Magnificent Magnesium

by Dennis Goodman

  Congenital heart murmur is linked to a family history of heart defects, or an illness and/or medication use that occurred during the pregnancy. Abnormal murmurs can appear at any time, but particularly later in life, and usually indicate a developing heart condition such as a narrow or leaky valve (see page 30). Factors that raise the risk of heart murmurs include high blood pressure, rheumatic fever, a weakened heart muscle, and a past heart attack.

  People with innocent murmurs are unlikely to experience symptoms aside from the murmur itself—a disruption, extra beat, or whooshing sound that’s heard when listening to the heartbeat. People with abnormal murmurs may also have symptoms that derive from the underlying condition causing the murmur, including chest pain (angina), shortness of breath, excessive sweating, dizziness or fainting, chronic cough, bluish skin (particularly around the lips and fingertips), swelling or sudden weight gain, enlarged liver or neck veins, and poor appetite and failure to grow in infants.

  Physicians can detect a heart murmur using a stethoscope. The stethoscope also allows them to evaluate the murmur according to how loud it is, where in the heart it is located, when it occurs and for how long, and whether its sound changes with changes in body position. If further tests are necessary, they may include chest X-rays, an electrocardiogram (EKG), an echocardiogram, transesophageal echocardiogram (TEE), a CT scan, or an MRI.

  Treatment is unnecessary for innocent murmurs; even with abnormal murmurs, physicians may elect to monitor the effects over time. Additional medical care, when ordered, usually treats the heart condition that is the source of the murmur, and might involve anticoagulants, diuretics, angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), statins, beta blockers, or digoxin. If necessary, surgery or catheterization might be performed in order to repair or replace heart valves, or to patch a hole in the heart.

  Heart Muscle Disease

  Heart muscle disease, or cardiomyopathy, refers to any of a number of diseases that affect the heart muscle. In cardiomyopathy, the heart muscle becomes enlarged, thick, or rigid; sometimes, it is even replaced with scar tissue. As a result, the heart’s ability to pump blood to the rest of the body is impaired. Left untreated, heart muscle disease can lead to heart failure and death.

  There are three main types of cardiomyopathy: dilated, hypertrophic, and restrictive. Dilated cardiomyopathy is the most common of the three. In this condition, the heart’s main pumping chamber, the left ventricle, becomes enlarged, or dilated, and can no longer effectively pump blood out of the heart. Hypertrophic cardiomyopathy is characterized by abnormal growth or thickening of the heart muscle, once again preventing blood from being pumped out of the heart. Restrictive cardiomyopathy is a condition in which the heart muscle weakens and loses its ability both to pump out and fill with blood between heartbeats.

  Cardiomyopathy can be inherited (passed on by one or both of your parents) or acquired (developed as a result of another condition or factor). Around one-third of all cases of dilated cardiomyopathy are inherited; other risk factors include coronary heart disease or heart attack, high blood pressure, diabetes, thyroid disease, viral hepatitis, HIV, and the abuse of alcohol and certain drugs. Most cases of hypertrophic cardiomyopathy are inherited, caused by a mutation that makes the heart muscle grow especially thick; some cases, however, are associated with diabetes or thyroid disease. Restrictive cardiomyopathy is often linked to diseases such as hemochromatosis, in which excess iron builds up in your body; sarcoidosis, an inflammatory disease; amyloidosis, in which excess protein builds up in your body; and some types of cancer and cancer treatments.

  In the early stages of cardiomyopathy, symptoms may not be apparent; in many cases, the first symptom will be the last—a sudden collapse due to heart failure. Otherwise, common symptoms include sensations of breathlessness, even when at rest; swelling of the ankles, feet, and legs; bloating and fluid buildup in the abdomen; fatigue; dizziness; fainting; chest pain; cough; and arrhythmia.

  A variety of diagnostic tests can be used to detect heart muscle disease. Your doctor will need to take into account your personal and family history, and also screen for symptoms, including heart murmurs and swelling of the ankles, feet, abdomen, or neck veins. If cardiomyopathy is suspected, you may be asked to undergo additional tests, including chest X-rays, electrocardiogram (EKG), angiogram, MRI, or, in some cases, cardiac catheterization with biopsy, in which a catheter is inserted into the groin and then threaded upward to the heart in order to extract a small sample of heart tissue for analysis. Sometimes, your doctor will order a specific blood test that measures the level of a chemical known as brain natriuretic peptide (BNP), which is often elevated when the heart is under stress.

  Treatment for heart muscle disease varies according to the type, but the primary goal is always to manage symptoms and keep them from worsening. Drugs prescribed for dilated cardiomyopathy include angiotension-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), beta blockers, diuretics, and digoxin. The insertion of an implantable cardioverter device (ICD) may also be necessary to help regulate the contractions between the heart’s left and right ventricles.

  Beta blockers and calcium channel blockers are the two most common classes of drugs used to manage hypertrophic cardiomyopathy. If necessary, an ICD or a regular pacemaker may be implanted. In some cases, other types of surgery may be performed. The first is known as septal myectomy, a form of open-heart surgery in which parts of the thickened, overgrown heart muscle wall (known as the septum) are removed to improve blood flow. A second type of surgery, known as septal ablation, or septal alcohol ablation, destroys a small portion of the thickened heart muscle. This is accomplished by injecting alcohol through a catheter into the artery that delivers blood to the septum.

  In cases of restrictive cardiomyopathy, doctors often recommend a low-salt diet along with careful monitoring of water intake. Diuretic and blood pressure medications will often be prescribed. Beta blockers and calcium channel blockers may also be used along with blood thinners and drugs in order to regulate heart rhythm. In certain cases, a pacemaker may be surgically implanted or a heart transplant may be performed, but surgery is rarely undertaken, due to poor likelihood of success.

  High Blood Pressure (Hypertension)

  High blood pressure, or hypertension, affects 76.4 million Americans today. Blood pressure is essentially a measure of the force (pressure) exerted by circulating blood on the walls of your arteries. Hypertension occurs when the force becomes so strong that it begins to stretch or cause damage to the arteries. Serious cases of hypertension can eventually create other health problems, including heart attack and stroke.

  There are two types of hypertension: primary (essential) hypertension and secondary hypertension. Primary hypertension usually develops gradually over many years, and can be caused by a number of genetic and environmental factors, including age, gender, race, family history, stress, excessive sodium or alcohol consumption, poor diet, lack of exercise, and being overweight or obese. Secondary hypertension is usually caused by an underlying health condition, such as kidney disease, adrenal gland tumors, congenital heart conditions, or by the use of pharmaceutical drugs, including birth control pills, cold and flu remedies, decongestants, and pain medications, and illegal drugs such as amphetamines and cocaine.

  Most of the time, there are no symptoms of hypertension. When symptoms do appear, it is usually a sign that the condition has progressed and may even be life threatening. The most common symptoms are dull headaches, dizzy spells, and sometimes nose bleeds.

  High blood pressure is easily diagnosed; a simple blood pressure reading can be taken using an automatic cuff-style monitor at the doctor’s or even at some local drugstores. Many communities also offer free blood pressure screenings throughout the year. If you are particularly concerned, you can even buy a monitor for home use.

  Usually, physicians will take two or more blood pressure readings during separate appointments
before making a diagnosis of hypertension. That’s because blood pressure levels vary over the course of the day, and can also spike in the presence of doctors due to nervousness or anxiety—a phenomenon known as “white coat” hypertension. For this reason, many doctors wait until their patients are relaxed and comfortable before taking blood pressure readings.

  In any blood pressure reading, there are two measurements taken. The first (top) number is your systolic blood pressure, or the pressure that is exerted on your blood vessels when your heart contracts, pumping blood through your body. The second (bottom) number is your diastolic blood pressure, or the pressure exerted on your blood vessels when your heart relaxes. For people age fifty or older, a high systolic reading with a normal diastolic reading most frequently indicates hypertension. (For more information on blood pressure levels, consult the inset below.)

  Once a diagnosis of hypertension is made, other screening tests may be ordered to determine whether the hypertension is a symptom of an underlying condition. These include blood tests or an electrocardiogram (EKG) or echocardiogram to screen for other possible signs of heart disease, or perhaps a urine test to screen for kidney problems.

  Proper treatment of hypertension begins with a healthy, low-sodium diet, regular moderate exercise, and stress management. Blood pressure medications may also be necessary and can range from diuretics and vasodilators (drugs which cause the arteries to relax and widen) to angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), beta blockers, and calcium channel blockers. Once you have been diagnosed with high blood pressure, regular checkups will also be advised in order to monitor your condition.

  Mitral Valve Prolapse

  While both of the valves that connect your upper and lower heart chambers can develop disorders, mitral valve prolapse, or MVP, is the more common valve condition. In MVP, the mitral valve, which connects your left atrium and left ventricle, doesn’t close properly. Instead, this valve bulges, or prolapses, into the left atrium every time that the heart muscle contracts. In some cases, this can cause blood to leak backwards into the left atrium, causing what is known as mitral valve regurgitation.

  Although MVP can develop at any age, it’s most common in men above the age of fifty, and tends to be inherited from a parent. A number of diseases can also increase the risk of MVP, including adult polycystic kidney disease (a genetic disorder of the kidneys), Ebstein’s anomaly (a rare heart defect that causes leakage between heart chambers), or certain conditions that affect the connective tissues, including Ehlers-Danlos and Marfan syndromes. Scoliosis, or abnormal curvature of the spine, can also increase the risk of MVP.

  Many people with MVP do not experience any symptoms and are therefore surprised to discover that they have this heart condition. When symptoms are present, they may include arrhythmia, dizziness, shortness of breath, fatigue, and/or chest pain. People who have MVP are at a higher risk for a condition called endocarditis, in which the inner tissue of the heart becomes infected with bacteria.

  The easiest way to test for MVP is with a stethoscope; if MVP is present, your doctor will hear clicking sounds or a heart murmur, as both are good aural indicators of an abnormal flow of blood in the heart. Other diagnostic tests associated with leaky valve (mitral regurgitation) may include chest X-ray, electrocardiogram (EKG), echocardiogram, stress testing, and cardiac catheterization.

  Most cases of MVP are not serious and do not require treatment or even changes in lifestyle. If symptoms are present, usually due to an arrhythmia or a leaky valve, your doctor may decide to monitor your condition to ensure that it doesn’t worsen, or prescribe drugs such as aspirin, anticoagulants, or beta blockers. Surgery is rarely necessary, but occasionally open heart surgery is performed in order to repair or replace the leaky mitral valve.

  Pericarditis and Pericardial Effusion

  Pericarditis is an inflammation of the pericardium, the thin set of membranes that encases the heart. When the pericardium is inflamed, its two layers rub against each other, causing painful friction. There are two kinds of pericarditis: acute, which lasts for six weeks or less, and chronic, which can last for six months or longer. Although unpleasant, pericarditis is rarely fatal.

  By contrast, pericardial effusion is more serious. In this condition, fluid builds up between the two layers of the pericardium, putting pressure on the heart and preventing it from functioning properly. Severe cases of pericardial effusion can force the heart’s chambers to compress or even collapse; this condition is life-threatening and is called cardiac tamponade.

  While the cause of pericarditis is not always clear, viral or bacterial infections are often to blame. Risk factors for pericarditis also include chest injury, kidney disease, heart attack, lupus, and rheumatic fever. Pericardial effusion is often, but not always, a response to pericardial inflammation. It can also be caused by viral, bacterial, fungal, or parasitic infections; autoimmune diseases (lupus, HIV); certain types of cancer; and trauma to the heart (caused by injury or surgery).

  Acute pericarditis produces sharp, stabbing chest pains that come and go quickly; sufferers may believe they’re experiencing heart attacks. Other symptoms include fever, weakness, difficulty breathing, and coughing. Chronic pericarditis will cause fatigue, coughing, shortness of breath, and swelling of the stomach and legs; chest pain is often absent.

  Symptoms of pericardial effusion include shortness of breath or difficulty breathing, chest pain behind the breastbone or the left side of the chest that is exacerbated by inhalation and worsens when lying down, coughing, dizziness, low-grade fever, and rapid heart beat. Symptoms may not be initially apparent, manifesting only when the fluid buildup increases.

  Your doctor may be able to diagnose pericarditis or pericardial effusion using a simple chest exam with a stethoscope; other tests include electrocardiogram (EKG), echocardiogram, chest X-rays, MRI, and CT scan. Blood tests may also be ordered to help determine underlying causes.

  Treatment for pericarditis and pericardial effusion might include anti-inflammatory drugs such as aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, and corticosteroids such as prednisone. If bacterial infection is suspected as the cause of the inflammation, antibiotics will be prescribed. In cases of cardiac tamponade, a procedure called pericardiocentesis or even open-heart surgery may be required in order to drain the pericardium. Often, a catheter will be left in the pericardium in order to encourage further drainage; it is then removed after a few days. Rarely, the pericardium itself will be removed, in a procedure called pericardiectomy.

  Premature Ventricular Contractions

  Premature ventricular contraction, or PVC, is a common condition that occurs when one of the ventricles produces an extra, abnormal heartbeat, disrupting the regular heart rhythm and thus, potentially, the flow of blood. Most people will experience a PVC at one time or another—it’s often described as the sensation of the heart “skipping a beat,” although in fact the heart is actually adding one.

  The causes of PVC aren’t always clear, but are generally thought to be rooted in faulty electrical impulses. Other factors that increase the likelihood of a PVC include biochemical changes or imbalances in the body (e.g. low potassium or magnesium), alcohol or drug abuse, overexertion, excess caffeine consumption, smoking, hypertension, anxiety, and other underlying heart conditions. Certain medications, particularly those used to treat asthma, can also trigger PVCs. While most cases of PVC are harmless, in others they can lead to arrhythmias which, if they become chaotic enough, can result in sudden cardiac death.

  Many people who have a PVC will never even notice it. If you do notice, you might feel as if your heart is racing, flip-flopping, or fluttering, or as if it has either skipped a beat or stopped.

  The standard method for detecting PVC is an electrocardiogram (EKG), with or without a stress test. In some cases, devices such as the Holter monitor or an event recorder can also be used. A Holter monitor is a small, portable device that can be ca
rried in your pocket or attached to your belt. It automatically records your heart rhythms for a twenty-four hour period, so that your doctor can better detect any anomalies. An event recorder is a small portable EKG device that can also be carried on your person the way a Holter monitor can. When PVC symptoms are experienced, the recorder is activated with the push of a button so that a brief EKG recording is made. This enables doctors to see the heart rhythm as the PVCs occur.

  Because PVCs are usually innocuous, treatment is rarely required for people who have no underlying heart conditions. If the symptoms are particularly frequent or troubling, however, your doctor may encourage you to make lifestyle changes that can minimize PVC triggers, such as avoiding alcohol, limiting caffeine intake, quitting smoking, and stress management. In the event that medication is required to treat a PVC, beta blockers are the drugs most commonly used.

  Stroke

  A stroke is caused when the blood supply to the brain is interrupted or severely reduced, either because an artery has ruptured (burst) or because it has been blocked by a clot. Deprived of oxygen and other nutrients that the blood transports, brain cells begin to die within minutes after a stroke occurs. Prompt medical attention is thus essential to limiting brain damage and other potential complications. Nearly 800,000 Americans will experience a stroke each year; it is the fourth most common cause of death in the United States and a leading cause of disability.

  There are two main types of stroke. The most common is called an ischemic stroke, which accounts for 87 percent of all strokes each year. An ischemic stroke occurs when an artery to the brain becomes blocked by a blood clot, causing severely reduced blood flow (ischemia). There are two subcategories of ischemic strokes: thrombotic strokes, in which the blood clot forms in an artery that has already been narrowed (usually by atherosclerosis), and embolic strokes, in which the clot breaks off from another location (usually the heart) and travels to one of the brain’s blood vessels, which are too narrow to allow the clot through.