Most patients have little or no disability and a normal life expectancy . Higher rates of morbidity or mortality are linked to the complications of the disorder, sudden cardiac death, progressive heart failure, cardiac dysrhythmia, and stroke due to emboli   . The initial presenting sign may be sudden cardiac death, particularly in preadolescents and adolescents . Older individuals may also present with sudden cardiac death but more often they present with symptoms of cardiac dysfunction   . The clinical picture of hypertrophic cardiomyopathy varies greatly, from asymptomatic individuals to mildly disabling symptoms such as exercise intolerance and chest pain, to life threatening arrhythmias and heart failure . Clinical presentation may even vary within the same family and/or phenotype  .
Signs and symptoms of hypertrophic cardiomyopathy include the following    :
Sudden cardiac death generally occurs during exercise, usually in individuals with structural cardiac disease  . It also may have a circadian distribution with deaths clustering in the morning and early evening  . Dyspnea is the most common presenting symptom, occurring in as many as 90% of symptomatic patients  .
Angina is rare in children but common in adults . It can occur without detectable coronary atherosclerosis  . Increased myocardial oxygen consumption caused by ventricular hypertrophy resulting in endocardial ischemia, especially during exertion  . Syncope is very common, resulting from inadequate cardiac output with exertion or from cardiac arrhythmia. It occurs more commonly in children and young adults . It may identify patients at high risk for sudden cardiac death and indicates the need for an urgent workup and aggressive treatment   . Orthopnea and paroxysmal nocturnal dyspnea are early signs of congestive heart failure  .
Complications of hypertrophic cardiomyopathy include   :
Sudden cardiac death is the most devastating consequence of hypertrophic cardiomyopathy   . It has the highest incidence in preadolescents and adolescents and is usually related to extreme exertion and ventricular fibrillation . Hypertrophic cardiomyopathy can cause various arrhythmias, including atrial fibrillation, atrial flutter, ventricular ectopy, ventricular tachycardia, and ventricular fibrillation  . Uncontrolled hypertension is seen in 37-56% of patients . This comorbidity presents significant diagnostic and therapeutic problems . Control of blood pressure is on of the primary goals of treatment .
Echocardiography is the primary means of diagnosing hypertrophic cardiomyopathy and determining optimal treatment and follow-up  . Diagnosis is based on the presence of left ventricular hypertrophy  . Ventricular wall thickness >/= 15 mm is indicative of the disorder with a wall thickness of more than 30 mm indicating a higher risk of sudden cardiac death  . Congestive heart failure is seen in late stage hypertrophic cardiomyopathy  . It is indicative of severe myocardial dysfunction and is the cause of disability and decreased quality of life .
There are no specific laboratory blood tests required for the evaluation of hypertrophic cardiomyopathy  . Definitive diagnosis is genetic testing for mutant genes  . Genetic testing, though diagnostic for the condition, is currently expensive and may not yet be widely available . It is becoming more accessible and is the only means of identifying the specific phenotype involved   which can be helpful in determining optimal treatment regimes and complication prevention strategies.
Two-dimensional (2-D) echocardiography is diagnostic and cost-effective in identifying hypertrophic cardiomyopathy  . Identification of left ventricular wall thickening is diagnostic for the condition  . An accurate and complete family history is necessary for the diagnosis of genetic cardiomyopathy  . The family history should include at least 3 generations including the incidence of heart disease demographics, medical information, age of onset and patterns of inheritance .
Other studies that may be useful include the following   :
Early identification and appropriate treatment of individuals with hypertrophic cardiomyopathy is imperative . The management of patients with hypertrophic cardiomyopathy has change over the past 20 years, particularly with the development of implantable cardiac defibrillators (ICDs) and alcohol septal ablation . To improve quality of life current recommendations for the treatment suggest a step-wise incremental approach . This means the use of therapies to maintain control and prevent complications with the least amount of medication and/or least invasive surgical intervention in order to minimize the risk for adverse effects  .
The aim of treatment is to decrease the occurrence and risk of sudden cardiac death, alleviate out-flow obstruction, control hypertension, and prevent congestive heart failure and cardiac disability  . Of greatest importance to any therapy is early identification of patients and immediate institution of effective medical and/or surgical intervention .
The staged approach may include  :
The purpose of medication therapy is to reduce the pressure gradient across the left ventricular outflow tract or reduce the occurrence of arrhythmias . Medications commonly used in the treatment of hypertrophic cardiomyopathy include   :
Two thirds of patients with outflow obstruction who are symptomatic can be managed long term with medical treatment alone .
Activity restrictions may include total abstinence from competitive athletic activities and strenuous physical exertion, such as heavy lifting, lifting weights, and snow shoveling   . These restrictions should apply if  :
Consultations indicated in hypertrophic cardiomyopathy :
Patient and family education:
The overall survival of patients with hypertrophic cardiomyopathy is similar to that of the general population  . Most patients are asymptomatic. In many the first indication of the disease may be sudden cardiac death, usually from ventricular tachycardia or fibrillation  . Death from hypertrophic cardiomyopathy is often sudden, unexpected, and usually associated with sports or vigorous exertion .
Patients who present at a younger age, particularly infants and young children, have a much higher mortality rate and a much greater degree of ventricular hypertrophy . They are symptomatic earlier in the disease course, most likely because they have more malignant genotype  . Early diagnosis is needed in order to initiate treatment before the advent of sudden cardiac death or progressive cardiac dysfunction and disability  . A diagnosis of hypertrophic cardiomyopathy is not always ominous and is compatible with normal lifespan .
Hypertrophic cardiomyopathy (HCM) is a genetic disorder inherited as autosomal dominant pattern or sporadic  . The estimate of the prevalence of the disorder varies between sources with some reporting it to be rare and others as a common disease   . Studies of outpatients referred for echocardiographic evaluation report that hypertrophic cardiomyopathy is an uncommon disease occurring in only 0.5% of this population . Other sources reporting the same numbers consider the incidence to be a common occurrence  . Prevalence in the general population is not known  .
Familial hypertrophic cardiomyopathy is a heterogeneous genetic disease as the genetic defects can occur at more than one location  . The presence of the gene mutation in one parent results in a 1:2 chance of each child inheriting the gene and therefore the disease. If both parents have the mutation their children have a 3:4 chance of having the disorder . A minority of cases may be caused by spontaneous mutations  . The genetic error has been found to be a mutation on one of a variety of genes responsible for producing sarcomeric proteins  . Alterations in these proteins result in abnormalities in cardiac development and cardiomyopathy   .
Hypertrophic cardiomyopathy is typically diagnosed when patients present with unexplained left ventricular hypertrophy  or with sudden cardiac death . Further characteristics of hypertrophic cardiomyopathy include outflow tract obstruction, diastolic dysfunction, arrhythmias, stroke, infective endocarditis and sudden cardiac death  . Detection of patients at high risk of sudden cardiac death is difficult .
Hypertrophic cardiomyopathy can be classified as obstructive or non-obstructive types  . The obstructive form is due to obstruction of the left ventricular outflow tract. Hypertrophy occurs in left ventricle usually the interventricular septum. This results in an obstruction to the outflow of blood from the left ventricle . The non-obstructive form of the disorder may show defects in the atrioventricular (AV) node or sinoatrial (SA) node and result in cardiac arrhythmias . Hypertrophic cardiomyopathy is the leading cause of sudden cardiac death in preadolescent and adolescent children  . These events are generally due to a cardiac arrhythmia, usually ventricular fibrillation .
Symptoms of hypertrophic cardiomyopathy include    :
Some individuals are asymptomatic and go undiagnosed throughout their lives . Treatment for the disorder is aimed at controlling and minimizing the cardiac complications of the abnormalities of the heart. Antihypertensive and anti-arrhythmia medications are useful in decreasing ventricular outflow issues and cardiac arrhythmias   . Surgical interventions, SA node obliteration, intercardiac pacing, or implantable cardioverter defibrillator, can be helpful in correcting arrhythmias and preventing sudden cardiac death   .
Hypertrophic cardiomyopathy is an uncommon condition with prevalence of only 0.05-0.2% of the outpatient population referred for echocardiography  . Incidence in the general population is unknown . Evidence of the disease found by echocardiography occurs in approximately 25% of first-degree relatives of patients with hypertrophic cardiomyopathy   .
The genetic inheritance pattern of hypertrophic cardiomyopathy is autosomal dominant so no sex predilection should occur  . However, it is slightly more common in males than in females . This may be due to other confounding factors. Hypertrophic cardiomyopathy usually presents at a younger age in females and they tend to be more symptomatic and more likely to be disabled by their symptoms than males .
In general, hypertrophic cardiomyopathy has occurrence peaks in two age groups with highest incidence in the second and third decade of life . However, hypertrophic cardiomyopathy can present at any age  . Reported annual mortality rates in patients with hypertrophic cardiomyopathy are 1% to 3-6%, and have significantly improved over the past 40 years . The risk of sudden death in children is as high as 6% per year .
Hypertrophic cardiomyopathy is a genetic disease  that is due to defects in one or more of the genes encoding for the sarcomeric proteins, such as myosin heavy chain, actin, tropomyosin, and titin   . The risk for mortality and degree of cardiac hypertrophy vary with the specific genotype . Alterations in sarcomeric proteins cause changes in to cardiac musculature. Abnormal calcium kinetics and abnormal calcium fluxes result in an increase in intracellular calcium concentration, which may produce hypertrophy and cellular disarray . Myocardial hypertrophy and disorganization of the muscle fibers result in the abnormal myofibrillar architecture  . This may also cause in abnormal coronary arteries with reduction in the size of the lumen and thickening of the vessel walls . Muscle fiber abnormality in hypertrophic cardiomyopathy most often occurs in the ventricular septum and causes extensive fibrosis of the walls of the heart  . This occurs in more than 80% of cases . As a result of these abnormalities in cardiac musculature the following findings may occur  :
A narrowing of the left ventricular outflow tract occurs in many patients with hypertrophic cardiomyopathy   . The narrowing is caused by the asymmetry and hypertrophy of the septum and possibly by an abnormal location of the mitral valve . Cardiac arrhythmias are common due to fibrosis of the septum. The septum may be at least 4-6 mm thicker than normal for each age group and thicker than the posterior wall  . In more than 80% of cases of sudden cardiac death the cause is ventricular fibrillation  .
Common electrocardiographic findings include ST-T wave abnormalities and left ventricular hypertrophy, axis deviation (right or left), conduction abnormalities (P-R prolongation, bundle-branch block), sinus bradycardia with ectopic atrial rhythm, and atrial enlargement  .
Genetic testing can and screening of first-degree relatives can be used to identify asymptomatic family members of the index case  . Electrocardiography following this determination may help to reduce sudden cardiac death and complications in these individuals  . Patients must abstain from strenuous and competitive athletic activity and physical exertion  . However, since many individuals are asymptomatic and undiagnosed this is not an efficient preventive measure for sudden cardiac death .
Cardiovascular screening before competitive sports participation has been reported to reduce the frequency of unexpected sudden death from hypertrophic cardiomyopathy  . But large-scale screening of athletes may not be feasible or cost-effective  . Screening individuals before participation in exercise may reduce exercise associate symptoms   . High-risk patients should be excluded from certain activities and possible prodromal symptoms should be evaluated immediately. All fitness personnel should be trained for emergencies . Early identification of at risk individuals is imperative to prevent complications such as ventricular obstruction, cardiac dysfunction, arrhythmias, stroke, infective endocarditis and sudden cardiac death .
Hypertrophic cardiomyopathy (HCM) is a genetic disorder   . It is characterized by myocardial hypertrophy resulting in cardiac dysfunction occurring in without an obvious precipitating cause   . Its symptomatology and presentation varies widely and may often be asymptomatic  . It is the leading cause of sudden cardiac death, particularly among children and adolescents (especially young athletes)   . This is the most distinctive presentation of the disorder.
Hypertrophic cardiomyopathy is a progressive disease that worsens with age if left untreated . Congestive heart failure may occur in the late stages of the disorder . Management is aimed at controlling the underlying cardiac conditions with medication and/or surgical intervention  . Although the condition cannot be prevented, early identification and treatment of individuals at risk can prevent the complications of the condition  . Since this is a familial genetic disease, screening of close blood relatives of affected patients is the beat means of doing this . Cardiac evaluation of athletes before they participate in strenuous physical activity and sports is recommended but may not be financially feasible  .
What is hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy is a rare genetic disorder that affects the production of sarcomeric proteins important in the normal development of heart musculature. Its incidence in the general population is unknown because many with the defective gene are asymptomatic. The occurrence in patients seen in out-patient cardiac care is only 0.2 to 0.5%.
This disorder is the primary cause of sudden cardiac deaths, especially in children, adolescents, and young athletes. Long-term effects of the abnormal heart development include progressive heart failure and abnormal cardiac rhythm.
What are the symptoms of hypertrophic cardiomyopathy?
Symptoms of hypertrophic cardiomyopathy include:
What causes hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy is a genetic disorder inherited from one or both parents and results in abnormal musculature of the heart. There are no known predisposing factors for the gene mutations.
How is it diagnosed?
Hypertrophic cardiomyopathy is suspected when the patient presents with one or more of the clinical symptoms of the disorder, especially sudden cardiac death in young children and adolescents. Clinical diagnosis can be made using a two-dimensional electrocardiograph. Definitive diagnosis is made by genetic analysis for the presence of the gene mutation.
What are the complications?
How is it treated?
Hypertrophic cardiomyopathy is treated by controlling and preventing the complications of the disorder. Medications are used to control high blood pressure and heart arrhythmias which interfere with cardiac function. Ventricular fibrillation, a dysrhythmia that is not conducive with life, is the primary cause of sudden cardiac death. It can be treated with anti-arrhythmia medications, but the implantation of an implantable cardioverter defibrillator (ICD) is the most effective treatment. Other surgical procedures such as mitral valve replacement, therapeutic obliteration of faulty conduction pathways, and repair of obstructions to blood flow through the heart may be necessary in patients with severe cardiac disease.
How can hypertrophic cardiomyopathy be prevented?
There are currently no known means of preventing the inheritance of the hypertrophic cardiomyopathy gene abnormality. Early identification and treatment of the disorder help to prevent and/or limit the complications of the disease. Individuals known to have hypertrophic cardiomyopathy should not participate in strenuous sports and physical activity.
Screening and evaluation with electrocardiography of athletes may be helpful in preventing sudden cardiac death associated with sports. Evaluation and genetic testing of blood relatives of any one diagnosed with the abnormality is recommended.