December 26, 2017

Heart Attacks

Cardiovascular disease

Although cardiovascular disease (CVDs) is not contagious, but this has devoted nearly a third of global mortality and 10% of global illness. While the prevalence of CVD in many advanced countries is declining, the burden of disease in developing countries is increasing over the next 10 years. Since in advanced countries have taken a lot of cost-effective prevention and control for this kind of disorder, the incidence of CVD is declined in recent years. However, the burden of cardiovascular disease (CVD) in developing countries is enormous and growing, due to lack of adequate training and preventative measures. As an example, in Iran, the highest mortality is due to cardiovascular disease. The prevalence of cardiovascular disease in particular coronary artery disease, is 19.4% (in individuals 35 to 79 years old) that means nearly one of each five Iranians in range of aged 35-79 years old has one type of coronary artery disease. Congestive heart failure, with a yearly prevalence of over 5 million in the USA, causes 50% mortality rate in 5 years.

Congenital disease constitutes the largest group of congenital anomalies, with an epidemic of 8 per 1000 births. Some of these cases are associated with chromosomal aberrations, social conditions, congenital infection factors, and environmental contamination. Heart disease can damage the health of the community and ultimately increase the cost of treatment in the country. CVD disease include heart attacks, heart failure, cardiomyopathy and peripheral vascular disease, which are destroyed in all of these disease in a part of the heart cells. Therefore, the pumping of blood ability for heath is difficult. Regarding to the facts that various therapeutic methods have been shown to be highly effective, but there is no strong performance. In this case, stem cells can be considered as an appropriate substitute for heart cells in damaged areas.

Stem cells have the ability to rebuild themselves and also have the ability to differentiate to at least one and usually more adult stem cells. Stem cell transplantation makes healthy cells replace the lost cells in ischemic region and repair the damaged tissue of the heart. As a result, the ability of heart muscle contraction and heart output have increased and also be prevented from the entry of the heart into a failure phase. A similar subgroup of bone marrow cells has the ability to reconstruct the hematopoietic system after bone marrow transplantation also has the ability to differentiate into heart muscle cells, smooth muscle cells and endothelium.

Improvement of myocardial contractility is the success mark of myocardial reperfusion, which significantly reduced premature mortality and improves prognosis in patients with acute myocardial infraction (AMI), although heart failure is still a major challenge, recent experimental and clinical studies suggested that intra myocardial injection or intravenous injection of bone marrow derived stem cells (BMC) or blood derived stem cells (CPC) may play role in the reconstruction of myocardial infraction and increased ischemic myocardial neovascularization and lead to a sustained improvement in cardiac function without any side effects.

Ischemia heart disease

Definition of disease: Myocardial infraction (MI) or acute myocardial infraction (AMI), commonly known as heart attack. A heart attack happens when the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart cannot receive oxygen. Ischemic heart disease is divide into two groups: heart failure and myocardial infarction. Heart attack is the permanent and irreversible death a part of the heart muscle (myocardium) is due to disturb of blood flow and an intense ischemic event.

Heart failure means a severe reduction in heart function and pumping power, which results in the blood being not adequately pumped. Heart failure occurs when the heart cannot effectively pump blood into all parts of the body. In this case, the oxygen does not reach the body adequately, after some months, the heart will be enlarged. Therefore, the thickness of muscle fibers and heart rate will increase in patients.

The most common symptoms of this disease are chest pain or discomfort in the shoulder, arm, back and neck areas. Other symptoms include dizziness, shortness of breath, weakness and fatigue feeling, cold sweating. Among the factors that increase the risk of heart attack, high blood pressure are estimated 47% of the statics, and the other factors is including smoking, diabetics, impaired mobility, high blood cholesterol, inappropriate diet and alcohol consumption.

Causes:

Lifestyle: It seems that smoking is about 36%, obesity is about 20%, and lack of exercise and mobility are 7-12% and less common causes are job stress is nearly 3%. The other evidence showed decline and increase in saturated fat may also affect the risk of heart attack.

Diseases: Diabetes, high blood pressure, high blood cholesterol levels (abnormal levels of lipoprotein in the blood), high triglycerides, obesity, a number of acute and chronic infections, influenza and helicobacter pylori among others are associated with atherosclerosis and myocardial infraction. Other factors are including genetic mutation and inheritance which play major role in this disorder.

Diagnosis:

Diagnostic process begins with accurate medical history of subject and medical examination.

Electrocardiogram: the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin. After recording, some abnormal cases of electrical activity in the heart may indicate myocardial ischemia.

Echocardiogram: This method uses sound waves to produce images of your heart. This commonly used test allows to identify coronary areas that do not perform well with blood pumping.

Nuclear scan: The small amounts of active substance is injected to blood stream. During exercise, the radiotracer that runs on the heart and lungs is monitored and thus allows you to identify problems with blood flow.

Coronary angiography: This process uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in heart.

Heart CT scan: This test can determine the coronary artery calcification (a sign of atherosclerosis) and also CT coronary artery angiography for visibility of the heart arteries.

Fitness test: The time of walking on a treadmill or fixed bike, heart rate, blood pressure and respiration is controlled. Exercise makes the heart pump the blood faster and stronger to whole of body. In this case, fitting test is an identify test to find heart problems.

Survey on the prevalence of disease:

Studies and research around of country show that the age of the heart attack is going to decline in society. Changing lifestyle and tendency towards increasing of use fast foods, tobacco and sedation causes increased the risk of cardiovascular disease.

Considering the increase in the growth of the heart disease in the past two decades, which had been prevalent between the ages of 55-60. Todays this event happens to young people under the age of 30 years, in this way, there is need to find appropriate strategy to prevalent from this problem.

According to the World Health Organization (WHO) in 2005, cardiovascular disease had devoted 17.5 million people death (30%) in the world, and this number will increase to 23 million persons till 2030.

Survey conducted in 29 states of Iran in 1383 demonstrated that cardiovascular disorder had 138000 victims, which estimated 378 persons a day, whom the average age of death was 69 years. Based on this study, the first cause of death in the country in 1383 was cardiovascular disease. Also 12.1% of people over 30 are suffering from heart disorder and angina pectoris in the country. By announcing that 43% of men and 38% of woman are overweight. It is said that if any Iranian can reduce the daily salt consumption from 10 grams to 3 grams, blood pressure will decrease much more 50%. In fact, the risk of heart attacks in people with high blood pressure and diabetic is 6 times rather than normal people.

In general, cardiovascular disease has been considered as a major global challenge. The WHO estimates that 12.2% of the world’s deaths in 2004, due to ischemic heart disease. The results show that cardiovascular disease and main causes of prevalence this disorder in Iran has expanded with fast speed. In this case, it is necessary to adopt a comprehensive plan to prevent the onset of these disease. Obviously, the treatment of this disease imposes a high cost on the health system of the country.

Treatments

A number of lifestyle recommendations for people who suffer from heart attacks are including Mediterranean diet, exercise, quit smoking and loss weight. However, in order to improve the blood flow to hear muscle, there are various treatments depending on the complication.

Pharmaceutical treatments:

1- Blood diluents: Aspirin and other blood thinners prevent clots from blocking, avoiding to block the vessels.

2- Beta-blockers: Beta-blockers block the effects of adrenaline (epinephrine), which can improve the heart’s ability to perform.

3- Calcium channel blockers: These drugs affect the movement of calcium in the cells of the heart and blood vessels. As a result, the drugs relax blood vessels and increase the supply of blood and oxygen to the heart, while reducing its workload.

4- Angiotensin receptor blocker (ARBs): ARBs are used to decrease blood pressure. This drug decrease certain chemicals that narrow the blood vessels so blood can flow more easily through your body. They also decrease certain chemicals that cause salt and fluid build-up in the body.

5- Cholesterol-lowering drugs: These drugs reduce the deposits that have accumulated in coronary arteries.

6- Surgical treatment (Angiography), PCI, open heart surgery (CABG), external reinforcement alternative

7- Stem cell transplantation

Heart Failure:

The heart pumps the blood containing nutrients and oxygen to all body cells. If the heart cannot receive adequate blood, a person will have a sense of fatigue and weakness, while performance of daily activities such as walking, climbing stairs, and moderate exercise will be a challenge for patient. The heart failure causes blood flows more slowly through the body that leads to high blood pressure. In response to the pressure in the chambers, the ventricles and atria’s walls become bigger, thicker and harder. The above compensatory processes may meet body’s requirements for a short period, but gradually heart muscle is weakened and its efficiency is reduced. Following to poor performance of heart, water and sodium are held by kidneys, leading to swelling of the limbs that is followed by generalized swelling of body. Since in this type of heart failure, water retention is considered as the main symptoms, it is called congestive cardiac failure (CCF).

Classification of heart failure:

Class Symptoms

 

I (Mild) There is no limit to physical activity, and normal activity does not cause excessive tiredness, heart rate, or shortness of breath.
II (Mild)  Limited physical activity. There is no discomfort in resting, but normal physical activity leads to fatigue, heart rate or shortness of breath.
III (Medium) Significant limitation in physical activity. There is no discomfort in resting, but activities are less than usual also cause tiredness, heart rate, or shortness of breath.
IV (Severe)  Any physical activity will be accompanied by a discomfort feeling, symptoms of heart failure exist in resting and any physical activity makes this discomfort worse.

 

Common symptoms of heart failure:

It should be noted that a healthy heart, at first tries to compensate the heart failure problems, so that they do not show much symptoms. This compensation is done in three ways:

  • A large heart leads to enter more blood to heart and then increasing blood pumping.
  • Increase the thickness of the muscle fibers of the heart leads to heart muscle reinforce to pump more blood to the body.
  • Increase of heart rate

With this compensation, the heart temporary compensate the failure capacity and sometimes it takes time for years to appear. It should be noted this compensation has a certain amount and then signs of failure will appear.

Some underlying diseases like hyperthyroidism and severe anemia may exacerbate heart failure. In this cases, increasing in the age leads to heart loses pumping capacity.

 

Diagnosis:

Diagnosis process begins with accurate medical history of subject and medical examination. The physical asks some questions about symptom, medical history, drugs, and habits. Then, the perfect clinical examination will be done with special attention to heart.

 

Diagnose tests:

  • Measurement of brain natriuretic peptide (BNP) level: BNP is secreted in response to changes in blood pressure by the heart at the primary phases of heart failure or in serious causes. BNP levels are related to changes in disease severity. BNP levels are higher than normal levels in heart failure, even when the given disease is under control.
  • Chest radiography: The presence of fluid around the heart and lungs is explored in a plain chest X-ray of cardiac size.
  • Electrocardiogram (ECG): The electrical activity of heart is recorded by electrocardiogram.
  • Ejection fraction (EF): The heart motion may be explored by means of ultrasound waves via echocardiography. Likewise, a fraction of blood that exists from heart through a contraction of ventricles may also be measured by the aid of this device. The percentage value of EF is reduced in SHF (contraction).
  • Cardiac catheterization: In this method, catheter enters into the body through vessels to reach to heart. A contrast material is injected by catheter to observe heart activity as well as coronary arteries.

Treatments:

Today, there are several therapeutic choices for heart failure. The best therapeutic steps are to closely monitor drug therapies and to change lifestyle and condition of patients. Prevention of progression of disease is the most important objective of treatment. By this trend, the necessity for hospitalization as well as mortality rate is reduced. The next goal is to reduce the symptoms and to improve quality of life. To understand how the disease progresses and to consider the available treatment options, we divide heart failure into different phases:

  • Phase A: This step includes patients who have a high risk of developing heart failure. Hypertension, diabetes, coronary artery disease, metabolic syndrome, a history of talking cardio toxic drugs (hazardous for heart), a history of alcohol abuse, a history of rheumatic fever, and familial history of cardiomyopathy are considered as some factors which may increase risk of morbidity in these patients.

Therapy of phase A: Regular exercise, quitting smoking, control of blood fat and cholesterol levels, quitting alcohol and drug abuse, administration of angiotensin receptor blockers (ARB) or angiotensin converting enzyme inhibitors (ACEI) in the cases of hypertension and control of diabetes may reduce the risk of CAD. Beta-blocker is administered in the cases with the history of heart attack.

  • Phase B: According to the conducted investigations, this group of patients suffer from SHF, but there is no record of symptoms of heart failure in their medical history. A history of heart attack, heart valve disorder, and cardiomyopathy are the most common disorders in this group. EF of these patients is 40% in echocardiography.

Therapy of phase B: All therapies used at phase A are also recommended for this phase. All patients at phase B must take one of drugs from groups ACEI or ARB. In patients with history of heart attack, beta-blockers and aldosterone inhibitors are also administered. Sometimes, it is required a surgery to repair coronary arteries and heart valve disorder.

  • Phase C: This phase includes the patient who experienced symptoms of heart failure or have these symptoms currently. Dyspnea, fatigue, and inability in doing physical activity are the symptoms of this disease.

Therapy of phase C: All therapies employed in phase A and B may be used at this phase as well. Digoxin and diuretics are also administered if the symptoms are stable. In the cases where the patient has still the symptoms despite of receiving above therapies, aldosterone synthase inhibitors (ASI) can act as a contributor. Reducing salts and fluid intake as well as weight control are necessary. The other used methods include cardiac resynchronization therapy (CRT) by pacemaker and culture of implantable cardiovascular defibrillator (ICD).

Phase D: Patients suffer from SHF, and despite optimal treatment, disease may progress.

Therapy of phase D: All therapeutic methods in phase A, B, and C are also utilized in this phase. Patient’s condition determines the other efforts. Some measures are made including heart transplantation, surgical treatments, research treatments, permanent receiving of immunotherapeutic drugs, and the final vital efforts used for different patients.

In some cases, pharmaceutical therapies for patients with heart failure include several different drugs, but there are some problems in this regard, such as long-term process to develop ideal drug therapies, importance of patient’s cooperation to complete the therapeutic process during this period, and presence of a wide range of side effect following several drugs used together. The side effects are vertigo, weakness, coughing, mal digestion, headache, blurred vision, oblivion, fatigue, etc. The above mentioned- problems may highlight the role of a permanent and modern treatment.