Cardiac Hypertrophy/ “Athlete’s Heart”
The body’s ability to adapt to changing conditions is a constant endeavor. Maintaining during intense change causes the body to adjust rapidly. The cardiovascular system’s ability to adapt during exercise has numerous adjustments to counteract the body’s newly acquired needs. The heart is capable of altering many functions such as stroke volume, heart rate, and cardiac output. In addition the heart can also undergo hypertrophy and increase in size. Cardiac hypertrophy occurs when the heart becomes stressed. Analyzing the causes of stress, and the heart’s ways of adapting we will explore the how cardiac hypertrophy is a relatively simple disorder which with knowledge can be prevented.
Cardiac hypertrophy is the enlargement of the lower, ventricular walls of the heart. Most commonly occurring in the left ventricular side, cardiac hypertrophy can occur on one side or both. Characterized by abnormal heart muscle growth it can be a healthy response to pregnancy or exercise. However, an increase in heart size could also be a sign of hypertension, diabetes, muscular dystrophy, obesity, or cardiomyopathy. Hypertrophy of the heart can be adaptive or maladaptive, therefore the growth may not lead to an increase in cardiac output.
Statistics 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
Cardiac output adapts throughout a training program. The "American Council on Exercise's Personal Trainer Manual" lists exercise adaptations as increased ventricle size, decreased exercise heart rate and increased stroke volume. Therefore, your heart can maintain a high cardiac output with less effort. Most improvement to cardiac output is contributed to increased stroke volume. Positive adaptations occur in as little as three months of aerobic training.
Long-term hypertension can result in a variety of consequences. These consequences are the result of the heart having to adapt and work harder, i.e. against an increased afterload due to the increased systolic pressure. The heart adapts via hypertrophy of the smooth muscle. Chronic hypertension can also lead to a disruption of the endothelium, thus increasing the
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).
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
Ryan Gillyard is a fifteen-year-old athlete boy who was passionate to play Division I college football. He was a “linebacker” and “running back” in football. He lived in Upper Darby and passed away on April 18, 2015.
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
Hypertrophic cardiomyopathy (HCM) is a primary disease of the myocardium (the muscle of the heart) in which a portion of the myocardium ishypertrophied (thickened) without any obvious cause. It is perhaps best known as a leading cause of sudden cardiac death in young athletes.[7] The occurrence of hypertrophic cardiomyopathy is a significant cause of sudden unexpected cardiac death in any age group and as a cause of disabling cardiac symptoms. Younger people are likely to have a more severe form of hypertrophic cardiomyopathy.
Thanks for bringing up the idea of genetic counseling, because dominant and recessive genes are revealed and making the diagnosis will be much easier. As we know, hypertrophic obstructive cardiomyopathy is a common inherited cardiac disorder. The thickening of the septal wall decreases the outflow to the left ventricle wall. Increased heart rate and decrease intravascular volume leads to the obstruction of the left ventricular outflow. If the condition is not resolved ventricular dysrhythmias and sudden death may occur and this is commonly seem in more than 33% of young athletes (Huether & McCance, 2012). Individuals with such family history needs consistent health check up with the cardiologist. Good job.
6. Automaticity – ability of heart to beat spontaneously and repetitively without external neurohormonal control. The heart is capable of beating outside the body, given proper laboratory conditions. Automaticity is evidently linked to fluid and electrolyte balance rather than to nervous system control.
To conclude, hypertrophic cardiomyopathy, the cardiac sarcomere disorder, has been brought to the forefront of our attentions due to its rare yet fatal effects in young athletes; however, it is frequently asymptomatic and relatively common. In most cases, HCM will have no bearing on the person’s quality of life or lifespan. However, a minority, particularly young athletes, may be of an exception, with the myocardial disarray and thickened ventricular wall leading to complications. Dr Tom Riddington of the Guardian quotes: “since the 19th century more than 80 footballers are known to have died suddenly while playing, all young men, all otherwise apparently fit and healthy.” This highlights its significance with relation to sudden
While hypertrophic cardiomyopathy often goes undiagnosed, more severe cases will show symptoms. Most cases are not diagnosed because there are no symptoms or because the patient can continue going about life without any significant struggles. It is usually hard to tell if someone has hypertrophic cardiomyopathy just by looking at them. When symptoms do occur, they include the following: shortness of breath and chest pain (especially during exercise), fainting, abnormal heart rhythms (arrythmias), or a heart murmur, which a doctor is able to detect by listening to the heart. It is important for someone with hypertrophic cardiomyopathy to visit a doctor if any of the above symptoms occur frequently, interrupting normal daily routines.
I chose to summarize this review article to understand the reasons behind exercising a patient with hypertrophic cardiomyopathy (HCM). Prior to the reading, my knowledge of stress echos only covered the bases of diagnosing coronary artery disease. This review focuses on the patients subjective complaints and its correlation with sudden death from HCM.
It’s no secret that physical activity can have a positive effect on your cardiovascular functioning and overall health. The heart is an organ that is mostly composed of muscle, and just like all the other muscles in your body, it needs to be worked in order to maximize its efficiency. The heart is designed to pump blood throughout the body, the weaker the heart, the faster it has to pump to compensate for the amount of work needed to distribute the blood. There have been studies that highlight the adaptations that occur within the athlete’s heart; cavity enlargement as well as wall thickness within the ventricles are two adaptations thought to play a major role in lower heart rate during rest and exercise (Kovacs and Baggish, 2016).
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).
The literature on the effects of exercise of cardiac output maintains the idea that exercise should affect cardiac output- pulse rate, systolic blood pressure, diastolic blood pressure, QRS-pulse lag, P-T and T-P intervals, because of increased heart rate. For our experiment, we tested this theory by measuring our cardiac output before and after some rigorous exercise. We measured the individual cardiac output and then combined the data to compose a class-wide data average. We compared the results of the experiment to what we expected, which was that exercise does affect our heart. Our data from this experiment supported the notion that exercise does, in fact, change cardiac output.