Noise in the signal-averaged electrocardiogram and accuracy for identification of patients with sustained monomorphic ventricular tachycardia after myocardial infarction

Late potentials are detected at various noise levels in clinicalstudies. The aim of this study was, in a case-control design,to assess the effect of residual noise level on the identificationof patients with sustained monomorphic ventncular tachycardiaafter myocardial infarction. Electrocardiograms from 16 patientswith prior myocardial infarction and documented sustained monomorphicventricular tachycardia and 41 patients with prior myocardialinfarction and without ventncular tachycardia, were analysedby two signal averaging procedures to noise level 0·2and 0·4 µV Standard time domain parameters weremeasured. Two definitions of late potential were analysed: (1)if any two of the following criteria were present (signal-averagedQRS duration >120 ms, late potential duration >40 ms,and root-mean-square voltage of the terminal 40 ms of the filteredQRS <25µV); or (2) if the signal-averaged QRS duration120 ms. Overall the signal-averaged electrocardiogram performedbetter at noise level 0·4µV compared to noise level0·2µV with respect to identification of patientswith or without ventricular tachycardia after myocordial infarction.Reducing noise level from 0·4 to 0·2 µVincreased the sensitivity, but the consequence was a substantialdecrease in specificity. Our data indicate that when a highsensitivity is the goal, the definition based only on signal-averagedQRS duration 120 ms should be applied; sensitivity was 88% andspecificity 59% at noise level 0·4 µV. If a highspecificity is the goal, the definition should be based on thedefinition with two abnormal parameters; sensitivity was 69%and specificity 68% at noise level 0·4µV.     

Postoperative Intensive Care Treatment after Esophageal Resection

The aim of this article is to give a short review of problems associated with the intensive caretreatment of patients after esophageal resection.Pulmonary dysfunction,supraventricular tachyarrhyth-mia,anastomotie leakage and mental disorders are the topics covered.Systemic inflammatory reaction andsepsis is the linking topic between these specific complications.Pulmonary dysfunction having an incidenceof up to 40% is the most important complication.Low tidal volume ventilation,pain management includingepidural analgesia and early tracheostomy are the mainstay of therapy.Supraventricular tachyarrhythmiais an early indicator of emerging complications.Its symptomatic treatment is standardized using electriccardioversion,beta-blockers and amiodarone.Anastomotic leakage must be suspect in any septic episode.Endoscopy and contrast studies allow for precise diagnosis.Interventional endoscopy is increasingly suc-cessful in the therapy of these leakages.Microbiological surveillance and specific antibiotic therapy ensurethat a complication does not cause a septic cascade leading to multiorgan failure.The workload on ICUcaused by a patient after esophageal resection still exceeds that of most other patients with gastrointestinalsurgery.     

经导管射频消融术治疗快速性心律失常2 064例结果分析

目的 通过对射频消融（RFCA）治疗快速性心律失常的结果进行分析，以总结RFCA的治疗经验。方法 对我科开展RFCA治疗快速性心律失常11年的工作进行总结，对2064例患者的治疗结果进行回顾性分析。结果 2064例患者中2008例RFCA治疗成功，成功率达97．3％。并发症发生率为0．73％（15／2064），其中前5年为1．48％（9／609），后6年为0．41％（6／1455）；2例安置了永久性心脏起搏器。复发率为1．54％（31／2008），有28例再次行RFCA治疗获得成功。结论 （1）RFCA治疗快速性心律失常安全、有效、成功率高、并发症发生率低。（2）RFCA治疗快速性心律失常的成功率及并发症发生率与术者的操作技术及经验密切相关。     

Radioiodine ablation of the thyroid to prevent recurrence of amiodarone-induced thyrotoxicosis in patients with resistant tachyarrhythmias.

Amiodarone-induced thyrotoxicosis (AIT) is a common complication of amiodarone therapy. Although permanent withdrawal of amiodarone is recommended due notably to the risk of worsening of tachyarrhythmias, some patients may require the reintroduction of amiodarone several months after normalizing their thyroid function. We, retrospectively, assessed the effects of (131)I therapy to prevent recurrence of AIT in euthyroid patients requiring reintroduction of amiodarone. SUBJECTS AND METHODS: Amiodarone was required in 10 cases of recurrent symptomatic paroxysmal atrial fibrillation (AF) and in 5 cases of ventricular tachycardia (VT) (M = 12, F = 3, mean age: 63 +/- 14). The underlying heart disease was dilated cardiomyopathy (n = 4), ischaemic heart disease (n = 4), hypertensive heart disease (n = 2), arrhythmogenic right ventricular dysplasia (n = 27) and valvulopathy (n = 1). Two patients had idiopathic paroxysmal AF. RESULTS: A mean (131)I dose of 579 +/- 183 MBq was administered 34 +/- 37 after the episode of AIT. Amiodarone was reintroduced in 14 of 15 patients after a mean interval of 103 +/- 261 d. Fourteen patients developed definite hypothyroidism necessitating l-thyroxine but we observed no late recurrence of AIT. After a mean follow-up of 22 +/- 16 months, tachyarrhythmias were controlled in 12 of 14 patients. CONCLUSION: (131)I therapy appears to be an effective and safe approach to prevent the recurrence of AIT in a patient requiring the reintroduction of amiodarone for tachyarrhythmias.     

起搏预防和终止快速性房性心律失常的疗效观察(附3例报告)

观察AT501起搏器起搏预防和终止快速性房性心律失常的疗效。3例病窦综合征(SSS)患者,同时伴有快速性房性心律失常,置入Medtronic公司生产的AT501起搏器,术后1个月打开三种独立的起搏预防治疗功能和3个可程控的起搏终止治疗功能。经8～10个月的随访,患者的临床症状较术前明显改善,通过9790程控仪回顾心律失常发生事件,发现AT501起搏器对快速性房性心律失常的检测准确率为98%,起搏预防治疗功能和起搏终止治疗功能可减少快速性房性心律失常的发作,其中起搏终止治疗的成功率为56%,在270～360ms快速性房性心律失常检测区成功率为78%,在220～270ms快速性房性心律失常检测区成功率为40%。结论:初步临床应用表明,AT501起搏器置入后通过对起搏器的起搏预防和终止治疗功能合理程控,可安全、有效地减少快速性房性心律失常的发作。     

Cardiovascular Complications and Their Association With Mortality in Patients With Thrombotic Thrombocytopenic Purpura

BackgroundDespite widespread availability of plasmapheresis, the mortality in thrombotic thrombocytopenic purpura remains high. Cardiovascular complications have been reported as an important cause of morbidity in these patients. The burden and prognostic implications of these complications have not been well studied. We analyzed the rates of cardiovascular complications in thrombotic thrombocytopenic purpura, temporal trends, and studied its impact on in-hospital mortality.MethodsWe analyzed the National Inpatient Sample (NIS) from January 2005 to September 2015 to identify adult patients with thrombotic thrombocytopenic purpura. This group was further refined by excluding patients who did not receive therapeutic plasmapheresis, and other conditions that can mimic thrombotic thrombocytopenic purpura. We identified the age- and sex-stratified rates of cardiac arrhythmias, cardiac conduction system disorders, heart failure, acute coronary syndrome, myocarditis, pericarditis, takotsubo cardiomyopathy, cardiogenic shock, cardiac arrest, and stroke. We also compared in-hospital mortality with and without cardiovascular complications.ResultsAmong 15,054 thrombotic thrombocytopenic purpura hospitalizations (mean age 46.4 years, 69% in the 18- to 54-age group, 66.2% women, and 42.9% white), a cardiovascular complication was observed in 3802 (25.3%) hospitalizations. The following cardiovascular complications were identified: stroke (10.4%), heart failure (8.3%), acute coronary syndrome (6.4%), atrial tachyarrhythmia (5.9%), ventricular tachyarrhythmia (2.0%), cardiogenic shock (0.5%), takotsubo cardiomyopathy (0.1%), atrioventricular block (0.2%), myocarditis or pericarditis (0.3), and cardiac arrest (1.9%). Rates of several cardiovascular complications were significantly higher in patients 55 years or older compared to a younger age group, whereas males had higher rates of acute coronary syndrome and tachyarrhythmias compared to females. Overall, the cardiovascular complication rate was stable during the study period. The presence of a major cardiovascular complication was associated with a significantly higher in-hospital mortality (19.7%) as compared with no major cardiovascular complication (4.1%) (adjusted odds ratio 2.09, 95% confidence interval 1.41-3.09, P <0.001). Results were generally consistent in age and sex subgroups.ConclusionCardiovascular complications were frequently observed at a rate of 1 in 4 in patients hospitalized for thrombotic thrombocytopenic purpura and were associated with substantially higher in-hospital mortality. These findings underscore the need to promptly identify and treat these complications to improve outcomes.     

Linear lesions for treating the recurrence of persistent atrial tachyarrhythmia after cryoballoon ablation of atrial fibrillation

Overall, 133 patients underwent 170 procedures for the treatment of persistent ATa following an index cryoballoon pulmonary vein isolation (n = 715). After all the procedures, > 90% of the patients had a roof line, a mitral isthmus and/or septal line, and a cavotricuspid isthmus line. Ninety-two patients (69.2%) were in sinus rhythm after a median of 36 months since the index cryoballoon PVI. ATa: atrial tachyarrhythmia; cryo: cryoballoon; CTI: cavotricuspid isthmus; LSPV: left superior pulmonary vein; LIPV: left inferior pulmonary vein; PVI: pulmonary vein isolation; RF: radiofrequency; RSPV: right superior pulmonary vein; RIPV: right inferior pulmonary vein.