How your heart works
Your heart is located under the ribcage in the center of your chest between your right and left lungs.A normal, healthy, adult heart is about the size of an average fist:
Your heart is a muscle that pumps blood to the rest of your body. Your heart is part of your circulatory system, which consists of a network of arteries, veins, and capillaries that carry blood to and from all areas of your body. Electrical signals force your heart to contract and thus pump your blood to the rest of your body.
Your blood carries the oxygen and nutrients that your organs need to work normally. Blood also carries waste products such as carbon dioxide back to your heart and into your lungs to be passed out of your body and into the air. If disease or injury weakens your heart (your pump), your body's organs won't receive enough blood to work normally.
The heart has four chambers: The right and left atria and the right and left ventricles. The right side of your heart gets venous blood back from your body and then pumps it to your lungs. When you breathe in, oxygen passes from your lungs into your blood. Carbon dioxide, a waste product, is passed from the venous blood to your lungs and removed from your body when you breathe out.
The left atrium receives oxygen-rich blood from your lungs. The pumping action of your left ventricle sends this oxygen-rich blood to the rest of your body:
- Vena Cava
- Right Atrium
- Right Ventricle
- Main Pulmonary Artery
- Left & Right Pulmonary arteries
- Left & Right Pulmonary veins
- Left Atrium
- Left Ventricle
- Aorta
- Blood flow to the rest of your body
This animation shows how blood flows to and
The Right Side of Your Heart
The superior and inferior venae cavae are in blue to the left of the heart muscle as you look at the picture. These veins are the largest veins in your body. After your body's organs and tissues have used the oxygen in your blood, the venae cavae carry the venous (= oxygen-poor) blood back to the right atrium of your heart.
The superior vena cava carries venous blood from the upper parts of your body, including your head, chest, arms, and neck. The inferior vena cava carries venous blood from the lower parts of your body.
The blood from the venae cavae flows into your heart's right atrium and then on to the right ventricle. From the right ventricle, the blood is pumped through the pulmonary arteries to your lungs. There, the blood picks up more oxygen.
The Left Side of Your Heart
The oxygen-rich (= arterial) blood passes from your lungs back to your heart, enters the left atrium and is pumped into the left ventricle. From there the arterial blood is pumped to the rest of your body through the aorta.
Like all of your organs, your heart needs blood rich with oxygen for its own energy supply.. This oxygen is supplied through the coronary arteries as blood is pumped out of your heart.
Your coronary arteries are initially located on your heart's surface. Deeper branches eventually reach the muscle cells where the energy exchange takes place. Procedures such as Percutaneous Cardiac Interventions (PCI) and Coronary Artery Bypass Grafting (CABG) are only performed to the arteries on the surface. Your coronary arteries (shown in red in the drawing) carry arterial blood to all parts of your heart.
- See more at: http://www.cardiachealth.org/how-does-your-heart-work-anatomy-heart-coronary-arteries#sthash.Qy02TmNj.dpuf
As a rule, these days patients are only referred by their cardiologists for CABG if a PCI has failed or is technically too difficult to perform. CABG patients are older, sicker, and have complicating factors such as poor heart function and Diabetes. They have multi-vessel disease and/or Left Main Stenosis, and often coronary arteries too small for PCI. In addition, CABG is used as a bail-out procedure for catastrophic Percutaneous Coronary Intervention (PCI) failures. All these factors influence outcomes such as survival and postoperative complications. A patient who is relatively young with a good heart runs an operative risk of dying of less than 1-2% in the hands of an experienced cardiac surgeon. The statistics below indicate how many patients in a surgical practice are not in this category:
- Overall mortality related to CABG: 3-4%.
- About 5% of patients require exploration because of bleeding. This second surgery increases the risk of chest infection and lung complications.
- Stroke occurs in 1-2%, primarily in elderly patients.
- Mortality and complications increase with:
- age (older than 70 years),
- poor heart muscle function,
- disease obstructing the left main coronary artery,
- diabetes,
- chronic lung disease, and
- chronic kidney failure.
- Mortality may be higher in women, primarily due to their advanced age at the time of CABG surgery and smaller coronary arteries.
Women develop coronary artery disease about 10 years later than men because of hormonal "protection" while they still regularly menstruate (although in women with risk factors for coronary artery disease, especially smoking, elevated lipids, and diabetes, the possibility for the development of coronary artery disease at a young age is very real).
Women are generally of smaller stature than men, with smaller coronary arteries. These small arteries make CABG surgery technically more difficult and prolonged. The smaller vessels also decrease both short and long-term graft function.
What are the long-term results after CABG surgery?
Recent data has shown that in CABG patients with elevated LDL cholesterol (bad cholesterol) levels, use of cholesterol-lowering medications (particularly the statin family of drugs) to lower LDL levels to below 80 will significantly improve long-term graft patency as well as improve survival benefit and heart attack risk. Patients are also advised about the importance of lifestyle changes to lower their chance of developing further atherosclerosis in their coronary arteries. These include stopping smoking, exercise, reducing weight and dietary fat, as well as controlling blood pressure and diabetes.
Frequent monitoring of CABG patients with physiologic testing can identify early problems in grafts. PCI, in addition to aggressive risk factor modification, may significantly limit the need for repeat CABG years later.
Repeat CABG surgery is occasionally necessary, but may have a higher risk of complication.
How do CABG surgery and angioplasty (PTCA) compare?
Ongoing studies are comparing the treatment results of angioplasty (PTCA) versus bypass (CABG surgery) in patients who are candidates for either procedure. Both procedures are very effective in reducing angina symptoms, preventing heart attacks, and reducing death.
Studies have shown an advantage to CABG in patients with multi-vessel disease, Left Main Stenosis, impaired heart function and Diabetes.
Coronary artery disease (CAD) happens when arteries that supply blood to the heart muscle develop a blockage.
Chest pains caused by angina is the heart's response to insufficient blood supply caused by CAD. It is a warning signal that there is not enough blood flow for the needs of that moment. A person with narrowed arteries may develop angina during any activity that increases the heart's demand for blood beyond the available supply.
The most common symptom in both women and men is chest pain. But for women this may not be the most prominent symptom. "Chest pain" may feel like a burning, tightness, pressure or some other sensation. A better word than “pain” might be “discomfort.” This discomfort may radiate, or seem to originate, in the jaw, back, mid-stomach or either arm.One of the distinguishing factors between women and men is that women tend to report more associated symptoms. These may include classic symptoms such as shortness of breath, nausea and vomiting – but may also include several less classic symptoms including fatigue, dizziness and palpitations.While it is most common for both genders to get their symptoms with physical exertion, women may also experience their symptoms at rest, during sleep and with emotional stress. Likewise, women may have an increased frequency of symptoms around the time of their menstrual period.
People who have angina are usually managed initially with medical treatment, unless testing indicates severe disease with symptoms that do not respond to treatment. If medications, diet , exercise and cessation of smoking don't significantly improve symptoms of angina or if the person cannot tolerate his therapy, cardiac catherisation followed by angioplasty/stenting or coronary artery bypass graft surgery may be recommended. Women often have atypical symptoms caused by coronary artery disease.
If you are concerned about your heart, you can try this questionnaire for the Prediction of Coronary Artery Disease (CAD).
If angina symptoms worsen despite medical therapy, unstable or crescendo angina is present. There is another condition, silent angina, which occurs in patients who don't have any symptoms: usually the diagnosis is made incidentally, as part of other testing or findings, for instance prior to major surgery. These patients may be at a particular high risk, because they don't get warned with angina symptoms that their heart is not getting enough blood. All these situations may require aggressive treatment.
Here is a list of different types of angina (in order of severity):
- Chronic stable angina
- Silent angina
- Unstable angina
- Crescendo angina
- Angina at rest (your “engine” is not getting enough fuel while idling)
- Angina complicated by heart failure or heart attack:
Tests that show whether you are at risk include:
An exercise test can often determine if you have a risk of a heart attack or cardiac death. The test involves running on a treadmill or bicycling while an electrocardiogram is continuously monitored. In some cases, a radioactive tracer such as thallium or sestamibi is used to identify the particular regions in the heart that are not getting enough blood. In others, a Cardiac ECHO is performed before and after the test to demonstrate changes in the way the heart muscle works.
Treatment Options:
Several factors can help determine whether medical or interventional treatment is a better choice.
As a result of studies that compared medical to interventional treatment, many experts do not recommend intervents initially unless you have certain characteristics, you cannot tolerate aggressive medical treatment or do not improve on your present management.
Percutaneous Coronary Intervention (PCI), uses a balloon to dilate narrowed arteries in the heart and may include placement of a stent to hold the artery open.
Coronary artery bypass graft surgery (CABG) involves sewing one end of an artery or vein above a blocked coronary artery and the other end below the blockage ("bypass"), thereby allowing blood an alternate pathway to the heart.
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