Right Ventricular Mechanical Changes after Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy: Vector Velocity Imaging Study

Objectives: The impairment of right ventricular (RV) myocardial mechanics is evident in hypertrophic cardiomyopathy (HCM). It is independently influenced by LV mechanics and correlated to the severity of LV phenotype. We investigated the changes in RV global and regional deformation following surgical septal myectomy using vector velocity imaging (VVI). Methods: 25 HCM patients, 68% males with mean age (34.5 ± 12 years) were examined before and within two months after surgical myectomy using VVI. In addition to conventional echocardiographic parameters, peak systolic strain (εsys), strain rate (SR) and time to peak εsys (TTP) of regional RV free wall (RVFW) & septal walls were analyzed in longitudinal (long) directions from apical four-chamber view and their (Δ) changes were calculated. Similar parameters were quantified in LV from apical 2 & 4 CH views. Intra-V-delay was defined as SD of TTP and inter-V dyssynchrony was estimated from TTP difference between the most delayed LV segment & RVFW. Results: All study patients showed improvement of their functional class from NYHA class III to class I and reduction of LVOT gradient to below 20 mmHg except one patient who had 30 mmHg gradients at rest. There was significant reduction of septal thickness, left atrial diameter & volume, LVOT gradient, LVMI, severity of mitral regurgitation, tricuspid annular velocities (P < 0.0001), RV diameter (P < 0.02) and increase in LV internal dimensions(P < 0.001) post myectomy. However, there was significant reduction of RV and LV systolic mechanics;RV global εsys % (from -16.1% ± 4.4% to -12.9% ± 2.9%, P < 0.0001) and LV global εsys %: from -11.6% ± 2.8% to -9.4% ± 2.2%, P < 0.0001) respectively. The magnitude of reduction of RV strain (ΔRV εsys %, ΔSRsys) was directly correlated LV maximal wall thickness (r = 0.46, P < 0.01) and ΔRV dyssynchrony (TTP-SD) (r = 0.4, P < 0.05) and negatively correlated to age (r = -0.46, P sys (r = -0.52, P < 0.01) and pre-op LV EF % (r = -0.43, P , the reduction in RV diastolic mechanics: ΔRV SRe & SRa were directly correlated to PAP and LVOT gradient before surgery (r = 0.62, P Conclusion: Despite the improvement of patient functional status and reduction LVOT gradient, RV mechanics shows further deterioration after surgical myectomy. The magnitude of reduction is modestly related to cardiac phenotype and pre-op mechanical function.

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.

Surgical outcomes and strategy of hypertrophic obstructive cardiomyopathy

Objective： To evaluate the surgical clinical results of hypertrophic obstructive cardiomyopathy. Methods： We retrospectively collected data on 24 patients who underwent surgical management in the past ten years in two hospitals in China and Madras Medical Mission in India. Myomectomy was carried out on all patients. Among them 3 patients underwent mitral valve replacement; 2 patients underwent mitral valve repair （anterior mitral leaflet plication）; 2 patients underwent aortic valve replacement; 1 patient underwent aortic valve repair; 2 patients underwent aortic root replacement; 1 patient underwent Bentall＇s procedure and 1 patient underwent coronary artery bypass grafting because of a breached muscle bridge, Results： One patient died of post-operative heart failure. The mean follow-up time was 4.3 years, There was significant improvement in the symptomatic status. Sixteen patients were asymptomatic with good effort tolerance and only four patients had New York heart association （NYHA） Classes Ⅰ-Ⅱ due to associated valvular lesions, Conclusion： Our experience proved that symptomatic hypertrophic obstructive cardiomyopathy or non-symptomatic hypertrophic obstructive cardiomyopathy with combined heart disease is indication for surgery as surgical intervention could get better clinical results in this kind of patients compared with other non-surgical method because it beneficially reduces the systolic anterior motion （SAM） of the mitral valve leaflet, which could not be avoided by other non-surgical treatment.

Mid-ventricular hypertrophic obstructive cardiomyopathy(MVHOCM) complicated with coronary artery disease:a case report

Mid-ventricular hypertrophic obstructive cardiomyopathy (MVHOCM) is a rare type ofcardiomyopathy that can be accompanied by apical aneurysm.We presented here a case report of MVHOCM with cornary artery disease.The sixty-four years old man was sent to hospital because ofventricular tachycardia.Large inversion T wave was showed on electrocardiography in the presence of abnormal coronary arteries and normal cardiac enzyme.Echocardiography showed an hourglass appearance of the left ventricle with an aneurysm in the apex and a pressure gradient between the outflow tract of left ventricle and the middle of the left ventricle was revealed by left-heart catheterization.

Transcatherter chemical myocardial ablation for hypertrophic obstructive cardiomyopathy: short to mid term results.

Objective: Hypertrophic obstructive cardiomyopathy is still a troublesome clinical problem, lack of good treatment method. We use transcatheter chemical myocardial ablation to treat hypertrophic obstructive cardiomyopathy and analysis 25 cases results, to search a novel technique for hypertrophic obstructive cardiomyopathy.Method: From Nov.1996 to Oct.2001 25patients with symptomitical and drug resistents hypertrophic obstructive cardiomyopathy acccepted a nonsurgical treatment, that is percutaneous transseptal myocardial ablation (PTSMA) in our department including 16 males and 9 females, with mean age 44.1 years All patients meet echocardiography diagnosis criterias of hypertrophic obstructive cardiomyopathy, With clinical symptoms of angiana pectors, sycope, short breath etc. No improvement to long term Medical theraphy, rest pressure left ventricular outflow tract gradients over 30 mmHg, or over 50mmHg during provocal test either by invasion or indirect measurement with Doppler echocardiography, 5 patients accepted treatment With Sigwart’s method as previous described, other 20 cases with pigtail catheter left ventricular Continuous curve to measure left ventricular outflow tract gradient, percutaneous insert 1.5mm to 2.0mm balloon catheter into first septal branch of left anterior descending coronary artery, via inflated balloon , inject 3-5ml absolute alcohol into the artery , keep inflating balloon for other 5 minutes continue monitoring pressure gradients and ECG, temporary pacemaker and defibrillator were stand by.Results: All patients, left ventricular outflowtract gradients were significantly reduced, more than 50%, 6 cases occurred serve bradycardia, hypotension need immediate administration, 17 cases with trancient complete right branch block, and in five cases, with permonant complete right branch block,2 cases with transient complete AV block. In follow up, symptom and life quality of all patients were dramitically improved, in first month post procedure, septum thickness reduction, 6mm in average and, 6.8 mm reduction were achieved in 1.5 to 2 years.and 12 cases were follow ed up for more than 4 years ,the longest one has been 6 years still in perfect condition. Anther 5 cases chemical myocardial ablation can not be oerforned for vessels anatomy reasons accepted dual chamber pacing,get compariale results with PTSMA.Conclusion: Our results shown that this technique is a safety and reliable, might be an alternative method to patients with hypertrophic obstructive cardiomyopathy and we although should mention, our anther 5 patients whese can not be performed PTSMA received DDDR pacemaker, with symptom improvement and pressure gradients reduction for two years, as demonstrated by other experts, is althought a opitmal therapy for HOCM.

Angle of Attack between Blood Flow and Mitral Valve Leaflets in Hypertrophic Obstructive Cardiomyopathy: An In Vivo Multipatient CT-based FSI Study

The mechanisms of systolic anterior motion(SAM)of the mitral valve in hypertrophic obstructive cardiomyopathy(HOCM)remain unclear.To investigate the angle of attack between blood flow and mitral valve leaflets at pre-SAM time point,patient-specific CT-based computational models were constructed for 5 patients receiving septal myectomy surgery to obtain pre-and post-operative 2D vector flow mapping.The comparisons between pre-and post-operative angles of attack based on 2D vector flow mapping of 5 patients were performed.It was found that there was no statistically significant difference between pre-and post-operative angles of attack(61.1±t wa o vs.56.2±56.o,p=0.306,n=5).Therefore,we propose that the angle of attack might not play an important role in the initiation of SAM.

Uric acid is associated with cardiac death in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND The role of uric acid(UA) in survival of patients with hypertrophic obstructive cardiomyopathy(HOCM) has not been fully evaluated. This study aimed to determine whether UA could be an independent risk factor of cardiac death in patients with HOCM.METHODS A total of 317 patients with HOCM, who were receiving conservative treatment in Fuwai Hospital from October2009 to December 2014, all of them completed UA evaluations, were analyzed. Patients were divided into three groups according to the UA levels: Tertile 1(≤ 318 μmol/L, n = 106), Tertile 2(319 to 397 μmol/L, n = 105), and Tertile 3(≥ 398 μmol/L, n = 106).RESULTS During a median follow-up of 45 months, 29 cardiac deaths(9.1%) occurred, including 6 sudden cardiac deaths and23 heart failure-related deaths. Cardiac death in Tertile 3(n = 16, 55.2%) was significantly higher than in Tertile 1(n = 6, 20.7%)and Tertile 2(n = 7, 24.1%). In univariate model, UA level(continuous value) showed predictive value of cardiac death [hazard ratio(HR) = 1.006, 95% CI: 1.003-1.009, P = 0.009]. Univariate Cox survival analysis had shown a significant higher property of cardiac death in patients of Tertile 3 when compared with those of Tertile 1, but cardiac death in patients of Tertile 2 did not show significant prognositic value compared with those of Tertile 1(HR = 3.927, 95% CI: 0.666-23.162, P = 0.131). UA was found to be an independent risk factor(HR = 1.005, 95% CI: 1.001-1.009, P = 0.009) of cardiac death in the multivariate regression analysis after the adjustment for age, body mass index, atrial fibrillation, hemoglobin, creatinine, high-sensitivity C-reactive protein, interventricular septum/left ventricular posterior wall ratio, left ventricular outflow tract and left ventricular ejection fraction.CONCLUSIONS UA concentration was found to be independently associated with cardiac death in HOCM patients receiving conservative treatment. Randomized trials of UA-lowering agents for HOCM patients are warranted.

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.

Multimodality imaging in apical hypertrophic cardiomyopathy

Apical hypertrophic cardiomyopathy(AHCM) is a relatively rare morphologic variant of HCM in which the hypertrophy of myocardium is localized to the left ventricular apex. Symptoms of AHCM might vary from none to others mimic coronary artery disease including acute coronary syndrome, thus resulting in inappropriate hospitalization. Transthoracic echocardiography is the firstline imaging technique for the diagnosis of hypertrophic cardiomyopathies. However, when the hypertrophy of the myocardium is localized in the ventricular apex might results in missed diagnosis. Aim of this paper is to review the different imaging techniques used for the diagnosis of AHCM and their role in the detection and comprehension of this uncommon disease.

Speckle tracking echocardiography to assess regional ventricular function in patients with apical hypertrophic cardiomyopathy

AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM.

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.

RISK OF PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY UNDERGOING NONCARDIAC SURGERY

Objective To determine the risk of noncardiac surgery in patients with hypertrophic cardiomyopathy.Methods We reviewed the medical records of all patients who were diagnosed as hypertrophic cardiomyopathy at Peking Union Medical College Hospital from January 1998 to August 2006 and identified 24 patients who subsequently underwent noncardiac surgery.Results There were no intraoperative cardiac events.Postoperative cardiac events were identified in 3 patients including 1 death due to acute myocardial infarction and 2 episodes of transient hypotension.Conclusions The risk of anesthesia and noncardiac surgery is low in patients with hypertrophic cardiomyopathy.During the perioperative period,beta-blockers and/or calcium channel blockers should be given;vasodilator and inotropic agents should be avoided due to the side effects on hemodynamics.

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.

ASSESSMENT OF DIASTOLIC FUNCTION IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY BY DOPPLER TISSUE IMAGING

To determine the clinical application of pulsed Doppler tissue imaging in assessing the left ventricular diasto-lic function and in discriminating between normal subjects and patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction. Methods We measured the peak diastolic velocities of mitral annulus in 81 patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction and 50 normal volunteers by Doppler tissue imaging using the apical window at 2-ch-amber and long apical views, respectively. The myocardial velocities were determined with use of variance F statistical analysis. Results Early diastolic myocardial velocities of mitral annulus were higher in normal subjects than in patients with hy-pertrophic cardiomyopathy with either delayed relaxation, pseudonormal filling, or restrictive filling. However, peak myocar-dial velocities of mitral annulus during atrial contraction were similar in normal subjects and patients with hypertrophic cardiomyopathy. Conclusion Doppler tissue imaging can directly reflect upon left diastolic ventricular function. Early phase of diastole was the best discriminator between control subjects and patients with hypertrophic cardiomyopathy.

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.

Clinical outcome of cardiac resynchronization therapy in dilated-phase hypertrophic cardiomyopathy

Backgrounds Clinical trials have demonstrated that cardiac resynchronization therapy （CRT） is effective in patients with ＂non-is- chemic cardiomyopathy＂. However, patients with dilated-phase hypertrophic cardiomyopathy （DHCM） have been generally excluded from such trials. We aimed to compare the clinical outcome of CRT in patients with DHCM, idiopathic dilated cardiomyopathy （IDCM）, or ischemic cardiomyopathy （ICM）. Methods A total of 312 consecutive patients （DHCM： n = 16; IDCM： n = 231; ICM： n = 65） undergoing CRT in Fuwai hospital were studied respectively. Response to CRT was defmed as reduction in left ventricular end-systolic volume （LVESV） _〉 15% at 6-month follow-up. Results Compared with DHCM, IDCM was associated with a lower total mortality （HR： 0.35, 95% CI： 0.13-0.90）, cardiac mortality （HR： 0.29; 95% CI： 0.11-0.77）, and total mortality or heart failure （HF） hospitalizations （HR： 0.34, 95% CI： 0.17-0.69）, independent of known confounders. Compared with DHCM, the total mortality, cardiac mortality and total mortality or HF hospitalizations favored ICM but were not statistically significant （HR： 0.59, 95% CI： 0.22-1.61; HR： 0.59, 95% CI： 0.21-1.63; HR： 0.54, 95% CI： 0.26-1.15; respectively）. Response rate to CRT was lower in the DHCM group than the other two groups although the differences didn＇t reach statistical significance. Conclusions Compared with IDCM, DHCM was associated with a worse outcome after CRT. The clinical outcome of DHCM patients receiving CRT was similar to or even worse than that of ICM patients. These indicate that DHCM behaves very differently after CRT.

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.

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.