Electro-anatomical mapping of the left atrium before and after cryothermal balloon isolation of the pulmonary veins

Introduction  The 28 mm cryoballoon catheter is a device used for pulmonary vein isolation (PVI). The aim of this study was to evaluate the extent of the ablation in the antral regions of the left atrium. Methods and Results  Eighteen patients with drug refractory, symptomatic, paroxysmal AF were enrolled. A 3D electroanatomic reconstruction of the left atrium was made before and after successful PVI with the 28 mm cryoballoon. Markers were placed at the ostium. Sixteen patients were mapped. Fourteen patients had 4 veins each, and 2 patients had a common ostium of the left sided veins. All separate ostia were isolated in the antral region. The two common ostia showed ostial isolation. There was a significant difference in vein size between the common (29 and 31 mm) and the separate ostia (19 ± 4 mm) (p < 0.01). The performance of an additional segmental ablation if balloon PVI did not eliminate all electrical activity, did not influence the extent of the ablation. The earliest left atrial activation during sinus rhythm was located in the superior septal region before ablation in all patients. After ablation, two patients showed a substantial downward shift towards the middle and inferior septal region respectively (NS). Four patients demonstrated a slight downward shift of the first activation. Conclusions  In cryoballoon PVI, the majority of the veins undergo antral isolation. Veins with a diameter larger than the balloon, are isolated ostially. In individual cases, the left atrial activation sequence appears to be altered after ablation.     

Psychosocial status predicts mortality in patients with life-threatening ventricular arrhythmias

BACKGROUND: Quality-of-life (QoL) instruments evaluate various aspects of physical, mental, and emotional health, but how these psychosocial characteristics impact long-term outcome after cardiac arrest and ventricular tachycardia (VT) is unknown. OBJECTIVE: The purpose of this study was to evaluate the relationship of baseline QoL scores with long-term survival of patients enrolled in the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial. METHODS: Formal QoL measures included SF-36 mental and physical components, Patient Concerns Checklist, and Ferrans and Powers Quality-of-Life Index-Cardiac Version. Multivariate Cox regression was used to assess the association of survival and these measures, adjusting for index arrhythmia type, gender, race, age, ejection fraction, history of congestive heart failure, antiarrhythmic therapy, and beta-blocker use. RESULTS: During mean follow-up of 546 +/- 356 days, 129 deaths occurred among 740 patients. Higher baseline SF-36 physical summary scores (P <.001), higher baseline QoL Index summary scores (P = .015), and lower baseline Patient Concerns Checklist summary scores (P = .047) were associated with longer survival, even after adjustment for clinical variables. When QoL measures were examined simultaneously, only the SF-36 physical summary score remained significant (P = .002). CONCLUSION: During recovery after sustained VT or cardiac arrest, formal baseline QoL assessment provides important prognostic information independent of traditional clinical data.     

An algorithm to discriminate supraventricular from ventricular tachycardia in automated external defibrillators valid for adult and paediatric patients

AimTo adapt adult automated external defibrillator (AED) arrhythmia analysis algorithms for paediatric use through the addition of an algorithm to accurately discriminate supraventricular tachycardia (SVT) from ventricular tachycardia (VT) that is valid for both adult and paediatric patients.Materials and methodsAn adult database of 89 SVT and 191 VT records from 280 patients and a paediatric database of 322 SVT and 66 VT records from 260 paediatric and adolescent patients were used. The databases were split into two equal groups with respect to numbers of records and patients for development and testing. The discrimination method consisted of a logistic regression classifier based on two features obtained from the spectral analysis of 3.2 s ECG segments of the records.ResultsThe algorithm had an overall accuracy of 98.2% (656/668, one-sided confidence interval (CI) 97.1%). In terms of SVT/VT discrimination, the SVT specificity was 98.1% (403/411, one-sided CI 96.5%), and the VT sensitivity was 98.4% (253/257, one-sided CI 96.5%). In terms of shock/no-shock decisions, the specificity for SVT increased to 99.0% (407/411, one-sided CI 97.8%), 98.8% (318/322, one-sided CI 97.2%) for the paediatric and 100% (89/89, one-sided CI 96.5%) for the adult patients.ConclusionA new algorithm to discriminate SVT/VT was designed that showed high SVT specificity and VT sensitivity in both adults and children. This algorithm could be incorporated into current AEDs with arrhythmia analysis algorithms designed for adult patients to accurately diagnose fast-rate paediatric SVT.     

全国儿童心内电生理检查及射频消融多中心资料分析

目的 探讨射频导管消融（RFCA）治疗小儿不同类型快速心律失常的成功率、复发率、安全性及对消融效果的影响因素.方法 收集国内8家医院小儿心内科1994年4月26日至2012年9月30日接受心内电生理检查及RFCA的快速型心律失常患儿3 058例,年龄0.33-16.50（7.6＆#177;3.8）岁.分析不同心动过速类型RFCA方法及效果、心动过速复发及并发症的发生情况,比较不同年龄组的RF-CA效果及复发情况.结果 接受心内电生理检查患儿共计3 058例,包括室上性心动过速（SVT）2 561例（83.7％）及室性心动过速/室性早搏（VT/PVC） 497例（16.3％）.SVT患儿经心内电生理检查证实房室折返性心动过速（AVRT）1 630例（63.6％）,房室结折返性心动过速（AVNRT） 750例（29.3％）,心房扑动/切口折返性房性心动过速（AFL/IRAT） 40例（1.6％）,局灶性房性心动过速（FAT）141例（5.5％）.2 958例患儿接受RFCA,首次消融成功率96.8％,复发率4.8％,其中经电生理检查证实为原旁路/消融点复发3.6％,新的旁路/起源部位/心律失常类型1.2％.1 580例AVRT患者接受RFCA,首次消融成功率97.7％,复发率4.0％,其中原旁路复发2.4％,新的旁路/心动过速类型复发1.6％.右前/中间隔旁路首次消融成功率较低（88.2％）,原旁路复发率较高（19.4％）.740例AVNRT患者接受RFCA,首次消融成功率99.3％,复发率4.4％,其中原消融类型复发4.0％.40例AFL/IRAT患者接受RFCA,首次消融成功率97.5％,随访无复发.131例FAT患者接受消融,首次消融成功率84.7％.其中采用二维标测成功率81.0％;采用三维标测指导冷盐水灌注导管消融成功率91.5％.FAT患者消融复发率12.6％,其中原消融点复发率11.7％.467例VT/PVC接受RFCA,首次消融成功率93.1％,其中采用二维标测成功率92.1％;采用三维标测指导冷盐水灌注导管消融成功率100％.起源于不同部位VT/PVC首次消融成功率以左心室中后间隔起源为最高,达96.9％;最低为多源性VT/PVC,为66.7％.VT/PVC消融复发率6.4％,其中原消融点复发5.5％.不同年龄组首次消融成功率比较差异无统计学意义.RFCA并发症17例（0.55％）,包括完全性房室阻滞4例（0.13％）,二度房室阻滞6例（0.20％）,血气胸1例（0.03％）,麻醉意外1例（0.03％）及血管并发症5例（0.16％）.结论 RFCA可安全有效地用于治疗小儿快速型心律失常,成功率高,复发率低,是根治某些类型小儿快速型心律失常的首选方法.低龄患儿RFCA成功率、复发率及并发症与其他年龄组患儿比较差异无统计学意义,但消融术难度有所增加,需谨慎选择.采用三维标测指导射频导管消融可明显提高难治性心律失常的消融成功率.丰富的经验及熟练的操作是避免并发症发生的重要因素.