Screening for arrhythmogenic right ventricular cardiomyopathy: a value of genetic testing

To the editor:We read with great interest the article by Yan and o-author 1 entitled A case of sudden death due to arrhythmogenic right ventricular cardiomyopathy,which was published in the previous issue of Chinese Medical Journal. They presented a case of sudden death due to arrhythmogenic right ventricular cardiomyopathy (ARVC) based on autopsy findings.In lethal cases due to ARVC,they also suggested taking genetic testing as a regular examination to identify their family members who are at risk of ARVC,and seek treatment early.This case gives detailed information and highlights the structural abnormalities and management of the ARVC.     

RADIOFREQUENCY ABLATION OF IDIOPATHIC RIGHT VENTRICULAR TACHYCARDIA

This paper presents our experieaee with radioreqencey ablation (RFA) for idiopathic ventricular tschycardia (VT) arising from right ventricle in 12 patients(pts). The age range d patients was 21～50, with a mean of 38. 5 years. Ten out of 12 were females, 1 patient had eandia failure due to almost incessant VT while the rest had normal left ventricular function.Twelve pts had VT arising from the fight ventricle; of those, 9 were from the outflow truct, 2 from the RV apex, and l from the RV inflow. In all tats the diagnostic study and therapeutic RFA were combined in a single procedure, pacemapping and local aetlvition time were used to guide the site of RFA in Ors with VT arising froth the tight ventricle.RFA was successful in 11 of the 12 pts ( 91%). Ntmaher of RF applications were 1～27, mean 9. 6; fluoroscopy time were 4～75, mean 26. 9 minutes. RFA for idiopathic RV has a high success rate. This mode of treament should be considered as a nonphartaaeologieal curative treatment for symptomatic pts.     

Clinical study of 39 Chinese patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy

Background There are few studies on the clinical profile of Chinese patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy （ARVD/C）. The purpose of this study was to describe the clinical characteristics of ARVD/C patients from China, particularly to define the features of electrocardiograph and treatment outcomes.
Methods Thirty-nine patients hospitalized in Fu Wai Cardiovascular Hospital from 1998 to 2006 were included. The data were obtained from the medical archive and the follow-up records.
Results Of these patients 33 were male and 6 female （age at the first presentation was （34.9 ± 9.8） years）. The most common symptoms were palpitation （62%） and syncope （44%）. Right precordial QRSd 〉 110 ms was detected in 69% of the patients, epsilon wave in 59%, and a ratio of QRSd in V1＋V2＋V3/V4＋V5＋V6 ≥ 1.2 in 82%. The most frequent features of electrocardiogram in patients without right bundle-branch block were T-wave inversions and S-wave upstroke in V1-V3 〉55 ms （96% and 90% of 28 patients, respectively）. Radiofrequency catheter ablation （RFCA） for ventricular tachycardia （VT） was successful in 15 （68%） of 22 patients. The recurrence rate of VT was 46% （7/15） during the follow-up of （16.7 ± 11.2） months. Seven patients had cardioverter/defibrillator （ICD） implanted plus drug therapy and 17 patients took antiarrhythmic drugs alone. During the follow-up of （35.6 ± 19.0） months, all patients with ICD implanted received at least one appropriate ICD shock. One patient died of ventricular fibrillation suddenly and one patient underwent heart transplantation for progressive biventricular heart failure during the drug therapy alone.
Conclusions This study demonstrated the clinical and ECG features of the 39 ARVD/C Chinese patients. ICD provided life-saving protection by effectively terminating malignant arrhythmias, and the high recurrence of VT was the major problem of RFCA therapy.     

Mutation of plakophilin-2 gene in arrhythmogenic right ventricular cardiomyopathy

Background Arrhythmogenic right ventricular cardiomyopathy （ARVC） is one of the leading causes of sudden cardiac death. Recent studies have shown that ARVC, which is an inheritable genetic change, results from mutations in genes encoding desmosomal proteins. Plakophilin-2 is an important component of the desmosome. Because the full range of genetic variations related to ARVC is unknown and no related studies of the Chinese population have been reported, we aimed to investigate the genetic variation of plakophilin-2 in ARVC patients from the Southern Region of China.
Methods Genomic DNA was isolated from peripheral blood samples of all 34 ARVC patients, who were screened through a clinical evaluation. They were used to detect variations in the sequences of the plakophilin-2 genes by polymerase chain reaction amplification in combination with direct sequencing.
Results In exon-1 of the plakophilin-2 gene, a deletion mutation （c.145_148 del GACA） was found in one family pedigree. The mutation was also found in exon-2, 4, and 11 of the plakophilin-2 gene. The QT interval dispersion of the ECG was considerably longer in the mutation group than in the non-mutation group of ARVC patients, and this result was statistically significant （P 〈0.05）.
Conclusion We discovered a plakophilin-2 mutation that prolongs the QT interval dispersion in the southern Chinese ARVC population.     

Potential proarrhythmic effect of cardiac resynchronization therapy during perioperative period: data from a single cardiac center

Background Cardiac resynchronization therapy （CRT） could improve heart function, symptom status, quality of life and reduce hospitalization and mortality in patients with severe heart failure （HF） with optimal medical management. However,the possible adverse effects of CRT are often ignored by clinicians.Method A retrospective analysis of CRT over a 6-year period was made in a single cardiac center.Results Fifty-four patients were treated with CRT（D） device, aged （57±11） years, with left ventricular ejection fraction of （32.1±9.8）%, of which 4 （7%） developed ventricular tachycardia/ventricular fibrillation （VT/VF） or junctional tachycardia after operation. Except for one with frequent ventricular premature beat before operation, the others had no previous history of ventricular arrhythmia. Of the 4 patients, 3 had dilated cardiomyopathy and 1 had ischemic cardiomyopathy,and tachycardia occurred within 3 days after operation. Sustained, refractory VT and subsequent VF occurred in one patient, frequent nonsustained VT in two patients and nonparoxysmal atrioventricular junctional tachycardia in one patient. VT was managed by amiodarone in two patients, amiodarone together with beta-blocker in one patient, and junctional tachycardia was terminated by overdrive pacing. During over 12-month follow-up, except for one patient＇s death due to refractory heart and respiratory failure in hospital, the others remain alive and arrhythmia-free.Conclusions New-onset VT/VF or junctional tachycardia may occur in a minority of patients with or without prior history of tachycardia after biventricular pacing. Arrhythmia can be managed by conventional therapy, but may require temporary discontinuation of pacing. More observational studies should be performed to determine the potential proarrhythmic effect of CRT.     

Assessment of left ventricular longitudinal regional myocardial systolic function by strain imaging echocardiography in patients with hypertrophic cardiomyopathy

To assess the left ventricular longitudinal regional myocardial systolic function by strain imaging （SI） echocardiography and to study the relationship between regional myocardial systolic function and left ventricular structure in patients with hypertrophic cardiomyopathy （HCM）. S1 echocardiography were performed in 18 patients with HCM and 17 healthy subjects. For each wall, regional myocardial systolic strain was analyzed at the basal, mid, and apical level respectively. And the peak systolic strain was measured. Our results showed that the patients with HCM had reduced peak systolic strain at almost each segment of different walls when compared with healthy subjects. There was significant correlation between the mid-septum peak systolic strain and the thickness of IVS, so was the correlation between the mid-septum peak systolic strain and the IVS to LVPW thickness ratio. This study demonstrated that the left ventricular longitudinal regional myocardial systolic function was abnormal in HCM, and this kind of abnormalities existed extensively in hypertrophic and non-hypertrophic cardiac segments. The degrees of left ventricle hypertrophy and asymmetry are related to the myocardial regional systolic function in HCM.     

Myocardial infarction due to isolated left circumflex or right coronary artery occlusion.

The electrocardiographic (ECG) patterns related to clinical spectrum and angiographic features were assessed in 41 patients with first myocardial infarction due to isolated left circumflex coronary artery (LCX) occlusion, and compared to those in 45 patients with right coronary artery (RCA)-related infarction. The occurrence of inferior Q waves was similar in patients with LCX and RCA occlusion, but lateral Q waves and an abnormal R wave in lead V1 were more frequently seen in patients with LCX-related infarction (46% vs 7% and 51% vs 4%, respectively). Compared with patients with LCX-related infarction without an abnormal R wave in lead V1 and those with RCA occlusion, patients with LCX-related infarction and an abnormal R wave in lead V1 associated with inferior and/or lateral Q waves had larger left ventricular end-diastolic and end-systolic volumes, lower ejection fraction, higher incidence of total occlusion of a dominant LCX without collaterals, and more cardiac events during follow-up. The study suggests that the presence of lateral Q waves and an abnormal R wave in lead V1 after myocardial infarction may be a useful marker of LCX occlusion, and that patients with LCX-related infarction may have different status of left ventricular function depending on the size of circulation and the status of residual flow to the infarct region during LCX occlusion.

     

The manifest right accessory pathway led to reversible left ventricular dyssynchrony and dysfunction

We report observations in a 7 year old girl with manifest right accessory pathway (AP) and depressed cardiac function. Her Echocardiogram showed LV dilatation with asynchronous ventricular wall motion and LVEF reduction. The electrophysiological study demonstrated a para-his AP. She underwent successfully ablation and without any complications. The Echo validated that asynchronous ventricular wall motion disappeared after ablation. Her cardiac size and function was normal after follow up of three month. Our findings suggested that manifest AP leading to asynchronous ventricular motion was a possible cause of left ventricular dilation and dysfunction. Catheter ablation could reverse cardiac remodeling in such patient. Case report A seven year old girl was referred to our hospital for fainting episode in last six month. To exclude cephalic syncope, she underwent electroencephalogram, the result was negative. The electrocardiogram (ECG) showed right AP. An apparent delta wave looked like LBBB pattern with short PR interval (80ms) and long QRS duration (180ms) (figure 1 left panel). Echocardiogram (Echo) revealed left ventricle dilatation and left ventricular ejection fraction reduction (LVDd=52mm, LVEF=46%). Asynchronous ventriclular wall motion and moderate mitral valve regurgitation also observed on Tissue Doppler Imaging (TDI). She underwent electrophysiology study (EPS) and ablation procedure on the 5th hospital day. The intracardiac electrogram showed a para-His AP with antegrade conduction. The orthodromic SVT (201 bpm) was induce right ventricular apex programmed stimulation. During SVT episode, her symptom was similar to spontaneous one. After successful ablation, delta wave on ECG disappeared and SVT can not be induced with or without isoproterenol. Normal atrial-ventricular conduction was kept without any complications. Prior to discharge, Echo showed the LVEF slightly improved and TDI indicated that asynchronous ventricular wall motion disappeared. She was discharged without any medication.     

PATHOLOGICAL CHARACTERISTICS OF GONADS IN NINE PATIENTS WITH TRUE HERMAPHRODITISM

The gonadal histopathology, and its correlation with the clinical features has been investigated in 9 true hermaphroditism patients, aged 5-21 yr. Seven of 9 patients had been raised as females, of which the chromosomal karyotype was 46XX in 5 cases, 46XX/46XY and 46XX/47XXY in 2 cases. Two of 9 patients were raised as males, the chromosomal karyotypes being 46XX and 46XX/46XY. All 9 patients had testieular tissue excised, and biopsies of the conserved ovaxian tissue were performed. Ovotestis was the most common form of the abnormal gonads; two of 9 patients had bilateral ovotestes, seven had unilsteral ovotestes (5 in right side, 2 in left side). In seven patients with a unilateral ovotestis, 6 had a contralateral ovary and one had a contralateral testis. Microscopically, the ovarian tissue of 11 ovotestes, including 6 biopsies from contealateral ovaris, were normal, with many primordal follicles and a few growing follicles.In two of the patients, aged over 15 years, evidence of ovulation was observed. In comparison, the testicular tissue of the ovotestis and the one left inguinal testis was histologically abnormal, with immature seminiferous tubbers, most of which filled with Sertoli cells only, Three of 9 patients married after surgical treatment. Two of these subsequently conceived and delivered of normal infants by cesarean section.     

Cardiac resynchronization therapy arrhythmogenic mechanism in a canine heart failure model

To the editor： Malignant ventricular tachyarrhythmias after cardiac resynchronization therapy （CRT） have been reportedrecently. Such arrhythmia is always lethal to the patients. The specific mechanisms for this phenomon are still unknown.l.2 We investigated the electrophysiological mechanisms of malignant arrhythmias in chronic heart failure （CHF） canines models induced by CRT. A CHF canine model was established by complete left bundle branch block （LBBB） followed by acute right ventricular apical pacing. After echocardiogram examination to ensure the successful establishment of the animal model, a CRT pacemaker was implanted. The 12-lead electrocardiogram before and after activation of biventricular pacing （BivP） was recorded. The changes in transmural dispersion of repolarization （TDR） and QTc intervals were compared. Various ventricle-to-ventricle （VV） delays were used to alter the TDR and QTC intervals and to induce malignant ventricular tachyarrhythmias. In a canine with sustained ventricular tachycardia （VT） induced by CRY, the origin of the VT was identified using 3D electroanatomic mapping with an EnSite 3000 Array.     

致心律失常性右心室心肌病临床分析

目的 :分析致心律失常性右心室心肌病的临床特点。方法 :将 2 3例致心律失常性右心室心肌病患者常规行超声心动图、心电图、胸片、动态心电图、心房调搏及心内电生理检查。结果 :本组 2 3例患者多有晕厥发作 ,频发室性早搏 (95 7% ) ,右心室源性短阵室速 (87% ) ,心电图多为右束支传导阻滞 (87% ) ,超声心动图右心室内径为 (5 0 1± 8 83)mm ,右心房内径为 (48± 8 79)mm ,右心室与左心室舒张末期内径之比为 1 0 9,右心功能减退 ,射血分数 (EF)为(0 32 5± 0 0 90 2 )。结论 :致心律失常性右心室心肌病 ,多有发作性晕厥 ,右束支传导阻滞 ,频发室早及左束支传导阻滞型室速 ,右心室、右心房增大 ,右心室功能减退 ,右心室与左心室舒张末期内径之比增大     

致心律失常性右心室心肌病临床分析

OBJECTIVE: To investigate the clinical features of arrthythmogenic right ventricular cardiomyopathy (ARVC), and to evaluate the diagnosis of ARVC. METHODS: Twenty-three cases of ARVC underwent ECG, chest x-ray, Holter, transesophageal atrial pacing (TEAP) and intracardiac electrophysiological examination. RESULTS: A syncope attack occurred; the percentage of frequent ventricular premature beats was 95.7%, salvos of the right ventricular originated ventricular tachycardia (VT) was 87%, and the right bundle branch block (RBBB) demonstrated by ECG was 87%; UCG showed that the enlarged right ventricular diametric was (50.1 +/- 8.83) mm, and the right atrium diametric was (48 +/- 8.79) mm; the ratio of right ventricular diametric to left ventricular diametric in the end-diastolic period was 1.09. The right ventricular function [ejection fraction: (0.325 +/- 0.0902)] decreased, which was confirmed by echocardiogram. CONCLUSION: The diagnosis of ARVE can be established on the basis of the repeated syncope attack; RBBB, frequent ventricular premature beats, VT of LBBB patterms, an enlarged right heart and decreased right ventricular function can be found, the ratio of right ventricular dimaetric to left ventricular diametric increases in the end-diastolic period.     

特发性室速的临床特点分析

目的探讨特发性室速的临床特点.方法收集23例特发性室速和21例病因明确的继发性室速病人的资料,分别从临床表现、心电图特点和治疗进行对比分析.结果两组比较,特发性室速病人年龄较轻,病程较长,出现晕厥及血压下降者较少;室速发作时,左室特发性室速心电图主要表现为右束支传导阻滞(RBBB) 电轴左偏,右室特发性室速主要表现为左束支传导阻滞(LBBB) 电轴右偏(或下偏):射频消融对特发性室速治愈率高,并发症少;特发性室速预后好.结论掌握特发性室速的临床特点,有利于此类病人的诊断、治疗和预后判断.     

致心律失常型右心室心肌病伴发心律失常性心肌病1例

致心律失常型右心室心肌病(arrhythmogenic right ventricular cardiomyopathy,ARVC)是一种遗传性心肌病,以右心室心肌被纤维和脂肪组织替代为病理特征,约50％的患者双心室受累[1].西方人群该病患病率约为1/5000 ～1/1000,临床比较少见.在该病发展的不同阶段,先后出现心律失常、右心室结构及功能异常以及全心衰竭等临床表现,是35岁以下人群心脏性猝死(sudden cardiac death,SCD)的重要原因之一[2].该病的心律失常以室性心律失常为特征,但房性心律失常同样很多见,长时间的快速性房性心律失常可以导致心功能进一步恶化.本文报告1例北京大学第三医院收治的ARVC伴发房性心动过速,并导致心律失常性心肌病的病例.     

右室不同起搏部位对老年病窦综合征患者左心室收缩功能的影响

目的 比较右室不同起搏部位对老年病窦综合征(SSS)患者左心室收缩功能的影响.方法 选取该院2014-2016年收治的78例SSS患者,按照右室不同起搏部位分为右室心尖部(RVA)起搏组(40例)和右室流出道(RVOT)起搏组(38例),比较术前、术后3个月和术后9个月两组起搏器QRS波时限、总计右心室起搏百分比和左心室收缩功能指标.结果 两组患者术前QRS波时限和各项左心室收缩功能指标比较,差异均无统计学意义(P＞0.05).术后3个月和术后9个月,RVA起搏组患者QRS波时限较RVOT起搏组长,差异有统计学意义(P＜0.05).术后9个月两组总计起搏百分比比较,差异无统计学意义(P＞0.05);而RVOT起搏组左心室射血分数高于RVA起搏组,左心室舒张末内径小于RVA起搏组,差异均有统计学意义(P＜0.05).结论 RVOT起搏对SSS患者左心室收缩功能的作用优于RVA起搏.     

单导管射频消融治疗主肺动脉干室性早搏／室性心动过速临床观察

目的探讨起源于主肺动脉干（MSPA）室性早搏（PVCs）/室性心动过速（VT）的心电图特征、标测方法及单导管射频消融治疗的疗效与安全性。方法选取经肺动脉造影证实起源于MSPA的PVCs／VT患者12例（MSPA组）以及右心室流出道（RVOT）前间隔起源的PVCs／VT患者59例（RVOT组）,均采用单导管常规标测技术进行标测、消融。比较分析两组患者心电图特征,随访MSPA组患者的疗效。结果MSPA组患者体表心电图具有下壁导联R波振幅高以及胸前导联移形较早（多位于V2～V3）的特点,其有效靶点高电压（8V）可起搏心室,并与自发PVCs/VT的QRS波形12导联完全相同,有效靶点心室电位较PVCs／VT体表心电图QRS波起始点提早（33.91±3.69）ms,10例可记录到远场A、V波,6例可记录到融合或分离的尖峰或碎裂电位。所有消融治疗均成功,无并发症发生,随访期间无复发病例。结论起源于MSPA的PVCs／VT并非罕见．单导管标测及消融安全、有效．     

右室间隔部起搏对慢快综合征患者血流动力学及抗心律失常的研究

目的:探讨对慢快综合征患者行间隔部起搏后远期的血流动力学影响及间隔部起搏对阵发性房颤的控制效果。方法:需要植入DDD型起搏器的78例慢快综合征患者,按照心室电极的位置,随机分为右心室间隔部(RVS)起搏和右室心尖(RVA)起搏两组,对起搏器植入前、植入后第6个月和第12个月的QRS波宽度、左室射血分数、左室舒张末期内径、P波离散度、房颤负荷以及术中阈值、电极阻抗、感知差异进行分析。结果:术后6个月、12个月随访两组患者,RVS组患者QRS时限较术前有延长趋势但未达显著水平(P>0.05),RVA组患者QRS时限较术前显著延长(P<0.05);RVS组患者心功能和左室舒张末径较手术前无明显变化,RVA组患者心功能较手术前明显降低,左室舒张末径较手术前明显增加,两组相比,RVA组患者左室射血分数较RVS组患者低,两组左室舒张末期内径有明显差异(P<0.05);术后RVS组患者较术前P波离散度和房颤负荷无明显变化,而RVA组患者较术前P波离散度和房颤负荷增加。结论:右心室间隔部起搏是安全、有效的,右心室间隔部起搏将稳定或改善慢快综合征患者的远期心功能,最大限度减少阵发性房颤的发作。     

射频消融治疗特发性室性心动过速9例临床报告

目的观察射频消融技术治疗特发性室性心动过速 (IVT)的临床效果。方法根据发作IVT时的体表 12导联心电图定位起源部位 ,行心内电生理检查 ,寻找稳定诱发IVT的条件 ,采用激动标测或 (和 )起搏标测相结合的方法标测靶点 ,对起源左心室间隔部的IVT寻找Purkinie电位 (p电位 ) ,标测靶点后放电消融。结果 11例呈RBBB图形伴电轴左偏或重度右偏 ,靶点在左心室间隔面中、下部 ,10例找到p电位。 7例为LBBB图形伴电轴不偏或右偏 ,靶点在右心室流出道 ;1例为LBBB图形伴电轴左偏 ,靶点在右心室流人道。l例IVT同时起源右室流出道的间隔部和游离壁 ,l例左心室特发性室性心动过速 (ILVT)合并房室结折返性心动过速的患者先消融房室结双径路 ,再行ILVT的消融。 1例右心室特发性室性心动过速 (IRVT)消融虽未立即成功 ,因延迟作用 3周后心动过速消失。消融成功患者的临床症状消失 ,未出现手术相关的并发症 ,随访期内所有病例存活。结论射频消融治疗IVT临床疗效肯定、成功率高、安全 ,应作为首选的根治方法。     

Left posterior fascicular block: a new endpoint of ablation for verapamil-sensitive idiopathic ventricular tachycardia

Verapamil-sensitive idiopathic left ventricular tachycardia with a right bundle-branch block and left-axis deviation morphology, which occurs in young adults without structural heart disease is an uncommon but well described clinical arrhythmia. This ventricular tachycardia (VT) is known to be due to re-entry mechanism and the re-entrant circuit is localized in the left ventricular septum.1-10 However, the relationship between Purkinje potential and the reentrant circuit is still controversia…