In this article we will discuss about the Coronary Heart Disease (CHD):- 1. Meaning of Coronary Heart Disease 2. Clinical Features of Coronary Heart Disease 3. Risk Factors 4. Prevention and Management.
Meaning of Coronary Heart Disease:
Coronary heart disease (CHD) or ischaemic heart disease (IHD) is synonymous terms for a group of syndromes arising from failure of the coronary arteries to supply sufficient blood to the myocardium. These syndromes are in most cases associated with atherosclerosis of the coronary arteries. They include myocardial infarction, angina pectoris and sudden death without infarction.
Clinical Features of Coronary Heart Disease:
a. The prominent symptom is a severe, pressing or constricting pain, poorly localized deep in the centre of the chest and radiating down the left or both arms.
b. In angina pectoris this pain comes on with exertion or excitement; it forces the patient to stop and when he does so, that pain passes off in a few minutes.
c. Patients with angina can suffer several attacks of pain in a day and they can go on like this for long periods of time.
d. In myocardial infarction the pain often comes on at rest; it is very severe, lasts for hours and is only relieved by strong opiates like morphine. It is accompanied by general symptoms such as weakness, collapse, cardiac arrhythmias and circulatory shock.
e. Some patients have a mild myocardial infarction without noticing pain (silent coronary).
f. There are also several other causes of pain in and around the chest which can mimic CHD, such as Pericarditis, Pulmonary embolism, Oesophageal and respiratory disease.
g. The E.C.G. often changes temporarily during an attack of angina, it is usually normal between attacks. But soon after the onset of myocardial infarction, the ECG may undergo a permanent change and show the infarct pattern.
h. Patients with angina or who have had a myocardial infarct are liable to develop cardiac failure or arrhythmias.
Risk Factors of Coronary Heart Disease:
A. Sex and age:
a. Men are more prone to CHD than women and incidence rises with age in both sexes.
b. Greatly increased incidence are found in women after the menopause, and by the age of 70 there is no difference between the sexes.
c. The secretion of the ovarian hormones during the reproductive life of women aids in the relative immunity against the rise in cholesterol level.
d. The concentration of plasma total cholesterol is lower in women aged 20 to 45 years than men of the same age group but HDL cholesterol is higher.
e. If both ovaries of women are removed before the age of 35, the plasma total cholesterol will increase with the increase in CHD.
B. Family history:
a. Some families are more susceptible to CHD than others.
b. Family clustering of any disease may be due to either inherited susceptibility or family sharing of environmental experience e.g., an atherogenic diet. More than 50 per cent of plasma cholesterol is genetically determined.
c. In families susceptible to CHD, there is often a high incidence of other diseases which have multiple aetiology, e.g., hypertension, diabetes mellitus, gout and hyperlipidemia.
C. Behaviour patterns and personality traits:
People with behaviour pattern A above an increased incidence and prevalence of CHD. Such people show an excessive sense r of time urgency, a preoccupation with vocational deadlines and enhanced aggressiveness and competitive drive. This behaviour pattern is probably constitutional.
D. Hyperlipidemia:
A patient with a very high plasma cholesterol is at high risk of developing the disease at an early age but for the majority with values not greatly raised the increased risk is small.
E. Hypertension:
The incidence of CHD in men aged 45 to 65 years with blood pressures exceeding 160/95 was more than five times that in normotensive men (blood pressure 140/90 or less). Elevations in both diastolic and systolic pressures correlate positively with CHD, the diastolic pressure perhaps being more important in younger people.
F. Obesity:
1. Obesity is associated with an increased risk of death from heart disease.
2. A moderately increased plasma cholesterol or mild hypertension or Grade I obesity (plumpness), each by itself, carries only a small risk of CHD, a combination of any two of them increases it much more, and in a patient with all three the prognosis is very uncertain unless they are reduced by appropriate treatment.
G. Diabetes Mellitus:
This is an important risk factor both in its clinically recognised and latent forms. This association is not due solely to blood lipid disturbances. Diabetics are particularly prone to hypertension and proliferative lesions of the small blood vessels.
H. Hyperuricaemia and gout:
There is a positive association between these abnormalities and CHD, although not all hyperuricaemia represents pre-gout.
I. Electrocardiographic abnormalities:
a. Persons with an abnormal ECG or with ECG changes or left ventricular hypertrophy have an increased risk of developing CHD.
b. If the changes are present when the patient is at rest, they may represent early CHD.
c. Abnormalities which appear on exercise usually indicate relatively advanced is-chaemia.
J. Cigarette smoking:
a. Peripheral vascular disease and CHD, particularly myocardial infarction, occur much more frequently in heavy cigarette smokers than in those who do not smoke.
b. There is a clear relationship between CHD and the amount of smoking.
c. The mechanism by which nicotine or some other constituent of tobacco causes this adverse effect is not clear. However, it may be due to the vasoconstrictor action of nicotine, to inhalation of carbon monoxide, or to some undesirable effect on the coagualibility of the blood.
d. Heavy smoking may be a manifestion of a susceptible personality and a reaction to stress and strain.
e. Patients with CHD should give up smoking.
K. Diet:
a. A high intake of saturated fatty acids may raise plasma cholesterol and so promote the formation of atheroma.
b. A low intake of polyunsaturated fatty acids may modify platelet function and so promote the formation of thrombi.
c. An intake of energy above requirements leads to obesity and high intake of salt may lead to hypertension in susceptible individuals.
d. It has been found that some individuals suffer a heart attack early in life. In that case, diet is less important than genetic hypercholesterolemia or cigarette smoking in the aetiology of coronary artery disease.
e. Excessive intake of alcohol should be avoided.
f. A higher proportion of energy should come from bread, potatoes, and other vegetables and lower proportion from separated fats and fatty meats.
L. Lack of exercise:
a. Physical activity protects against CHD. Bus conductors have a lower incidence than bus drivers, and postmen who deliver letters have a lower incidence than telephonists and post office clerks.
b. Active recreations are also important. In middle-aged Harvard alumni, the incidence of heart attacks was lower in those who have been physically active.
M. Emotional stress and tension:
a. The modern prosperous communities suffer from more stress and strain than their less wealthy predecessors. Increased risk of myocardial infarction could be due to acute or chronic adrenergic overdrive caused by stress. Possible mediating factors include plasma noradrenaline and FFA.
b. The stress of racing driving raise plasma triglycerides and FFA but not plasma cholesterol. The same reaction probably occurs in some urban drivers.
N. Drinking water:
The harder the drinking water the lower the death rate from cardiovascular disease. Calcium and magnesium in hard waters may have a protective action and there are several trace elements in hard water that may be beneficial.
Soft waters, being more acidic, are more likely to dissolve potentially toxic trace elements like lead and cadmium from pipes or rocks.
Since there is no concrete evidence to be based on it will be premature to advise modification of water supplies in the hope of preventing cardiovascular disease.
O. Coffee and alcohol:
a. Myocardial infarction is associated with high consumption of coffee though has not yet been confirmed.
b. Moderate alcohol consumption is not a risk factor, and in patients with disorders directly attributable to alcohol the incidence of CHD is no higher than normal.
Prevention and Management of Coronary Heart Disease:
a. Smoking must be stopped.
b. The diet should be moderate so as to prevent being overweight.
c. Physical exercise should be taken as much as possible without causing undue breath- lessness or fatigue.