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Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,An Electrophysiologic Overview,Ventricular Tachyarrhythmias,Module Objectives,Ventricular Tachyarrhythmias,Identify the mechanisms for ventricular tachycardias,Differentiate types of ventricular tachycardias using ECG and intracardiac electrogram recordings,Discuss treatment options for ventricular tachycardias,After completion of this module,the participant should be able to:,Module Outline,Ventricular Tachyarrhythmias,Description,Characteristics,Mechanisms,Sustained vs.nonsustained,Premature ventricular contractions,Module Outline,Ventricular Tachyarrhythmias,Classification,Monomorphic,Idiopathic,Description,ECG recognition,Treatment ablation,Bundle branch,Description,ECG recognition,Treatment ablation,Module Outline,Ventricular Tachyarrhythmias,Classifications-continued,Ventricular flutter,ECG recognition,Ventricular fibrillation,ECG recognition,Polymorphic,Torsades de pointes,Description,ECG recognition,Treatment,Summary,Ventricular Tachycardia(VT),Originates in the ventricles,Can be life threatening,Most patients have significant heart disease,Coronary artery disease,A previous myocardial infarction,Cardiomyopathy,Mechanisms of VT,Reentrant,Reentry circuit(fast and slow pathway)is confined to the ventricles and/or bundle branches,Automatic,Automatic focus occurs within the ventricles,Triggered activity,Early afterdepolarizations(phase 3),Delayed afterdepolarizations(phase 4),Reentrant,Reentrant ventricular arrhythmias,Premature ventricular complexes,Idiopathic left ventricular tachycardia,Bundle branch reentry,Ventricular tachycardia and fibrillation when associated with chronic heart disease:,Previous myocardial infarction,Cardiomyopathy,Automatic,Automatic ventricular arrhythmias,Premature ventricular complexes,Ischemic ventricular tachycardia,Ventricular tachycardia and fibrillation when associated with acute medical conditions:,Acute myocardial infarction or ischemia,Electrolyte and acid-base disturbances,hypoxemia,Increased sympathetic tone,Automaticity,Abnormal Acceleration of Phase 4,Fogoros:Electrophysiologic Testing.3,rd,ed.Blackwell Scientific 1999;16.,Triggered,Triggered activity ventricular arrhythmias,Pause-dependent triggered activity,Early afterdepolarization(phase 3),Polymorphic ventricular tachycardia,Catechol-dependent triggered activity,Late afterdepolarizations(phase 4),Idiopathic right ventricular tachycardia,Triggered,Fogoros:Electrophysiologic Testing.3,rd,ed.Blackwell Scientific 1999;158.,Sustained vs.Nonsustained,Sustained VT,Episodes last at least 30 seconds,Commonly seen in adults with prior:,Myocardial infarction,Chronic coronary artery disease,Dilated cardiomyopathy,Non-sustained VT,Episodes last at least 6 beats but 30 seconds,Premature Ventricular Contraction,PVC,Ectopic beat in the ventricle that can occur singly or in clusters,Caused by electrical irritability,Factors influencing electrical irritability,Ischemia,Electrolyte imbalances,Drug intoxication,Classification,Ventricular Tachycardia,Monomorphic,Idiopathic VT,Bundle branch reentry tachycardia,Ventricular flutter,Ventricular fibrillation,Polymorphic,Torsades de pointes(TdP),Monomorphic VTs,Monomorphic VT,Heart rate:100 bpm or greater,Rhythm:Regular,Mechanism,Reentry,Abnormal automaticity,Triggered activity,Recognition,Broad QRS,Stable and uniform beat-to-beat appearance,ECG Recognition,ECG used with permission of Dr.Brian Olshansky.,Intracardiac Recording of VT,EGM used with permission of Texas Cardiac Arrhythmia,P.A.,Idiopathic Right Ventricular Tachycardia,Right ventricular idiopathic VT,Focus originates within the right ventricular outflow tract,Ventricular function is usually normal,Usually LBBB,inferior axis,Treatment options:,Pharmacologic therapy(beta blockers,verapamil),RF ablation,Kay NG.Am J Med 1996;100:344-356.,ECG Recognition,Case History:Idiopathic VT,First episode,9 hours of palpitations,In ER,found to be in wide-complex tachycardia of LBBB,inferior axis,at 205 bpm,Converted with IV lidocaine;placed on tenormin,Second episode,While on tenormin,patient had onset of palpitations at airport,In ER,converted with IV lidocaine,Patient underwent EP study,39 y.o.female with no prior cardiac history,Case History:Idiopathic VT,Case History:Idiopathic VT,At EP study,tachycardia focus was mapped and localized to right ventricular outflow tract,The focus was successfully ablatedusing radiofrequency energy,with no subsequent inducible or clinical VT,Endocardial Activation Mapping,Using an ablation catheter,map the area around and inside of the right ventricular outflow tract,Find the electrograms that precede the onset of the QRS complex during tachycardia,This area identifies the site of earliest activation,and possibly the“site of origin”of the arrhythmia,Pace Mapping,Pace mapping helps to localize the“site of origin”after endocardial mapping has been performed,If the heart is paced from this regi
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