Magnificent Magnesium

by Dennis Goodman

  Here is the most important statistic to remember: For half of the people who die of a heart attack, death is the first and last symptom that they ever experience. In other words, prior to their deaths, most victims never experienced any sort of symptom to warn them that they were at risk for heart attack. This is why it is so important to work regularly with your physician to determine your risk and monitor the health of your heart and overall cardiovascular system.

  THE MOST COMMON TYPES OF HEART DISEASE

  We can certainly see the devastation that cardiovascular disease produces. In order to understand the different ways that cardiovascular disease affects us, let’s take a closer look at the fifteen most common types. They include:

  •Angina Pectoris

  •Arrhythmias/Atrial Fibrillation (Irregular Heartbeat)

  •Atherosclerosis

  •Cardiac Arrest

  •Congestive Heart Failure

  •Coronary Heart Disease (CHD)

  •Enlarged Heart (Cardiomegaly)

  •Heart Attack (Acute Myocardial Infarction)

  •Heart Murmur

  •Heart Muscle Disease (Cardiomyopathy)

  •High Blood Pressure (Hypertension)

  •Mitral Valve Prolapse

  •Pericarditis/Pericardial Effusion

  •Premature Ventricular Contraction (PVC)

  •Stroke

  This section will define what each condition is, explain why it occurs, describe its symptoms, and explain how it is currently diagnosed and treated.

  Angina Pectoris

  The term angina pectoris is derived from Latin and means “squeezing of the chest.” Angina is chest pain caused by a decreased supply of blood to the heart muscle, usually due to a lesion on the walls or valves or the heart, or because of a narrowing of the coronary arteries. As a result of this constriction or blockage, the heart receives less oxygen—a condition called ischemia. Spasms of the coronary arteries can also be involved.

  Risk factors for angina pectoris include smoking, lack of exercise, chronic stress, and high blood pressure. Being overweight or obese also increases risk, as does diabetes. The risk for angina also increases as you age.

  Classical or typical symptoms of angina include pain, pressure, or other discomfort in the middle of the chest. This chest pain can radiate to the throat, jaw, upper back, arms, and even teeth. Unfortunately, cases of angina often go misdiagnosed or undiagnosed in women, who are more likely to suffer atypical symptoms, including palpitations, dizziness, heartburn, indigestion, nausea, numbness in the arms, weakness, and shortness of breath. Symptoms typically worsen after a heavy meal or physical exertion, and during times of emotional stress, as all of these situations demand that more oxygen be pumped to the heart.

  There are two types of angina: stable and unstable. Stable angina is the most common type, and is characterized by typical symptoms that are predictable. Ordinarily, symptoms last around five minutes or so, and then subside.

  Unstable angina is a more serious condition, with symptoms being more severe and less predictable, and usually lasting much longer. Unstable angina symptoms can occur even at times of rest. Because unstable angina is often a precursor and warning sign of a heart attack, prompt medical attention should be sought at the first sign of unstable angina.

  Angina can be diagnosed using a number of tools. An electrocardiogram (EKG), which records the electrical activity of heart, can detect signs of ischemia and is also useful for monitoring changes to the heart muscle caused by a lack of oxygen. Even when EKG readings are normal, however, angina may still be present. Physicians who suspect that this is the case may also use exercise stress testing, in which a patient is asked to perform activities that stress the heart (such as walking on a treadmill or using a stationary bike) while their EKG readings are continuously monitored.

  If the exercise stress test remains inconclusive, your physician may order a stress echocardiogram or nuclear heart scan. Stress echocardiography combines ultrasound imaging of the heart muscle with exercise stress testing in order to screen for abnormalities in your heart’s contractions. Since there is no radiation exposure, stress echocardiography is preferred to nuclear heart scans. In a nuclear heart scan, a safe, radioactive trace substance such as thallium or Cardiolite is injected into your bloodstream and an external camera is used to monitor the activity of this trace substance as it travels through your veins to your heart. Typically, there are two parts to this test; one set of images will be taken after a mild stress test (similar to the one described above), and another set will be produced later, when your body is at rest. Both these tests allow your physician to see how well blood is flowing through your heart, and can identify any muscle areas that might be damaged or narrowed.

  If your stress test yields abnormal results, your doctor may also order a coronary computed tomography angiogram (CTA). This test uses a computed tomography (CT) scan to visually track the progress of an intravenous dye containing iodine through the bloodstream, making it possible to see the coronary arteries and determine if any blockages are present. For most patients, a CTA is an excellent, noninvasive way to diagnose angina.

  In some cases, cardiologists may also order or perform a cardiac catheterization with angiography. During this procedure, small, hollow plastic tubes (catheters) are inserted through arteries in the groin or forearm and threaded into the openings of the coronary arteries under the guidance of X-rays. Iodine contrast dye is injected into the arteries while an X-ray video is recorded, providing doctors with images of the location and severity of coronary artery disease. Cardiac catheterization is commonly regarded as the most accurate test to detect coronary artery narrowing. It is particularly useful in cases where there is a high likelihood that therapeutic intervention will be required, because it allows for immediate treatment. If a blocked artery is found, a metal tube called a stent can be placed inside the troubled area, supporting the artery and facilitating blood flow.

  If angina symptoms are present but not severe, or if no serious blockages are seen on a CTA or cardiac catheterization, doctors may simply instruct their patients to make healthy lifestyle changes. With better food choices, smaller meals, rest, and stress reduction, many patients will see their symptoms improve. Otherwise, medical treatments may be advised. Treatment options include conventional medications, such as nitroglycerin tablets or sprays to reduce the heart muscle’s demand for oxygen; beta blockers, to reduce the effects of adrenaline on the heart; and calcium channel blockers, to lower blood pressure and reduce the pumping force of the heart muscle, and thus its need for oxygen.

  If the above measures fail to correct the problem, angina patients may be advised to consider surgery. In addition to the stent placement described above, the two most common surgical procedures for angina pectoris are angioplasty and coronary artery bypass surgery. During an angioplasty, a small balloon is inserted into the narrowed artery and inflated; this dilates the narrowed artery and allows blood to flow more freely. In some cases, a small mesh tube, or stent, may also be placed inside the artery to hold it open. Coronary artery bypass surgery, a form of open heart surgery, is a procedure that redirects blood around a blocked artery (bypassing it), creating a new pathway for blood to flow to and from the heart. This is done by taking an artery or vein from the patient’s leg or chest wall and sewing one end above the blocked coronary artery and the other end below the blockage.

  Regardless of the type of surgery performed, angina patients are still vulnerable to future heart attack. It is therefore essential that all angina sufferers make the necessary lifestyle changes to lower their risk, following a heart-friendly diet, maintaining a healthy weight, exercising regularly, reducing stress, and keeping appropriate levels of cholesterol and blood sugar.

  Arrhythmia/Atrial Fibrillation

  Arrhythmia is a condition characterized by an abnormal or irregular heartbeat caused by faulty electrical impulses to the heart. Unlike other organs and muscles in your body, your heart has
its own “electrical generator”—a specialized group of cells located in the heart’s upper right chamber (right atrium). As you’ll read in Chapter 3, this group of cells, known as the sinoatrial (SA) node, creates a series of electrical impulses that make your heart pump blood in an even, continuous flow. Arrhythmia occurs either when the SA node is damaged or when there is some other disruption to the heart’s conduction of electrical signals (see page 78 for more information). There are two basic kinds of irregular heart rhythms. The first is known as bradycardia, and is characterized by heartbeats that are too slow—fewer than sixty beats per minute. The second type is known as tachycardia, and is characterized by a racing heartbeat of more than 100 beats per minute.

  The most common form of arrhythmia is atrial fibrillation (AF), in which the heart’s two top chambers (the atria) beat quickly and irregularly, causing blood to pool within and preventing the atria from working in harmony with the heart’s lower two chambers (the ventricles). According to the Centers for Disease Control and Prevention (CDC), approximately 2.66 million people currently suffer from atrial fibrillation, and as many as 12 million people will have the condition by 2050. Less common, but very serious, are the two forms of arrhythmia that occur in the lower two chambers (ventricles) of the heart: ventricular tachycardia and ventricular fibrillation. The result of these two conditions is that the ventricles are unable to pump blood to the rest of your body. Your blood pressure drops, and your vital organs cease to receive the blood they need to operate. Ventricular arrhythmias are the most common cause of death related to heart attack. Immediate attention—cardiopulmonary resuscitation (CPR) and/or defibrillation—is necessary to prevent death.

  A number of factors can increase the risk of arrhythmia, including high blood pressure, smoking, excessive alcohol consumption, and the use of pharmaceutical drugs, including over-the-counter cold and flu medications. Other risk factors include sleep apnea (a condition in which breathing is interrupted during sleep), thyroid problems, and other pre-existing heart conditions (including coronary artery disease, heart valve problems, and congestive heart failure).

  Symptoms of arrhythmia can often go undetected, manifesting as a brief and barely noticeable skipped heartbeat. In more serious cases, where arrhythmia prevents the heart from pumping enough blood, patients can feel sensations of fluttering in the chest or neck, along with dizziness or lightheadedness, fatigue, and fainting. Other symptoms include chest pain and shortness of breath. If you experience any of these symptoms, contact your physician or seek medical help immediately. In some cases, arrhythmia can trigger a heart attack and even cause death.

  Arrhythmia is most often detected with an electrocardiogram (EKG), which also helps physicians determine where in the heart the problem starts. Stress testing and tilt table tests (used to detect the cause of arrhythmia-induced fainting) are also commonly used, as are tests that specifically map the heart’s electrical system and any flaws that may have arisen in it, including electrophysiology studies (EP studies). During an EP study, thin, flexible catheters with electrodes on their tips are threaded through the heart’s blood vessels in order to provide a precise picture of the pathways that electrical impulses take while traveling through the heart. The electrodes can also be used either to trigger or to stabilize an arrhythmia, enabling the doctor to pinpoint the exact location of the problem.

  If an arrhythmia is detected, your doctor may ask you to alter your lifestyle with an improved diet, exercise, and stress management. Medications may also be prescribed in order to control arrhythmia directly, or to deal with associated risks; anticoagulants (blood thinners, beta blockers, and calcium channel and/or sodium channel blockers) are all commonly used. Should all of these options fail, other treatment options may be required.

  The most common nondrug procedures used to treat arrhythmia are cardioversion, defibrillation, cardiac ablation, and the Maze procedure. Cardioversion is used to temporarily normalize arrhythmias that could otherwise cause heart attack or death. Using either fast-acting drugs or an electric shock delivered with defibrillator paddles directly over the heart, the abnormal heartbeat is interrupted, allowing the heart’s electrical system to regain control and restore a normal heart rhythm. Defibrillation is a somewhat more intense form of cardioversion that is performed in emergency situations involving severe or highly irregular arrhythmias, as in cardiac arrest; it employs a stronger set of electrical shocks to jolt the heart rhythm back to normal.

  In some cases of tachycardia and ventricular fibrillation, an electrical device known as an implantable cardioverter defibrillator (ICD) may be surgically inserted into a patient’s chest, as a pacemaker might be. When an arrythmia occurs, the ICD delivers a shock to reset the heartbeat and get the SA node to send a normal electrical signal. (See the inset on page 79 for more information.)

  In severe cases of arrhythmia, physicians may elect to perform more invasive surgical procedures to remove damaged or otherwise abnormal tissue in the heart muscle that is triggering arrhythmia. During cardiac ablation, a thin tube (catheter) is inserted into a vein and then guided into the heart muscle. Once there, the tip of the catheter emits a burst of energy to destroy the areas of heart tissue shown to be causing abnormal electrical signals.

  The Maze procedure is an invasive surgical procedure used to treat atrial fibrillation. During the Maze procedure, the surgeon makes a number of incisions, which are then sewn up again, creating scar tissue. These scars serve as barriers, forcing the electrical impulses responsible for your heartbeat to travel along a single, uniform pathway into the ventricles so that a normal heart rhythm can be restored.

  Atherosclerosis

  Atherosclerosis refers to a hardening or blockage of the arteries due to the accumulation of a waxy substance called plaque. Plaque builds up as part of your body’s inflammatory response to damage in the walls of the arteries. When your arteries are damaged as the result of high blood pressure, cigarette smoke, environmental toxins, or the presence of other irritants, your body sends cholesterol and other substances to the wound in an attempt to repair it. Collectively, these fatty deposits are known as plaque. Over time, they can build up, narrowing and hardening the arteries, and thus reducing the flow of blood and increasing blood pressure levels. (For a more complete explanation of how atherosclerosis develops, see Chapter 4.)

  Risk factors for atherosclerosis include age, diabetes and insulin resistance, high blood pressure, high cholesterol, obesity, smoking, and a family history of heart disease. Because inflammation is an integral part of the process by which atherosclerosis develops, doctors have theorized that factors that increase inflammation can often indirectly contribute to atherosclerosis, too. For example, several studies have shown that there was a strong association between atherosclerosis and Chlamydophila pneumoniae, one of the bacteria that causes pneumonia. Scientists theorized that because C. pneumoniae infections seemed to cause or contribute to the inflammation that in turn causes atherosclerosis, treating the infections with antibiotics would potentially help reduce the atherosclerosis. Unfortunately, subsequent studies showed that patients with atherosclerosis derived no overall benefit from antibiotics, and the theory was deemed less plausible.

  Atherosclerosis can go undetected for years before symptoms present themselves. In fact, in recent years, an alarming number of teens and preteens have been found to have some degree of atherosclerotic plaques. Overall, nearly 5 million Americans are diagnosed with atherosclerosis each year, while a significantly higher number of Americans have already been diagnosed and are living with this condition.

  Symptoms of atherosclerosis depend on the extent of the blockage and the specific arteries affected. In arteries of the heart, atherosclerosis can manifest as chest pain or pressure (angina), while in leg or arm arteries atherosclerosis can cause intermittent pain. In the arteries that lead into the brain, atherosclerosis can produce warning signs of stroke, including slurred speech, drooping muscles in the face, and numbness or weakness in the
arms or legs. In arteries leading to the genitals, atherosclerosis can cause erectile dysfunction in men, while in women, the same condition can reduce blood flow to the vagina, resulting in less pleasurable sex. Unfortunately, many patients will not show symptoms until the atherosclerosis is severe, blocking over 70 percent of the affected artery. This makes atherosclerosis harder to diagnose and treat.

  Blood tests that screen for LDL (“bad”) cholesterol, HDL (“good”) cholesterol, and total cholesterol levels—as well as other markers such as homocysteine, C-reactive protein (CRP), and lipoprotein-associated phospholipase (Lp-PLA-2)—can indicate whether atherosclerosis is likely to be present. Other diagnostic tests include the various forms of stress testing, although these methods have certain drawbacks. Stress tests only detect large blockages that have obstructed at least 70 percent of your arterial passage. Accordingly, you can still be at serious risk for heart attack even if your doctor says you “passed a stress test.” Your arteries may not be severely blocked, but they may not necessarily be clean and healthy, either.

  Fortunately, there are more effective and noninvasive tests that can detect plaque in the coronary or carotid (neck) arteries before a significant blockage develops. Two of the most common procedures used for early detection of atherosclerosis—that is, before most symptoms arise—are coronary calcium scoring by CT scan, which measures the amount of plaque in your coronary arteries, and carotid intima-media thickness testing (CIMT), which uses ultrasound technology to screen your carotid arteries for plaque.

  Should atherosclerosis be detected, your doctor may prescribe aspirin or cholesterol-lowering drugs—statins or other natural alternatives. You will probably be asked to make certain lifestyle changes, involving a low-cholesterol diet, regular exercise, and the avoidance of unhealthy behaviors such as smoking and alcohol consumption. Because stress is a major risk factor for heart disease, learning to reduce or control it is essential for the proper treatment of atherosclerosis, as you will read later in this chapter. By adopting these lifestyle changes, you can prevent plaque from developing or progressing, significantly reducing the likelihood that atherosclerosis will threaten your life.