About the Heart
The Heart is a fist-sized muscle that is located in the centre of the chest, between your lungs. It works as a pump to move blood throughout your circulatory system. Blood delivers oxygen and nutrients to, and removes waste from, all the cells in your body.
The heart contains four chambers and four one-way valves. The two upper chambers are called the atria. The two lower chambers are called ventricles.
The four one-way valves keep blood flowing in one direction through each chamber as the heart pumps. The valves open to let blood flow through and then close to prevent blood from flowing back.
The Coronary Arteries
Coronary arteries supply oxygen and nutrient-rich blood to the heart muscle itself.
There is a right and left coronary artery. The left coronary artery divides further into the left anterior descending artery and the circumflex artery.
Coronary Artery Disease
Coronary artery disease occurs when the coronary arteries become narrowed with deposits of fat and cholesterol. This can either decrease or completely stop the blood supply to part of the heart. The result can be angina or a heart attack.
Coronary Artery Bypass Graft Surgery
A test called an angiogram is used to determine the need for this surgery. Bypass surgery improves blood flow to the heart. It is called “bypass” because arteries or veins are taken from another part of your body and used to create new routes around (bypassing) narrowed and blocked arteries. In most situations, more than one artery or vein will be used.
The bypass may be done with:
- An artery from your chest wall (internal thoracic or internal mammary artery)
- Part of a vein from your leg (saphenous vein)
- An artery from your arm (radial artery)
After the bypass is done, blood can flow through the new artery and around the blocked coronary artery to deliver oxygen and nutrients to your heart muscle.
This may eliminate or reduce your chest pain (angina), increase your ability to be physically active, help to improve your quality of life and in some patients, prolong life. Your surgeon will decide on the exact number of coronary arteries to be bypassed during your operation.
Bypass Surgical Incision
An incision is made through the patient’s chest and breastbone to allow access to the heart. Some patients may undergo minimally invasive coronary bypass surgery via a smaller incision between the ribs. This surgery is called single- or multi-vessel small thoracotomy (SVST or MVST). You may have small incisions in your leg if veins are used for bypass and/or an incision in your arm if a radial artery is taken for a bypass.
Heart Valve Surgery
The main job of heart valves is to make sure blood flows in the right direction as it is pumped through the heart. Each valve has either two or three leaflets that open and close with the flow of blood. When you have a valve problem, the blood flow becomes disrupted and your heart can get enlarged, leading to problems with heart failure. Problems with heart valves include not opening properly (stenosis) because it has become thickened and stiﬀ or not closing properly (regurgitation or insuﬀiciency) because it is weak or torn.
The heart valves that most ofen require surgery are the mitral valve, aortic valve and the tricuspid valve.
Heart valves may develop problems when:
- They are not formed normally at birth
- They become damaged or scarred from diseases such as rheumatic fever or other bacterial infections
- They become weakened or hardened through the normal wear and tear of age
Heart valve surgery is required when:
- The valve cannot maintain the regular flow of blood through the heart
- The heart begins to enlarge and not work properly
- Symptoms of shortness of breath, dizziness and fatigue increase
Heart valve surgery may involve:
- Repairing the valve leaflets to allow the valve to open and close properly
- Inserting a supporting ring to support the valve leaflets
- Removing the valve and replacing it with a tissue or mechanical valve
Tissue valves are chemically treated or engineered animal valves that are very similar to natural heart valves. They usually do not require you to be on blood thinner medication for the long term. However, they are not as durable as mechanical valves and may deteriorate over time and need to be replaced.
Mechanical valves are made of durable metals, carbon, ceramics and plastics. They are longer lasting than tissue valves but require that you take an anticoagulant (blood thinner) medication for the rest of your life and have frequent blood tests to check the effectiveness of the drug. Your surgeon will discuss options with you. In some cases, a repair may not be possible and the valve will need to be replaced
Combined Valve and Bypass Surgery
In some instances, a patient may need both valve surgery and coronary artery bypass surgery at the same time. Your physician will discuss this with you.
The aorta is the largest blood vessel in your body. Its main job is to pump blood from the heart to all of the organs. If the aorta becomes enlarged or dilated, surgery is performed to replace this enlarged section.
A tube or graft made of a polyester material replaces the aorta. Occasionally, the aortic valve is repaired or replaced during the same operation. Your surgeon will discuss this with you before the surgery.
Continuous monitoring is very important for patients with aortic diseases. This will be arranged through the Aortic Clinic.
Preparation for aortic surgery is the same as for bypass or valve surgery.
The Surgical Incision
An incision is made through the patient’s breastbone to allow access to the heart.