Transient complete atrioventricular block induced by a chest thump in a patient with ventricular tachycardia

We describe an unusual case of transient complete atrioventricular block induced by a chest thump during resuscitation in a patient with ventricular tachycardia.     

Bundle branch re-entry ventricular tachycardia in a patient with complete heart block.

A 58-year-old male patient presented episodes of palpitations in the context of atrioventricular block treated by a dual-chamber pacemaker. Clinical and electrophysiological studies identified the tachyarrhythmia to be bundle branch re-entrant ventricular tachycardia, which was successfully treated by radiofrequency ablation of the proximal right bundle branch.     

Fetal ventricular pacing for hydrops secondary to complete atrioventricular block

The advent of ultrasound recording has expanded the capabilities for treatment of the fetus in utero. The diagnosis of specific disease processes has allowed for prenatal intervention by new techniques designed to improve fetal survival. The application of ventricular pacing in a hydropic fetus with complete atrioventricular (AV) block is reported. Complete AV block resulted from maternal collagen vascular disease. The application of ventricular pacing was to allow for further in utero development and for reversal of hydrops fetalis after improvement in cardiac output. Despite fetal death 4 hours after placement of the ventricular pacing lead, this procedure when applied earlier in the development of hydrops may allow for fetal survival. Ventricular pacing was accomplished without apparent trauma to mother or fetus and no evidence of fetal injury was seen at necropsy. Therefore, in the fetus who would otherwise die in utero before the point of viability ex utero, fetal ventricular pacing may be a rational alternative to current observation.     

Transient complete atrioventricular block associated with herb intake.

We report a case of transient complete atrioventricular block in a 38-year-old man, after intake of a mixture of herbs, intended to aid cigarette smoking cessation. Since all other causes of conduction disturbances were excluded, a side-effect of the herbal remedy was identified as the most likely diagnosis. Given that most patients are unaware of the potential risks of the intake of various herbs, we would urge that their usage be regulated.     

Permanent ventricular pacing via a low posterolateral cardiac vein in a patient with a mechanical tricuspid valve prosthesis and complete atrioventricular block

In the presence of an artificial tricuspid valve, permanent pacing is generally achieved with an epimyocardial approach. This report describes the implantation of a dedicated pacing electrode in a low posterolateral cardiac vein in a patient with a mechanical prosthetic tricuspid, mitral and aortic valve in whom an epimyocardial lead and pacemaker generator had to be removed because of infection.     

Radiofrequency ablation in a patient with atrioventricular reentrant tachycardia and atrioventricular nodal reentrant tachycardia with 2:1 atrioventricular block.

The authors report the case of 15-year-old girl with a history of palpitations and shortness of breath during exercise. The electrocardiogram showed ventricular preexcitation suggesting a Wolff-Parkinson-White syndrome with a posteroseptal accessory pathway. During the electrophysiological study a left posterospetal accessory pathway was identified and an orthodromic atrioventricular reentry tachycardia was reproducibly induced (cycle length 400 ms). After disappearance of the ventricular pre-excitation with radiofrequency ablation, a dual physiology of atrioventricular node condution was documented and a slow-fast atrioventricular nodal reentrant tachycardia was repeatedly induced. Upon induction, this tachycardia presented a proximal atrioventricular block with 2:1 condution converted to 1:1 condution with overdrive pacing from the proximal coronary sinus (cycle length 270 ms). Radiofrequency ablation of the slow pathway was performed with success. We discuss the need to suspect and seek different arrhythmogenic substracts of tachycardia in a single patient, the electrophysiologic conditions that could explain the inducibility of different arrhythmias in this case, and the controversy regarding ablation of more than one reentry circuit in a single procedure.     

Paroxysmal complete atrioventricular block in a patient with pulmonary atresia and intact ventricular septum

Sudden death in pulmonary atresia and intact ventricular septum with right ventricular dependent coronary circulation is a well-established complication, and is thought to be caused by myocardial ischaemia. We report a case of paroxysmal complete atrioventricular block that raises the possibility of an additional mechanism of sudden death.     

Right ventricular dysplasia with complete atrioventricular block: Necessity and limitation of left ventricular epicardial pacing

This paper reports a case of right ventricular dysplasia, in which the patient presented with atrioventricular block and was followed for more than 8 years under left ventricular epicardial pacing. Five years after first epicardial pacemaker implantation, loss of capture occurred. Replacement of the epicardial leads was performed.     

Tachycardia after pacemaker implantation in a patient with complete atrioventricular block.

The atrioventricular (AV) node allows ante- and retrograde conduction between atria and ventricles. It is commonly assumed that these AV nodal conduction properties go hand in hand. However, ante- and retrograde AV conduction can be completely independent from each other in individual patients. We report about a patient with permanent AV block III degrees requiring implantation of a pacemaker. As soon as a dual-chamber device was connected to the implanted leads, a tachycardia started at the maximum tracking rate, which was subsequently reprogrammed from 120 to 170 bpm. Non-invasive electrophysiologic testing showed that this patient demonstrated 1:1 ventriculoatrial (VA) conduction up to 170 bpm leading to endless loop tachycardia (ELT) while the antegrade AV block III degrees persisted. This case impressively illustrates that one has to take into account that patients with antegrade AV block III degrees may still have a high VA conduction capacity leading to ELT. Dual-chamber devices therefore have to be programmed accordingly, activating dedicated reactions after ventricular premature beats and automatic ELT detection and termination algorithms.     

Transient complete atrioventricular block occurring 1 week after radiofrequency ablation for the treatment of atrioventricular nodal re-entrant tachycardia.

Atrioventricular (AV) block following radiofrequency (RF) ablation for the treatment of AV nodal re-entrant tachycardia (AVNRT) is a rare but serious complication of this procedure. Almost all such cases occur during or immediately after radiofrequencey (RF) energy application, followed by prompt recovery. The present report describes a 22-year-old woman with first-degree AV block on electrocardiography, who developed complete AV block 1 week after RF ablation for the treatment of the uncommon form of AVNRT (slow/slow). The patient's complete AV block persisted for another 1 week before she recovered.     

右心室流出道间隔部起搏对完全性房室传导阻滞患者心功能的影响

目的：比较右心室流出道间隔部（RVS）起搏与右心室心尖部（RVA）起搏对左右心室间收缩同步性、左室重构及心功能的影响。方法：①入选Ⅲ度房室传导阻滞患者61（男39,女22）例,随机分入RVS部起搏组（RVS组,n=33）和RVA部起搏组（RVA组,n=28）。②比较两组患者植入术中及术后12月心室电极导线参数（起搏阈值、R波感知及阻抗）的差异。③观察两组患者术前及术后12月QRS波时限;术后应用组织多普勒同步图（TSI）分别测定两组左、右心室侧壁基底部收缩达峰时间差（△Ts）。评价心室间不同步的程度。④行多普勒超声心动图（UCG）检查,观察两组术前及术后12月左室舒张末期内径（LVEDD）及左室射血分数（LVEF）的变化,比较不同起搏部位对心功能的影响。结果：①两组患者测试的起搏阈值、R波感知及导线阻抗无统计学差异。②两组患者术后QRS波时限均较术前延长（均P〈0．01）,RVA组较RVS组延长更为明显（P〈0．01）。RVS组与RVA组ATs分别为（27±14）ms和（90±22）ms,有统计学差异（P〈0．01）。③术后12／了＇月两组LVEDD均较术前增加,RVA明显大于RVS组[（54±5）mm阮（51±5）mm,P〈0．05]。RVA组术后12月LVEDD较术前明显增加[（54±5）mmvs．（50±4）mm,P〈0．05],术后12月两组LVEF均较术前降低[RVS组：（0．58-4-0．14）傩．（0．63±0．09）,P〈0．01;RVA组：（0．51±0．12）伽．（0．64±0．13）,P〈0．01],组间比差异不显著。结论：RVS起搏对心室问同步性、左室重构的影响要优于RVA起搏。     

右室间隔起搏与心尖部起搏对完全性房室传导阻滞患者心功能影响的比较

目的:初步探讨右室间隔起搏(RVSP)和右室心尖部起搏( RVAP)对完全房室传导阻滞( CAVB) 患者心功能的影响。方法:87例因CAVB植入起搏器的患者, 其中45例行RVSP术(RVSP组),42例行RVAP术(RVAP组),分别对术前及术后6、12和18个月,患者的QRS波时限、左室舒张末内径（LVEDD）、 左室射血分数（LVEF）、每搏量（SV）、心脏指数（CI）、加速度指数（ACI）进行检查比较。结果:所有患者均完成12个月随访, 79例完成18个月随访。术后RVAP组QRS波时限较RVSP组明显增宽(P<0.05),术后12个月RVAP组LVEF、SV、ACI均较RVSP组明显降低(P<0.05),术后18个月RVAP组LVEDD较RVSP组明显增大(P<0.05),RVAP组CI均较RVSP组降低,但尚未达到显著性差异。结论:RVSP较RVAP有利于CAVB患者心功能的保护。     

右室心尖部起搏与右室流出道起搏对Ⅲ度房室传导阻滞患者疗效的对比研究

目的:比较右室心尖部起搏与右室流出道起搏对Ⅲ度房室传导阻滞患者心室间运动同步性及左室内运动同步性,以及对患者心功能的影响。方法:选取因Ⅲ度及高度房室传导阻滞患者置入双腔起搏器患者共38例。其中心室电极置入右室流出道者20例(RVOT组),置入右室心尖部18例(RVA组),超声心动图术前测量左室舒张末内径(LVEDD),左室收缩末内径(LVESD)、左室射血分数(LVEF)、E/A值、心室间激动延迟时间(IVMD)、室间隔与左心室后壁间收缩延迟时间(SPWMD)。术后1个月、12个月随访。结果:术后1个月,与RVOT组比较,RVA组IVMD、SPWMD明显延长[IVMD(39.83±6.01)∶(31.95±7.86)ms,P=0.02],[SP-WMD(97.83±20.81)∶(84.6±10.89)ms,P=0.023]。术后12个月,与ROVT组比较,RVA组LVEDD明显增大[(49.11±2.39)∶(47.4±1.96)mm,P=0.02],LVESD明显增大[(34.28±3.41)∶(32.5±1.5)mm,P=0.04];LVEF明显降低[(59.56±3.38)∶(62.8±2.14)%,...     

右室流出道间隔部与心尖部起搏对完全性CHB患者心功能的影响

目的:比较右室流出道间隔部(RVOTS)起搏与右室心尖部(RVA)起搏对完全性房室传导阻滞(CAVB)患者心功能的影响。方法:50例CAVB患者被随机分为RVOTS组(25例)和RVA组(25例),全部植入房室全能(DDD)型起搏器,分别观察术前,术后6个月、12个月的左室射血分数(LVEF)及左室短轴缩短率(FS)的变化。结果:所有患者以DDD模式或心房同步心室抑制(VDD)模式起搏,心室起搏比例为100%。所有患者均完成1年随访。术后6个月两组LVEF、FS无显著差异(P均>0.05);术后12个月,ROVTS组LVEF[(57.29±2.87)%比(50.03±2.98)%]、FS[(34.24±2.59)%比(29.06±3.72)%]显著优于RVA组(P均<0.05)。结论:右室流出道间隔部起搏的左室收缩功能显著好于右室心尖部起搏。     

Transient complete atrioventricular block following a nonpenetrating chest trauma

Cardiac contusion may cause disorders of impulse formation and propagation in the specific conduction system. Transient complete atrioventricular block following a nonpenetrating chest trauma is a rare complication.We describe the case of a patient who presented a transient complete atrioventricular block, and later a transient right bundle branch block and a left anterior hemiblock, following a nonpenetrating chest trauma due to a car accident. The difficulty for diagnosing myocardial contusion is pointed out, and the usefulness of the electrophysiological study for detecting baseline conduction system disorders is discussed.     

Control of supraventricular tachycardia by VVI pacing in a patient with drug-induced enhanced atrioventricular conduction

A 56-year-old male with atrial fibrillation developed rapid ventricular response up to 200 beats/min or more in the postoperative stage of emergency aortocoronary bypass surgery. Resuscitation for cardiac arrest triggered this rapid ventricular rate. The idea that retrograde conduction into atrioventricular node may prevent ventricular capture of atrial fibrillation was tested. The ventricle was then paced at rapid rate followed by a gradual decrease in the pacing rate to 120 beats/min. By this method, ventricular rate was controlled and hemodynamics stabilized, with more efficiency of intra-aortic balloon counterpulsation. VVI pacing may be used in this manner to control irregular and rapid ventricular response of atrial fibrillation.     

右室心尖部和高位室间隔起搏对完全性房室传导阻滞患者心功能的影响

目的评价右室心尖部(RVA)起搏和高位右室间隔(HRVS)起搏对完全房室传导阻滞(CAVB)患者心功能的影响。方法 118例因CAVB植入起搏器的患者,其中52例为RVA起搏(RVA组),66例为HRVS起搏(HRVS组)。分别对术前、术后6个月及术后1年、2年的左室射血分数(LVEF)和2年内因心力衰竭住院人数进行随访观察。结果所有患者均完成1年随访,101例完成2年随访。术后6个月和1年时两组LVEF比较无差别(0.55±0.08vs0.55±0.08,P=0.926;0.54±0.09vs0.55±0.07,P=0.407),但是对于术前LVEF(0.50者,术后1年时LVEF两组有差别(0.40±0.04vs0.44±0.04,P=0.01)。术后2年,HRVS组优于RVA组(0.51±0.10vs0.55±0.06,P=0.01)。2年内,RVA组因心力衰竭住院人数多于HRVS组[31.1%(14/45)vs12.5%(7/56),P=0.02]。结论 HRVS起搏对CAVB患者心功能的长期影响低于RVA起搏。