Synchronized electrical cardioversion is the process by which an abnormally fast heart rate or cardiac arrhythmia is terminated by the delivery of a therapeutic dose of electrical current to the heart at a specific moment in the cardiac cycle. Measuring heart rate The Pulse rate (which in most people is identical to the heart rate can be measured at any point on the body where an Artery 's pulsation Dysrhythmia redirects here For the American band see Dysrhythmia (band. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic Cardiac cycle is the term referring to all or any of the events related to the flow of blood that occur from the beginning of one heartbeat to the beginning of the next
Pharmacologic cardioversion uses medication instead of an electrical shock to convert the cardiac arrhythmia. Dysrhythmia redirects here For the American band see Dysrhythmia (band.
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Synchronized electrical cardioversion
To perform synchronized electrical cardioversion two electrode pads are used, each comprising a metallic plate which is faced with a saline based conductive gel. An electrode is an Electrical conductor used to make contact with a nonmetallic part of a circuit (e The pads are placed on the chest of the patient, or one is placed on the chest and one on the back. These are connected by cables to a machine which has the combined functions of an ECG display screen and the electrical function of a defibrillator. Defibrillation is the definitive treatment for the life-threatening Cardiac arrhythmias Ventricular fibrillation and Ventricular tachycardia. A synchronizing function (either manually operated or automatic) allows the cardioverter to deliver a reversion shock, by way of the pads, of a selected amount of electrical current over a predefined number of milliseconds at the optimal moment in the cardiac cycle which corresponds to the R wave of the QRS complex on the ECG. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. A millisecond (from Milli- and Second; abbreviation ms is one thousandth of a Second. Cardiac cycle is the term referring to all or any of the events related to the flow of blood that occur from the beginning of one heartbeat to the beginning of the next Timing the shock to the R wave prevents the delivery of the shock during the vulnerable period (or relative refractory period) of the cardiac cycle, which could induce ventricular fibrillation. Cardiac cycle is the term referring to all or any of the events related to the flow of blood that occur from the beginning of one heartbeat to the beginning of the next Ventricular fibrillation ( V-fib or VF) is a condition in which there is uncoordinated contraction of the Cardiac muscle of the ventricles in the If the patient is conscious, various drugs are often used to help sedate the patient and make the procedure more tolerable. However, if the patient is haemodynamically unstable or unconscious, the shock is given immediately upon confirmation of the arrhythmia. Dysrhythmia redirects here For the American band see Dysrhythmia (band. When synchronized electrical cardioversion is performed as an elective procedure, the shocks can be performed in conjunction with drug therapy until sinus rhythm is attained. Sinus rhythm is a term used in medicine to describe the normal beating of the heart as measured by an Electrocardiogram ( ECG) Multiple electrical shocks may cause burns of the epidermis at the pad sites. Epidermis is the outermost layer of the Skin. It forms the waterproof protective wrap over the body's surface and is made up of stratified squamous Epithelium with After the procedure, the patient is monitored to ensure stability of the sinus rhythm.
Synchronized electrical cardioversion is used to treat hemodynamically significant supraventricular (or narrow complex) tachycardias, including atrial fibrillation and atrial flutter. Atrial fibrillation ( AF or afib) is a Cardiac arrhythmia (abnormal heart rhythm that involves the two upper chambers ( atria) of the Heart Atrial flutter is an abnormal heart rhythm that occurs in the atria of the Heart. It is also used in the emergent treatment of wide complex tachycardias, including ventricular tachycardia, when a pulse is present. Ventricular tachycardia ( V-tach or VT) is a Tachycardia, or fast heart rhythm that originates in one of the ventricles of the Heart Pulseless ventricular tachycardia and ventricular fibrillation are treated with unsynchronized shocks referred to as defibrillation. Ventricular tachycardia ( V-tach or VT) is a Tachycardia, or fast heart rhythm that originates in one of the ventricles of the Heart Ventricular fibrillation ( V-fib or VF) is a condition in which there is uncoordinated contraction of the Cardiac muscle of the ventricles in the Defibrillation is the definitive treatment for the life-threatening Cardiac arrhythmias Ventricular fibrillation and Ventricular tachycardia. Electrical therapy is inappropriate for sinus tachycardia, which should always be a part of the differential diagnosis. Sinus Tachycardia (also colloquially known as sinus tach or sinus tachy) is a rhythm with elevated rate of impulses originating from the Sinoatrial A differential diagnosis (sometimes abbreviated DDx, ddx
Pharmacologic cardioversion
Various antiarrhythmic agents can be used to return the heart to normal sinus rhythm. Antiarrhythmic agents are a group of Pharmaceuticals that are used to suppress fast rhythms of the Heart ( Cardiac arrhythmias) such as Atrial fibrillation Sinus rhythm is a term used in medicine to describe the normal beating of the heart as measured by an Electrocardiogram ( ECG) Pharmacological cardioversion is an especially good option in patients with fibrillation of recent onset. Drugs that are effective at maintaining normal rhythm after electric cardioversion, can also be used for pharmacological cardioversion. Drugs like amiodarone, cardizem, and metoprolol are frequently given before cardioversion to decrease the heart rate, stabilize the patient and increase the chance that cardioversion is successful. Amiodarone is an Antiarrhythmic agent (medication used for irregular heart beat used for various types of tachyarrhythmias (fast forms of irregular heart beat both ventricular Diltiazem is a member of the group of drugs known as Benzothiazepines which are a class of Calcium channel blockers used in the treatment of Hypertension Metoprolol is a selective β1 receptor blocker used in treatment of several diseases of thecardiovascular system especially Hypertension. There are two classes of agents that are most effective for pharmacological cardioversion.
Class I agents: Procainamine, quinidine and disopyramide are Class Ia agents, while flecainide and propafenon are Class Ic agents.
Class III agents: Amiodarone and sotalol are effective Class III agents.
If the patient is stable, Adenosine may be administered first, as the medicine performs a sort of "chemical cardioversion" and may stabilize the heart and let it resume normal function on its own without using electricity. Adenosine is a Nucleoside composed of a Molecule of Adenine attached to a Ribose sugar molecule ( Ribofuranose) moiety via a β-N9-
See also
External links
- Cardioversion from the National Institutes of Health
- Pharmacological Cardioversion from the American Academy of Family Physicians
- Synchronized Electrical Cardioversion from eMedicine Online
- Cardioversion from the Heart Rhythm Society
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