Coronary artery disease
The heart like any other organ in the body needs constant supply of blood to survive. Blood reaches different parts of the heart through the coronary arteries. Coronary arteries are of vital importance for the sustenance of life.
The different normal functions of the coronary arteries include:
1. Carrying blood to different parts of the heart
2. Regulating blood supply to the heart in the face of varying blood pressure
3. Increasing blood supply to the heart in the face of increased cardiac demand like during exercise.
The coronary arterial system: Can be divided into four parts
1. Left main coronary artery (LMCA)
Which divides into
2. Left anterior descending artery (LAD) And
3. Left circumflex artery (LCX)
4. Right coronary artery (RCA)
Left main coronary artery, left anterior descending and left circumflex coronary artery
Right coronary artery
What is coronary artery disease (CAD)
Any disease which involves coronary arteries is CAD. Usually the most common form is reduction in the size of the coronary arteries. Many disease conditions can result in coronary artery disease but the most common cause of CAD is atherosclerosis. Other diseases like autoimmune diseases, congenital diseases can result in CAD.
Why CAD occurs?
CAD occurs due to a variety of reasons, which are called risk factors. You can read more about risk factors here.
What are the types of CAD?
CAD is a septum of diseases and it is divided to two categories
1. Chronic stable angina (CSA): In CSA there is a pattern of chest discomfort associated with exertion or emotional excitability. The occurrence of angina is after a predictable amount of work.
2. Acute coronary syndromes ( ACS)
ACS are are again divided into three types
A. Unstable angina: When there is new onset angina, worsening of previous angina, rest angina, it is called unstable angina
B. Non-ST elevation myocardial infarction
C. ST elevation myocardial infarction – the classic heart attack
This classification is important for the point of view of management and the aggressiveness of treatment.
What are the symptoms of coronary artery disease?
A. Angina : Chest pain or discomfort .
B. Angina equivalents – fatigue , dyspnoea (shortness of breath) , eructations, palpitation
C. Sudden onset acute severe chest pain
D. Cold sweating
Read more about symptoms of heart disease here.
What to do?
First of all see your doctor for evaluation and treatment. Some of the general management modalities are discussed here.
For the diagnosis of CAD the following investigations may be needed:
A. ECG – is of central importance in CAD. ECG in many occasions shows changes suggestive of reduced myocardial blood flow
B. Stress test – Different types of stress tests are available like treadmill test, nuclear stress tests. A stress test can be done by performing exercise on a treadmill or by giving drugs in patients who are unable to do exercise. It is done when the symptoms are not typical and ECG changes are not typical.
C. Echocardiography – is for assessment of structure and function of heart
D. CT coronary angiography – It is a noninvasive imaging modality for the diagnosis of CAD. It is like any other CT scan. Contrast injections are given to visualize the coronary arteries
E. MRI coronary angiography – Not very widely used for imaging of coronary arteries
F. Coronary angiography – this is the gold standard for the diagnosis of coronary artery disease and any percutaneous treatment for CAD can be done in the same setting
A. Risk factor control – Risk factor control is one of the most effective interventions for reducing the impact of coronary heart disease. Proper control of blood pressure, diabetes, quitting smoking, treatment of abnormalities of cholesterol are some of the steps that greatly reduce the incidence and prevalence of CAD.
B. Medications- Patients with CAD will on some medications indefinitely (usually life long). For chronic stable angina, the first line of treatment is usually medical management. Even patients who undergo coronary artery stenting or bypass surgery need to take medicines life long.
C. Coronary angiography and percutaneous coronary interventions are usually advised for patients who have more serious symptoms or for whom symptoms are not easily controlled with medicines. In presence of certain high risk factors patients should undergo early angiography and intervention or surgery
D. Coronary artery bypass grafting (CABG)
Drugs used in treatment of CAD:
1. Anti- platelets e.g. Aspirin, Clopidogrel, Prasugrel, ticagrelor, etc
2. Statins e.g. rosuvastatin, atorvastatin etc
C. Beta blockers (metoprolol, bisoprolol etc)
D. Ace inhibitors or angiotensin receptor blockers
E. Anticoagulants (heparin)
H. Therapies for refractory angina
Details about each class of drug I will post each week( Monday )
So please follow up
Cardiac interventions for CAD:
Known as percutaneous coronary intervention(PCI). In this procedure coronary angiography is done and then stenting is done as required.
Coronary artery bypass grafting:
CABG may be needed where PCI is not feasible or doesn’t give optimum results.
Finally there are a spectrum of patients who have drug refractory angina who are not suitable for PCI or CABG. They have refractory angina and the treatment options are limited in such patients.
Conclusion: Coronary artery disease is the leading cause of death and suffering in the world. The most common symptoms include chest pain, shortness of breath. It is diagnosed by ECG, stress tests, coronary angiography etc. The treatment include risk factor reduction, medical management and PCI or bypass surgery as needed.
Key words: Patient information, Coronary artery disease, heart disease, coronary angiography, ECG, Angina, CAD, PCI, CABG