Selective his bundle pacing eliminates crochetage sign:A case report

BACKGROUND Crochetage sign is a specific electrocardiographic manifestation of ostium secundum atrial septal defects(ASDs),which is associated with the severity of the left-to-right shunt.Herein,we reported a case of selective his bundle pacing(SHBP)that eliminated crochetage sign in a patient with ostium secundum ASD.CASE SUMMARY A 77-year-old man was admitted with a 2-year history of chest tightness and shortness of breath.Transthoracic echocardiography revealed an ostium secundum ASD.Twelve-lead electrocardiogram revealed atrial fibrillation with a prolonged relative risk interval,incomplete right bundle branch block,and crochetage sign.The patient was diagnosed with an ostium secundum ASD,atrial fibrillation with a second-degree atrioventricular block,and heart failure.The patient was treated with selective his bundle pacemaker implantation.After the procedure,crochetage sign disappeared during his bundle pacing on the electrocardiogram.CONCLUSION S-HBP eliminated crochetage sign on electrocardiogram.Crochetage sign may be a manifestation of a conduction system disorder.

Ventricular tachycardia originating from the His bundle: A case report

BACKGROUND Ventricular tachycardia(VT)commonly occurs among patients with heart failure and can even cause sudden cardiac death.VT originating from the His bundle branch has been rarely reported.We present the case of a patient with VT from the His bundle branch.CASE SUMMARY A 58-year-old female complained of paroxysmal palpitations and dizziness for approximately 6 mo.She had a history of fatty liver and cholecystitis,and carotid atherosclerosis could not be excluded from the ultrasound results.An evaluation of the electrocardiogram obtained after admission showed spontaneous conversion between two different morphologies.The possible electrophysiologic mechanism suggested that the dual-source VT originated from the same source,the His bundle branch.Finally,the His bundle branch was ablated,and a dualchamber pacemaker was inserted into the patient’s heart.No further VT occurred during the 3-year follow-up after hospital discharge.CONCLUSION The diagnosis of VT originating from the His bundle is rare and difficult to establish.The results of this study showed VT originating from the His bundle based on a careful evaluation of the electrocardiogram,and the diagnosis was confirmed by an intracardiac electrophysiologic examination.

Effects of atrial septal defects on the cardiac conduction system

The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bundle Pacing(S-HBP)without requiring surgical closure.The mechanisms behind the appearance and resolution of the crochetage sign remain unclear.The authors observed the dis-appearance of the crochetage sign post-S-HBP,suggesting a possible correlation between these specific R waves and the cardiac conduction system.This editorial aims to explore various types of ASD and their relationship with the cardiac con-duction system,highlighting the diagnostic significance of the crochetage sign in ASD.

Cardiac atrioventricular conduction improved by autologous transplantation of mesenchymal stem cells in canine atrioventricular block models

Objective Atrioventricular block(AVB)is a common and serious arrhythmia.At present,there is no perfect method of treatment for this kind of arrhythmia.The purpose of this study was to regenerate cardiac atrioventricular conduction by autologous transplantation of bone marrow mesenchymal stem cells(MSCs),and explore new methods for therapy of atrioventricular block.Methods Eleven Mongrel canines were randomized to MSCs transplantation(n=6)or control(n=5)group.The models of permanent and complete AVB in 11 canines were established by ablating His bundle with radiofrequency technique.At 4 weeks after AVB,bone marrow was aspirated from the iliac crest.MSCs were isolated and culture-expanded by means of gradient centrifugal and adherence to growth technique,and differentiated by 5-azacytidine in vitro.Differentiated MSCs(1ml,1.5×10^(7)cells)labeled with BrdU were autotransplanted into His bundle area of canines by direct injection in the experimental group,and 1ml DMEM in the control group.At 1-12 weeks after operation,the effects of autologous MSCs transplantation on AVB models were evaluated by electrocardiogram,pathologic and immunohistochemical staining technique.Results Compared with the control group,there was a distinct improvement in atrioventricular conduction function in the experimental group.MSCs transplanted in His bundle were differentiated into analogous conduction system cells and endothelial cells in vivo,and established gap junction with host cardiomyocytes.Conclusions The committed-induced MSCs transplanted into His bundle area could differentiate into analogous conduction system cells and improve His conduction function in canine AVB models.

CLINICAL AND EXPERIMENTAL STUDY OF DL-TETRAHYDROPALMATINE EFFECT IN THE TREATMENT OF SUPRAVENTRICULAR ARRHYTHMIA

Short-term efficacy and safety or dl-tetrahydropeimtine (dl-THP) effect in treatmentof supraventricularoremature beats (SVPS ) were studied with doubl-blind control. A 24h ambulato ry elettrocardiogram (Holier) was Performed to hudge the therapeutic efficacy before and after themedicatiou in all the 33 petients who took 300 mg/d, 450 mg/d, 600 mg/d dl-THP tblet in turn perweek. Total effective rate is 66. 7% ; more than 90% SVPBS disappear .in 18. 2% ; and more than75% SVPB. disappear in 48. 5%. Otherwise total affective rate is 13. 3% in placebo group. There issignificant differnce between the two groups (P < 0. 01). The important adverse reactions areletharey (24' 2% ), occasional nausea and vomiting. We demonstrate that dl-THP can prolong A-Hinterval by determining His bundle,electrogram (HBE) in rabbits, so P-R interval lengthed can befound in surface ECG. Exploitation of dl-THP veinous preartion may be one of the,rfertove drugto treat paroxysmal supraventricular tacbycardia(PSVT).