The term cardiovascular disease (CVD) covers a broad spectrum of conditions which involve the heart, arteries, veins, and small capillaries that connect the arteries to the veins.
Cardiovascular disease is among the main causes of death worldwide, but it can be prevented by leading a healthier lifestyle. CVD can be broadly classified into the following diseases.
- Heart attack or coronary heart disease occurs due to blockage in the blood supply to the heart muscles.
- Congestive heart failure occurs when the heart’s ability to pump blood is reduced.
- Arrhythmia is irregular heartbeats. Normally, the human heart beats 60 to 100 times per minute and deviations from this rate may cause complications like strokes and heart failure.
- Heart valve problems: As a result of damage, heart valves may not open enough to let blood through, or they may not fully close, leading to leakage.
- Aortic disease means damage to the largest artery, the aorta.
- Rheumatic heart disease occurs when the valves of the heart are damaged due to inflammation from rheumatic fever.
- Stroke happens when blood supply to a part of the brain is cut off due to a blood clot. It can also occur if a blood vessel bursts inside the brain causing internal haemorrhage (bleeding).
- Peripheral arterial diseaseis the narrowing of the blood vessels of the limbs.
Symptoms
A disease of the blood vessels often presents no symptoms. Angina or chest pain may manifest as the first signs, while a heart attack is a more severe and progressive stage of the underlying disease. While a heart attack may have sudden symptoms, Angina can have the following frequent symptoms: Some frequent symptoms of a heart attack are:
- Chest pain radiating in the left shoulder, arm and left side of the lower jaw.
- Breathing difficulty,
- Nausea and sweating
- Dizziness
Strokes often present with the following symptoms:
- Drooping of one half of the face, weakness in an arm or leg
- This may be followed by sudden numbing of these parts
- Confusion, slurred speech
- Vision problems
- Loss of balance, difficulty in walking
- Dizziness and unconsciousness
Peripheral arterial disease may cause numbness in the legs and recurrent ulcers on the feet. Sometimes, low hair density or hair loss is seen in affected parts of the legs.
Rheumatic heart disease shows the following symptoms:
- Shortness of breath,
- General fatigue,
- Irregular heartbeat,
- Chest pain.
Causes
The main cause for most of the conditions under CVD is atherosclerosis. This is defined as a build-up of plaque (hard deposits) composed primarily of cholesterol and fatty substances along the inner walls of arteries.
Due to this, the arteries become narrow and lose their elasticity over time, affecting their ability to relax or contract, leading to thickening of the arterial walls. As a result, there is less space for blood to flow through the arteries. Lesser blood means lower supplies of oxygen and nutrients to the organs. Due to the blockage and narrowing of arteries, it may lead to pooling of blood at the affected region and get clotted. Along with plaques, these blood clots break down and travel within the artery throughout the body and get lodged into distant organs halting the blood supply to that organ.
When an organ receives reduced blood supply, it can lead to Ischemia. When this happens in the heart, it is called ischemic heart disease.
When the brain is involved, it is termed an ischemic stroke. Sometimes, the blocked blood vessel may rupture or become leaky, leading to blood oozing out of the brain – this results in a haemorrhagic stroke, a more severe and often fatal condition. If the haemorrhage occurs in right part of the brain, the left side of the body is affected and vice-versa. The most common reason for this condition is uncontrolled hypertension.
When this affects the blood vessels of the legs, it causes peripheral artery disease.
Atherosclerosis may cause pooling of blood and lead to the formation of clots. These clots can get dislodged and travel along the artery to distant organs like the brain, kidney or eyes. Blood supply to these organs is thus affected. When a clot gets lodged in a blood vessel in the brain, it causes an ischaemic stroke.
A haemorrhagic stroke, on the other hand, is due to a sudden leak or rupture of a blood vessel in the brain. The most common reason for this condition is uncontrolled hypertension (high blood pressure).
Rheumatic fever is an abnormal immune response to a bacterial infection that has not been treated properly. It leads to an inflammatory disease that slowly damages the tissues of the heart valves and results in scar formation. The valves become narrow or start leaking, thereby affecting the heart’s functions. It occurs in pre-teen children, mostly in developing countries with poor medical care.
There are certain risk factors associated with CVD:
- High blood pressure, and high cholesterol levels.
- Smoking
- Diabetes and obesity
- Inactive lifestyle and unhealthy diet
- Family history of CVD.
Diagnosis
There are many procedures which aid in the diagnosis of CVD. The mandatory ones include:
- Blood tests help determine the levels of various cardiac enzymes and cholesterol.
- It is important to know whether the affected person had a recent history of rheumatic fever or sepsis (a bacterial infection in the blood that mainly affects the heart’s valves).
- An electrocardiogram (ECG) records the electrical activity of the heart and determines if a heart attack has occurred.
- Chest X-rays can show if the heart is enlarged.
- An echocardiogram (2D-echo) is used to produce images of the heart size, and details about heartbeats.
- Exercise Stress Test: Those who undergo a medical test on a treadmill are connected with other equipment to monitor heart functions during the activity.
- CT scans and MRIs provide more detailed information than X-rays.
- Coronary catheterisation and angiography: Dyes are injected into the blood vessels through catheters, and images called angiograms are taken. They provided detailed information about blocked arteries.
Treatment
The following medicines are generally prescribed and continued even after surgery:
- Blood pressure should be brought under control. Commonly used medicines are calcium channel blockers and beta-blockers
- Anticoagulants to reduce the clotting ability of blood.
- Aspirin and other antiplatelet agents help to prevent clotting.
- Angiotensin-converting enzyme inhibitors which allow blood to flow more easily and increase the heart’s efficiency.
- Statins to bring down blood cholesterol levels.
Surgery
Most routine heart surgeries involve these procedures:
- Placing medical devices like a pacemaker– which is a small device placed in the chest to control heartbeat; or an artificial or prosthetic valve.
- Open heart surgery and patches to close birth defects such as congenital holes in the heart.
- Coronary Artery Bypass Graft (CABG) provides an alternative route for blood flow, bypassing the blocked portion of the vessel.
- Balloon angioplasty is done to open a blocked vessel and stents are placed to keep the artery wide enough.
- Heart transplantation is a final resort in select cases.
