Open Heart Surgery

If the patient is there for coronary artery bypass surgery, chances are three or four major heart arteries are 80-90% blocked, and blood is snaking its way to and away from the heart at a snail’s pace.

But the patient may be on the operating table because a heart valve is not closing tightly, or opening fully, and the faulty valve either needs repair or replacement.

Or, the heart’s natural rhythm has been disrupted by an arrhythmia, either in the heart’s upper chambers – the atria, or the heart’s lower chambers, the ventricles, or by a disconnect between the upper and lower chambers. Depending on the type of arrhythmia, electrical impulses that cause the heart to beat may be chaotic, irregular or sluggish. The surgeon’s challenge is to restore the heart’s natural rhythm.

Today, Robert Holmes, M.D., one of two cardiovascular surgeons with active practices at McLaren Bay Region, is ready to open up his patient’s chest and perform a quadruple coronary artery bypass graft (CABG) procedure. The patient (H.G.) is 57, and has blockages of 85-90% in four of his coronary arteries.

H.G. came into the Emergency Department with crushing chest pain. He was evaluated and immediately set up for a cardiac catheterization that revealed the severity of blocked arteries. Just 14 hours later, he’s on the operating table for the fight of his life.

The blocked arteries will not be touched. The best approach is to surgically remove enough of the left greater saphenous vein for the bypass grafts. This vein is used because it does only about 10% of the work of circulating blood from the leg back to the patient’s heart. This is removed with a scope through small incisions. The left internal mammary artery in the chest wall is also used for a graft.

The patient is already under anesthesia and vital signs will be monitored throughout the surgery. The surgical field is completely sterile. The chest wall is opened and Dr. Holmes separates the breastbone. The heart is stopped, and H.G. is connected to the heart-lung machine. During surgery, the heart-lung machine adds oxygen to the blood and circulates it through the body during surgery.

What first drew Dr. Holmes to cardiovascular surgery was how technology could take over a patient’s heart-lung functions, so the surgeon could work on a quiet heart. For each arterial re-routing, one end of the graft is stitched to an opening below the blocked coronary artery, and the other end stitched to an opening made in the aorta. Once all connections have been made, the patient is taken off the heart-lung machine, and the chest wall sewn up. Six hours of surgery, and it went by as though it were a minute, so intense is the concentration for such a complicated surgery.

"There are no reliable catheter-based interventions to repair a leaky valve, or to replace a non-functioning one," says Dr. Holmes. "A tear in a valve may mean sewing a ring around the valve’s opening so it tightens, and blood flows as it should to the next chamber, instead of backing up.

"If a valve is not opening or closing correctly, we replace is with a prosthetic valve that opens and closes just as the original valve did. The patient is usually put on a ‘blood thinner’ to prevent blood clots from forming on or around the valve."

Wonder how your heart knows when to beat, or contract? An electrical impulse released in the sinoatrial (SA) node (top of the heart’s upper right chamber) causes the atria to contract. The signal follows to the atrioventricular (AV) node – the pathway to the heart’s lower chambers, or ventricles, causing them to contract.

The most common heart rhythm interruption is atrial fibrillation, where the heart’s upper chambers contract in a rapid, irregular manner. Uncorrected, blood pools in the heart’s chambers, and can lead to blood clots, and possible stroke.

"Sometimes," says Dr. Holmes, "we do the MAZE procedure in conjunction with bypass surgery or valve repair. MAZE surgery does exactly what its name implies – it creates a maze of new electrical pathways, so electrical impulses return to their natural rhythm."

During the MAZE procedure, electrodes are attached to the patient’s chest, and connected to an electrocardiogram that monitors the heart’s rhythm and electrical activity. The procedure is done under anesthesia, and the patient’s heart-lung functions are transferred to the heart-lung machine.

Again, a quiet heart for the surgical team to work with. In conjunction with this procedure, radiofrequency ablation produces a lesion with heat to destroy tissue causing a re-routing of electrical pulsing. Incisions are made in a maze pattern to direct the heart’s electrical impulses to the heart’s lower chambers. A pacemaker or defibrillator may be implanted as part of the procedure.

Dr. Holmes knows he can tick off the usual risk factors, but he focuses on four:

• Lifestyle risk factors (poor diet, lack of exercise, and smoking): "Most people know the risk factors for heart disease. They’re all controllable, and can significantly reduce your risk for a coronary event. Often, the state of mind is: ‘It can’t happen to me.’"
• Diabetes: "Due to many complicated metabolic factors, people with diabetes develop a more advanced form of coronary artery disease than non-diabetics."
• High Blood Pressure: "It causes damage to the lining of the blood vessels, which can lead to blockages."
• Genetics: "If you have heart disease in your family, you need to take risk reduction very seriously. Genetics is the strongest risk factor for heart disease. Your family physician may want to start you on a cholesterol-lowering medication if your LDL, or bad cholesterol, and triglycerides stay above recommended levels."
"Most people know the risk factors for heart disease. They’re all controllable, and can significantly reduce your risk for a coronary event. Often, the state of mind is: ‘It can’t happen to me.’" "Due to many complicated metabolic factors, people with diabetes develop a more advanced form of coronary artery disease than non-diabetics." "It causes damage to the lining of the blood vessels, which can lead to blockages." "If you have heart disease in your family, you need to take risk reduction very seriously. Genetics is the strongest risk factor for heart disease. Your family physician may want to start you on a cholesterol-lowering medication if your LDL, or bad cholesterol, and triglycerides stay above recommended levels."

"People with genetic risk for heart disease generally do not metabolize cholesterol well, adds Dr. Holmes. And, that’s with a healthy diet, a good aerobic exercise program, no smoking, and acceptable blood pressure. For these patients, the commitment to a heart healthy regimen is a lifelong one."

Dr. Holmes: "We do some very complex cardiovascular and peripheral vascular surgeries here, and we have consistent good outcomes. We use a team approach. We have among the best cardiac and cardiac intensive care nurses in the state. Patients come to the office and tell me about the exceptional care they received from the nursing staff. They express similar positive reviews for our Cardiac Rehab program.

"Cardiac surgery patients, in particular, intrinsically sense this is a life-altering event. This is the big one, and they’ve gotten a second chance. The entire cardiac team reinforces how to get the heart back in shape:

• Eat a heart-healthy diet (The American Heart Association cookbook is an excellent start and is available in most bookstores).
• Begin a regular aerobic exercise regimen, working up to 30 minutes a day.
• If you smoke, quit.
• See your cardiologist or family physician to decide what medications could help lower your blood cholesterol levels.
• Evaluate the stress in your life, and do what you can to reduce it.

"That’s a major ‘to-do’ list. A vast majority of patients make these changes because one heart attack is enough."