植入心脏起搏器患者晕厥复发的原因分析

目的　回顾性分析４３０例心脏起搏患者术后２５ 例再发生晕厥原因,并提出及时有效的处理步骤和措施。方法　全组２５例均为１９８６年１ 月～１９９８ 年６月住院植入ＶＶＩ起搏器患者,其中男性１１例,女性１４ 例,年龄３９～７６ 岁。基础心律失常：病态窦房结综合征１３ 例,三度房室阻滞８ 例,双束支－三分支阻滞４ 例。结果　２５ 例患者中再晕厥与起搏器有关１４ 例（５６％ ）;快速室性心律失常７ 例（２８％ ）;其他原因４例（１６％ ）。结论　植入永久性心脏起搏器后再晕厥是临床急诊,遇到时应及时找出原因并予以相应处理。术后加强基础心脏病的治疗及室性心律失常的防治至关重要     

Cardiac arrest caused by undersensing of a temporary epicardial pacemaker

The R-on-T phenomenon is a well-known entity that predisposes to dangerous arrhythmias. Typically, a premature ventricular complex occurring at the critical time during the T wave of the preceding beat precipitates ventricular tachycardia and fibrillation. This phenomenon can occur not only in asynchronous ventricular pacemakers, but also in synchronous pacemakers, if loss of sensing of the intrinsic rhythm becomes evident. A patient who was fitted with a temporary epicardial wire, following cardiac surgery and experienced repeated episodes of polymorphic ventricular tachycardia caused by the R-on-T phenomenon, is described.     

Incessant ventricular tachycardia due to multiple cardiac rhabdomyomas in an infant with Tuberous Sclerosis

We report a case of incessant ventricular tachycardia managed successfully with medications. The transthoracic echocardiogram showed multiple cardiac rhabdomyomas involving ventricular free wall and outflow tracts. Computerized tomography of brain showed multiple subependymal tubers confirming Tuberous Sclerosis. The follow up assessment showed sinus rhythm and regressing cardiac rhabdomyomas.     

Cardiac hydatid cyst revealed by ventricular tachycardia

Hydatid disease is a human parasitic infestation caused by the larval stage of Echinococcus Granulosus. The liver and the lungs are the most common locations. Cardiac involvement is rare and accounts for 0.5–2% of all hydatid disease. We report an unusual presentation of cardiac hydatid cyst revealed by ventricular tachycardia in a patient with a history of cerebral hydatid cyst.     

Stellate ganglion block: A therapeutic alternative for patients with medically refractory inappropriate sinus tachycardia?

Inappropriate sinus tachycardia (IST) is a clinical syndrome characterized by presence of non-paroxysmal tachyarrhythmia manifesting with increased resting heart rate and exaggerated or persistent response to exercise or position. When IST is intolerable and medically refractory, invasive therapies such as sinus node modification or atrioventricular node ablation with placement of permanent pacemaker are tried to control symptoms. We present a 34 year old patient with symptomatic IST unresponsive to medical therapy who underwent anesthetic block of the right and left stellate ganglia. At four month follow up the patient demonstrated sustained improvement in heart rate and reported freedom from previous symptoms.     

Ventricular tachycardia without apparent heart disease: long-term follow-up

The purpose of the study was to evaluate the long-term prognosis of ventricular tachycardia (VT) in patients without structural heart disease (HD).

Methods

Holter monitoring, exercise test, echocardiography, right angiography, coronary angiography, and electrophysiologic study were performed in 810 patients with VT.

Results

Eighty patients (mean age, 45 ± 17 years) had no apparent HD. VT was reproduced at electrophysiologic study in 62 patients. Mean follow-up was 9.7 ± 7 years. Initially, 91% were treated with drugs. Defibrillator was implanted in 4, including 2 for arrhythmogenic right ventricular cardiomyopathy diagnosed later. VT ablation was performed in 3 patients. Three patients older than 70 years died of nonarrhythmic cause. Other patients are alive without antiarrhythmic drug treatment in 50%. Three developed a dilated cardiomyopathy; and 2, atrial fibrillation.

Conclusions

Invasive treatment was rarely required in patients with VT without HD. The prognosis was only dependent on the age and the pattern of electrocardiogram in VT.     

Nifekalant in the treatment of life-threatening ventricular tachyarrhythmias

The aim of the present study is to review the literature and discuss nifekalant’s potential use as a first aid drug in an emergency care setting.The PubMed database was used to identify papers,using Keywords nifekalant,MS-551,amiodarone and lidocaine.Nifekalant hydrochloride,formally known as MS-551,is a classⅢ antiarrhythmic agent which acts only by increasing the time course of myocardial repolarization.It was developed and is currently being used only in Japan for the treatment of ventricular tachyarrhythmias.It is a non-selective K+channel blocker without any β-blocking actions.Administration of nifekalant suppressed sustained ventricular tachyarrhythmias in acute coronary syndrome patients,and in cardiac arrest victims as well as during or after cardiac surgery.The major adverse effect of nifekalant is QT interval prolongation and occurrence of torsades de pointes which requires frequent monitoring of the QT interval during nifekalant infusion with adequate dose adjustment.Nifekalant is a possible effective antiarrhythmic agent for refractory ventricular tachyarrhythmias.Further clinical studies are required before nifekalant is routinely used in the emergency care setting.     

fQRS as a marker of granulomatous disease in patients presenting with ventricular tachycardia and normal left ventricular ejection fraction

Background

Granulomatous myocarditis may present with sustained monomorphic ventricular tachycardia (SMVT) in the presence of normal left ventricular ejection fraction (LVEF), and could be mistaken for idiopathic ventricular tachycardia (IVT). The use of cardiac imaging for diagnosis can be limited by availability and high cost. ECG is readily available and inexpensive. Fragmented QRS (fQRS) on ECG has been found to be associated with myocardial scar. We hypothesized that fQRS could be useful in the diagnosis of granulomatous VT (GVT).

Methods

We compared the 12-lead ECG of 16 patients with GVT and 42 patients with IVT who presented with SMVT.

Results

The presence of fQRS was significantly higher in the GVT group compared to the IVT group (75% versus 19.1%, p < 0.001). The location of fQRS correlated with delayed enhancement cardiac magnetic resonance imaging (DE-CMR) in the same segment in 4/16 patients in the GVT group. It correlated with an affected segment on either DE-CMR or 18FDG positron emission computed tomography in 4/11 patients in the GVT group who had both imaging modality. Whenever fQRS was present in contiguous leads other than the inferior leads, it always corresponded to an affected segment on imaging.

Conclusions

In patients presenting with SMVT and no structural heart disease, the presence of fQRS is strongly associated with granulomatous myocarditis. fQRS on the surface ECG is a helpful tool the presence of which should prompt a CMR for a definitive diagnosis.     

去肾交感神经术对猪急性心肌梗死后心功能及心室重构的影响

目的:探讨去肾交感神经术(renal sympathetic denervation,RDN)对急性心肌梗死(AMI)后心功能及心室重构的影响。方法:微球栓塞前降支中远端构建AMI猪模型。实验分组为:对照组,建模后未接受RDN(n=10);RDN组,建模后1周接受RDN(n=10)。建模后1周(RDN前)及建模后4周对两组猪利用超声心动图检测左心功能和左心室大小,并检测相关血清学指标。结果:建模后4周,与对照组相比,RDN组的左室射血分数(EF)明显升高[(55.34±7.12)%对(50.52±2.23)%,P=0.035],左室收缩末期内径(LVESD)明显减小[(24.43±2.23)mm对(29.33±3.53)mm,P=0.020];与自身RDN治疗前比较,RDN组EF[(55.34±7.12)%对(49.23±4.58)%,P=0.034]和E/A(0.93±0.24对0.85±0.10,P=0.048)明显升高,LVESD明显减小[(24.43±2.23)mm对(26.55±2.11)mm,P=0.048];RDN组的去甲肾上腺素[(247.31±103.13)ng/L对(337.90±60.33)ng/L,P0.05]和肾素[(414.92±202.40)ng/L对(587.54±235.62)ng/L,P0.05)]水平显著低于对照组。结论:RDN可以提高猪AMI后的左心收缩功能,改善心室重构。