The core consists of an outer layer, the pericardium, a call muscular layer and an inner layer myocardium, endocardium. The myocardium is the part that is responsible for exercising the power to carry out the blood pumping and that shapes the heart chambers, the atria and ventricles.
When for whatever reason the walls of the ventricles become enlarged and hypertrophy, thicken, the heart is diminished its relaxivity, which can not correctly filled and is disturbed blood pumping it into the bloodstream. In these cases, the patient is said to have hypertrophic cardiomyopathy.
Most cases of hypertrophic cardiomyopathy are due to a genetic defect on chromosome 14, although alterations have also been described in other chromosomes. This change follows a pattern of autosomal dominant inheritance, although sometimes this genetic alteration may occur without a family history. Besides causing a thickening of the walls, there is usually alteration of the organization of the muscle fibers in the coronary arteries.
The walls of the left ventricle and myocardium thicken slowly relaxes, so it loses its elastic capacity and could not relax properly to their chambers to fill with blood during diastole phase of the cardiac cycle. The wall tends to be most affected separating the two ventricles, although sometimes the hypertrophy of the ventricular walls is symmetrical.
Furthermore, there is often an alteration associated mitral valve so that the front of the valve is pulled during removal from the blood and hinders the outlet thereof during systole. This phenomenon is known as systolic anterior motion or SAM.
Hypertrophic cardiomyopathy can padecerse without the patient present any symptoms, but in turn is a major cause of sudden cardiac death in young people that they have suffered without warning symptoms.
If these symptoms are due to the defect of the pumping capacity of the heart’s blood. Patients may present with dyspnea secondary to heart failure caused by a defect in the ventricular filling capacity. Dyspnea is the most common symptom of this disease.
Other symptoms that may occur are patients syncope, dizziness, palpitations or angina, as in the case of aortic valve stenosis.
Atrial fibrillation, angina pectoris, myocardial infarction or sudden death are complications of hypertrophic cardiomyopathy. Sudden death, infrequent as a whole, tends to affect teenagers and young people in general as a result of severe ventricular arrhythmia. Family history, syncope or asymptomatic ventricular tachycardias are poor prognostic factors.
Hypertrophic cardiomyopathy should be evaluated in patients with a history of this disease in his family and suspected in patients with or without a family history, present symptoms compatible with it, especially if they are young.
A cardiac auscultation seen a blow in the left ventricle during systole phase increases with exercise, to make a Valsalva maneuver or when standing up suddenly, while decreasing squatting or lifting limbs lower.
The electrocardiogram observe nonspecific signs of enlarged left ventricular walls. They can detect arrhythmias secondary to hypertrophic cardiomyopathy.
Chest radiography usually shows no changes at most a slight enlargement of the cardiac silhouette.
The echocardiogram will assess the thickening of the walls of the left ventricle and quantify the severity of the impairment of cardiac function. It will be appreciated thick wall separating the two ventricles than 15 mm, when it is normal to have a thickness of between 8 and 11 mm. If the thickening is greater than 11 mm can be said that there is hypertrophy, but can not speak of hypertrophic cardiomyopathy. Hypertension can cause a thickening of the walls of the left ventricle, but without reaching the extremes of hypertrophic cardiomyopathy. Echocardiography can also evaluate the abnormal movement of the anterior leaflet of the mitral valve in systole phase (SAM) and quantify the proportion of blood in heart ejecting each pump, which is usually between 30% and 70% normal value. Another test that can assess hypertrophic cardiomyopathy radionuclide ventriculography.
If you perform a hemodynamic study that pressures will be late ventricular filling will be higher in case of suffering from hypertrophic cardiomyopathy.
Treatment of hypertrophic cardiomyopathy is based on the use of drugs that reduce the contractility of the heart, are calcium antagonists, beta-blockers and some antiarrhythmic drugs such as amiodarone.
In cases of severe obstruction can perform a surgical resection of the thickened ventricular septum, either by open surgery (myectomy), or by creating a controlled ischemia in that part of the heart muscle. These options, today, are used less frequently.
If significant risk of sudden death, the patient may benefit from using autoimplantable defibrillator (ICD), a device connected to the heart via electrodes monitors the heart rhythm and if it detects an altered heart rate and try to reverse it to a normal rhythm by electrical shock.
Since this is a hereditary disease that nature often has no symptoms, no specific measures to prevent it.However, if the patient has a family history of HCM or sudden death, it is advisable to make regular checks with the cardiologist.
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