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Short PR
In electrocardiography, the PR interval is the period, measured in milliseconds, that extends from the beginning of the P wave (the onset of atrial depolarization) until the beginning of the QRS complex (the onset of ventricular depolarization); it is normally between 120 and 200 ms in duration. The PR interval is sometimes termed the PQ interval. Interpretation Variations in the PQ interval can be associated with certain medical conditions: * Duration ** A long PR interval (of over 200 ms) indicates a slowing of conduction between the atria and ventricles, usually due to slow conduction through the atrioventricular node (AV node). This is known as first degree heart block. Prolongation can be associated with fibrosis of the AV node, high vagal tone, medications that slow the AV node such as beta-blockers, hypokalemia, acute rheumatic fever, or carditis associated with Lyme disease. ** A short PR interval (of less than 120ms) may be associated with a Pre-excitation syndrom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acute Rheumatic Fever
Rheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection. Signs and symptoms include fever, multiple painful joints, involuntary muscle movements, and occasionally a characteristic non-itchy rash known as erythema marginatum. The heart is involved in about half of the cases. Damage to the heart valves, known as rheumatic heart disease (RHD), usually occurs after repeated attacks but can sometimes occur after one. The damaged valves may result in heart failure, atrial fibrillation and infection of the valves. Rheumatic fever may occur following an infection of the throat by the bacterium ''Streptococcus pyogenes''. If the infection is left untreated, rheumatic fever occurs in up to three percent of people. The underlying mechanism is believed to involve the production of antibodies against a person's own tissues. Due to their genetics, some peop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pericarditis
Pericarditis is inflammation of the pericardium, the fibrous sac surrounding the heart. Symptoms typically include sudden onset of sharp chest pain, which may also be felt in the shoulders, neck, or back. The pain is typically less severe when sitting up and more severe when lying down or breathing deeply. Other symptoms of pericarditis can include fever, weakness, palpitations, and shortness of breath. The onset of symptoms can occasionally be gradual rather than sudden. The cause of pericarditis often remains unknown but is believed to be most often due to a viral infection. Other causes include bacterial infections such as tuberculosis, uremic pericarditis, heart attack, cancer, autoimmune disorders, and chest trauma. Diagnosis is based on the presence of chest pain, a pericardial rub, specific electrocardiogram (ECG) changes, and fluid around the heart. A heart attack may produce similar symptoms to pericarditis. Treatment in most cases is with NSAIDs and possibly t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Block
Heart block (HB) is a disorder in the heart's rhythm due to a fault in the natural pacemaker. This is caused by an obstruction – a block – in the electrical conduction system of the heart. Sometimes a disorder can be inherited. Despite the severe-sounding name, heart block may cause no symptoms at all in some cases, or occasional missed heartbeats in other cases (which can cause light-headedness, syncope (fainting), and palpitations), or may require the implantation of an artificial pacemaker, depending upon exactly where in the heart conduction is being impaired and how significantly it is affected. Heart block should not be confused with other conditions, which may or may not be co-occurring, relating to the heart and/or other nearby organs that are or can be serious, including angina (heart-related chest pain), heart attack (myocardial infarction), any type of heart failure, cardiogenic shock or other types of shock, different types of abnormal heart rhythms ( arrhythmias ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Junctional Rhythm
Junctional rhythm describes an abnormal heart rhythm resulting from impulses coming from a locus of tissue in the area of the atrioventricular node(AV node), the "junction" between atria and ventricles. Under normal conditions, the heart's sinoatrial node(SA node) determines the rate by which the organ beats – in other words, it is the heart's "pacemaker". The electrical activity of sinus rhythm originates in the sinoatrial node and depolarizes the atria. Current then passes from the atria through the atrioventricular node and into the bundle of His, from which it travels along Purkinje fibers to reach and depolarize the ventricles. This sinus rhythm is important because it ensures that the heart's atria reliably contract before the ventricles. In junctional rhythm, however, the sinoatrial node does not control the heart's rhythm – this can happen in the case of a block in conduction somewhere along the pathway described above, or in sick sinus syndrome, or many other si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrioventricular Reentrant Tachycardia
Atrioventricular reentrant tachycardia (AVRT), or atrioventricular reciprocating tachycardia, is a type of abnormal fast heart rhythm and is classified as a type of supraventricular tachycardia (SVT). AVRT is most commonly associated with Wolff–Parkinson–White syndrome, but is also seen in permanent junctional reentrant tachycardia (PJRT). In AVRT, an accessory pathway allows electrical signals from the heart's ventricles to enter the atria and cause earlier than normal contraction, which leads to repeated stimulation of the atrioventricular node.Josephson ME. Preexcitation syndromes. In: Clinical Cardiac Electrophysiology, 4th, Lippincott Williams & Wilkins, Philadelphia 2008. p.339 Signs and symptoms An episode of SVT may present with palpitations, dizziness, shortness of breath, or losing consciousness (fainting). The electrocardiogram (ECG) would appear as a narrow-complex SVT. Between episodes of tachycardia the affected person is likely to be asymptomatic; howev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lown–Ganong–Levine Syndrome
Lown–Ganong–Levine syndrome (LGL) is a pre-excitation syndrome of the heart. Those with LGL syndrome have episodes of abnormal heart racing with a short PR interval and normal QRS complexes seen on their electrocardiogram when in a normal sinus rhythm. LGL syndrome was originally thought to be due to an abnormal electrical connection between the atria and the ventricles, but is now thought to be due to accelerated conduction through the atrioventricular node in the majority of cases. The syndrome is named after Bernard Lown, William Francis Ganong, Jr., and Samuel A. Levine. Signs and symptoms Pathophysiology LGL syndrome was originally thought to involve a rapidly conducting accessory pathway (bundle of James) that connects the atria directly to the bundle of His, bypassing the slowly conducting atrioventricular node. However, the majority of those with LGL in whom electrophysiological studies have been performed do not have any evidence of an accessory pathway or str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolff–Parkinson–White Syndrome
Wolff–Parkinson–White syndrome (WPWS) is a disorder due to a specific type of problem with the electrical system of the heart. About 60% of people with the electrical problem developed symptoms, which may include an abnormally fast heartbeat, palpitations, shortness of breath, lightheadedness, or syncope. Rarely, cardiac arrest may occur. The most common type of irregular heartbeat that occurs is known as paroxysmal supraventricular tachycardia. The cause of WPW is typically unknown and is likely due to a combination of chance and genetic factors. A small number of cases are due to a mutation of the PRKAG2 gene which may be inherited from a person's parents in an autosomal dominant fashion. The underlying mechanism involves an accessory electrical conduction pathway between the atria and the ventricles. It is associated with other conditions such as Ebstein anomaly and hypokalemic periodic paralysis. The diagnosis of WPW occurs with a combination of palpitations and when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pre-excitation Syndrome
Pre-excitation syndrome is a heart condition in which part of the cardiac ventricles are activated too early. Pre-excitation is caused by an abnormal electrical connection or accessory pathway between or within the cardiac chambers. Pre-excitation may not cause any symptoms but may lead to palpitations caused by abnormal heart rhythms. It is usually diagnosed using an electrocardiogram, but may only be found during an electrophysiological study. The condition may not require any treatment at all, but symptoms can be controlled using medication or catheter ablation. Types Several types of pre-excitation syndrome have been described. Pathophysiology Normally, the atria and the ventricles are electrically isolated, and electrical contact between them exists only at the "atrioventricular node". In all pre-excitation syndromes, at least one more conductive pathway is present. Physiologically, the normal electrical depolarization wave is delayed at the atrioventricular node to all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyme Disease
Lyme disease, also known as Lyme borreliosis, is a vector-borne disease caused by the ''Borrelia'' bacterium, which is spread by ticks in the genus ''Ixodes''. The most common sign of infection is an expanding red rash, known as erythema migrans (EM), which appears at the site of the tick bite about a week afterwards. The rash is typically neither itchy nor painful. Approximately 70–80% of infected people develop a rash. Early diagnosis can be difficult. Other early symptoms may include fever, headaches and tiredness. If untreated, symptoms may include loss of the ability to move one or both sides of the face, joint pains, severe headaches with neck stiffness or heart palpitations. Months to years later repeated episodes of joint pain and swelling may occur. Occasionally shooting pains or tingling in the arms and legs may develop. Despite appropriate treatment about 10 to 20% of those affected develop joint pains, memory problems and tiredness for at least six months. Lym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carditis
Carditis (pl. carditides) is the inflammation of the heart. It is usually studied and treated by specifying it as: * Pericarditis is the inflammation of the pericardium * Myocarditis is the inflammation of the heart muscle * Endocarditis is the inflammation of the endocardium * Pancarditis, also called perimyoendocarditis, is the inflammation of the entire heart: the pericardium, the myocardium and the endocardium * Reflux carditis refers to a possible outcome of esophageal reflux (also known as GERD Gerd or GERD may refer to: * Gerd (given name), a list of people with the given name or nickname * Gerd (moon), a moon of Saturn * Gerd Island, South Orkney Islands, Antarctica * Gastroesophageal reflux disease, a chronic symptom of mucosal damage ...), and involves inflammation of the esophagus/stomach mucosa References Heart diseases {{circulatory-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypokalemia
Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an abnormal heart rhythm, which is often too slow and can cause cardiac arrest. Causes of hypokalemia include vomiting, diarrhea, medications like furosemide and steroids, dialysis, diabetes insipidus, hyperaldosteronism, hypomagnesemia, and not enough intake in the diet. Normal potassium levels are between 3.5 and 5.0 mmol/L (3.5 and 5.0 mEq/L) with levels below 3.5 mmol/L defined as hypokalemia. It is classified as severe when levels are less than 2.5 mmol/L. Low levels may also be suspected based on an electrocardiogram (ECG). Hyperkalemia is a high level of potassium in the blood serum. The speed at which potassium should be replaced depends on whether or not there are symptoms or abnormalities on an electrocardiogram. Pot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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