الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
anatomy of the conductive system of the heart including (Sinus Node, Internodal and Intraatrial Conduction, Atrioventricular Junctional Area and Intraventricular Conduction System , Atrioventricular Node, Bundle of His and Terminal Purkinje Fibers)should be known by anaesthetist.
Conductive systems is a specialized tissue initiate and conduct rhythmic depolarization, causing the myocardial cells to contract in an ordered way.Electrical impulse in the heart involves the passage of ions through ionic channels . The sodium , potassium , calcium and chloride ions are the major charge carriers and their movement across the cell membrane creates a flow of current during action potential. Cardiac action potentials varies between non-pacemaker and pacemaker cells and also between cells in different areas of the heart.
The Electrocardiogram ’(ECG) is the primary tool in detection and analysis of cardiac arrhythmias. . It may indicate rate and rhythm, abnormal conduction pathways, myocardial damage and hypertrophy or atrophy of areas of the heart .
ECG is a standard monitor used during anesthesia, for maximum intraoperative ECG data the use of a continuous 12-lead ECG would be ideal. However, at the presents time this is neither feasible nor practical so that three- lead, or five-lead systems are used for intraoperative monitoring. Invasive electrocardiographic monitoring is used for diagnosing complicated arrhythmias, It include (Esophageal and Endotracheal) electrocardiogram.
Arrhythmia is defined as “Abnormality of cardiac rate, rhythm or conduction which can be either lethal (sudden cardiac death), or symptomatic (syncope, near syncope, dizziness, or palpitations) or asymptomatic”. Immediate diagnosis and intervention with appropriate therapy often will prevent conversion of arrhythmia into a life-threatening event.
Pathogenesis of arrhythmia may be due to (Injury to cardiac system, re entery, Automaticity,Mutation of ion channel, Ectopic foci orirritable foci).
There are several contributing factors such as (Patient related factors, Anaesthesia related factors and Surgery related factors).
There are many types of arrhythmia Classified into ;
a)Premature beats b)Bradyarrythmia c ) Tachyarrhythmia
ECG Characteristics,causes and mechanism should be known by anaesthetist.
Most of the available antiarrhythmic drugs can be classified according to whether they exert blocking actions on sodium, potassium, or calcium channels and block beta adrenoreceptors. The commonly used classification is Vaughan Williams classification . which based on the electro-physiological effect of the drug.
Drugs that block slow calcium channel, blocking the slow inward depolarization current e.g. verapamil.
Electrical therapy often be preferred to drug therapy in anesthesia and intensive care setting because many drugs used for treatment of dysrhthmias have the potential for producing adverse heamodynamic instability, or can precipitate new dysrhythmias or aggrevate existing one.
The preoperative period is important to minimize mortality and morbidity in patients undergoing both cardiac and non cardiac surgry.
Preoperative evaluation and assessment of cardiac risk help the anaesthetist to reach the possible causes of arrhythmia and manage it through(clinical presentation and physical examination, assessment of risk and diagnostic investigations).
Routine measures for all intraoperative arrhythmias such as adequate oxygenation , ventilation,Alteration in depth of anaesthesia and assurance optimum PaO , PaCO , acid base, electrolyte and temperature.
The post operative ECG monitoring is mandatory in the first and second days of surgery especially in major operations and high risk patients as (old age, presence of cardiac diseases and preoperative arrhythmia). arrhythmias are often due to non cardiac problems such as (infection, hypotension, hypoxia or metabolic disorders)
Lastly; management of arrhythmias depends on its type(not requiring drug therapy, requiring anti- arrhythmic drugs or cardiac pacing)in the perioperative period.