coronary sinus musculature and require ablation inside the coronary sinus.     

The efficacy of intermittent coronary sinus occlusion in the absence of coronary artery collaterals

The purpose of this study was to evaluate the efficacy of time-controlled intermittent coronary sinus occlusion (ICSO) in preserving regional and global mechanical function during acute ischemia in an animal preparation without significant arterial collateral vessels. Seventeen (eight control, nine ICSO) swine heart preparations undergoing extracorporeal coronary perfusion in situ were subjected to ligation of the left anterior descending coronary artery (LAD) distal to the first major diagonal branch. Data were obtained before and immediately after coronary artery ligation in both animal groups. ICSO, 15 sec of occlusion alternating with 5 sec of release, was then begun in the treatment group. Additional data were obtained in both control and treatment groups at 15 min intervals for 1 hr starting immediately after coronary artery ligation. Global left ventricular function was assessed by shifts in left ventricular end-diastolic pressure and left ventricular dP/dt with left ventricular systolic pressure maintained at about 100 mm Hg. Regional mechanical function was evaluated with transmurally placed ultrasonic crystals. Pressure was also measured directly in the coronary sinus and LAD distal to the ligature. Regional myocardial blood flow was measured in the ischemic bed using 9 micron diameter radiolabeled microspheres injected before, immediately after, and 60 min after coronary artery ligation in both treated and control animals. LAD mean pressure measured distal to the ligation (less than 16 mm Hg) and ischemic bed myocardial blood flow (less than 0.01 ml/g/min) confirmed the absence of significant arterial-arterial collaterals in this preparation. Mean coronary sinus pressure increased significantly (p less than .001) in treated animals during ICSO (e.g., 11.2 +/- 1.6 to 66.2 +/- 10.0 mm Hg at 15 min after coronary ligation). Mean LAD pressure distal to the coronary ligature also increased during ICSO (14.2 +/- 1.2 to 26.8 +/- 1.6 mm Hg), with a similar but delayed rate of pressure rise. No significant differences in left ventricular end-diastolic pressure or left ventricular dP/dt were noted between control or treated animals after coronary ligation. Ischemic bed systolic wall thickening, present before coronary ligation, was not present after occlusion and was not improved during intermittent coronary sinus occlusion in the treatment group. We conclude that in an animal preparation without significant collateral circulation, intermittent coronary sinus occlusion is incapable of restoring regional or global left ventricular mechanical function during conditions of acute ischemia.