Predicting apical hypertrophic cardiomyopathy using T-wave inversion:Three case reports

BACKGROUND Apical hypertrophic cardiomyopathy(AHCM)is a subtype of hypertrophic cardiomyopathy.Due to its location,the thickening of the left ventricular apex can be missed on echocardiography.Giant negative T waves(GNTs)in left-sided chest leads are the hallmark electrocardiogram(ECG)change of AHCM.CASE SUMMARY The first patient was a 68-year-old woman complaining of recurrent chest tightness persisting for more than 3 years.The second was a 59-year-old man complaining of spasmodic chest tightness persisting for more than 2 years.The third was a 55-year-old woman complaining of recurrent chest pain persisting for 4 mo.In all three cases,GNTs were observed several years prior to apical cardiac hypertrophy after other causes of T-wave inversion were ruled out.CONCLUSION Electrophysiological abnormalities of AHCM appear earlier than structural abnormalities,confirming the early predictive value of ECG for AHCM.

Specific alterations of regional myocardial work in strength-trained athletes using anabolic androgenic steroids compared to athletes with genetic hypertrophic cardiomyopathy

Background:Strength-trained athletes using anabolic androgenic steroids(AAS)have left ventricular(LV)hypertrophy and myocardial fibrosis that can lead to sudden cardiac death.A similar feature was described in athletes with hypertrophic cardiomyopathy(HCM),which complicates the diagnosis for clinicians.In this context,we aimed to compare the LV function of the 2 populations by measuring global and regional strain and myocardial work using speckle-tracking imaging.Methods:Twenty-four strength-trained asymptomatic athletes using AAS(AAS-Athletes),22 athletes diagnosed with HCM(HCM-Athletes),and 20 healthy control athletes(Ctrl-Athletes)underwent a resting echocardiography to assess LV function.We evaluated LV global and regional strains and myocardial work,with an evaluation of the constructive work(CW),wasted work,and work efficiency(WE).Results:Compared to Ctrl-Athletes,both AAS-Athletes and HCM-Athletes had a thicker interventricular septum,with maj ored values in HCM-Athletes.LV strain was reduced in AAS-Athletes and even more in HCM-Athletes.Consequently,global WE was significantly diminished in both AAS and HCM-Athletes(93%±2%in Ctrl-Athletes,90%±4%in AAS-Athletes,and 90%±5%in HCM-Athletes(mean±SD);p<0.05).Constructive work and WE regional analysis showed specific alterations,with the basal septal segments preferentially affected in AAS-Athletes,and both septal and apical segments affected in HCM-Athletes.Conclusion:The regional evaluation of myocardial work reported specific alterations of the major LV hypertrophy induced by the regular use of AAS compared to the LV hypertrophy due to HCM.This finding could help clinicians to differentiate between these 2 forms of pathological hypertrophy.

Bicuspid aortic valve with associated aortopathy, significant left ventricular hypertrophy or concomitant hypertrophic cardiomyopathy: A diagnostic and therapeutic challenge

Due to its prevalence of 0.5%to 2%in the general population,with a 75%predominance among men,bicuspid aortic valve is the most common congenital heart defect.It is frequently accompanied by other cardiac congenital anomalies,and clinical presentation can vary significantly,with stenosis being the most common manifestation,often resulting in mild to moderate concentric hypertrophy of the left ventricle.Echocardiography is the primary diagnostic modality utilized for establishing the diagnosis,and it is often the sole diagnostic tool relied upon by clinicians.However,due to the heterogeneous clinical presentation and possible associated anomalies(which are often overlooked in clinical practice),it is necessary to employ various diagnostic methods and persist in finding the accurate diagnosis if multiple inconsistencies exist.By employing this approach,we can effectively manage these patients and provide them with appropriate treatment.Through a clinical case from our practice,we provide an overview of the literature on bicuspid aortic valve with aortophaty and the possible association with hypertrophic cardiomyopathy,diagnostic methods,and treatment options.This review article highlights the critical significance of achieving an accurate diagnosis in patients with bicuspid aortic valve and significant left ventricular hypertrophy.It is crucial to exclude other possible causes of left ventricular outflow tract obstruction,such as sub-or supra-aortic obstructions,and hypertrophic cardiomyopathy.

Myocardial Perfusion Abnormalities in Patients with Hereditary Hypertrophic Cardiomyopathy: A Study of Three Cases and Review of the Literature

Introduction: Hypertrophic cardiomyopathy (HCM) belongs to the very heterogeneous group of cardiomyopathies. This study aimed to study myocardial perfusion abnormalities on scintigraphy and assess the risk of sudden death from ventricular arrhythmia in hereditary sarcomeric HCM. Patients and Methods: This is a retrospective and prospective descriptive study over 18 months (January 01, 2021, to July 31, 2022) on the records of patients over 18 with the diagnosis of hypertrophic sarcomeric cardiomyopathy with or without ventricular rhythm disorders and who have undergone myocardial scintigraphy. Results: Three patients were included. The average age of our patients was 66 years old. Dyspnea is the primary symptomatology found in our patients. One patient presented with syncope and unsustained ventricular tachycardia. His risk score for sudden death from ESC at five years is estimated at 6.45%, and the patient received an ICD in primary prevention. The average sudden death risk score of our patients was 3.78%. The mean LV wall thickness was 20 mm. The mean maximum left intraventricular gradient was 39 mmHg. Myocardial fibrosis was present in all our patients. Myocardial scintigraphy was normal in all cases. Conclusion: Hypertrophic cardiomyopathy is a very heterogeneous group of cardiomyopathies. The rhythmic risk is multifactorial and constitutes a significant prognostic factor.

Mitral Valve Abnormalities during Hypertrophic Cardiomyopathy: Study on a Cohort in Dakar

INTRODUCTION: Mitral valve abnormalities in hypertrophic cardiomyopathy (HCM) are becoming increasingly well defined, and their role in intra-ventricular obstruction is well defined. The aim of this study was to evaluate mitral valve abnormalities in patients with HCM. PATIENTS AND METHODS: We conducted a descriptive cross-sectional study from May 1 to July 1, 2022 in the Cardiology Department of Aristide Le Dantec Hospital. All patients with HCM aged at least 18 years old were included. The parameters studied concerned mainly the mitral valvular apparatus (papillary muscles abnormalities, leaflet length, mitral insufficiency). RESULTS: A total of 10 patients were included. Mean age was 58.3. On Doppler echocardiography, mean interventricular septal thickness was 20.6 mm. The mean maximum intra-ventricular gradient was 21.06 mmHg. Two patients had significant intraventricular obstruction. The mean length of the anterior mitral valve leaflet was 28.7 ± 3.55 mm, with extremes of 22 and 33 mm. The posterior mitral leaflet averaged 14.8 ± 3.16 mm. Nine (9) out of 10 patients had an elongated anterior valve leaflet. Elongation of the posterior leaflet was noted in 6 patients. With regard to papillary muscle position, 6 patients had an anterolateral ascending pillary muscle. These patients had a mean intra-ventricular gradient of 25 mmHg, compared with 16.5 mmHg in the others cases. We found no direct insertion on the mitral valve. Mitral insufficiency was noted in 9 patients, including 5 with mild insufficiency and 4 with moderate one. CONCLUSION: Mitral valve abnormalities in HCM appear to be frequent. They should be analyzed for a better diagnostic and therapeutic approach.

Pulmonary vein isolation implemented by second-generation cryoballoon for treating hypertrophic cardiomyopathy patients with symptomatic atrial fibrillation:a case-control study

Background Atrial fibrillation(AF)is a generally acknowledged turning-point of the natural history of hypertrophic cardiomyopathy(HCM);however,data from the cryoballoon ablation(CBA)for AF in HCM patients are relatively scarce.The study aimed to evaluate the efficacy and safety of CBA in HCM patients with AF.Methods We retrospectively analyzed HCM patients among 1253 patients with symptomatic AF who underwent CBA for pulmonary vein isolation in a single center.The study analyzed the AF recurrence and assessed the CBA indexes,including nadir temperature,time-to-isolation,CBA failure,pulmonary vein potentials(PVPs),and redo procedure.Results A total of 108 patients were included(mean age:59.0±6.9 years),27 patients(25%)had HCM,with the median follow-up duration of 25.5 months.The one-year AF-free rates were 79.0%vs.63.0%(non-HCM vs.HCM),while the two-year AF-free rates were 77.8%vs.55.1%[hazard ratio(HR)=2.758,log-rank P=0.024].Patients with persistent AF had poor AF-free rates compared to those with paroxysmal AF(P<0.001).The CBA failure was the most common in the right inferior pulmonary veins,which had the lowest PVPs.Multivariate Cox regression analysis indicated that HCM and persistent AF were risk factors for AF recurrence(HR=2.74,95%CI:1.29–5.79,P=0.008;and HR=3.97,95%CI:1.85–8.54,P<0.001,respectively).Conclusions The CBA can be effectively and safely used to treat HCM patients with symptomatic AF.The freedom from AF for HCM patients after CBA is relatively low compared to that for non-HCM patients.

Left Ventricular Regional Systolic Function in Patient with Hypertrophic Cardiomyopathy by Quantitative Tissue Velocity Imaging

The left ventricular regional systolic functions in patients with hypertrophic cardiomyopathy （HCM） were assessed by using quantitative tissue velocity imaging （QTVI）. Left ventricular （LV） regional myocardial velocity along long- and short-axis in 31 HCM patients and 20 healthy subjects were analyzed by QTVI, and the regional myocardial systolic peak velocities （MVS） were measured. Mean MVS at each level including mitral annular, basal, middle and apical segments were calculated. The ratio of MVS along long-axis to that along short-axis （Ri） at basal and middle segments of the LV posterior wall and ventricular septum were calculated. The results showed that mean MVS was slower at each level including mitral annular, basal, middle and apical segments in the HCM patients than that in the healthy subjects （P〈0.01）. There were no significant differences in mean MVS between obstructive and non-obstructive groups in HCM patients. MVS of all regional myocardial segments along long-axis in the HCM patients were significantly slower than that in the healthy subjects （P〈0.05）, but there was no significant difference in MVS of all regional myocardial segments along long-axis between hypertrophied and non-hypertrophied group in the HCM patients. Ri was significantly lower in the HCM patients than that in the healthy subjects. The LV regional myocardial contractility along long-axis was impaired not only in the hypertrophied wall but also in the non-hypertrophied one in patients with HCM, suggesting that QTVI can assess accurately LV regional systolic function in patient with HCM and provides a novel means for an early diagnosis before and independent of hypertrophy.

Assessment of Regional Myocardial Function in Patients with Hypertrophic Cardiomyopathy by Tissue Strain Imaging

The value of tissue strain imaging （SI） in regional myocardial systolic and diastolic func tion assessment was studied. In 18 patients with nonobstructive hypertrophic cardiomyopathy （HCM） and 20 age-matched healthy subjects, regional myocardial longitudinal peak systolic strain in eject time （represented by εet） was measured at basal, mid and apical segments of septal, lateral and posterior walls of the left ventricle （LV） and compared between groups, εet had no significant difference between segments in control group （P〉0.05）, which displayed a decreasing trend from basal segments to apical ones. εet in the HCM group was significantly decreased （P（0. 05） as compared with that in the healthy group. In the HCM group, εet in the midseptum was significantly less than at the basal and apical septum, and was also less than at the rest LV walls in the same group （P〉0.01）. The systolic reversed εet was noticed in 35% of the hypertrophic segments in HCM group. Significantly negative correlation existed between the absolute value of εet and wall thickness in the midseptum （r= -0.83）. The post-systolic strain（PSS） segment number the and amplitudes in healthy group were significantly less than those in HCM group （P〈0.05）. Both regional myocardial systolic and diastolic functions were impaired in hypertrophic or non-hypertrophic segments in patients with the HCM, especially in hypertrophic segments. Strain imaging technique is a sensitive and accura tool in myocardial dysfunction assessment.

Identification of the Potential Function of circRNA in Hypertrophic Cardiomyopathy Based on Mutual RNA-RNA and RNA-RBP Relationships Shown by Microarray Data

The pathogenesis of hypertrophic cardiomyopathy(HCM)is very complicated,particularly regarding the role of circular RNA(circRNA).This research pays special attention to the relationships of the circRNA-mediated network,including RNA-RNA relationships and RNA-RNA binding protein(RNA-RBP)relationships.We use the parameter framework technology proposed in this paper to screen differentially expressed circRNA,messenger RNA(mRNA),and microRNA(miRNA)from the expression profile of samples related to HCM.And 31 pairs of circRNA and mRNA relationship pairs were extracted,combined with the miRNA targeting database;145 miRNA-mRNA relationship pairs were extracted;268 circRNA-mRNA-miRNA triads were established through the common mRNA in the 2 types of relationship pairs.Thus,268 circRNA-miRNA regulatory relationships were deduced and 30 circRNARBP relationship pairs were analyzed at the protein level.On this basis,a circRNA-mediated regulatory network corresponding to the two levels of RNA-RNA and RNA-RBP was established.And then the roles of circRNA in HCM were analyzed through circRNA-mRNA,circRNA-miRNA,and circRNA-RBP,and the possible role in disease development mas inferred.

Age-related Changes in Familial Hypertrophic Cardiomyopathy Phenotype in Transgenic Mice and Humans

β-myosin heavy chain mutations are the most frequently identified basis for hypertrophic cardiomyopathy （HCM）. A transgenic mouse model （αMHC403） has been extensively used to study various mechanistic aspects of HCM. There is general skepticism whether mouse and human disease features are similar. Herein we compare morphologie and functional characteristics, and disease evolu- tion, in a transgenic mouse and a single family with a MHC mutation. Ten male αWHC403 transgenic mice （at -5 weeks, -12 weeks, and -24 weeks） and 10 HCM patients from the same family with a β-myosin heavy chain mutation were enrolled. Morphometric, conventional echocardiographic, tissue Doppler and strain analytic characteristics of transgenic mice and HCM patients were assessed. Ten male transgenic mice （αMHC403） were examined at ages -5 weeks, -12 weeks, and -24 Weeks. In the transgenic mice, aging was associated with a significant increase in septal （0.59±0.06 vs. 0.64±-0.05 vs. 0.69±0.11 mm, P〈0.01） and anterior wall thickness （0.58±0.1 vs. 0.62±0.07 vs. 0.80-1-0.16 mm, P〈0.001）, which was coincident with a significant decrease in circumferential strain （-22%=1=4% vs. -20%-4-3% vs. -19%-4-3%, P=0.03）, global longitudinal strain （-19%-4-3% vs. -17%-4-2% vs. -16%±3%, P=0.001） and E/A ratio （1.9±0.3 vs. 1.7-4-0.3 vs. 1.4-4-0.3, P=0.01）. The HCM patients were classified into 1st generation （n=6; mean age 534-6 years）, and 2nd generation （n=4; mean age 32＋8 years）. Septal thickness （2.2±0.9 vs. 1.4±0.1 cm, P〈0.05）, left atrial （LA） volume （62±16 vs. 41±5 mL, P=0.03）, E/A ratio （0.77±0.21 vs. 1.1±0.1, P=0.01）, E/e＇ ratio （25±10 vs. 12±2, P=0.03）, global left ventricular （LV） strain （-14%±3% vs. -20%±3%, P=0.01） and global LV early diastolic strain rate （0.76±0.17 s1 vs. 1.3±0.2 s-1, P=0.01） were significantly worse in the older generation. In β-myosin heavy chain muta- tions, transgenic mice and humans have similar progression in morphologic and functional abnormali- ties. The αMHC4±3 transgenic mouse model closely recapitulates human disease.

Myocardial Fibrosis in the Pathogenesis, Diagnosis, and Treatment of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy(HCM)is a type of hereditary cardiomyopathy caused by gene mutation.Its histological features include cardiomyocyte hypertrophy and disarray as well as myocardial fi brosis.Gene mutation,abnormal signal transduction,and abnormal energy metabolism are considered the main mechanisms of myocardial fi brosis.There is a strong correlation between myocardial fi brosis and the occurrence,development,and prognosis of HCM.We review the application of myocardial fi brosis in the diagnosis and treatment of HCM,focusing on research progress and the application of magnetic resonance imaging on the basis of the characteristics of fi brosis in the diagnosis and prognosis of HCM.

Evaluation of cardiac structures and function in hypertrophic cardiomyopathy with magnetic resonance imaging

Objective：To assess the capability of magnetic resonance imaging（MRI） in evaluating the cardiac structures and function in the hypertrophic cardiomyopathy（HCM）. Methods：Fourteen healthy volunteers and eighteen cases with HCM verified by history, clinical presentation, electrocardiogram and echocardiography（ECG） were performed with MRI. The myocardial thickness of interventricular septum at the basal segment and that of posterolateral free wall of the left ventricle（LV） were measured. Some indexes for evaluating cardiac ftmction were measured using ARGUS auto-quantitative program. Results：The myocardial thickness of septum at the basal segment had significant difference between the HCM patients and the healthy volunteers. There was no significant difference between MRI and ECG in examining end-diastolic volume, ejection fraction of the LV. Conclusion：MRI can fully provide more information on the abnormalities of cardiac anatomy and function; thus, it is of great value in clinical application.

Ventricular fibrillation and sudden cardiac arrest in apical hypertrophic cardiomyopathy:Two case reports

BACKGROUND Apical hypertrophic cardiomyopathy(HCM)is considered to have a benign prognosis in terms of cardiovascular mortality.This serial case report aimed to raise awareness of ventricular fibrillation(VF)and sudden cardiac death(SCD)in apical HCM.CASE SUMMARY Here we describe two rare cases of apical HCM that presented with documented VF and sudden cardiac collapse.These patients were previously not recommended for primary prevention using implantable cardioverter-defibrillator(ICD)therapy based on current guidelines.However,both received ICD therapy for the secondary prevention of SCD.CONCLUSION These cases illustrate serious complications including VF and aborted sudden cardiac arrest in apical HCM patients who are initially not candidates for primary prevention using ICD implantation based on current guidelines.

Clinical analysis of 121 patients with hypertrophic cardiomyopathy

Objective：Several studies have analyzed the clinical profiles of patients diagnosed with hypertrophic cardiomyopathy（HCM）. We sought to identify its characteristics in a regional cohort of Nanjing and its adjacent region. Methods：Clinical profiles of 121 referred patients were collected and analyzed retrospectively. Data including family history, clinical symptoms, electrocardiography and recent echocardiography were collected. Results： The mean age of this population was 42 ±17 years（range from 6 to 76） at diagnosis of HCM. Most patients were male（60%）. 48 patients（39.7%） has a family history, 19 had a sudden death in a first degree relative and 96（79.3%） were recognized with cardiac symptoms. Left ventricular outflow obstruction （gradient≥30 mmHg at rest） was presented in 26（21.5%） patients. ECG abnormalities comprised of arrhythmia in 54（51.4%） and abnormal T wave in 72（68.6%） patients. FS were higher in female than male（P= 0.001）. Among younger patients（age ≤ 50 years）, LVDd and LVWP were smaller in females than males（P= 0.042 ＆ 0.023 respectively）. In older patients（age 〉 50 years）, LVDs was higher in male（P= 0.016） and EF was higher in female （P= 0.048）. Conclusion：HCM patients in the region are almost diagnosed with the presentation of cardiac symptoms; those without any symptoms could be recognized by ECG and family screening. Most cardiac hypertrophy affects the interventricular septum. LVDd, LVWP, LVDs, FS and EF showed significant differences related to age and gender.

Hypertrophic Cardiomyopathy as a Manifestation of Multiple Myeloma

Multiple myeloma （MM） is a malignancy of the plasma cell characterized by migration and localization to the bone marrow where cells then disseminate and facilitate the formation of bone lesions. It is associated with a constellation of disease manifestations, apart from osteolytic lesions, anemia and immuno-suppression due to loss of normal hematopoietic stem cell function, and cardiac amyloidosis due to monoclonal immunoglobulin secretion as well. Amyloid infiltration of the heart may frequently masquerade as hypertrophic cardiomyopathy （HCM）. HCM, of which underlying cause and pathogenesis are largely unknown, is characterized by left and/or right ventricular hypertrophy, with predominant involvement of the interventricular septum in the absence of other causes of hypertrophy, such as hypertension or valvular heart diseases. While excessive hypertrophy of the myocardium is most commonly associated with myocyte hypertrophy, infiltration with amyloid always needs to be considered. In this report we presented two cases of multiple myeloma that mimicked hypertrophic cardiomyopathy so closely that it required bone marrow or endomyocardial biopsy to establish the diagnosis.

Role of genetic screening in a chinese woman of childbearing age with hypertrophic cardiomyopathy

Objectives The objective of this study was to evaluate the role of genetic screening in a Chinese woman of childbearing age with hypertrophic cardiomyopathy.Methods and Results One 39 year-old woman with presyncope for 10 years was admitted.Both of her father and her son died of sudden death and she strongly desire to get another baby. A series of clinical and laboratory studies were performed. Hypertrophic cardiomyopathy was diagnosed finally and implantable Cardioverter Defibrillator was implanted to prevent sudden cardiac death for her.Genomic DNA was isolated and the most common causal genes for hypertrophic cardiomyopathy were screened.A known pathogenetic heterozygous mutation c.700 g】a(p.Argl86Gln) in TNNI3 was found,which was not found in 100 normal control individuals matched for age,sex and geographical region.Because 50%probability of the pathogenetic mutation is inherited to the offsprings,she will get a healthy baby in vitro fertilization which the egg comes from a healthy female donor to prevent from the inherited HCM.Conclusions We found a pathogenetic TNNI3 mutation in a Chinese woman of childbearing age with hypertrophic cardiomyopathy.The genetic screening definite DNA-based diagnosis and help to design a healthy fertilization in vitro for female with hypertrophic cardiomyopathy.

Clinical Analysis of 42 Patients With Hypertrophic Cardiomyopathy

Objectives To investigate the clinical manifestations of hypertrophic cardiomyopathy (HCM), and to find out the clinical clues to avoid misdiagnosis and provide reference for future clinical diagnosis and treatment. Methods A retrospective analysis of 42 consecutive patients with HCM hospitalized in our hospital between January 1995 and December 2002 was explored. Based on the family history of HCM, clinical manifestations, electrocar-diogram, echocardiogram, coronary angiography and left ventriculography, the clinical characteristics between HCM patients with left ventricular outflow tract obstruction (HOCM) and HCM patients without obstruction (HNOCM) were compared. The causes of misdiagnosis and losing diagnosis were analysis. Results 13 patients were in HOCM group and 29 patients were in HNOCM group. More patients with syncope were in HOCM group than in HNOCM group (6/13 vs. 2/29, P < 0.05). Patients with ejective murmur were in HOCM group only (P < 0.01). Left ventricular outflow tract pressure gradient (LVOTPG) only observed in HOCM group (P < 0.01). Ventricular tachycardia was seen in both groups. 28 out of 42 patients (66.67%) had misdiagnosis, and 4 out of 42 patients (9.53%) had losing diagnosis. Thus, coronary heart disease (CHD) had the highest rate of misdiagnosis. There were 20 CHD patients (71.43%) among 28 patients with misdiagnosis. Hypertension was in 3, congenital heart in 2, cerebro-embolism in 2, and myocarditis in 1. Conclusions For a patient with family history or sudden death history of HCM, unexplained syncope episodes, chest pain (angina), especially in young, an ejection murmur along the left sternum border, the presence of narrow and deep Q waves, or inversion of giant T waves in V3-V6, atrial fibrillation and /or cerebra-embolism echocardiogram should be given. CAG and LVG are necessary only if the result of echo is negative, and the patients with suspected HCM or CHD.

Hypertrophic cardiomyopathy and left ventricular non-compaction:Distinct diseases or variant phenotypes of a single condition?

Hypertrophic cardiomyopathy(HCM)is a genetically determined myocardial disease characterized by an increased thickness of the left ventricle(LV)wall that cannot be solely attributed to abnormal loading conditions.HCM may present with an intraventricular or LV outflow tract obstruction,diastolic dysfunction,myocardial fibrosis and/or ventricular arrhythmias.Differentiating HCM from other diseases associated with LV hypertrophy,such as hypertension,aortic stenosis,or LV non-compaction(LVNC),can at times be challenging.LVNC is defined by excessive LV trabeculation and deep recesses between trabeculae,often accompanied by increased LV myocardial mass.Previous studies indicate that the LVNC phenotype may be observed in up to 5%of the general population;however,in most cases,it is a benign finding with no impact on clinical outcomes.Nevertheless,LVNC can occasionally lead to LV systolic dysfunction,manifesting as a phenotype of dilated or non-dilated left ventricular cardiomyopathy,with an increased risk of thrombus formation and arterial embolism.In extreme cases,where LVNC is associated with a very thickened LV wall,it can even mimic HCM.There is growing evidence of an overlap between HCM and LVNC,including similar genetic mutations and clinical presentations.This raises the question of whether HCM and LVNC represent different phenotypes of the same disease or are,in fact,two distinct entities.

Machine learning modeling identifies hypertrophic cardiomyopathy subtypes with genetic signature

Previous studies have revealed that patients with hypertrophic cardiomyopathy(HCM)exhibit differences in symptom severity and prognosis,indicating potential HCM subtypes among these patients.Here,793 patients with HCM were recruited at an average follow-up of 32.78±27.58 months to identify potential HCM subtypes by performing consensus clustering on the basis of their echocardiography features.Furthermore,we proposed a systematic method for illustrating the relationship between the phenotype and genotype of each HCM subtype by using machine learning modeling and interactome network detection techniques based on whole-exome sequencing data.Another independent cohort that consisted of 414 patients with HCM was recruited to replicate the findings.Consequently,two subtypes characterized by different clinical outcomes were identified in HCM.Patients with subtype 2 presented asymmetric septal hypertrophy associated with a stable course,while those with subtype 1 displayed left ventricular systolic dysfunction and aggressive progression.Machine learning modeling based on personal whole-exome data identified 46 genes with mutation burden that could accurately predict subtype propensities.Furthermore,the patients in another cohort predicted as subtype 1 by the 46-gene model presented increased left ventricular end-diastolic diameter and reduced left ventricular ejection fraction.By employing echocardiography and genetic screening for the 46 genes,HCM can be classified into two subtypes with distinct clinical outcomes.

Mid-ventricular obstructive hypertrophic cardiomyopathy with apical aneurysm and sustained ventricular tachycardia： a case report and literature review

The case is a 54-year-old man with hypertrophic cardiomyopathy, mid-ventricular obstruction, apical aneurysm, and recurrence sustained monomorphic ventricular tachycardia （VT）. A coronary angiogram revealed myocardial bridging located in the middle of the left anterior descending coronary artery （LAD）, and the left ventriculogram showed an hour-glass appearance of the left ventricular cavity. There was a significant pressure gradient of 60 mmHg across the mid-ventricular obliteration at rest. A successful myectomy of the inappropriate hypertrophy myocardium and excision of the apical aneurysm were performed. Pathologic analysis demonstrated fibrosis in the apical aneurysm and thickened and narrowed vessels in the adjacent area. During the follow-up of eighteen months, the patient remained clinically stable and free from arrhythmic recurrence.