READER-FRIENDLY INFORMATION ON COMMON CARDIAC CONDITIONS
Angina: Angina is a fancy word for chest pain. This feeling of pressure, squeezing, or general discomfort in the chest area occurs under conditions of ischemia (when the heart muscle is deprived of oxygen-rich blood). There are several types of angina–stable, unstable, variant, and microvascular–and therefore, several causes. Stable angina (angina pectoris) refers to chest pain triggered or exacerbated by a certain event (e.g. vigorous exercise or excessive emotion) that causes the heart to work harder than usual; stable angina occurs at predictable times and is often relieved by stopping the strenuous activity. Unstable angina, angina that occurs suddenly and seemingly randomly, can be a heart attack, and you should go to an emergency room immediately. Variant angina (Prinzmetal’s angina, angina inversa) is a chronic condition where sharp and brief pains occur between night and early morning; this type of angina is often treated with nitrates and calcium antagonists. Microvascular angina is a spasm of the small arterial blood vessels, causing chest pain that lasts between ten to thirty minutes. All of these forms of angina may prefigure or be a heart attack, and if you experience chest pain, seek medical attention as soon as you can. Other cardiac conditions including atherosclerosis, pericarditis, and cardiomyopathy can cause angina; your chest pain may also be effected by anxiety, indigestion, lung infections, and pulmonary emboli.
Aortic Valve Regurgitation: Aortic valve regurgitation is where the aortic valve leaks (or regurgitates) blood. Oxygenated blood is supposed to flow from the inner chambers of the heart through the aorta to the body, but when the valve regurgitates, the blood flows back through the aorta into the left ventricle, forcing the heart to do more work, which in turn leads to a thickening of the heart walls (hypertrophic cardiomyopathy) and eventual heart failure. This problem can be fixed by a valvular replacement.
Aortic Valve Stenosis: Also known as aortic stenosis, aortic valve stenosis is the narrowing of the aortic valve. This narrowing inhibits the heart’s pumping of blood from the left ventricle to the rest of the body, which, like aortic valve regurgitation, causes hypertrophy and heart failure. Treatment may not be needed, but in severe cases a valvular replacement is done.
Atherosclerosis: Atherosclerosis is a type of arteriosclerosis–a general term referring to a thickening and hardening of the arteries–where plaque forms inside the arteries, clogging them. This plaque, made up of cholesterol, cellular debris, calcium, and fibrin, if left untreated, will either block the artery, depriving the heart of oxygen and causing a heart attack, or allow for blood to clot atop it, resulting in the same or, if the brain does not receive oxygen, a stroke. Atherosclerosis is highly preventable by not smoking, maintaining a healthy weight, and keeping your cholesterol in check.
Arrhythmia: An arrhythmia is an abnormal heart rhythm. Many of the conditions described in this database are arrhythmias including atrial fibrillation and inappropriate sinus tachycardia.
Atrial Fibrillation: Often abbreviated as A-Fib, atrial fibrillation is a type of supraventricular tachycardia where the atria, the upper chambers of the heart, beat irregularly. Instead of receiving a signal from the sinoatrial node and then contracting to pump blood to the ventricles, the atria get electrical impulses from in and around themselves, causing their walls to quiver rather than contract; not all of these electrical impulses cause contractions, and only the ones that do result in blood pumping into the ventricles, reducing the heart’s efficiency by about 10%. Because atrial fibrillation increases the chance of blood clots forming, patients with a-fib are five times more likely to have a stroke, and thusly, many patients with this condition are prescribed antithombotics (anticoagulants). Watch the American Heart Association’s awesome a-fib animation here.
Atrial Flutter: An atrial flutter is very similar to atrial fibrillation, but in these cases the atria’s electrical activity is coordinated, and the atria do, therefore, contract; when they do, however, they do so very rapidly, and the atrioventricular node cannot possibly transfer all of these impulses to the ventricles. The atria contract at about 250-350 bpm, but the ventricles, subjected to their own consequent tachycardia, contract at about 150. Like patients with a-fib, those with atrial flutter have an increased risk of blood clots and stroke; both conditions can also lead to a thickening of the atrial walls and consequent heart failure.
Blood Clot: Blood clotting is a coagulation of the blood to form a thrombus (clot). Almost immediately after a blood vessel is injured, platelets rush to the scene, changing their shape from smooth and round to rather spiny, allowing them to plug the broken vessel. The platelets trigger a rapid chain reaction; this is a complicated process, but basically thrombin is generated to convert fibrinogen, a protein found in blood plasma, into fibrin, which encases the platelets and blood cells, holding the forming thrombus together. This thrombus lasts until the blood vessel heals when it is then dissolved by a chemical-cellular counter-reaction. Blood clotting, at least as described above, is a normal and necessary bodily function; it should happen, and if it didn’t, you’d likely have bled to death by now! Thrombosis itself is not a bad thing, but certain conditions and circumstances (prolonged immobility, some medications, cardiac arrhythmias, clogging of the arteries) can cause the abnormal and dangerous formation of unwanted clots. Many such blood clots are caused by arteriosclerosis; blood can either clot atop built-up plaque or a bit of this plaque can break off, triggering a thorombiod response at the breakage site. A blocked artery can lead to a heart attack or, if the artery in question supplies blood to the brain, a stroke. Sometimes a thombus does not stay on the venous or arterial wall, instead breaking off and becoming what is known as an embolus; often, said embolus gets stuck in another vein or artery, causing an array of conditions dependent upon its location. Pulmonary embolism (PE) is a prime example; deep vein thrombosis (DVT) occurs (a clot forms in a vein deep in the body, typically the leg) and the clot embolizes (breaks off) eventually getting stuck in the pulmonary artery, cutting off some or all of the lung’s blood supply. Like other abnormal blood clots, pulmonary embolism is an potentially fatal condition that requires immediate medical attention.
Bradycardia: Bradycardia is a cardiac arrhythmia where the heart beats slower than normal. A bradycardic patient’s heart will beat less than 60 times per minute when at rest. In the short term, bradycardia is not a detrimental condition, though it may cause mild discomfort such as dizziness and fatigue, due to the fact that the brain is receiving a less than optimal amount of oxygenated blood; for some people, prolonged, untreated bradycardia results in angina, hypotension, heart failure, and syncope. Although there are medications to accelerate the heart-rate, these are potentially dangerous and not often used; if bradycardia is treated at all, it is with the implantation of a pacemaker.
Cardiac Arrest: To put it simply, cardiac arrest (or sudden cardiac death) is the cessation of all heart function. The myocardial electrical system malfunctions, the heart stops, and death occurs within a couple minutes unless CPR (cardiopulmonary resuscitation) is promptly administered and a defibrillator used to shock the heart back into normal rhythms.
Cardiomegaly: Cardiomegaly is a subtype of cardiomyopathy known vernacularly as an ‘enlarged heart’. This definition is slightly misleading, as it suggests the whole heart must be enlarged when in reality a designation of cardiomegaly only requires the enlargement of a component thereof. Read the cardiomyopathy section of this database for more information on the most common types of cardiomegaly.
Cardiomyopathy: Cardiomyopathy is literally means ‘heart muscle disease’; it is a very broad term referring to structural abnormalities of the myocardium including the various types of cardiomegaly. There are several common types of cardiomyopathy–dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular dysplasia; if the patient’s cardiomyopathy is not classifiable as one of the aforelisted types, it is deemed ‘unclassified’ and clinically referred to as such. Dilated cardiomyopathy, the most common type of cardiomyopathy, is when one or more of the heart’s chambers dilates (stretches out, becomes thinner); often, this first occurs in the left ventricle and as the spreads as the rest of the heart works harder to compensate for the left ventricular defect. Hypertrophic cardiomyopathy is a thickening of the ventricular walls due to enlarged myocytes (the heart muscle cells); the heart’s function is impaired and when blood flow is impaired as a result the condition progresses to obstructive hypertrophic cardiomyopathy. If the ventricular walls become rigid, which usually occurs when scar tissue replaces healthy heart muscle, restrictive cardiomyopathy can occur; the ventricles are unable to relax properly, so they fill with blood, forcing the atria to work harder and become overdeveloped. Arrhythmogenic right ventricular dysplasia is a condition in which the right ventricle is made up of scar tissue and therefore cannot contract properly, leading to arrhythmias and increasing the risk of sudden cardiac death; this type of cardiomyopathy is extremely rare, and researchers at the American Heart Association believe it to be an inherited ailment. Most cardiomyopathies are permanent and progressive with one notable exception–stress-induced cardiomyopathy (broken heart syndrome), which is a sudden temporary weakening of one of the heart’s chambers. You can acquire or inherit cardiomyopathy; your cardiomyopathy may also be idiopathic (of unknown cause).
Coronary Artery Disease: Coronary artery disease technically refers to any damage to or narrowing and/or blockage of the coronary arteries, typically, due to atherosclerosis. If the heart is not getting enough oxygen, angina and myocardial infarctions can result; coronary artery disease can also damage the heart to the extent that arrhythmias and heart failure are inevitable.
Congestive Heart Failure: The term ‘heart failure’ refers to a heart that cannot–for whatever reason–pump blood effectively. Technically, heart failure can be due to almost anything, and in some cases it is a reversible condition; congestive heart failure, which has unfortunately been shortened to simply ‘heart failure’, is a specific and severe type of heart failure, a sadly irreversible one. The heart tries to make up for its shortcomings by enlarging and pumping faster, and the body shrinks its blood vessels and diverts blood flow away from organs that are not absolutely essential to survival; while these compensations can be helpful in the short term, they ultimately end up worsening the heart failure. Congestive heart failure is marked by, as the name suggests, congestion, the pooling of fluid in/around the heart and other bodily tissues. Heart failure as a whole can, depending on what part of the heart is actually failing, be right-sided, left-sided, or biventricular, with the second two frequently caused by the first. It can also be systolic or diastolic, referring respectively to the ventricles’ failure to contract or relax. If the onset of the heart failure is abrupt, it is diagnosed as acute; if symptoms manifest more gradually, it is chronic. Medications and lifestyle changes may help to manage heart failure, but if the patient lives long enough, the heart will eventually stop working, and a heart transplant will be necessary.
Endocarditis: Endocarditis is not a common cardiac condition, and you likely do not have it; nonetheless, it is fascinating and included here. Endocarditis is an inflammation of the endocardium, the heart’s inner lining; frequently, though, the condition spreads to the heart valves as well. Vegetation/lesions (masses comprised of platelets, fibrin, inflammatory cells, and bacterial microcolonies) are signature to endocarditis, forming on the endocardium and perpetuating the inflammation. Endocarditis can be classified as infective or non-infective depending upon its cause, a bacterial microorganism or lack thereof. In the case of the former, the condition is treatable with antibiotics; corrective surgery and valvular replacements may be necessary in severe cases. Again, as endocarditis only effects <200,000 people in the United States annually, it is not probable that you are effected.
Heart Attack: Clinicians refer to a heart attack as a myocardial infarction, a far more descriptive term; ‘myo’ means muscle, ‘cardial’ heart, and ‘infarction’ death of tissue due to deprivation of blood supply. A heart attack or myocardial infarction is just that; a coronary artery becomes blocked or spasms and the consequent conditions of ischemia (lack of oxygen on account of reduced blood flow) damage the area of the heart supplied by said artery. Deprived of oxygen, the cells in this area die and, as the heart cannot completely repair itself, lasting damage is done; within eight weeks, the cells ‘heal’ as scar tissue, but this scar tissue will never pump/contract as well as a healthy heart muscle, forcing the heart to work harder and leading eventual to cardiomyopathy and/or heart failure. Symptoms of a heart attack include chest pain, shortness or breath, nausea/vomiting, fatigue/exhaustion, and back/jaw/arm pain; symptoms are different in women, who are more likely to have a heart attack without the signature symptom of chest pain. If you think you are having a heart attack, stop reading this website and call 911 now; even better, prevent a heart attack before it happens by maintaining a healthy weight, not smoking, and keeping your cholesterol in check!
Heart Block: Atrioventricular heart block (or simply heart block) is a type of bradycardia where the heart’s electrical signals do not effectively pass from the atria to the ventricles. It can be further classified as sinoatrial nodal, atrioventricular nodal, or infra-hisian (intra-hisian) depending upon the location of the causal defect. There are three degrees of heart block–first, second, and third. In first degree heart block, all of the electrical signals pass from the atria to the ventricles; they just do so at a slower than optimal rate. In Mobitz type 1 second degree heart block (Wenckenbach’s block), the rate at which the electrical impulses are transmitted to the ventricles gets slower and slower until the heart skips an entire beat; in Mobitz type 2 second degree heart block, some of the impulses do not make it to the ventricles at all. When none of the these impulses reach the ventricles, the condition has progressed to third degree heart block (complete heart block), and a pacemaker should be implanted before a serious cardiomyopathy develops.
Heart Disease: Heart Disease (also know as cardiovascular disease) is a general term describing any abnormality the heart and blood vessels including arrhythmias, blood clots, cardiomyopathies, endocarditis, heart attacks, hypertension, and sudden cardiac death. Strokes are considered cardiovascular diseases, because they are disorders of the blood vessels.
Heart Murmur: A heart murmur is the sound of blood circulating through the heart or its nearby blood vessels. Heart murmurs are divided into two categories– diastolic and systolic, the latter of which’s loudness/intensity is graded on a rather subjective 1-6 scale (6 being the loudest); a diastolic murmur occurs when the heart relaxes between beats, and a systolic murmur is one that occurs during the contraction itself. A significant amount of heart murmurs are ‘innocent’ (also known as ‘functional’ or ‘physiologic’) or harmless, simply sounds that certain hearts make while doing their job. Those that are not deemed benign by physician administered follow-up tests are typically caused by and signs of defective heart valves; the blood can be heard as it is forced through stenotic (narrowed) valves or when it is leaked through floppy ones.
Hypertension: Hypertension is the technical term for high blood pressure (>140/90 mm Hg). This should be addressed in the prehypertension stage (when the reading is 120-139/80-89 mm Hg) prior the appearance of serious cardiovascular complications. Patients who are mildly hypertensive tend to be otherwise asymptomatic, but that by no means negates the ensuing arterial damage; exorbitant amounts of pressure are still being put on the arteries and heart, elevating the risk of heart attack and stroke. Your doctor may suggest lifestyle changes or prescribe medication(s) like Thiazide diuretics, beta-blockers, or vasodilators. If you’re interested in learning more about blood pressure readings, check out this post!
Long QT Syndrome: Long QT Syndrome is a cardiac arrhythmia named for its appearance on an electrocardiogram. On an EKG the QT interval depicts the depolarization and re-polarisation of the ventricles; this disorder effects the repolarization, prolonging it, which is very dangerous, as it can disrupt the heart’s beating, leading to dangerous arrhythmias including ventricular fibrillation. This happens because of a defect in or a lack of ion channels on the heart cells; ion channels should release positively charged atoms (ions) to generate the necessary electrical signals, but they can be damaged or inhibited by certain genetic mutations and medications, causing Long QT Syndrome. Although it is rare and often misdiagnosed, Long QT Syndrome can be immediately diagnosed with an EKG and then treated with medications or a pacemaker.
Mitral Valve Prolapse: Mitral valve prolapse is sometimes called Barlow’s Syndrome, click-murmur syndrome, and/or floppy valve syndrome. It is a condition where the valve between the left atrium and left ventricle does not adequately close; instead, the valve’s leaflets prolapse (bulge, flop) towards the left atrium, allowing for mitral valve leakage and regurgitation, both of which can cause an audible heart murmur. Although generally benign, severe mitral valve prolapse can lead to an eventual enlarging of the left ventricle and heart failure; in cases that have progressed as far as this, a mitral valve repair will be performed, likely via catheterization.
Palpitations: Palpitations are perceived irregular heart rhythms. Sensations of racing, pounding, fluttering, or skipping a beat all constitute palpitations. Palpitations can be a symptom of an underlying disease such as a tachycardia subtype or a harmless result of stress; in the absence of additional symptoms including but not limited to angina, confusion, and syncope, palpitations are diagnosable as a condition of their own.
Pericarditis: Pericarditis is another rare cardiac condition (sorry guys!), reporting fewer than 200,000 cases in the United States annually. It is an inflammation of the pericardium, the two-layered sac-like tissue surrounding the heart. This inflammation is often painful, and the pain is perpetuated by the layers rubbing against each other and against the heart itself. Most cases of pericarditis are acute and idiopathic; however, fungal and viral pericarditis have occurred. When pericarditis persists, it is called chronic pericarditis, and it is probably due to repeated respitory infections or an autoimmune disorder (e.g. lupus, HIV/AIDS, cancer). Fortunately, most cases of pericarditis are easily and quickly resolved with little to no treatment.
Preventricular Complex: Preventricular complex, preventricular contraction, ventricular premature beats, and extrasystoles all refer to the same thing, an extra beat in one of the heart’s two the lower chambers (ventricles) that disrupts the normal cardiac rhythm. The occasional preventricular contraction (PVC) is harmless and almost everybody will experience one or two in their lifetime while exercising, during emotional stress, and/or after consuming caffeine; that being said, frequent, chronic, and/or patterned preventricular contractions can be indicative of or lead to heart disease.
Sick Sinus Syndrome: Sick sinus syndrome is not really a disease of its own. It refers to any defect in the sinoatrial (sinus) node, which can cause the heart muscle as a whole to contract at a rate that is either too fast or too slow; while a patient can suffer from either sinus tachycardia or sinus bradycardia, both can occur in an alternating fashion (tachy-brady syndrome).
Stroke: The National Stroke Association calls a stroke a ‘brain attack’; this is not only charming but apt, as a stroke, like a heart attack, is an ischemic infarction (a death of cells due to deprivation of oxygenated blood). Based upon the cause of the ischemia, a stroke is designated as either ischemic or hemorrhagic. An ischemic stroke occurs when a blood clot blocks a vessel supplying the brain, stopping or limiting the blood flow; an ischemic stroke can be either thrombotic or embolic depending on whether the clot originates in the brain or elsewhere. A hemorrhagic stroke happens when an aneurysm bursts or when a blood vessel breaks or leaks; a hemorrhagic stroke can be either intracerebral, occurring within a blood vessel, or subarachnoid, occurring in the subarachnoid space (the area between the brain and the tissue covering it). A transient ischemic attack (TIA) is a ‘mini-stroke’; it does not usually cause permanent damage, but it is still very dangerous, and it can prefigure an actual, larger stroke, one which can cause speech impediments, memory loss, paralysis, and even death. The signs of a stroke include face-drooping, arm weakness, and speech difficulty; remember the symptoms and save a life with the F.A.S.T. acronym and this catchy song.
Tachycardia: Tachycardia is the medical term for a resting heart rate of 100 bpm or above. It can be either ventricular (occurring in the ventricles) or supraventricular (occurring in the area of the heart above the ventricles). Atrial tachycardias such as a-fib are considered supraventricular, as are sinus tachycardias, of which there are several types, including inappropriate sinus tachycardia, which is sinus tachycardia that occurs seemingly randomly (without ‘appropriate’ provocation). Ventricular tachycardia and supraventricular tachycardia are sometimes referred to as wide and narrow complex tachycardias, respectively, due to the manifestation of their QRS Complexes on a diagnostic EKG. Tachycardia should be seen as a symptom, and its underlying cause should be treated.
Ventricular Fibrillation: Ventricular fibrillation, generally classified as the most dangerous cardiac arrhythmia, is a quivering of the ventricles. Because the ventricles are not contracting, the heart is unable to pump blood to the rest of the body; when this happens, a person will collapse within a few seconds and cardiac arrest will follow. Immediate medical intervention including CPR and automated external defibrillation is required; call 911 (or your country’s version thereof) immediately if you see anyone experiencing the signs of cardiac arrest.