Case Reports: Radiofrequency Catheter Ablation of Typical Atrial Flutter and the Atrioventricular Junction via the Superior Vena Caval Approach in a Patient with a Congenital Absence of an Inferior Vena Cava

The absence of an inferior vena cava is a rare congenital condition often without clinical significance. Alternative venous approaches are often needed to treat these patients. We report a case of successful ablation of both isthmus dependent flutter and the AV junction using the superior vena cava in a patient with an inferior vena cava anomaly.     

Site of Accessory Pathway Block After Radiofrequency Catheter Ablation in Patients with the Wolff-Parkinson-White Syndrome

Site of Accessory Pathway Block. Introduction: Recent studies have demonstrated that the most common site of accessory pathway conduction block following the introduction of a premature atrial stimulus during atrial pacing is between the accessory pathway potential and the ventricular electrogram. consistent with block at the ventricular insertion of the accessory pathway. However, no prior study has evaluated the site of conduction block during radiofrequency catheter ablation procedures. Therefore, the objective of this study was to determine the site of conduction block after catheter ablation of accessory pathways by analyzing and comparing the local electrograms recorded before and after radiofrequency energy delivery at successful ablation sites. Methods and Results: The electrograms evaluated in this study were obtained from 85 consecutive patients who underwent successful radiofrequency catheter ablation of a manifest accessory pathway. The 50 left free-wall accessory pathways were ablated using a ventricular approach and the 35 right free-wall or posteroseptal accessory pathways were ablated using an atrial approach. The characteristics of local electrograms recorded immediately before and immediately after successful ablation of the accessory pathway were determined in each patient. The site of accessory pathway block was determined by comparing the amplitude, timing, and morphology of the local eleclrograms at successful sites of radiofrequency catheter ablation before and after delivery of radiofrequency energy. A putative accessory pathway potential was present at the successful target site in 74 of the 85 patients (87%). Conduction block occurred between the atrial electrogram and the accessory pathway potential in 66 patients (78%) and between the accessory pathway potential and the ventricular electrogram in eight patients (9%). The site of block could not be determined in 11 patients (13%) in whom an accessory pathway potential was absent. Conduction block occurred most frequently between the atrial electrogram and the accessory pathway potential regardless of accessory pathway location. No electrogram parameter or accessory pathway characteristic was predictive of the site of conduction block. Conclusion: The results of this study demonstrate that conduction block occurs most frequently between the local atrial electrogram and the accessory pathway potential during radiofrequency catheter ablation of accessory pathways. This is true regardless of whether the accessory pathway is ablated from the atrial or ventricular aspect of the mitral or tricuspid annulus.     

Inferior Vena Cava Syndrome Due to Echinococcus multilocularis

Alveolar echinococcosis is an invasive, tumor-like zoonosis, accidentally transmitted to humans. We present a case of recurrent inferior vena cava (IVC) syndrome due to alveolar echinococcosis and strongly suspected on transthoracic echocardiographic examination.     

3-Dimensional Mapping and Radiofrequency Ablation of Atrial Flutter in a Patient with Interrupted Inferior Vena Cava

The presence of isolated interrupted inferior vena cava (IVC) is very rare. Though the occurrence of typical atrial flutter in this setting has recently been described, the use of 3-dimensional activation mapping to aid the management of such patients has not yet been described. We report the successful ablation of this arrhythmia in a 63-year-old woman using the superior route through the internal jugular vein with the help of a mapping system.     

上、下腔静脉阻塞综合征的诊断与治疗（病例报告及文献复习）

上、下腔静脉阻塞综合征很罕见，其诊断及治疗很困难。我们报告的病例，经皮球囊成形术治疗成功。治疗前后下腔静脉跨狭窄部压力阶差由５．３３ｋＰａ（４０ｍｍＨｇ）下降至０．５３ｋＰａ（４ｍｍＨｇ），１周后临床症状明显改善。根据我们的体会及文献复习，正确诊断上、下腔静脉综合征对治疗方式的选择极为重要。经皮血管成形术及血管内支架对上、下腔静脉综合征是一种安全、有效的治疗手段，仅在无血管内支架适应症时，才考虑外科手术。     

经上腔静脉途径射频消融右侧前上和前间隔房室旁道

报道经上腔静脉途径射频消融右侧前上和前间隔房室旁道的体会。 13例右侧前上或前间隔单一房室旁道患者 ,常规下腔静脉途径消融未能成功 ,失败原因包括 :消融电极与心肌接触不良或难以固定于三尖瓣环上。改经上腔静脉途径成功消融阻断所有房室旁道。平均放电 1.8± 0 .7次 ,输出功率 33± 4W ,消融靶点电图振幅明显高于下腔静脉途径 (1.4± 0 .3mVvs 0 .6± 0 .4mV ,P <0 .0 5 )。术后随访 17± 9个月 ,无 1例复发。作者认为对经下腔静脉途径消融失败的右侧前上和前间隔房室旁道采用上腔静脉途径消融可获得成功。     

导管射频消融治疗老年预激综合征

本文报道２３例老年预激综合征（ＷＰＷ）患者导管射频消融（ＲＦＣＡ）阻断旁道（ＡＰ）的临床疗效，采用单极和双极同步记录定位ＡＰ和确定消融靶点，成功阻断所有患者的ＡＰ传导，随访１～２１（１１±６．４）个月无复发。认为ＲＦＣＡ是老年ＷＰＷ患者安全有效的治疗方法。     

合并永存左上腔静脉畸形的快速心律失常的经导管射频消融治疗

阐明合并永存左上腔静脉畸形 (PLSVC)的快速心律失常经导管射频消融治疗的方法学和特殊性。自 1 997年 6月至 2 0 0 1年 6月共对 1 3例合并PLSVC的快速心律失常进行了经导管射频消融治疗 ,其中房室结折返性心动过速 (AVNRT) 7例、左侧旁道 3例 ;右侧旁道、房性心动过速 (简称房速 )和室性心动过速 (简称室速 )各 1例。冠状静脉窦标测电极均常规经左锁骨下静脉放置 ,其中 9例进行了冠状静脉窦造影 ,3例左侧旁道中的 2例采用了经主动脉逆行法消融、1例采用穿间隔法在二尖瓣环心房侧消融 ,7例AVNRT中的 5例采用Swartz鞘管支持消融导管实现稳定贴靠。消融成功率 1 0 0 % ,无并发症。结论 :多种快速心律失常可合并PLSVC ,经导管射频消融仍有较高的成功率 ,但是在冠状静脉窦电极放置、冠状静脉窦标测和AVNRT消融的方法学上有一定特殊性。     

Multiple and Recurrent Systemic Thrombotic Events Associated with Congenital Anomaly of Inferior Vena Cava

We describe a case of a 67-year-old woman with a history of cerebral infarction and pulmonary embolism that presented with chest pain. Subsequent evaluation resulted in a diagnosis of acute myocardial infarction and occult DVT, and imaging revealed a rare congenital absence of the infra-renal portion of the inferior vena cava, with lower extremity venous drainage diverted via an ascending lumbar vein. Associations between congenital absence of the inferior vena cava and thrombosis are discussed.     

Giant Hepatic Cyst: A Possible Cause of Inferior Vena Cava Syndrome

An 80-year-old man was transferred to our institution with lower limb edema and worsening dyspnea following the administration of diuretic medication. Transthoracic echocardiography and computed tomography revealed a giant hepatic cyst (176×190 mm) compressing his right atrium and inferior vena cava (IVC). Laparoscopic cyst deroofing combined with omental packing and subsequent tube drainage immediately alleviated all his symptoms. The procedure was uneventful, and he was discharged without any complications on postoperative day 9; he had no recurrent symptoms or hepatic cysts at the postoperative 2-month follow-up. Therefore, a giant hepatic cyst can cause IVC syndrome, and laparoscopic deroofing is a beneficial approach for the treatment of accessible cysts.     

A Focal Source of Atrial Fibrillation in the Superior Vena Cava: Isolation and Elimination by Radiofrequency Ablation with the Guide of Basket Catheter Mapping

Although it has been reported that pulmonary veins sometimes act as a focal driver of atrial fibrillation (AF), little has been reported concerning the contribution of the superior vena cava (SVC) to the maintenance of AF. Here we report a patient with sustained AF due to focal discharges inside the SVC after pulmonary vein isolation procedure. Stepwise radiofrequency current applications with the guide of multielectrode basket catheter mapping first disconnected the arrhythmogenic SVC from the right atrium and then eliminated the tachycardia.     

Development and Validation of an ECG Algorithm for Identifying Accessory Pathway Ablation Site in Wolff-Parkinson-White Syndrome

ECG Localization of Accessory AV Pathways. Introduction : Delta wave morphology correlates with the site of ventricular insertion of accessory AV pathways. Because lesions due to radiofrequency (RF) current are small and well defined, it may allow precise localization of accessory pathways. The purpose of this study was to use RF catheter ablation to develop an ECG algorithm to predict accessory pathway location.
Methods and Results : An algorithm was developed by correlating a resting 12-lead ECG with the successful RF ablation site in 135 consecutive patients with a single, anterogradely conducting accessory pathway (Retrospective phase). This algorithm was subsequently tested prospectively in 121 consecutive patients (Prospective phase). The ECG findings included the initial 20 msec of the delta wave in leads I, II, aVF, and V₁ [classified as positive (+), negative (-), or isoelectric (±)] and the ratio of R and S wave amplitudes in leads III and V₁ (classified as R ≥ S or R < S). When tested prospectively, the ECG algorithm accurately localized the accessory pathway to 1 of 10 sites around the tricuspid and mitral annuli or at subepicardial locations within the venous system of the heart. Overall sensitivity was 90% and specificity was 99%. The algorithm was particularly useful in correctly localizing anteroseptal (sensitivity 75%, specificity 99%), and mid-septal (sensitivity 100%, specificity 98%) accessory pathways as well as pathways requiring ablation from within ventricular venous branches or anomalies of the coronary sinus (sensitivity 100%, specificity 100%).
Conclusion : A simple ECG algorithm identifies accessory pathway ablation site in Wolff-Parkinson-White syndrome. A truly negative delta wave in lead II predicts ablation within the coronary venous system.     

Stent Placement for Malignant Inferior Vena Cava Syndrome in a Patient with Recurrent Colon Cancer

A 70-year-old man was admitted to our hospital with gait disturbance due to marked edema of the lower limbs for more than 6 months. He had been receiving systemic chemotherapy over two years for multiple recurrence after sigmoid colon cancer resection. Contrast-enhanced computed tomography demonstrated severe inferior vena cava (IVC) stenosis due to compression by lymph node metastases, i.e. IVC syndrome. As increased doses of diuretic agents failed to improve the edema, IVC stent placement was performed. This led to significant improvement of the edema and complete gait normalization. This case demonstrates the efficacy of IVC stent placement for IVC syndrome.     

Echocardiography of the Inferior Vena Cava, Superior Vena Cava, and Coronary Sinus in Right Heart Failure

Echocardiographic evaluation of the three major systemic venous channels that drain directly into the right atrium has hitherto received less attention than it deserves. Attention had been paid initially to inferior vena cava dilatation and lack of collapsibility (plethora) as signs of systemic venous congestion. Superior vena cava imaging has not been part of routine echographic evaluation; however, our recent observations on superior vena cava appearance by the right supraclavicular approach provide evidence that dilatation of superior vena cava correlates with that of inferior vena cava as a marker for venous congestion. The coronary sinus caliber, which has been virtually ignored, may also provide echographic signs of systemic congestion, namely, dilatation and lack of normal narrowing during atrial contraction.     

Reentrant Atrial Tachycardia Originating from the Superior Vena Cava

A 52-years old man with a previous pericardiotomy for idiopathic constrictive pericarditis underwent catheter ablation for drug-resistant atrial tachycardia (AT). The mechanism of the AT was considered as reentry because of resetting response and the entrainment phenomenon during AT. We introduced a 64-electrode basket catheter into the superior vena cava (SVC) during AT to obtain precise mapping. A fractionated potential preceding local atrial electrogram was recorded in the SVC. The earliest activation site of the potential was located at the anterior aspect of the SVC, 2 cm above the SVC-right atrium junction determined fluoroscopically. The fractionated potential at this site preceded the onset of the P wave by 115 msec. Radiofrequency catheter ablation at this site eliminated the tachycardia. At 6 months follow-up, the patient is free of AT. Reentrant AT involving the SVC is a candidate of RF ablation. Multielectrode basket catheter is useful for a detailed mapping of the SVC.