Weighted gene co-expression network analysis reveals similarities and differences of molecular features between dilated and ischemic cardiomyopathies

Cardiomyopathies represent the most common clinical and genetic heterogeneous group of diseases that affect the heart function.Though progress has been made to elucidate the process,molecular mechanisms of different classes of cardiomyopathies remain elusive.This paper aims to describe the similarities and differences in molecular features of dilated cardiomyopathy(DCM)and ischemic cardiomyopathy(ICM).We firstly detected the co-expressed modules using the weighted gene co-expression network analysis(WGCNA).Significant modules associated with DCM/ICM were identified by the Pearson correlation coefficient(PCC)between the modules and the phenotype of DCM/ICM.The differentially expressed genes in the modules were selected to perform functional enrichment.The potential transcription factors(TFs)prediction was conducted for transcription regulation of hub genes.Apoptosis and cardiac conduction were perturbed in DCM and ICM,respectively.TFs demonstrated that the biomarkers and the transcription regulations in DCM and ICM were different,which helps make more accurate discrimination between them at molecular levels.In conclusion,comprehensive analyses of the molecular features may advance our understanding of DCM and ICM causes and progression.Thus,this understanding may promote the development of innovative diagnoses and treatments.

Polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome with dilated cardiomyopathy: A case report

BACKGROUND Polyneuropathy,organomegaly,endocrinopathy,M-protein,skin changes(POEMS)syndrome is a rare paraneoplastic syndrome that encompass multiple systems.The most common clinical symptoms of POEMS syndrome are pro-gressive sensorimotor polyneuropathy,organ enlargement,endocrine disorders,darkening skin,a monoclonal plasma cell proliferative disorder,and lymph node hyperplasia.The organomegaly consists of hepatosplenomegaly and/or lym-phadenopathy;cases of cardiomyopathy are rare.Diagnoses are often delayed because of the atypical nature of the syndrome,exposing patients to possibly severe disability.Therefore,identifying atypical symptoms can improve the prognosis and quality of life among POEMS syndrome patients.lenalidomide and dexamethasone.CONCLUSION When patients with cardiomyopathy have systemic manifestations such as numb limbs and darkening skin,the POEMS syndrome is the most possible diagnosis.

Construction of A Prediction Model for Atrial Fibrillation in Patients with Dilated Cardiomyopathy and Heart Failure

Dilated cardiomyopathy(DCM)is a common myocardial disease characterized by enlargement of the heart cavity and decreased systolic function,often leading to heart failure(HF)and arrhythmia.The occurrence of atrial fibrillation(AF)is closely related to the progression and prognosis of the disease.In recent years,with the advancement of medical imaging and biomarkers,models for predicting the occurrence of AF in DCM patients have gradually become a research hotspot.This article aims to review the current situation of AF in DCM patients and explore the importance and possible methods of constructing predictive models to provide reference for clinical prevention and treatment.We comprehensively analyzed the risk factors for AF in DCM patients from epidemiological data,pathophysiological mechanisms,clinical and laboratory indicators,electrocardiogram and imaging parameters,and biomarkers,and evaluated the effectiveness of existing predictive models.Through analysis of existing literature and research,this article proposes a predictive model that integrates multiple parameters to improve the accuracy of predicting AF in DCM patients and provide a scientific basis for personalized treatment.

Study of pathogenic genes in a pedigree with familial dilated cardiomyopathy

BACKGROUND Dilated cardiomyopathy(DCM)is a genetically heterogeneous cardiac disorder characterized by left ventricular dilation and contractile dysfunction.The substantial genetic heterogeneity evident in patients with DCM contributes to variable disease severity and complicates overall prognosis,which can be very poor.AIM To identify pathogenic genes in DCM through pedigree analysis.METHODS Our research team identified a patient with DCM in the clinic.Through invest-igation,we found that the family of this patient has a typical DCM pedigree.High-throughput sequencing technology,next-generation sequencing,was used to sequence the whole exomes of seven samples in the pedigree.RESULTS A novel and potentially pathogenic gene mutation-ANK2p.F3067L-was discovered.The mutation was completely consistent with the clinical information for this DCM pedigree.Sanger sequencing was used to further verify the locus of the mutation in pedigree samples.These results were consistent with those of high-throughput sequencing.CONCLUSIONS ANK2p.F3067L is considered a novel and potentially pathogenic gene mutation in DCM.

Pediatric acute heart failure caused by endocardial fibroelastosis mimicking dilated cardiomyopathy:A case report

BACKGROUND Endocardial fibroelastosis(EFE)is a diffuse endocardial collagen and elastin hyperplasia disease of unknown etiology,which may be accompanied by myocardial degenerative changes leading to acute or chronic heart failure.However,acute heart failure(AHF)without obvious associated triggers is rare.Prior to the report of endomyocardial biopsy,the diagnosis and treatment of EFE are highly susceptible to being confounded with other primary cardiomyopathies.Here,we report a case of pediatric AHF caused by EFE mimicking dilated cardiomyopathy(DCM),with the aim of providing a valuable reference for clinicians to early identify and diagnose EFE-induced AHF.CASE SUMMARY A 13-mo-old female child was admitted to hospital with retching.Chest X-ray demonstrated enhanced texture in both lungs and an enlarged heart shadow.Color doppler echocardiography showed an enlarged left heart with ventricular wall hypokinesis and decreased left heart function.Abdominal color ultrasonography revealed a markedly enlarged liver.Pending the result of the endomyocardial biopsy report,the child was treated with a variety of resuscitative measures including nasal cannula for oxygen,intramuscular sedation with chlorpromazine and promethazine,cedilanid for cardiac contractility enhancement,and diuretic treatment with furosemide.Subsequently,the child’s endomyocardial biopsy report result was confirmed as EFE.After the above early interventions,the child’s condition gradually stabilized and improved.One week later,the child was discharged.During a 9-mo follow-up period,the child took intermittent low-dose oral digoxin with no signs of recurrence or exacerbation of the heart failure.CONCLUSION Our report suggests that EFE-induced pediatric AHF may present in children over 1 year of age without any apparent precipitants,and that the associated clinical presentations are grossly similar to that of pediatric DCM.Nonetheless,it is still possible to be diagnosed effectively on the basis of the comprehensive analysis of auxiliary inspection findings before the result of the endomyocardial biopsy is reported.

Diagnostic and classification value of immune-related lncRNAs in dilated cardiomyopathy

Background:Various physiological mechanisms are linked to dilated cardiomyopathy(DCM)development,including oxidative stress,immune irregularities,inflammation,fibrosis,and genetic changes.However,precise molecular drivers of DCM,especially regarding abnormal immune responses,remain unclear.This study investigates immune-related long non-coding RNAs(lncRNAs)in DCM’s diagnostic and therapeutic potential.Methods:GSE141910,GSE135055,and GSE165303 datasets were acquired from the GEO database.LASSO,SVM-RFE,and random forest algorithms identified DCM-associated immune-related lncRNAs.Diagnostic capabilities were assessed by Nomogram and receiver operating characteristic(ROC)curves.Multivariate linear regression explored lncRNA correlations with ejection fraction.Single-sample gene set enrichment analysis(ssGSEA)gauged immune cell infiltration/functions.Functional enrichment analyses were performed using Gene set variation analysis(GSVA),gene ontology(GO),and the Kyoto Encyclopedia of Genes and Genomes(KEGG).Consensus clustering categorized DCM cases.Results:Ten immune-related lncRNAs emerged:C10orf71-AS1,FHAD1-AS1,SCIRT,FNDC1-AS1,MELTFAS1,LOC101928834,GDNF-AS1,DCXR-DT,C3orf36,and LOC107985323.These lncRNAs,tied to immunomodulation,showed promising DCM diagnostic accuracy.Adjusted for confounders,they independently correlated with ejection fraction.Using lncRNA expression,DCM patients were grouped into subtypes.Subtype C1 displayed a higher level of immune cell infiltration and immune checkpoint expression compared to subtype C2,emphasizing the variations in the immune microenvironment.Conclusion:This study identifies ten immune-related lncRNAs for further exploration in DCM diagnosis and subtyping.Based on expression patterns,we propose two potential DCM subtypes.Notably,findings are preliminary and hypothesis-generating,demanding validation and further investigation.This research provides insights into DCM diagnosis and classification.

Value of cardiac magnetic resonance on the risk stratification of cardiomyopathies

Cardiomyopathies represent a diverse group of heart muscle diseases with varying etiologies,presenting a diagnostic challenge due to their heterogeneous manifestations.Regular evaluation using cardiac imaging techniques is impera-tive as symptoms can evolve over time.These imaging approaches are pivotal for accurate diagnosis,treatment planning,and optimizing prognostic outcomes.Among these,cardiovascular magnetic resonance(CMR)stands out for its ability to provide precise anatomical and functional assessments.This manuscript ex-plores the significant contributions of CMR in the diagnosis and management of patients with cardiomyopathies,with special attention to risk stratification.CMR’s high spatial resolution and tissue characterization capabilities enable early detec-tion and differentiation of various cardiomyopathy subtypes.Additionally,it offers valuable insights into myocardial fibrosis,tissue viability,and left ven-tricular function,crucial parameters for risk stratification and predicting adverse cardiac events.By integrating CMR into clinical practice,clinicians can tailor patient-specific treatment plans,implement timely interventions,and optimize long-term prognosis.The non-invasive nature of CMR reduces the need for invasive procedures,minimizing patient discomfort.This review highlights the vital role of CMR in monitoring disease progression,guiding treatment decisions,and identifying potential complications in patients with cardiomyopathies.The utilization of CMR has significantly advanced our understanding and management of these complex cardiac conditions,leading to improved patient outcomes and a more personalized approach to care.

Association between late gadolinium enhancement and outcome in dilated cardiomyopathy:A meta-analysis

BACKGROUND The prognostic value of late gadolinium enhancement(LGE)derived from cardiovascular magnetic resonance(CMR)is well studied,and several new metrics of LGE have emerged.However,some controversies remain;therefore,further discussion is needed,and more precise risk stratification should be explored.AIM To investigate the associations between the positivity,extent,location,and pattern of LGE and multiple outcomes in dilated cardiomyopathy(DCM).METHODS PubMed,Ovid MEDLINE,and Cochrane Library were searched for studies that investigated the prognostic value of LGE in patients with DCM.Pooled hazard ratios(HRs)and 95%confidence intervals were calculated to assess the role of LGE in the risk stratification of DCM.RESULTS Nineteen studies involving 7330 patients with DCM were included in this metaanalysis and covered a wide spectrum of DCM,with a mean left ventricular ejection fraction between 21%and 50%.The meta-analysis revealed that the presence of LGE was associated with an increased risk of multiple adverse outcomes(all-cause mortality,HR:2.14;arrhythmic events,HR:5.12;and composite endpoints,HR:2.38;all P<0.001).Furthermore,every 1%increment in the extent of LGE was associated with an increased risk of all-cause mortality.Analysis of a subgroup revealed that the prognostic value varied based on different location and pattern of LGE.Additionally,we found that LGE was a stronger predictor of arrhythmic events in patients with greater left ventricular ejection fraction.CONCLUSION LGE by CMR in patients with DCM exhibited a substantial value in predicting adverse outcomes,and the extent,location,and pattern of LGE could provide additional information for risk stratification.

Mechanism of Anti-β-adrenoceptor Antibody Mediated Myocardial Damage in Dilated Cardiomyopathy

Antibodies against &-adrenoceptor can be detected in serum of patients with dilated cardiomyopathy (DCM), which have 5-agonist-like activity, and induce a positive chronotropic effect on cardiac myocytes by its persistence at full strength. Effects of the antibodies against Padrenoceptor from sera of patients with DCM on myocardial cytotoxicity and cytoplasmic free Ca2+-concentration (LCa2+ji) were observed in the cultured single layer SD rat ventricular cells by using the cytotoxicity assay and fluorescent Ca2+- indicat0r fura-2/AM. The positive sera of the anti-&adrenoceptor antibodies from patients with DCM markedly enhanced myocardial [Ca2+]i. Betaloc, a 5, -receptor blocker, might inhibit the increase of the antibody-mediated myocardial [Ca2+]i, and the sera from healthy donors had no effect on myocardial [Ca2+]i,. Our results suggest that the anti-β-adrenoceptor antibody might increase myocardial [Ca2+]i, and result in myocardial damage. The antibodies might activate receptor-gating Ca2+-channel, thereby causing myocardial [Ca2+]i, rise and calcium overload. Early use of betaloc is recommended in the treatment of dilated cardiomyopathy.

Prognostic Value of Feature-Tracking Circumferential Strain in Dilated Cardiomyopathy Patients with Severely Reduced Ejection Fraction Incremental to Late Gadolinium Enhancement

Myocardial fiber deformation measurements have been reported to be associated with adverse outcomes in patients with acute heart failure and those with myocardial infarction.However,few studies have addressed the prognostic value of global circumferential strain(GCS)in dilated cardiomyopathy(DCM)patients with severely impaired systolic function.This study aimed to evaluate the prognostic value of cardiac magnetic resonance(CMR)-derived GCS in DCM patients with severely reduced ejection.Consecutive DCM patients with severely reduced ejection fraction(EF<35%)who underwent CMR were included.GCS was calculated from CMR cine images.The clinical endpoint was a composite of all-cause mortality,heart transplantation,implantable cardioverter defibrillator(ICD)implantation and aborted sudden cardiac death(SCD).A total of 129 patients with a mean EF of 15.33%(11.36%–22.27%)were included.During a median follow-up of 518 days,endpoint events occurred in 50 patients.Patients with GCS≥the median(−5.17%)had significantly reduced event-free survival as compared with those with GCS<the median(P<0.01).GCS was independently associated with adverse events after adjusting for clinical and imaging risk factors including extent of late gadolinium enhancement(LGE)(P<0.05).Adding GCS into the model including the extent of LGE resulted in significant improvements in the C-statistic(from 0.706 to 0.742;P<0.05)with a continuous net reclassification improvement(NRI)of 29.71%.It was concluded that GCS derived from CMR could be useful for risk stratification in DCM patients with severely reduced EF,which may increase common imaging risk factors including LGE.

Identification of a LMNA (c.646C>T) variant by whole-exome sequencing in combination with a dilated cardiomyopathy (DCM) related gene filter in a family with familiar DCM

Dilated cardiomyopathy（DCM）is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM concomitant with arrhythmias and sudden death resulting from gene mutation has been widely

HLA-DRB1 Gene Polymorphism in Patients with Dilated Cardiomyopathy

To probe into the genetic background and immunopathogenesis of dilated cardiomyopathy (DCM), HLA-DRB1 gene polymorphism in 68 patients with DCM and 175 normal control subjects were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) techniques. It was found that the frequencies of HLA-DRB1 15 and HLA-DRB1 03 alleles were significantly lower in DCM patients than those in normal controls (14. 71 % vs 29. 71 % and 4. 41 % vs 15. 43 %, respectively), the relative risks (RR) in the DCM patients being 0. 41 and 0. 25, respectively, all P<0. 05. However, the frequencied of HLA-DRB1 11 and HLA-DRB1. 12 alleles were significantly higher in the DCM patients than in controls (29. 4 % vs 12. 00 % and 36. 76 % vs 12. 57 %, respectively) with the RR in the DCM patients being 3. 06 and 4. 04, respectively, all P<0. 01. These findings further demonstrated that-immunogenetics might play a predominant pathogenetic role in partial DCM patients.

A novel mitochondrial tRNA gene mutation in a chinese family with dilated cardiomyopathy and sensorineural deafness

Objective： To determine whether a mutation of mitochondrial DNA induces familial dilated cardiomyopathy in Chinese families with cardiomyopathy, and analyzed the correlation between the genotype and phenotype. Methods： Affected members in three Chinese families of the familial dilated cardiomyopathy underwent clinical evaluation and DNA analysis. Polymerase chain reaction and direct DNA sequencing were used to screen for mitochondrial DNA mutation. The type of mtDNA variations and clinical situation were analysed on the patients with mitochondrial DNA mutation. Results： The mitochondrial A3434G mutation was identified in one of the three families,the 3434 th nucleotide A was replaced by G, which led to change of amino acid. No mutations were identified in the clinically unaffected members of the family and all members of the other two families. Conclusion： This study indicates that the mitochondrial A3434G mutation maybe related with familial dilated cardiomyopathy and deafness.

Nemaline myopathy with dilated cardiomyopathy and severe heart failure: A case report

BACKGROUND Nemaline myopathy(NM)is a rare type of congenital myopathy,with an incidence of 1:50000.Patients with NM often exhibit hypomyotonia and varying degrees of muscle weakness.Skeletal muscles are always affected by this disease,while myocardial involvement is uncommon.However,with improvements in genetic testing technology,it has been found that NM with a mutation in the myopalladin(MYPN)gene not only causes slow,progressive muscle weakness but also results in dilated or hypertrophic cardiomyopathy.CASE SUMMARY A 3-year-old pre-school boy was admitted to our hospital with cough,edema,tachypnea,and an increased heart rate.The patient was clinically diagnosed with severe dilated cardiomyopathy and heart failure,and subsequent gene examination confirmed the diagnosis of NM with a mutation in MYPN.Captopril,diuretics,low-dose digoxin,and dobutamine were administered.After 22 d of hospitalization,the patient was discharged due to the improvement of clinical symptoms.During the follow-up period,the patient died of refractory heart failure.CONCLUSION Decreased muscular tone and dilated cardiomyopathy are common features of MYPN-mutated NM.Heart transplantation may be a solution to this type of cardiomyopathy.

Left Atrial Volume Index in Patients with Dilated Cardiomyopathy—Correlation with Left Ventricular Function

Background: The aim of this study was to determine the relation of left atrial (LA) volume and LA volume index with left ventricular function and to determine the association of duration of symptoms and left atrial volume index in patients with dilated cardiomyopathy. Materials and Methods: This was an observational, single centre study conducted in India. A total of 50 patients who were admitted to department of cardiology from July, 2008 to February, 2009 with diagnosis of dilated cardiomyopathy and an ejection fraction of <40% were included. Results: Of the 50 patients, 34 (68%) were males. 27 (54%) patients were in NYHA class II and 23 (46%) patients were in NYHA class III. LA volume was found to be ≥40 ml in all patients. LV function and LA volume were found to be correlated (r = -0.789, p < 0.01). Similarly, there was a correlation between LV function and LA volume index (r = -0.826, p < 0.01). There was no correlation between LA volume index and duration of symptoms (r = 0.04). Conclusion: It can be concluded that there is a strong inverse correlation between LA volume and left ventricular function and also between LA volume index and left ventricular function. The patients with NYHA class III were having larger left atrial volume than those with NYHA class II. Moreover, the duration of symptoms has no correlation with left atrial volume index.

Development of dilated cardiomyopathy with a long latent period followed by viral fulminant myocarditis:A case report

BACKGROUND The clinical course of acute myocarditis ranges from the occurrence of a few symptoms to the development of fatal fulminant myocarditis.Specifically,fulminant myocarditis causes clinical deterioration very rapidly and aggressively.The long-term prognosis of myocarditis is varied,and it fully recovers without leaving any special complications.However,even after recovery,heart failure may occur and eventually progress to dilated cardiomyopathy(DCM),which causes serious left ventricular dysfunction.In the case of follow-up observation,no clear guidelines have been established.CASE SUMMARY We report the case of a 21-year-old woman who presented with dyspnea.She became hemodynamically unstable and showed sustained fatal arrhythmias with decreased heart function.She was clinically diagnosed with fulminant myocarditis based on her echocardiogram and cardiac magnetic resonance results.After 2 d,she was readmitted to the emergency department under cardiopulmonary resuscitation and received mechanical ventilation and extracorporeal membrane oxygenation.An implantable cardioverter defibrillator was inserted for secondary prevention.She recovered and was discharged.Prior to being hospitalized for sudden cardiac function decline and arrhythmia,she had been well for 7 years without any complications.She was finally diagnosed with dilated cardiomyopathy.CONCLUSION DCM may develop unexpectedly in patients who have been cured of acute fulminant myocarditis and have been stable with a long period of remission.Therefore,they should be carefully and regularly observed clinically throughout long-term follow-up.

Feasibility of Bone Marrow Stromal Cells Autologous Transplantation for Dilated Cardiomyopathy

The feasibility of bone marrow stromal cells autologous transplantation for rabbit model of dilated cardiomyopathy induced by adriamycin was studied. Twenty rabbits received 2 mg/kg of adriamycin intravenously once a week for 8 weeks （total dose, 16 mg/kg） to induce the cardiomyopathy model with the monitoring of cardiac function by transthoracic echocardiography. Marrow stromal cells were isolated from cell-transplanted group rabbits and were culture-expanded on the 8th week. On the 10th week, cells were labeled with 4,6-diamidino-2-phenylindole （DAP1）, and then injected into the myocardium of the same rabbits. The results showed that viable cells labeled with DAPI could be identified in myocardium at 2nd week after transplantation, Histological findings showed the injury of the myocardium around the injection site was relieved with less apoptosis and more expression of bcl-2. The echocardiography found the improvement of local tissue movement from （2.12±0.51） cm/s to （3.81±0.47） cm/s （P〈0.05） around the inject site, but no improvement of heart function as whole. It was concluded bone marrow stromal cells transplantation for dilated cardiomyopathy was feasibe. The management of cells in vitro, the quantity and the pattern of the cells transplantation and the action mechanism still need further research.

Multi-Task Learning Using Attention-Based Convolutional Encoder-Decoder for Dilated Cardiomyopathy CMR Segmentation and Classification

Myocardial segmentation and classification play a major role in the diagnosis of cardiovascular disease.Dilated Cardiomyopathy(DCM)is a kind of common chronic and life-threatening cardiopathy.Early diagnostics significantly increases the chances of correct treatment and survival.However,accurate and rapid diagnosis of DCM is still challenge due to high variability of cardiac structure,low contrast cardiac magnetic resonance(CMR)images,and intrinsic noise in synthetic CMR images caused by motion artifact and cardiac dynamics.Moreover,visual assessment and empirical evaluation are widely used in routine clinical diagnosis,but they are subject to high inter-observer variability and are both subjective and non-reproducible.To solve this problem,we proposed an effective unified multi-task framework for dilated cardiomyopathy CMR segmentation and classification simultaneously,and we firstly update one independent encoder from both recovery decoder and parallel attention path sharing some partial weights.This can encode both task choices into good embedding,but each one can achieve significant improvements respectively from the given embedding.It consists of three branches:extraction path,attention path,and recovery path,which allows the model to learn more higher-level intermediate representations and makes a more accurate prediction.We validated our approach on a DCM dataset,which contains 1155 CMR LGE images.Experimental results show that our multi-task network has achieved accuracy of 97.63%,AUC of 98.32%,demonstrating effectively segmenting the myocardium,quickly and accurately diagnosing the presence or absence of dilation.

Novel mutations of the Alstr?m syndrome 1 gene in an infant with dilated cardiomyopathy:A case report

BACKGROUND Alstr?m syndrome(AS)is a rare autosomal recessive disease that is generally induced by mutations of the Alstr?m syndrome 1(ALMS1)gene.We report a case of AS,extend the spectrum of ALMS1 mutations and highlight the biological role of ALMS1 to explore the relationship between dilated cardiomyopathy(DCM)and mutations in ALMS1.CASE SUMMARY We present the case of an infant with AS mainly manifesting with DCM that was caused by a novel mutation of the ALMS1 gene.Whole-exome sequencing revealed a simultaneous large deletion and point mutation in ALMS1,leading to frameshift and missense mutations,respectively,rather than nonsense or frameshift mutations,which have been reported previously.Upon optimized anti-remodeling therapy,biohumoral exams and arrhythmic burden of the infant were alleviated at follow-up after 6 mo.CONCLUSION We identified novel mutations of ALMS1 and extended the spectrum of ALMS1 mutations in an infant with AS.

Dyssynchrony Induced by Ventricular Preexcitation: A Risk Factor for the Development of Dilated Cardiomyopathy

Background:Signifi cant left ventricular dysfunction may arise in right-sided accessory pathways with ventricular preexcitation in the absence of recurrent or incessant tachycardia.This has just been realized and not enough attention has been paid to it.Methods:In the last 7 years,we identifi ed 12 consecutive children with a diagnosis of ventricular preexcitation–induced dilated cardiomyopathy.This report describes the clinical and echocardiographic characteristics of the patients before and after ablation.Results:Dyssynchronous ventricular contraction was observed by M-mode echocardiography and two-dimensional strain analysis in all patients.The basal and middle segments of the interventricular septum became thin and moved similarly to an aneurysm,with typical bulging during the end of systole.The locations of the accessory pathways were the right-sided septum(n=5)and the free wall(n=7).Left ventricular synchrony was obtained shortly after ablation.The left ventricular function recovered to normal and the left ventricular end-diastolic diameter decreased gradually during follow-up.Conclusions:A causal relationship between ventricular preexcitation and the development of dilated cardiomyopathy is supported by the complete recovery of left ventricular function and reversed left ventricular remodeling after the loss of ventricular preexcitation.Preexcitation-related dyssynchrony was thought to be the crucial mechanism.Ventricular preexcitation–induced dilated cardiomyopathy is an indication for ablation with a good prognosis.