Q: What is the normal heart?
A: The heart is located in the center of your chest, just beneath the breast-bone (sternum). It serves as a pumping system to take blood in from the body, sending it to the lungs for oxygen and returning the enriched oxygenated blood back to the body.
Valves, similar to one-way doors, control the continuous flow of blood through the four chambers of the heart. The cycle begins when blood from the body enters the top right chamber, the Right Atrium, and passes through the Tricuspid Valve into the Right Ventricle. The blood is pushed through the Pulmonic Valve and enters the lungs.
Once the blood is re-supplied with oxygen, it re-enters the heart through the Pulmonary Veins into the Left Atrium. The blood then passes down through the Mitral Valve into the Left Ventricle. As the powerful left ventricular muscle of the heart contracts, the oxygen-rich blood rushes through the Aortic Valve and is circulated throughout the body via the Aorta.
Q: When is Valve Surgery needed?
A: When heart valves are seriously harmed by birth defects, inflammation, degeneration or infection, surgery may be required to repair or replace them. Damage to these one-way valves can place excessive strain on the heart muscle and interfere with efficient blood flow to the organs of the body.
Some common problems that are treated by surgery include valves that "leak" (regurgitation) and valves that are constricted by scar tissue, a condition known as stenosis. When replacement of a valve is called for, your doctor will discuss with you which type of valve you will receive, and describe how it works.
Q: How the Coronary Arteries supply blood to the heart?
A: Your heart requires its own system of blood and oxygen, which is supplied through a network of vessels known as the Coronary Arteries. These vessels originate at the Aorta and run across the surface of the heart.
The Right Coronary Artery supplies blood to the right side of the heart and to a portion of the back side. Two of the major vessels off the Left Main Coronary Artery are the Left Anterior Descending (LAD) and the Circumflex. The LAD provides blood and oxygen to the front of the heart and to the bulk of its muscle tissue, while the Circumflex supplies the left wall and part of the back of the heart.
Q: When is Bypass Surgery necessary?
A: The inner surfaces of the healthy arteries are smooth and flexible, which permit blood to flow freely and reach the muscle of the heart. When walls become clogged with scar tissue which includes fatty materials, the result is a condition known as atherosclerosis.
Many factors can contribute to atherosclerosis - some of which are: high blood pressure, elevated blood cholesterol, smoking, diabetes, a family history of atherosclerosis and lack of regular physical activity. In some cases the reduced flow of blood to the heart can cause angina (chest pain, arm or throat discomfort), shortness of breath, or a heart attack. When blockage is severe, surgery may be required to reroute the blood supply around a damaged or blocked coronary artery, a process known as "bypass grafting."
The purpose of coronary bypass surgery is to circumvent the blockages in your coronary arteries. Surgeons use an artery in your chest, the internal mammary artery, and/or segments of leg veins called the saphenous veins. When the internal mammary artery is utilized, one end is usually left attached to the subclavian artery supplying blood to your arms and the cut end is connected just beyond the blockage in the coronary artery. When veins are used, one end of the vein is attached to the Aorta and the other end is connected just beyond the blocked area of the artery to "bypass" the obstruction. Other conduits that can be used include the radial artery from either forearm or veins from the upper arm (cephalic veins). The resulting improvement in blood flow through the arteries can reduce or eliminate angina, prevent heart attacks, and improve long-term survival.
Q: How does the surgeon get to your heart?
A: Surgery may also be needed to correct other types of heart problems. An aneurysm is an irregular bulge due to heart muscle wall weakness that sometimes appears after a major heart attack. In surgery, the bulge is cut out or patched. Atrial Septal Defect occurs when the wall that divides the heart's upper chambers does not close all the way. Ventricular Septal Defect results from a hole in the wall between the heart's lower chambers. Surgery is sometimes required to close these openings.
The surgeon can reach the patient's heart through several different types of incisions. A full or median sternotomy involves an incision through the breastbone (sternum), which is then spread apart. After the operation is complete, the breastbone is closed with stainless steel wires and the skin is sutured. The stretching of the muscles, bones and ligaments during surgery usually results in some pain and discomfort following the operation; however, the breastbone will heal back to full strength.
Minimally invasive and robotic operations use a series of smaller incisions placed between the ribs. Surgical instruments and a camera are placed through these incisions and the surgeon views the operative field on a monitor. Since the breastbone remains intact, minimally invasive and robotic procedures typically reduce postoperative pain and require less recovery time.
Q: When is Coumadin® required?
A: Coumadin® is a potent blood thinner. By comparison, aspirin is also a blood thinner but less potent and works by different mechanisms. Coumadin® is most commonly used in heart surgery when a patient has a mechanical heart valve. Another common use is among patients with a rhythm disturbance called atrial fibrillation. The use of Coumadin® can cause serious internal bleeding and therefore must be monitored closely with blood tests.
Q: How long will a porcine valve last?
A: A porcine valve usually lasts about 10 to 15 years.
Q: How long will a mechanical valve last?
A: A mechanical valve usually lasts forever.
Q: What is op-CAB?
A: Op-CAB refers to off-pump coronary artery bypass grafting. Ordinarily when performing a CABG (coronary artery bypass graft), the patient has to be placed on a heart-lung machine and the heart stopped during part of the operation. In Op-CAB, neither step is undertaken. The potential advantages, which are still being studied, include less bleeding, less need for blood transfusion, fewer strokes, and a faster recovery. However, Op-CAB is not suitable for every patient.
Q: How can I prevent infection of my new heart valve?
A: Infection of a heart valve can be reduced with antibiotics taken before any invasive procedures, such as a dental procedure.
Q: How long will my coronary bypass last?
A: A coronary bypass will last a very long time, although the exact time varies from individual to individual. In general, the mammary artery bypass will last much longer than the vein bypass. Most individuals will require only one operation, although some will require a second or even a third one.
Q: What is the internal mammary artery?
A: The internal mammary artery is located behind the chest wall. This artery is frequently used in one of the bypasses because it lasts longer than a vein bypass.
Q: Why is an IM artery different from a vein graft?
A: The internal mammary artery is an artery, whereas the vein graft is a vein. There are other properties unique to the internal mammary; for example, it seems to be protected from atherosclerosis.
Q: What is post-pericardiotomy syndrome?
A: Post- pericardiotomy syndrome is an inflammation of the tissues around the heart and is seen after an open-heart operation. Symptoms include fatigue, a sensation of not feeling well, and fever. Blood tests may show an elevated white count or inflammation.
Q: Will the Sapien aortic valve fit a larger than average patient?
Patient is a large 86-year old man with aortic stenosis. Can the Sapien valve expand to fit all valve sizes, or are there limitations given the size of the catheter? (and what is the normal size of an aortic valve?)
A: The Sapien valve comes in two sizes (23 and 26 mm), with a 29 mm size that is just beginning to be used in the US. At least 80% of patients are treatable with the 23 or 26 valves. Relatively few "normal" valves are smaller than 18 mm or larger than 26 mm, as they are measured by echocardiography or CT scan. A "big" man doesn't necessarily have a "big" valve, especially if "big" refers to weight more than height. There are size limitations for the valve delivery system based on the size of the major blood vessels in the lower body, but the transapical delivery alternative allows most patients to be treated regardless.
If the patient is in good general health for an 86-year-old, the Sapien valve might not be a relevant consideration, and he should have conventional open-heart aortic valve replacement (AVR). This will be true of one-third to one-half of patients over 80. If his surgical risk is moderately elevated by issues in addition to age, he would be eligible for the PARTNER II Trial of the Sapien valve, in which he would be randomized to receive either the Sapien valve or conventional AVR (50% chance of receiving Sapien). If his surgical risk is extreme, as determined by one or more surgical opinions, he can receive the Sapien valve without being part of a trial and without being randomized. These options can be sorted out at any center participating in the Sapien trials. Similar trials of the CoreValve device (different design) are ongoing in earlier stages, and I'm sure any CoreValve center would be delighted to evaluate him as well.