Keywords: HCM, sarcomere, thick and thin filaments, gene mutation, autosomal dominant, Doppler echocardiography, dual-chamber pacemaker, septal ablation, myomectomy)
Hypertrophic cardiomyopathy, HCM is a cardiac disorder with a genetic etiology, characterized by hypertrophy of the myocardium It is an important cause of morbidity and mortality in the affected population. Both men and women are affected equally and people of any age and race are at risk of developing HCM. It is the most common cause of sudden cardiac death SCD in young adults, especially athletes.
Description of the disorder Hypertrophic cardiomyopathy is characterized by interventricular septal hypertrophy (in absence of other cardiovascular conditions), causing decrease of left ventricle cavity and potentially leading to outflow obstruction. (1) (6) As a consequence of mutations in several genes encoding for thick and thin filaments which build the cardiac muscle, morphological changes occur leading to tangled, thickened myocardial fibers. It is an important cause of morbidity and mortality. Symptomatology varies a lot, from asymptomatic patients to those with severe cardiac function impairment. Some of the most common symptoms of HCM, which are not specific to this disorder may be: shortness of breath at rest or with exertion, fatigue, chest pain, arrhythmias, dizziness, but not only.
There is an ongoing debate about the onset of the hypertrophy and symptoms. Although it is confirmed that
Young children who have hypertrophic cardiomyopathy tend to have no symptoms of their condition until
As cardiomyopathy progresses, the heart becomes weaker and is less able to pump blood normally. This results in heart failure. There are different types of cardiomyopathy- hypertrophic, dilated, and restrictive. Hypertrophic cardiomyopathy occurs when the heart muscle cells enlarge which causes the thickening of the left ventricular wall. Although the ventricle size stays normal, the thickening makes it harder for the heart to pump blood. In some cases, the septum also thickens and expands to the left ventricle which causes a blockage of blood flow out of the left ventricle. The cause of the disease is unknown but hypertrophic cardiomyopathy is usually caused by changes in the genes in heart muscle proteins. It can also develop due to
Systolic heart failure is characterized by enlarged ventricles that are unable to fully contract to pump enough blood into circulation to adequately perfuse tissues. The enlargement in ventricles is due to an increased end-systolic volume. If the heart is not able to sufficiently pump the expected volume of blood with each contraction, which in a normal healthy heart is 50-60%, there will be a residual volume left in the heart after every pump (Heart Healthy Women, 2012). With the next period of filling, the heart will receive the same amount of blood volume from the atria combined with that residual volume from the previous contraction. This causes the ventricles to have to dilate to accommodate this increase in volume. The dilation causes the walls of the ventricles to stretch and become thin and weak. Also the myocardium, the muscle layer of the heart, will stretch and not be able to adequately make a full and forceful enough contraction to push blood from the ventricles (Lehne, 2010).
I would like to preface this paper by saying that I thought that everything that I heard was sound and it was nice to hear about T.D. Jakes’ success after such a rough patch in his own life. It really was an inspiration, and stories like that provide hope for thousands of hurting people. I would like to explore if this hope he talks about is a realistic hope or a false hope.
Even though HCM is a common genetic heart condition, there is no cure. However, there are multiple treatments used to relieve symptoms and prevent sudden cardiac death. The specific treatment prescribed varies based on the severity of the condition. Medications are used to relax the heart muscle and slow the heart rate. Doctors may use beta blockers, calcium channel blockers, or other medications to control heartbeats. Sometimes a person with HCM will use blood thinners to reduce the risk of blood clots in the heart. In addition to medications, a patient can get surgery to remove the thickened part of the heart. Septal myectomy is an open-heart procedure in which the surgeon removes part of the thickened septum, improving the blood flow and
defects correlating with areas of noncompacted myocardium. Post-mortemfollowup and 90% develop LV dysfunction within a period of 10 years of
Hypertrophic cardiomyopathy is an inherited disease that affects the cardiac muscle of the heart, causing the walls of the heart to thicken and become stiff. [1] On a cellular level, the sarcomere
This condition can masquerade as an acute myocardial infarction clinically, biochemically, and electrocardiographically; however, its underlying pathophysiology is quite different. A significant portion of these patients have serious complications including cardiogenic shock, heart failure, arrhythmias, cardiogenic shock, and death. The major distinguishing feature that differentiates this syndrome from ischemic cardiomyopathy is the lack of obstructive coronary disease and presence of regional wall motion abnormalities typically extending beyond a single epicardial coronary distribution, making TC a diagnosis of exclusion, after coronary anatomy has been delineated [1].
In fact, TTC is not even in the top three most common types of cardiomyopathy. The most common type is hypertrophic cardiomyopathy (or HCM). People with HCM have a heart muscle that is excessively thick and prone to scarring. This process makes the muscle stiff, which causes blood-pumping difficulties. The second most common subgroup is dilated cardiomyopathy (DCM). This occurs when the pumping chambers of the heart enlarge, which makes the muscle thin and weak. Many people with DCM have breathing problems due to the fluid build-up in their lungs. The third most common type of cardiomyopathy is arrhythmogenic right ventricular cardiomyopathy (ARVC), where heart muscle cells are replaced by scar tissue and fat cells. All three of these instances are
Systolic heart failure results from the inability of the cardiac muscle to contract effectively from inadequate cardiac output. As the cardiac output drops, compensatory mechanisms to try to restore its function through takes place by ventricular remodeling. During this remodeling phase, the heart begins to develop changes in its size and becomes hypertrophic that results in a decreased ability of the heart to contract, decreased available oxygen, and available ATP. Secondly, this hypertrophic states increases preload that results
According to the US Census Bureau, population estimates in 2004, in the United States it is estimated that approximately .02% of the population is effected by hypertrophic cardiomyopathy. Which is two in
These separate forms of the condition come with distinct traits that vary from one to the next. Dilated cardiomyopathy, “The most common form, this occurs when the muscle fibers of one or both pumping chambers are weak and unable to contract normally” (“Understand Pediatric” 1). Which means that the heart beats abnormally due to lack of blood flow. Often with DCM the heart is weak and fails because it cannot sufficiently pump blood throughout the body (“Understanding Pediatric” 1). The article on “Understanding Pediatric Cardiomyopathy” states that hypertrophic cardiomyopathy is the second most common form. HCM has a few characteristics that can be mistaken for dilated cardiomyopathy. Thick and stiff muscles may stop the heart from contracting properly, which may narrow the passageways for blood to move out of the heart (“Understanding Pediatric” 1). So, the muscles within the heart thicken to try and help blood flow. In an advanced form of hypertrophic cardiomyopathy, there is a chance that the muscles may thin to try to help the poor pumping action (“Understanding Pediatric” 1). When HCM tries to help the body it, in itself, can cause failure. A
Some people die right on the spot from HCM and there were no signs to show of it beforehand. For example, Gerald Grain was an average high school student in Chicago. He died after a routine long-distance run in gym class in September of 1997. He had no previous diagnostics of any heart disease and lived a normal life…until it ended. Robert Seigal, in ‘Sudden Death of Young Athletes”, writes about many more instances when high school athletes die due to normal physical exertion. Instances like that are reasons why heart doctors and general practitioners try to spread the awareness of “low-lying” conditions like HCM. All people should always educate themselves about their own
As this disease progresses and the workload of the heart is consistently increased, ventricular hypertrophy occurs. At first, the hypertrophied heart muscles will increase contractility, thus increasing cardiac output; however, as hypertrophy of the ventricular myocardial cells continues, it begins to have poor contractility, requires more oxygen to perform, and has poor circulation from the coronary arteries. This can result in heart tissue ischemia and lead into cardiac dysrhythmias (Lewis et al. 2014, 768).
Sixty cats were successfully enrolled during 18 months of the study period. Mean age of these cats was 9.0 +/- 4.0 years old with 33 males and 27 females. The breeds of the cats enrolled include Domestic short hair (21), Domestic long hair (14), Maine Coon (12), Ragdoll (4), Scottish Fold (4), Persian (2), Himalayan (2), and Sphynx (1). Twenty-five of 60 cats (41.6%) had a known history of HCM prior to the enrollment in this group. Echocardiographic examination prior to the enrollment confirmed HCM in all enrolled cats with thickened left ventricular walls (interventricular septal wall thickness during diastole: 7.1 +/- 0.4 mm, posterior wall thickness during diastole 6.9 +/- 0.5 mm) and diastolic dysfunction. Thirteen cats of 60 cats