Right ventricular obstruction in various types of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is most probably a genetically transmitted disease with different clinical and hemodynamic features. In hypertrophic obstructive cardiomyopathy (HOCM) the obstruction is predominantly in the left ventricular outflow tract (IHSS). In a minority of cases the obstruction is strictly located in midventricle (midventricular obstruction, MO). Hypertrophic nonobstructive cardiomyopathy (HNCM) includes asymmetric septal hypertrophy (ASH) and apical hypertrophy (AH). Right ventricular hypertrophic obstruction (RVHO) is an uncommon type of HCM and is almost always combined with other types of left ventricular HCM. We describe in the present report 1 case of RVHO with IHSS, 2 cases with MO and, to our knowledge, the first case with AH.     

Repeated percutaneous transluminal septal myocardial ablation leads to reduction of left ventricular outflow-tract pressure gradient in hypertrophic obstructive cardiomyopathy: a case report

A 61-year-old man with hypertrophic obstructive cardiomyopathy was treated twice with percutaneous transluminal septal myocardial ablation (PTSMA). The first procedure improved the left ventricular outflow tract pressure gradient (LVOTG) from 148 to 48 mmHg and the New York Heart Association (NYHA) class from III to II in a week. However, the LVOTG increased to 197 mmHg and the NYHA class worsened to III within 3 months. In spite of medical treatment with beta-blocker, syncope attack occurred suddenly. Repeated PTSMA was performed. Just after the second procedure, the LVOTG did not decrease. However, the LVOTG decreased to 81 mmHg and the NYHA class improved to II with 3 months. The different response of pressure gradient in the acute and chronic phase with repeated PTSMA was interesting.     

Fabry's disease cardiomyopathy: echocardiographic detection of endomyocardial glycosphingolipid compartmentalization.

OBJECTIVES: We sought to identify echocardiographic hallmarks of Fabry's disease cardiomyopathy (FC). BACKGROUND: The recognition of FC from other forms of left ventricular hypertrophy (LVH) by noninvasive imaging techniques is not yet available, and diagnosis, mostly in the absence of systemic manifestations, still relies on genetic and invasive studies. METHODS: Forty consecutive patients (mean age 39 +/- 15 years, 22 men and 18 women) with an established diagnosis of Fabry's disease were submitted to echocardiographic evaluation. Control population consisted of 40 consecutive patients with hypertrophic cardiomyopathy (HCM), 40 hypertensive patients with echocardiographic evidence of LVH, and 40 age- and gender-matched healthy subjects with no LVH. All HCM patients and FC with LVH and/or cardiac symptoms underwent cardiac catheterization with left ventricular endomyocardial biopsy. RESULTS: Echocardiography showed in 83% of FC patients (95% of FC patients with LVH) a binary appearance of endocardial border absent in all HCM, hypertensive, and healthy subjects. The sensitivity and specificity of this echocardiographic feature in detecting Fabry patients in study population were 94% and 100%, respectively. Comparison of echocardiographic with histologic and ultrastructural findings showed the binary appearance to reflect an endomyocardial glycosphingolipids compartmentalization, consisting of thickened glycolipid-rich endocardium, free glycosphingolipid subendocardial storage, and an inner severely affected myocardial layer with a clear subendocardial-midwall layer gradient of disease severity. CONCLUSIONS: Echocardiographic binary appearance of left ventricular endocardial border, reflecting endomyocardial glycosphingolipids compartmentalization, represents a sensitive and specific diagnostic hallmark of Fabry's disease cardiomyopathy.     

Apical Left Ventricular Hypertrophy and Mid‐Ventricular Obstruction in Fabry Disease

We report the case of a rare cardiac presentation of Fabry disease. Although concentric left ventricular hypertrophy is a major cardiac finding in Fabry disease, there is no case report of dynamic obstruction at mid‐left ventricular level. We describe a 59‐year‐old‐woman suffering from a severe form of Fabry disease, mimicking an apical hypertrophic cardiomyopathy with mid‐ventricular obstruction. Differentiation of Fabry disease from hypertrophic cardiomyopathy is crucial given the therapeutic and prognostic differences. Fabry disease should always be suspected in an adult, independently of the pattern of left ventricular hypertrophy.     

肥厚型梗阻性心肌病化学消融术后中长期疗效观察

目的评价经皮经腔间隔心肌化学消融术(PTSMA)治疗肥厚型梗阻性心肌病(HOCM)的中-长期疗效。方法选择2000年11月~2004年8月共11例HOCM的患者,成功地接受了PTSMA治疗,术后超声随访12~48个月以上,随访观察患者的室间隔厚度(IVS)、左心室流出道宽度(LVOT)、无创性左心室流出道压力阶差(LVOTPG)、心功能变化。结果11例患者均成功地实施了PTSMA,术后IVS、LVOTPG和NYHA较术前有显著改善,P<0.000 1,术后随访示IVS术后12个月、48个月较术后1周显著改善,P<0.05。结论PTSMA能显著降低室间隔厚度,改善心功能且稳定,中长期疗效肯定,随术后观察时间的延长疗效有进一步增加的趋势。     

肥厚型梗阻性心肌病经酒精室间隔消融术后心脏结构及功能变化

目的 探讨经皮穿刺腔内酒精室间隔心肌消融术（percutaneous transluminal alcohol septal myocardial ablation,PTSMA）对肥厚型梗阻性心肌病（hypertrophic obstructive cardiomyopathy,HOCM）患者心脏结构及功能的影响.方法 收集2006年1月至2012年12月在成都市第三人民医院住院的HOCM患者24例,比较其PTSMA术前、术后3个月及术后12个月的左心室流出道压力阶差、室间隔厚度、左心室后壁厚度、左心房内径、左心室舒张末期内径、纽约心脏病协会（NYHA）心功能分级、左心室射血分数和左心室短轴缩短率的变化.结果 HOCM患者进行PTSMA术后3个月及术后12个月左心室流出道压力阶差、室间隔厚度、左心室后壁厚度、左心房内径、左心室舒张末期内径、纽约心脏病协会心功能分级、左心室射血分数和左心室短轴缩短率与术前比较,差异有统计学意义（P＜0.05）;术后12个月相比术后3个月,以上指标变化差异无统计学意义（P＞0.05）.结论 PTSMA能显著改善HOCM患者左心室流出道梗阻及降低室壁厚度,改善患者心功能,是有效的治疗方法.     

Percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy.

Percutaneous transluminal septal myocardial ablation (PTSMA) is a new therapeutic option for patients with hypertrophic obstructive cardiomyopathy (HOCM). In the present study, the acute and follow-up results of PTSMA were evaluated. From August 1997 to March 2003 27 medically refractory patients (New York Heart Association (NYHA) functional class 2.9+/-0.6) with HOCM underwent PTSMA. The target septal branch was determined by probationary ballooning in 3 and by myocardial contrast echocardiography in 24 patients. The mean resting left ventricular outflow tract pressure gradient (PG) was reduced from 70+/-44 to 24+/-22 mmHg (p<0.0001); the peak concentration of creatine kinase was 1545+/-686 IU/L. Although transient trifascicular block was observed in 14 patients, permanent pacemaker implantation was not required. There were no major adverse cardiac events during the hospital stay; the mean clinical follow-up was 2.2+/-1.7 years. Repeated PTSMA was needed in 1 patient; however, symptomatic improvement had been well preserved in all patients (NYHA class 1.2+/-0.4). Follow-up echocardiographic examination showed sustained improvement in PG, septal and left ventricular posterior wall thicknesses, and the grade of systolic anterior movement and regurgitation of the mitral valve. In conclusion, PTSMA is a safe and effective therapeutic option for medically refractory patients with HOCM.     

Percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy: long term follow up of the first series of 25 patients

OBJECTIVE: To determine the long term outcome in patients treated with percutaneous transluminal septal myocardial ablation (PTSMA) for hypertrophic obstructive cardiomyopathy (HOCM). DESIGN AND SETTING: Observational, single centre study. PATIENTS: 25 patients (13 women, 12 men, mean (SD) age 54.7 (15.0) years) with drug treatment resistant New York Heart Association (NYHA) class 2.8 (0. 6) symptoms attributed to a high left ventricular outflow gradient (LVOTG) and a coronary artery anatomy suitable for intervention. INTERVENTION: PTSMA by injection of 4.1 (2.6) ml of alcohol (96%) into 1.4 (0.6) septal perforator arteries to ablate the hypertrophied interventricular septum. OUTCOME MEASURES: During in-hospital follow up, enzyme rise, the frequency of atrioventricular conduction lesions requiring permanent DDD pacing, and in-hospital mortality were assessed. Long term follow up (30 (4) months, range 24-36 months) included symptoms, echocardiographic measurements of left atrial and left ventricular dimensions and function, and LVOTG. RESULTS: Mean postinterventional creatine kinase rise was 780 (436) U/l. During PTSMA 13 patents developed total heart block, permanent pacing being necessary in five of them. One 86 year old patient died from ventricular fibrillation associated with intensive treatment (beta mimetic and theophylline) for coexistent severe obstructive airway disease. After three months, three patients underwent re-PTSMA because of a dissatisfactory primary result, leading to LVOTG elimination in all of them. During long term follow up, LVOTG showed sustained reduction (3 (6) mm Hg at rest and 12 (19) mm Hg with provocation) associated with stable symptomatic improvement (NYHA class 1.2 (1.0)) and without significant global left ventricular dilatation. CONCLUSIONS: PTSMA is an effective non-surgical technique for reduction of symptoms and LVOTG in HOCM. Prospective, long term observations of larger populations are necessary in order to determine the definitive significance of the procedure.     

Outcome of patients with hypertrophic obstructive cardiomyopathy after percutaneous transluminal septal myocardial ablation and septal myectomy surgery

OBJECTIVES: This study was conducted to evaluate follow-up results in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent either percutaneous transluminal septal myocardial ablation (PTSMA) or septal myectomy. BACKGROUND: Controversy exists with regard to these two forms of treatment for patients with HOCM. METHODS: Of 51 patients with HOCM treated, 25 were treated by PTSMA and 26 patients via myectomy. Two-dimensional echocardiograms were performed before both procedures, immediately afterwards and at a three-month follow-up. The New York Heart Association (NYHA) functional class was obtained before the procedures and at follow-up. RESULTS: Interventricular septal thickness was significantly reduced at follow-up in both groups (2.3 +/- 0.4 cm vs. 1.9 +/- 0.4 cm for septal ablation and 2.4 +/- 0.6 cm vs. 1.7 +/- 0.2 cm for myectomy, both p < 0.001). Estimated by continuous-wave Doppler, the resting pressure gradient (PG) across the left ventricular outflow tract (LVOT) significantly decreased immediately after the procedures in both groups (64 +/- 39 mm Hg vs. 28 +/- 29 mm Hg for PTSMA, 62 +/- 43 mm Hg vs. 7 +/- 7 mm Hg for myectomy, both p < 0.0001). At three-month follow-up, the resting PG remained lower in the PTSMA and myectomy groups (24 +/- 19 mm Hg and 11 +/- 6 mm Hg, respectively, vs. those before procedures, both p < 0.0001). The NYHA functional class was also significantly improved in both groups (3.5 +/- 0.5 vs. 1.9 +/- 0.7 for PTSMA, 3.3 +/- 0.5 vs. 1.5 +/- 0.7 for myectomy, both p < 0.0001). CONCLUSIONS: Both myectomy and PTSMA reduce LVOT obstruction and significantly improve NYHA functional class in patients with HOCM. However, there are benefits and drawbacks for each therapeutic method that must be counterbalanced when deciding on treatment for LVOT obstruction.     

Mavacamten,a novel revolutionizing therapy in hypertrophic obstructive cardiomyopathy: A literature review

Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiac diseases, defined as a left ventricular wall thickness of ≥15 mm, in the absence of other causes of abnormal ventricular loading. A major hallmark of this disease is the presence of left ventricular outflow tract obstruction, which develops in up to three quarters of patients, referred to as obstructive hypertrophic cardiomyopathy. Current treatment is offered to symptomatic patients, based on the presence of documented left ventricular obstruction, aimed at reducing symptoms and disease progression. This is achieved through pharmacological empirical therapy, surgery, alcohol ablation and/or pacing. Mavacamten is a first-in-class allosteric inhibitor of cardiac myosin that promises to provide clinicians with targeted therapy for these patients. The aim of this review is to provide a general overview of the modern approach to the diagnosis and management of HCM, as well as to integrate all the current knowledge on mavacamten, in anticipation of a future change in the treatment algorithm of patients with HCM.     

Fixed left ventricular outflow tract obstruction mimicking hypertrophic obstructive cardiomyopathy: pitfalls in diagnosis

We present a case series that highlights the diagnostic challenges with left ventricular hypertrophy (LVH) and left ventricular outflow tract obstruction (LVOTO). Fixed structural lesions causing LVOTO with secondary LVH may mimic hypertrophic obstructive cardiomyopathy (HOCM). Management of these two entities is critically different. Misdiagnosis and failure to recognize fixed left ventricular outflow tract (LVOT) lesions may result in morbidity as a result of inappropriate therapy and delay of definitive surgical treatment. It is thus necessary to identify the correct type and level of obstruction in the LVOT by careful correlation of clinical examination, Doppler evaluation, and advanced imaging findings.     

Long term exercise capacity in patients with hypertrophic cardiomyopathy treated with percutaneous transluminal septal myocardial ablation

BACKGROUND: In hypertrophic obstructive cardiomyopathy, percutaneous transluminal septal myocardial ablation (PTSMA) improves functional capacity in the short term. However, long term functional capacity is unknown. AIM: To assess the long term exercise capacity of patients with hypertrophic obstructive cardiomyopathy undergoing PTSMA. METHODS: Twenty three patients (56.5% male, mean age 44.5+/-13.6 years) who underwent PTSMA were included. All patients had also undergone a symptom limited cardiopulmonary exercise treadmill test before the procedure, then after 3 months (early follow-up) and after a mean 7.2+/-1.0 years (long term follow-up). RESULTS: Before PTSMA, mean maximal pressure gradient in the left outflow tract (LVOTGmax) was 82+/-29 mmHg, 17 patients had NYHA functional class> or = III and peak oxygen uptake (pVO2) was 18+/-4 ml/kg/min. PTSMA led to a reduction in mean LVOTGmax (to 29+/-19 mmHg, p<.0001), improvement of heart failure symptoms (NYHA> or =III in 1 patient, p<.0001) and an increase of pVO2 (to 22+/-6 ml/kg/min, p=.0002) at short term. LVOTGmax, functional class and pVO2 did not change significantly during long term follow-up compared to early follow-up. However, there was a continuous improvement in percentage predicted pVO2 over time. CONCLUSIONS: In patients with hypertrophic obstructive cardiomyopathy and symptoms of heart failure, PTSMA leads to stable long term improvement of objectively measured exercise capacity.     

肥厚梗阻型心肌病化学消融术中、术后严重并发症及防治

目的 :报告经皮室间隔心肌化学消融术治疗肥厚梗阻型心肌病术中、术后出现的严重并发症 ,探讨其原因和机制 ,总结经验、教训 ,以期减少其发生。方法 :2 0例肥厚梗阻型心肌病患者用Sigwart法行化学消融术 ,观察术中、术后出现的严重并发症。结果 :2 0例患者中合并下壁急性心肌梗死 2例 ,前壁心肌梗死 1例 ;术后心室颤动 1例 ;永久性Ⅲ度房室传导阻滞 1例 ;术后严重血流动力学障碍 1例 ;术中左冠状动脉回旋支栓塞 1例。结论 :肥厚梗阻型心肌病化学消融术中及术后可发生多种严重并发症 ,明确靶血管与消融心肌之间的关系、选择恰当的一支或多支间隔支动脉行化学消融 ,是减少并发症的关键     

Development of left ventricular hypertrophy in adults in hypertrophic cardiomyopathy caused by cardiac myosin-binding protein C gene mutations

OBJECTIVES: We sought to determine whether the development of left ventricular hypertrophy (LVH) can be demonstrated during adulthood in genetically affected relatives with hypertrophic cardiomyopathy (HCM). BACKGROUND: Hypertrophic cardiomyopathy is a heterogeneous cardiac disease caused by mutations in nine genes that encode proteins of the sarcomere. Mutations in cardiac myosin-binding protein C (MyBPC) gene have been associated with age-related penetrance. METHODS: To further analyze dormancy of LVH in patients with HCM, we studied, using echocardiography and 12-lead electrocardiography, the phenotypic expression caused by MyBPC mutations in seven genotyped pedigrees. RESULTS: Of 119 family members studied, 61 were identified with a MyBPC mutation, including 21 genetically affected relatives (34%) who did not express the HCM morphologic phenotype (by virtue of showing normal left ventricular wall thickness). Of these 21 phenotype-negative individuals, 9 were children, presumably in the prehypertrophic phase, and 12 were adults. Of the 12 adults with normal wall thickness < or = 12 mm (7 also with normal electrocardiograms), 5 subsequently underwent serial echocardiography prospectively over four to six years. Of note, three of these five adults showed development of LVH in mid-life, appearing for the first time at 33, 34 and 42 years of age, respectively, not associated with outflow obstruction or significant symptoms. CONCLUSIONS: In adults with HCM, disease-causing MyBPC mutations are not uncommonly associated with absence of LVH on echocardiogram. Delayed remodeling with the development of LVH appearing de novo in adulthood, demonstrated here for the first time in individual patients with prospectively obtained serial echocardiograms, substantiates the principle of age-related penetrance for MyBPC mutations in HCM. These observations alter prevailing perceptions regarding the HCM clinical spectrum and family screening strategies and further characterize the evolution of LVH in this disease.     

经皮经腔间隔心肌消融术与室间隔部分切除术治疗梗阻性肥厚型心肌病的Meta分析

目的:对比评价经皮经腔间隔心肌消融术(消融)与室间隔部分切除术(手术)治疗梗阻性肥厚型心 肌病(OHCM)的疗效。方法:检索Pubmed,找到3篇对比消融与手术治疗OHCM的文章进行Meta分析。结 果:共计177例患者,86例消融,91例手术。消融使平均室间隔厚度由22.1mm降至15.1mm(P<0.05),手术 使平均室间隔厚度由22.0mm降至13.9mm(P<0.05),两种治疗方法相比较差异无统计学意义(P>0.05); 消融使平均左室流出道(LVOT)压差由10.1kPa降至2.1kPa(P<0.05),手术使平均LVOT压差由9.9kPa降 至1.3kPa(P<0.05),手术优于消融(P<0.05);消融使平均左室舒张末期内径由41.8mm增至45.2mm(P <0.05),手术使平均左室舒张末期内径由41.8mm增至43.9mm(P<0.05),消融与手术相比较差异无统计学 意义(P>0.05);消融使平均NYHA分级由3.17升至1.47(P<0.05),手术使平均HYNA分级由2.97升至 1.36(P<0.05),消融与手术相比较差异无统计学意义(P>0.05)。结论:消融与手术治疗OHCM的客观指标 与主观指标均较为接近,进行消融与手术治疗大规模随机对照试验应是切实可行的也是必要的。     

经皮室间隔心肌化学消融治疗肥厚梗阻型心肌病即刻疗效和随访结果

目的评价单中心经皮室间隔心肌化学消融（PTSMA）治疗肥厚梗阻型心肌病（HOCM）的即刻疗效以及随访结果。方法2001年4月至2008年3月连续30例HOCM患者[男性18例,女性12例,平均年龄（44±17）岁]接受IYFSMA治疗并在随后接受随访。结果1例患者术后3d死于心源性休克,另1例患者因术后Ⅲ°房室传导阻滞（AVB）接受双腔起搏器治疗。左室流出道压力阶差（LVOTG）从（80±23）mmHg降至（27±19）mmHg（P〈0．01）;肌酸激酶（CK）及肌酸激酶MB亚型（CK—MB）峰值分别为（1517±926）U／L和（172±95）ng／ml。在平均（30±25）个月的随访期中,有3例患者死亡,其中2例分别在术后6个月和68个月猝死,1例在术后6个月死于脑卒中。大部分存活患者症状显著改善或消失,心功能分级从术前2．6±0．8降至1．9±0．6（P〈0．01）。结论PTSMA能有效降低HOCM患者的左室流出道压力阶差（LVOGT）并改善患者症状。     

肥厚型心肌病患者小动脉弹性指数水平与左心室流出道梗阻的关系

目的：探讨肥厚型心肌病（HCM）患者小动脉弹性指数（C2）水平与左心室流出道梗阻的关系. 方法：纳入2010年1月至2013年7月间因肥厚型心肌病于我院心内科住院的患者69例,收集相关临床资料,比较C2水平与相关指标的关联性.再根据左心室流出道梗阻情况的不同,将HCM患者分为梗阻性HCM与非梗阻性HCM,比较两组患者的C2水平. 结果：N末端B型利钠肽原（NT-proBNP）、左室流出道最大压差（LVOTPG）与C2呈显著负相关,左室短轴缩短率（LVFS）与C2呈显著正相关,左室后壁宽度（LVPWD）与C2无显著相关性,超敏肌钙蛋白I（c-TNI）、左室射血分数（LVEF）、左室舒张末期内径（LVEDD）与C2呈非线性相关.梗阻性HCM患者的C2水平显著低于非梗阻性HCM患者. 结论：C2与LVOTPG密切相关,该指标可作为HCM患者左心室流出道梗阻病情进展的动态评价指标.     

Comparison of percutaneous transluminal septal myocardial ablation versus septal myectomy for the treatment of patients with hypertrophic obstructive cardiomyopathy--a meta analysis

BACKGROUND: The effects of percutaneous transluminal septal myocardial ablation (PTSMA) with septal myectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM) are not thoroughly compared. METHODS: Three articles comparing the effects of PTSMA and septal myectomy treatment for HOCM were identified from a search in Pubmed, and a meta analysis was conducted. RESULTS: 177 patients (86 underwent PTSMA and 91 underwent septal myectomy) were included. Interventricular septum thickness was decreased from 22.1 to 15.1 mm (p<0.05) in PTSMA group and from 22.0 to 13.9 mm (p<0.05) in septal myectomy group; left ventricular end-diastolic dimension was increased from 41.8 to 45.2 mm (p<0.05) in PTSMA group and from 41.8 to 43.9 mm (p<0.05) in septal myectomy group; NYHA class was improved from 3.17 to 1.47 (p<0.05) in PTSMA group and from 2.97 to 1.36 (p<0.05) in septal myectomy group; there were no differences in the two groups. However, left ventricular outflow tract gradient was decreased from 76.0 to 15.7 mm Hg (p<0.05) in PTSMA group and from 74.7 to 9.4 mm Hg (p<0.05) in septal myectomy group and the effect of septal myectomy was better than PTSMA (p<0.05). CONCLUSIONS: The effects of septal myectomy treatment for HOCM are better with regard to relief of LVOT gradient, and lower risk of pacemaker requirement, compared to PTSMA. Large randomized clinical trials further comparing the two treatments are suggested.     

The prognostic importance of left ventricular outflow obstruction in hypertrophic cardiomyopathy varies in relation to the severity of symptoms

OBJECTIVES: The aim of this study was to investigate whether the prognostic importance of left ventricular (LV) outflow obstruction in hypertrophic cardiomyopathy (HCM) is influenced by other predictors of morbidity and mortality. BACKGROUND: It remains unknown whether the effect of outflow obstruction on clinical outcome in HCM is influenced by other determinants of survival. METHODS: We assessed the impact of severity of symptoms, LV wall thickness, atrial fibrillation, and age on the prognostic importance of outflow obstruction in a large HCM population. RESULTS: Of 526 consecutive HCM patients, 141 (27%) had outflow obstruction. During a follow-up of 4.5 +/- 4.1 years, 34 patients died of HCM. The incidence of cardiovascular death was significantly higher among patients with LV obstruction than among those without obstruction (relative risk [RR] = 2.14; p = 0.02). The prognostic power of the outflow gradient changed in relation to severity of symptoms (p = 0.024). At initial evaluation, LV obstruction was a significant predictor of cardiovascular mortality only in New York Heart Association (NYHA) functional class I to II patients (hazard ratio [HR] = 2.38; p = 0.025). During follow-up, at time of development of severe symptoms, the outflow gradient lost its prognostic significance (HR = 1.18; p = 0.66), whereas NYHA functional class III to IV was associated with an eight-fold increase in risk of cardiovascular mortality (HR = 7.90; p < 0.001). CONCLUSIONS: In patients with HCM, the prognostic importance of LV outflow obstruction varies in relation to the severity of symptoms. In patients with mild or no symptoms, obstruction is an important predictor of cardiovascular death. After development of severe symptoms, NYHA functional class becomes the dominant marker of prognosis independently of the presence of an outflow gradient.     

Ultrasonic tissue characterization in hypertrophic cardiomyopathy: analysis of three-layered appearance of the ventricular septum by apical approach]

In normal hearts, two-dimensional echocardiography from the apical window displays the left ventricular wall as a three-layered appearance (TLA): central bright layer and bilateral sonolucent zones. The TLA is considered to reflect the normal myocardial architecture: the predominant latitudinal fiber bundles of the midwall layer, and longitudinal or oblique ones on both sides. We analysed the TLA of the ventricular septum in 20 normal subjects, 20 patients with left ventricular hypertrophy due to pressure load (LVH), and 81 patients with hypertrophic cardiomyopathy (HCM). Of the 81 HCM patients, the layering was often obscure or absent in 53 (65%), whereas LVH patients showed clear TLA as well as normal hearts. In patients with severe layering disorder (n = 30), the age at diagnosis was lower (40 +/- 15 vs 50 +/- 12, p less than 0.05), and familial occurrence (53 vs 11%, p less than 0.01) and severe functional limitation (NYHA greater than or equal to III) were more common (27 vs 4%) than in those with clear TLA (n = 28). The disturbed layering detectable by echocardiography may reflect the disorder of basic myocardial fiber architecture in the ventricular septum, and is likely to become a useful marker of the pathologic severity of the disease.