Unit – IV A
Heart Related Disorders
- A healthy adult has a blood pressure reading of about 120/80 mm Hg (120 mm Hg – systolic and 80 mm Hg – diastolic). This often rises normally with age to about 130/90 at 60.
- Abnormally high blood pressure is known as hypertension. Hypertension is defined as the “Systolic pressure equal to or greater than 160 mm Hg and (or) the diastolic pressure equal to or greater than 95 mm Hg”.
- Abnormally low pressure is termed hypotension.
- Hypertension puts a strain on the heart and blood vessels.
- Apart from increasing the risk of having a stroke or developing heart failure or coronary artery disease, high blood pressure may cause kidney damage and retinopathy (damage to the retina at the back of the eye).
- Hypertension is linked with obesity and in some people to a high intake of salt, alcohol, smoking appears to aggravate the effects of hypertension.
- Alcohol consumption and smoking should be avoided.
- Obese persons should make an attempt to reduce weight through restriction of food intake and try regular exercise.
- The dietary intake of animal fat (milk, cream, cheese fatty meat and eggs) should be reduced. A restricted intake of salt is recommended.
Coronary Artery Disease (CAD):
- Myocardial infarction is a coronary artery disease which involves sudden death of part of the heart muscle due to blockage in the coronary artery. It may cause severe unremitting chest pain.
- Narrowing of coronary arteries is called atherosclerosis, (deposition of fatty substances in the lining of arteries called plaque) due to which blood flow to the heart reduces.
- Severe heavy crushing pain may spread up to the neck and in to the arms especially the left arm. Excessive sweating, shortness of breath, nausea and vomiting, anxiety sometimes accompanied by fear of dying.
- About one in five people experience no chest pain in myocardial infarction. However, there may be fainting, sweating and pale skin. This pattern of symptom is known as “silent infarction”. This type of infarction is common in people with diabetes mellitus or those with elevated blood pressure.
- The narrowing of coronary artery is usually due to an accumulation of droplets of fatty substances, like cholesterol.
- The fibrous cover of the fat deposit sometimes rupture, triggering the formation of a blood clot. If this blood clot blocks the artery, blood flow to an area of the heart muscle stops, causing myocardial infarction and leads to death of tissue.
- Habitual cigarette smokers have a substantially increased risk of dying from myocardial infarction.
- High blood pressure is a major risk factor and the risk increases with higher pressure.
- The risk of atherosclerosis and coronary artery disease increases dramatically in those who are more than 30 percent overweight.
- A raised blood cholesterol level increases the risk. A high fat diet is also a factor.
- Physical inactivity is also a major factor.
- Angina is a term that describes a strangling or constrictive pain. Angina has become synonymous with the heart disorder called Angina pectoris.
- This heart disorder refers to chest pain caused by insufficient supply of oxygen to the heart muscle, usually a result of poor blood supply. Heaviness and severe pain in chest, pain in neck lower jaw, left arm and left shoulder.
- Angina pectoris usually occurs when the demand for oxygen is increased during exercise and at the time of stress.
- The pain usually comes on suddenly. The pain ranges from a tight ache to intense crushing agony. It lasts for 30 minutes or more and it is not relieved by rest
- Inadequate blood supply to heart due to coronary artery disease such as atherosclerosis
- Severe attack of anaemia which reduces the oxygen carrying capacity of blood.
- Polycythemia (Increased number of red blood cells) which thickens the blood, causing it to slow its flow through the heart muscle.
- Thyrotoxicosis (a disorder caused by excessive secretion of thyroxine) can precipitate angina pectoris by making the heart work harder and faster than its blood supply will permit.
Heart Failure or Cardiac arrest:
Due to cardiac arrest heart stops working.
- Progressive weakening of cardiac muscles.
- Failure of heart to pump blood effectively.
- Hypertension may result in enlargement of the heart.
- Advanced age, malnutrition, chronic infection, toxins, severe anaemia, hyperthyroidism are other reasons for weakening of heart muscles.