Therapeutic options in hypertrophic cardiomyopathy: A pediatric perspective

Hypertrophic cardiomyopathy (HCM) is the most prevalent genetic cardiomyopathy in children and young adults. Despite advances in understanding the molecular etiology of this disorder, the clinical phenotypes vary widely from asymptomatic septal hypertrophy, to frank congestive heart failure due to left ventricular outflow tract obstruction (LVOTO), to unexpected sudden cardiac death. Thus, isolating a specific genetic defect in this disease does little to predict the clinical consequence. This is best seen in large families with several people affected by HCM who all have the identical mutation but who may have very different clinical phenotypes. Evaluating individuals with HCM consists of establishing the diagnosis through cardiac imaging, noninvasively assessing the risk for sudden death, and medically or surgically treating symptomatic LVOTO when it is present.     

肥厚型心肌病预后评估的研究进展

肥厚型心肌病是最常见的遗传性心脏病,其临床表现及预后极富多样性。该病患者的不良转归主要有:猝死、心力衰竭以及心房颤动所致的栓塞事件等。现就影响肥厚型心肌病预后的因素作一综述。     

Gender-related differences in the clinical presentation and outcome of hypertrophic cardiomyopathy

OBJECTIVES: The goal of this study was to assess gender-related differences in a multicenter population with hypertrophic cardiomyopathy (HCM). BACKGROUND: Little is known regarding the impact of gender on the heterogeneous clinical profile and clinical course of HCM. METHODS: We studied 969 consecutive HCM patients from Italy and the U.S. followed over 6.2 +/- 6.1 years. RESULTS: Male patients had a 3:2 predominance (59%), similar in Italy and the U.S. (p = 0.24). At initial evaluation, female patients were older and more symptomatic than male patients (47 +/- 23 years vs. 38 +/- 18 years; p < 0.001; mean New York Heart Association [NYHA] functional class 1.8 +/- 0.8 vs. 1.4 +/- 0.6; p < 0.001), and more frequently showed left ventricular outflow obstruction (37% vs. 23%; p < 0.001). Moreover, female patients were less often diagnosed fortuitously by routine medical examination (23% vs. 41% in male patients, p < 0.001). Female gender was independently associated with the risk of symptom progression to NYHA functional classes III/IV or death from heart failure or stroke compared with male gender (independent relative hazard 1.5; p < 0.001), particularly patients > or =50 years of age and with resting outflow obstruction (p < 0.005). Hypertrophic cardiomyopathy-related mortality and risk of sudden death were similar in men and women. CONCLUSIONS: Women with HCM were under-represented, older, and more symptomatic than men, and showed higher risk of progression to advanced heart failure or death, often associated with outflow obstruction. These gender-specific differences suggest that social, endocrine, or genetic factors may affect the diagnosis and clinical course of HCM. A heightened suspicion for HCM in women may allow for timely implementation of treatment strategies, including relief of obstruction and prevention of sudden death or stroke.     

WJC 6~th Anniversary Special Issues(3):Cardiomyopathy Hypertrophic cardiomyopathy in 2013:Current speculations and future perspectives

Hypertrophic cardiomyopathy(HCM),the most variable cardiac disease in terms of phenotypic presentation and clinical outcome,represents the most common inherited cardiomyopathic process with an autosomal dominant trait of inheritance.To date,more than 1400 mutations of myofilament proteins associated with the disease have been identified,most of them "private" ones.This striking allelic and locus heterogeneity of the disease certainly complicates the establishment of phenotype-genotype correlations.Additionally,topics pertaining to patients' everyday lives,such as sudden cardiac death(SCD)risk stratification and prevention,along with disease prognosis,are grossly related to the genetic variation of HCM.This review incorporates contemporary research findings and addresses major aspects of HCM,including preclinical diagnosis,genetic analysis,left ventricular outflow tract obstruction and SCD.More specifically,the spectrum of genetic analysis,the selection of the best method for obstruction alleviation and the need for a unique and accuratefactor for SCD risk stratification are only some of the controversial HCM issues discussed.Additionally,future perspectives concerning HCM and myocardial ischemia,as well as atrial fibrillation,are discussed.Rather than enumerating clinical studies and guidelines,challenging problems concerning the disease are critically appraised by this review,highlighting current speculations and recommending future directions.     

Hypertrophic cardiomyopathy in 2013: Current speculations and future perspectives

Hypertrophic cardiomyopathy (HCM), the most variable cardiac disease in terms of phenotypic presentation and clinical outcome, represents the most common inherited cardiomyopathic process with an autosomal dominant trait of inheritance. To date, more than 1400 mutations of myofilament proteins associated with the disease have been identified, most of them “private” ones. This striking allelic and locus heterogeneity of the disease certainly complicates the establishment of phenotype-genotype correlations. Additionally, topics pertaining to patients’ everyday lives, such as sudden cardiac death (SCD) risk stratification and prevention, along with disease prognosis, are grossly related to the genetic variation of HCM. This review incorporates contemporary research findings and addresses major aspects of HCM, including preclinical diagnosis, genetic analysis, left ventricular outflow tract obstruction and SCD. More specifically, the spectrum of genetic analysis, the selection of the best method for obstruction alleviation and the need for a unique and accurate factor for SCD risk stratification are only some of the controversial HCM issues discussed. Additionally, future perspectives concerning HCM and myocardial ischemia, as well as atrial fibrillation, are discussed. Rather than enumerating clinical studies and guidelines, challenging problems concerning the disease are critically appraised by this review, highlighting current speculations and recommending future directions.     

Pharmacological treatment of hypertrophic cardiomyopathy: current practice and novel perspectives

Hypertrophic cardiomyopathy (HCM) is entering a phase of intense translational research that holds promise for major advances in disease‐specific pharmacological therapy. For over 50 years, however, HCM has largely remained an orphan disease, and patients are still treated with old drugs developed for other conditions. While judicious use of the available armamentarium may control the clinical manifestations of HCM in most patients, specific experience is required in challenging situations, including deciding when not to treat. The present review revisits the time‐honoured therapies available for HCM, in a practical perspective reflecting real‐world scenarios. Specific agents are presented with doses, titration strategies, pros and cons. Peculiar HCM dilemmas such as treatment of dynamic outflow obstruction, heart failure caused by end‐stage progression and prevention of atrial fibrillation and ventricular arrhythmias are assessed. In the near future, the field of HCM drug therapy will rapidly expand, based on ongoing efforts. Approaches such as myocardial metabolic modulation, late sodium current inhibition and allosteric myosin inhibition have moved from pre‐clinical to clinical research, and reflect a surge of scientific as well as economic interest by academia and industry alike. These exciting developments, and their implications for future research, are discussed.     

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.     

Sudden cardiac death in familial hypertrophic cardiomyopathy. Identification of high-risk patients

Hypertrophic cardiomyopathy (HCM) is a relatively frequent, genetically determined primary cardiomyopathy, characterized by most often asymmetric hypertrophy of the ventricular septum with or without systolic obstruction of the left ventricular outflow tract. HCM is a genetically heterogeneous disease, with 12 different disease-causing genes beeing indentified to date. Histologically the disease is characterized by hypertophy and disarray of myofibrils as well as by an increase in myocardial fibrosis. Clinically, these changes may lead to palpitations, dyspnoe on exertion, and/or angina pectoris. However, they also lead to an increased propensity to the development of severe ventricular tachyarrhythmias and sudden cardiac death. The incidence of sudden death is significantly increased in HCM, particularly in affected young subjects. Risk stratification in HCM should include a complete clinical-cardiological evaluation that should also consider new diagnostic features, e. g. MR imaging. Major risk factors for sudden cardiac death include a survived cardiac arrest (ventricular fibrillation), non-sustained and sustained ventricular tachycardia, a history of premature familial sudden death, unexplained syncope, an abnormal blood pressure response on exercise, and left ventricular thickness greater than or equal to 3 cm. Ideally, risk stratification should also include genetic testing, since some gene mutations seem to be associated with a higher risk for sudden cardiac death than others. However, genetic testing in HCM in not yet available on a routine basis. The implantation of a cardioverter/defibrillator is first-line therapy in patients with documented ventricular tachycardia/fibrillation or patients who have survived sudden cardiac death. These devices also play an important role in the primary prevention of sudden cardiac death in HCM. Algorithms and scores are available to estimate the risk of sudden death, however, the decision to implant a cardioverter/defibrillator remains an individual decision in every single patient.     

Implantable defibrillators and prevention of sudden death in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death in young people, including trained athletes. The implantable cardioverter-defibrillator (ICD), although initially designed as a treatment for older patients with coronary artery disease, has more recently proved to be a safe and effective therapeutic intervention in young patients with HCM, both for primary or secondary prevention of sudden death. The largest such report of >500 patients showed that the ICD intervened appropriately to abort ventricular tachycardia/fibrillation (VT/VF) in 20% of patients over an average follow-up period of only 3.7 years, at a rate of about 4% per year in those patients implanted prophylactically, and often with considerable delays of up to 10 years. Extensive experience with high-risk HCM patients showed that appropriate device discharges for VT/VF occur with similar frequency in patients with 1, 2, or > or = 3 noninvasive risk markers. Despite the extreme morphology characteristic of HCM, often with massive degrees of left ventricular (LV) hypertrophy and/or LV outflow tract obstruction, ICDs performed in a highly effective fashion, with failure to convert life-threatening arrhythmias extraordinarily rare. In conclusion, in a large high-risk HCM cohort, ICD interventions for life-threatening ventricular tachyarrhythmias were frequent and highly effective in restoring normal rhythm. An important proportion of ICD discharges occurred in primary prevention patients with only one risk factor. Therefore, a single marker of high risk may represent sufficient evidence to justify the recommendation for a prophylactic ICD in selected patients with HCM.     

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.     

Approach to hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is a genetic disease characterized by marked left ventricular (LV) hypertrophy. A dynamic LV outflow obstruction is present in approximately 20% of patients. Many affected individuals remain asymptomatic throughout life, others develop heart failure symptoms or atrial fibrillation (AF), and some die suddenly, often young and in the absence of previous symptoms. Stratification of sudden death risk is based on several markers, including a previous cardiac arrest, sustained ventricular tachycardia, family history of sudden death, extreme LV hypertrophy (>/= 30 mm), syncope, nonsustained ventricular tachycardia on Holter, and abnormal exercise blood pressure response. The implantable cardioverter-defibrillator is the most effective treatment for sudden death prevention, and should be considered in patients with either one strong or multiple risk factors. Important symptoms of heart failure develop in a minority of patients, largely as a consequence of diastolic dysfunction, and are usually treated with beta blockers, or verapamil. In patients with LV obstruction and severe symptoms unresponsive to medications, myectomy operation or alcohol septal ablation is indicated for relieving the gradient and improving quality of life. AF develops in approximately 20% of patients. Amiodarone is the most effective medication for preventing AF recurrences. In chronic AF, beta blockers or verapamil are usually effective for heart rate control. The threshold for anticoagulants is low, because even brief AF episodes have a substantial embolization risk.     

Left ventricular remodeling of hypertrophic cardiomyopathy: longitudinal observation in rural community.

BACKGROUND: The purpose of the present study was to assess the clinical long-term course of hypertrophic cardiomyopathy (HCM) in a rural Japanese cohort. METHODS AND RESULTS: A total of 137 consecutive HCM patients (mean age at diagnosis: 52+/-13 years) were enrolled. During a follow-up period of 11.4+/-5.7 years, 28 patients died of HCM-related causes. Eleven patients died suddenly, 10 died of progressive heart failure, 6 died of stroke associated with atrial fibrillation and 1 died of a postoperative complication of alcohol septal ablation. For the overall study group, 5-, 10- and 15-year cumulative survival rates were 91%, 88% and 79%, respectively. Although sudden death was the predominant cause of HCM-related death during the follow-up period of <10 years, heart failure death increased after follow-up period of >10 years. Fifteen (13%) of 114 patients who had follow-up echocardiography became ;end-stage' HCM and 8 patients died of severe and refractory heart failure. They already showed minimally dilated left ventricular (LV) dimension and lower LV fractional shortening at initial evaluation. CONCLUSIONS: Although HCM patients in a Japanese rural community showed relatively benign clinical course (the same as cohorts in the developed world), heart failure death because of LV remodeling became equally important to sudden death when they were followed for more than 10 years.     

Prognostic significance of left atrial size in patients with hypertrophic cardiomyopathy (from the Italian Registry for Hypertrophic Cardiomyopathy)

This study assessed left atrial (LA) dimension as a potential predictor of outcome in hypertrophic cardiomyopathy (HC). From the Italian Registry for Hypertrophic Cardiomyopathy, 1,491 patients (mean age 47 +/- 17 years; 61% men; 19% obstructive), followed for 9.4 +/- 7.4 years after the initial echocardiographic evaluation, constituted the study group. The mean LA transverse dimension was 43 +/- 9 mm and was larger in patients with severe symptoms (48 +/- 9 mm for New York Heart Association classes III and IV vs 42 +/- 9 mm for classes I and II, p <0.001), atrial fibrillation (47 +/- 9 vs 42 +/- 8 mm in sinus rhythm, p <0.001), and left ventricular outflow obstruction (46 +/- 9 mm for >or=30 mm Hg at rest vs 42 +/- 9 mm for <30 mm Hg at rest, p <0.001). On univariate analysis, each 5-mm increase in LA size was associated with a hazard ratio (HR) of 1.2 for all-cause mortality (p <0.0001). On multivariate analysis, a LA dimension >48 mm (the 75th percentile) had a HR of 1.9 for all-cause mortality (p = 0.008), 2.0 for cardiovascular death (p = 0.014), and 3.1 for death related to heart failure (p = 0.008) but was unassociated with sudden death (p = 0.81). Similar results were obtained after the exclusion of patients with atrial fibrillation (HR 1.7, p = 0.008) or outflow obstruction (HR 1.8, p = 0.003). The predictive power of LA dimension >48 mm was also validated in an independent HC cohort from the United States, with similar HRs (1.8 for all-cause mortality, p = 0.019). In conclusion, in a large cohort of patients with HC from a nationwide registry, a marked increase in LA dimension were predictive of long-term outcome, independent of co-existent atrial fibrillation or outflow obstruction. LA dimension is a novel and independent marker of prognosis in HC, particularly relevant to the identification of patients at risk for death related to heart failure.     

Prognostic significance of atrial fibrillation in advanced heart failure. A study of 390 patients

BACKGROUND. Atrial fibrillation is common in advanced heart failure, but its prognostic significance is controversial. METHODS AND RESULTS. We evaluated the relation of atrial rhythm to overall survival and sudden death in 390 consecutive advanced heart failure patients. Etiology of heart failure was coronary artery disease in 177 patients (45%) and nonischemic cardiomyopathy or valvular heart disease in 213 patients (55%). Mean left ventricular ejection fraction was 0.19 +/- 0.07. Seventy-five patients (19%) had paroxysmal (26 patients) or chronic (49 patients) atrial fibrillation. Compared with patients with sinus rhythm, patients with atrial fibrillation did not differ in etiology of heart failure, mean pulmonary capillary wedge pressure on therapy, or embolic events but were more likely to be receiving warfarin and antiarrhythmic drugs and had a slightly higher left ventricular ejection fraction. After a mean follow-up of 236 +/- 303 days, 98 patients died: 56 (57%) died suddenly, and 36 (37%) died of progressive heart failure. Actuarial 1-year overall survival was 68%, and sudden death-free survival was 79%. Actuarial survival was significantly worse for atrial fibrillation than for sinus rhythm patients (52% versus 71%, p = 0.0013). Similarly, sudden death-free survival was significantly worse for atrial fibrillation than for sinus rhythm patients (69% versus 82%, p = 0.0013). By Cox proportional hazards model, pulmonary capillary wedge pressure on therapy, left ventricular ejection fraction, coronary artery disease, and atrial fibrillation were independent risk factors for total mortality and sudden death. For patients who had pulmonary capillary wedge pressure of less than 16 mm Hg on therapy, atrial fibrillation was associated with poorer 1-year survival (44% versus 83%, p = 0.00001); however, in the high pulmonary capillary wedge pressure group, atrial fibrillation did not confer an increased risk (58% versus 57%). CONCLUSIONS. Atrial fibrillation is a marker for increased risk of death, especially in heart failure patients who have lower filling pressures on vasodilator and diuretic therapy. Whether aggressive attempts to maintain sinus rhythm will reduce this risk is unknown.     

Hypertrophische Kardiomyopathie

Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease phenotypically expressed in the general population at about 0.2%. Annual mortality rate is about 1% in unselected patients, 3-6% in patients with severe symptoms, and 17% following resuscitation from ventricular tachycardia (VT)/ventricular fibrillation (VF). 50-80% of deaths are sudden. Beneath effective treatment in severe symptoms of heart failure (most common in midlife and beyond) the prevention of sudden death (most common in young patients) continues to be a major challenge. The highest risk has been associated with any of the following markers: 1. prior cardiac arrest or spontaneous sustained VTs, 2. a family history of premature HCM-related death, 3. extreme left ventricular hypertrophy (> or = 30 mm), 4. syncope, 5. multiple bursts of nonsustained VTs, 6. hypotensive blood pressure response to exercise, and 7. marked septal scarring (hyperenhancement in magnetic resonance imaging). Treatment options in patients with drug-refractory symptoms or increased risk of sudden death are surgical myectomy, transcoronary ablation of septal hypertrophy (TASH), dual-chamber pacing, ablation of atrial fibrillation (or the AV node), and the implantable cardioverter defibrillator (ICD). 1. Surgical myectomy effectively improves symptoms, hemodynamics and probably prognosis. Long-term results are well known, but patients' preference and the number of experienced surgical centers are fading. Randomized studies are missing. 2. TASH induces quite similar improvements in symptoms and hemodynamics. It is remarkably evaluated for a postprocedural follow-up of up to 10 years, and it is the preferred mode of treatment in patients. However, information on long-term prognosis, rhythmogenic effects and randomized studies are missing. For the prevention of sudden death, TASH has to be combined with an ICD. 3. Dual-chamber pacing was evaluated in randomized crossover studies, but symptomatic and hemodynamic improvements and patients' preference are substantially lower than for TASH. 4. The ICD has the potential to alter prognosis in secondary (class I indication) and primary prevention. HCM patients should undergo a risk stratification assessment. Prophylactic implants base on a clinical profile with two or more risk markers (sometimes one risk marker). 5. Ablation of atrial fibrillation or the AV node is indicated to improve symptoms in patients with fast ventricular rates despite medical treatment. For the prevention of sudden death, it has to be combined with an ICD.     

心源性猝死危险因素分析

目的探讨和分析心源性猝的危险因素。方法收集和整理在我院2012年04月-2013年10月诊治时发生心源性猝死的心肌患者64例为研究对象,对上述收集对象的临床资料进行整理和分析。结果本组单因素分析显示自发性持续室速、心室颤动(心脏骤停)、晕阙、左室流出道梗阻、非持续性室速等因素为心肌疾病患者发生心源性猝死的危险因素;多因素Logistic分析发现自发性持续性室速、心室颤动、晕阙以及猝死家族史是发生心源性猝死的重要危险因素。结论心肌疾病患者发生心源性猝死的为危险因素呈现综合化、多样化,临床治疗中应给予针对性的预防或治疗,这对降低心肌疾病患者心源性猝死率有着积极的意义。     

Significance and control of cardiac arrhythmias in patients with congestive cardiac failure

A wide spectrum of ventricular and supraventricular tachyarrhythmias occurs in the setting of congestive cardiac failure. However, the two most clinically significant are atrial fibrillation and ventricular tachycardia and fibrillation.In the past there has been much emphasis on premature ventricular contractions and more recently, on nonsustained ventricular tachycardia. For the most part, these arrhythmias are asymptomatic in heart failure. They are markers of sudden arrhythmic death but their suppression by antiarrhythmic drugs have not resulted in a reduction of total mortality. Two approaches have been used to this end. The first is the use of beta-adrenergic blocking drugs and antiarrhythmic agents such as amiodarone. Beta-blockers have been shown to significantly reduce sudden death as well as total mortality, while the effects of amiodarone have been less decisive. The prospective role of the implantable cardioverter defibrillator (ICD) is undergoing critical evaluation in patients with cardiac failure at high risk for sudden death. The elective role of the ICD is well established as first-line therapy in patients with heart failure resuscitated from sudden death and in those with sustained ventricular tachycardia in conjunction with conventional therapies for cardiac decompensation.The prevalence of atrial fibrillation rises as a function of severity of cardiac failure, but it is also in known that persistent atrial fibrillation with an uncontrolled ventricular response may induce heart failure. Controlled ventricular response may prevent congestive heart failure and improve left ventricular function. The two most common causes of atrial fibrillation in cardiac failure in Europe and America are ischemic heart disease and hypertension, while mitral valve disease remains the prevalent cause elsewhere. The choice of antiarrhythmic drugs for maintaining sinus rhythm is critical in the prevention of heart failure aggravation and proarrhythmic reactions of antiarrhythmic drugs. Amiodarone and dofetilide are most widely used in this context.     

肥厚型心肌病临床特点和长期预后的回顾性分析

目的探讨肥厚型心肌病(HCM)的临床特点及影响长期预后的因素。方法回顾分析117例经超声心动图检查确诊的HCM患者的临床资料、ECG、超声心动图特点。结果患者的主要症状为心前区不适、胸痛、心悸、呼吸困难、头晕、晕厥、心脏杂音等。ECG主要表现为房性期前收缩、心房颤动、房性心动过速、室性心动过速、合并异常Q波、ST-T改变、左心室高电压等。平均追踪随访(4.5±2.8)年,死亡18例,猝死3例,心力衰竭、肺部感染死亡4例,脑卒中死亡4例,肿瘤及其相关原因死亡7例。患者年龄、性别、症状和超声心动图参数与患者的预后无明确的相关性。结论HCM临床表现并不特异,超声心动图具有重要的诊断价值。     

Long-term effects of surgical septal myectomy on survival in patients with obstructive hypertrophic cardiomyopathy

OBJECTIVES: This study sought to determine the impact of surgical myectomy on long-term survival in hypertrophic cardiomyopathy (HCM). BACKGROUND: Left ventricular (LV) outflow tract obstruction in HCM increases the likelihood of heart failure and cardiovascular death. Although surgical myectomy is the primary treatment for amelioration of outflow obstruction and advanced drug-refractory heart failure symptoms, its impact on long-term survival remains unresolved. METHODS: Total and HCM-related mortality were compared in three subgroups comprised of 1,337 consecutive HCM patients evaluated from 1983 to 2001: 1) surgical myectomy (n = 289); 2) LV outflow obstruction without operation (n = 228); and 3) nonobstructive (n = 820). Mean follow-up duration was 6 +/- 6 years. RESULTS: Including two operative deaths (procedural mortality, 0.8%), 1-, 5-, and 10-year overall survival after myectomy was 98%, 96%, and 83%, respectively, and did not differ from that of the general U.S. population matched for age and gender (p = 0.2) nor from patients with nonobstructive HCM (p = 0.8). Compared to nonoperated obstructive HCM patients, myectomy patients experienced superior survival free from all-cause mortality (98%, 96%, and 83% vs. 90%, 79%, and 61%, respectively; p < 0.001), HCM-related mortality (99%, 98%, and 95% vs. 94%, 89%, and 73%, respectively; p < 0.001), and sudden cardiac death (100%, 99%, and 99% vs. 97%, 93%, and 89%, respectively; p = 0.003). Multivariate analysis showed myectomy to have a strong, independent association with survival (hazard ratio 0.43; p < 0.001). CONCLUSIONS: Surgical myectomy performed to relieve outflow obstruction and severe symptoms in HCM was associated with long-term survival equivalent to that of the general population, and superior to obstructive HCM without operation. In this retrospective study, septal myectomy seems to reduce mortality risk in severely symptomatic patients with obstructive HCM.     

Hypertrophic Cardiomyopathy: Role of the Implantable Cardioverter-Defibrillator

Objectives. We report the occurrence of cardiac events during long-term follow-up in patients with hypertrophic cardiomyopathy (HCM) after cardioverter-defibrillator implantation.Background. The identification of patients at high risk for sudden death and the prevention of recurrence of sudden death in HCM represents a difficult problem.Methods. We retrospectively analyzed the occurrence of cardiac events during follow-up of 13 patients with HCM who received an implantable cardioverter-defibrillator (ICD) because of aborted sudden death (n = 10) or sustained ventricular tachycardia (n = 3) (group I). Findings were compared with those in 215 patients with an ICD and other structural heart disease or idiopathic ventricular fibrillation (group II).Results. After a mean (±SD) follow-up period of 26 ± 18 months, 2 of 13 patients in group I received appropriate shocks. The calculated cumulative incidence of shocks was 21% in group I and 66% in group II after 40 months (p < 0.05). We observed a low incidence of recurrence of ventricular tachycardia/fibrillation during follow-up in patients with HCM. No deaths occurred.Conclusions. Our data suggest that ventricular tachyarrhythmias may not always be the primary mechanism of syncope and sudden death in patients with HCM. The ICD seems to have a less important impact on prognosis in patients with HCM than in patients with other etiologies of aborted sudden death.