Heart arrhythmiaSynonymsCardiac arrhythmia, cardiac dysrhythmia, irregular heartbeatVentricular fibrillation (VF) showing disorganized electrical activity producing a spiked tracing on an electrocardiogram (ECG).SpecialtyCardiologySymptomsPalpitations, lightheadedness, passing out, shortness of breath, chest pain[1]ComplicationsStroke, heart failure[2][3]Usual onsetOlder age[4]TypesExtra beats, supraventricular tachycardias, ventricular arrhythmias, bradyarrhythmias[3]CausesProblems with the electrical conduction system of the heart[2]Diagnostic methodElectrocardiogram, Holter monitor[5]TreatmentMedications, medical procedures (pacemaker), surgery[6]FrequencyMillions[4] Heart arrhythmia (also known as arrhythmia, dysrhythmia, or irregular heartbeat) is a group of conditions in which the heartbeat is irregular, too fast, or too slow.[2] A heart rate that is too fast above 100 beats per minute in adults is called tachycardia and a heart rate that is too slow below 60 beats per minute is called bradycardia.[2] Many types of arrhythmia have no symptoms.[1] When symptoms are present these may include palpitations or feeling a pause between heartbeats.[1] In more serious cases there may be lightheadedness, passing out, shortness of breath, or chest pain.[1] While most types of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure.[2][3] Others may result in cardiac arrest.[3] There are four main types of arrhythmia: extra beats, supraventricular tachycardias, ventricular arrhythmias, and bradyarrhythmias.[3] Extra beats include premature atrial contractions, premature ventricular contractions, and premature junctional contractions.[3] Supraventricular tachycardias include atrial fibrillation, atrial flutter, and paroxysmal supraventricular tachycardia.[3] Ventricular arrhythmias include ventricular fibrillation and ventricular tachycardia.[3][7] Arrhythmias are due to problems with the electrical conduction system of the heart.[2] Arrhythmias may occur in children; however, the normal range for the heart rate is different and depends on age.[3] A number of tests can help with diagnosis including an electrocardiogram (ECG) and Holter monitor.[5] Most arrhythmias can be effectively treated.[2] Treatments may include medications, medical procedures such as inserting a pacemaker, and surgery.[6] Medications for a fast heart rate may include beta blockers or agents that attempt to restore a normal heart rhythm such as procainamide.[6] This latter group may have more significant side effects especially if taken for a long period of time.[6] Pacemakers are often used for slow heart rates.[6] Those with an irregular heartbeat are often treated with blood thinners to reduce the risk of complications.[6] Those who have severe symptoms from an arrhythmia may receive urgent treatment with a controlled electric shock in the form of cardioversion or defibrillation.[6] Arrhythmia affects millions of people.[4] In Europe and North America, as of 2014, atrial fibrillation affects about 2% to 3% of the population.[8] Atrial fibrillation and atrial flutter resulted in 112,000 deaths in 2013, up from 29,000 in 1990.[9] Sudden cardiac death is the cause of about half of deaths due to cardiovascular disease or about 15% of all deaths globally.[10] About 80% of sudden cardiac death is the result of ventricular arrhythmias.[10] Arrhythmias may occur at any age but are more common among older people.[4] Arrhythmia may be classified by rate (tachycardia, bradycardia), mechanism (automaticity, re-entry, triggered) or duration (isolated premature beats; couplets; runs, that is 3 or more beats; non-sustained= less than 30 seconds or sustained= over 30 seconds). Continue reading →

Cardiac arrestSynonymsCardiopulmonary arrest, circulatory arrest, sudden cardiac arrest (SCA), sudden cardiac death (SCD)[1]CPR being administered during a simulation of cardiac arrest.SpecialtyCardiologySymptomsLoss of consciousness, abnormal or no breathing[1][2]Usual onsetOlder age[3]CausesCoronary artery disease, major blood loss, lack of oxygen, very low potassium, heart failure[4]Diagnostic methodFinding no pulse[1]PreventionNot smoking, physical activity, maintaining a healthy weight[5]TreatmentCardiopulmonary resuscitation (CPR), defibrillation[6]PrognosisAverage survival 8%[7]Frequency13 per 10,000 people per year (outside hospital in the US)[8] Cardiac arrest is a sudden loss of blood flow resulting from the failure of the heart to effectively pump.[9] Symptoms include loss of consciousness and abnormal or absent breathing.[1][2] Some individuals may experience chest pain, shortness of breath, or nausea before cardiac arrest.[2] If not treated within minutes, it typically leads to death.[9] The most common cause of cardiac arrest is coronary artery disease.[4] Less common causes include major blood loss, lack of oxygen, very low potassium, heart failure, and intense physical exercise.[4] A number of inherited disorders may also increase the risk including long QT syndrome.[4] The initial heart rhythm is most often ventricular fibrillation.[4] The diagnosis is confirmed by finding no pulse.[1] While a cardiac arrest may be caused by heart attack or heart failure, these are not the same.[9] Prevention includes not smoking, physical activity, and maintaining a healthy weight.[5] Treatment for cardiac arrest includes immediate cardiopulmonary resuscitation (CPR) and, if a shockable rhythm is present, defibrillation.[6] Among those who survive, targeted temperature management may improve outcomes.[10][11] An implantable cardiac defibrillator may be placed to reduce the chance of death from recurrence.[5] In the United States, cardiac arrest outside hospital occurs in about 13 per 10,000 people per year (326,000 cases).[8] In hospital cardiac arrest occurs in an additional 209,000.[8] Cardiac arrest becomes more common with age.[3] It affects males more often than females.[3] The percentage of people who survive with treatment is about 8%.[7] Many who survive have significant disability.[7] However, many American television programs have portrayed unrealistically high survival rates of 67%.[7] Cardiac arrest is preceded by no warning symptoms in approximately 50 percent of people.[12] For those who do experience symptoms, they will be non-specific, such as new or worsening chest pain, fatigue, blackouts, dizziness, shortness of breath, weakness and vomiting.[13] When cardiac arrest occurs, the most obvious sign of its occurrence will be the lack of a palpable pulse in the victim. Continue reading →

Introduction to Arrhythmia An irregular heartbeat is an arrhythmia (also called dysrhythmia). Continue reading →