Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + • Evaluation of tachycardia mechanism, in preparation for catheter ablation procedure.• Evaluation of wide QRS tachycardia, where ECG interpretation does not clarify mechanism of tachycardia.• Evaluation of sudden cardiac arrest.• Evaluation of unexplained syncope.• Risk stratification for risk of cardiac arrest in patients with repaired congenital heart disease.• Evaluation of conduction system, or risk of tachycardia, particularly prior to surgery for congenital heart disease. + • Lack of vascular access. + • Cardiac catheterization laboratory; nursing and technical support staff.• Biplane fluoroscopy.• Electrode catheters, usually multiple, with recording equipment.• Sedation and intravenous access as necessary.• Cardiac defibrillator.• Resuscitation medications. + • Vascular injury, peripheral or coronary.• Bleeding.• Infection.• Pneumothorax.• Cardiac perforation.• Thromboembolism.• Initiation of hemodynamically unstable arrhythmia, or conversion of one mechanism of tachycardia into another tachycardia.• Arrhythmias may require direct current cardioversion or defibrillation.• Radiation exposure.• Risk of death: < 0.5%. + • Invasive electrophysiology studies are performed prior to virtually all ablation procedures.• Patients with unexplained cardiac arrest, particularly with congenital heart disease, may undergo electrophysiologic studies to identify cause and direct therapy.• In the setting of structural heart disease, electrophysiologic studies may help identify patients at increased risk of sudden cardiac arrest, such as patients with repaired tetralogy of Fallot.• Patients with cardiac ion channelopathies, such as long QT syndrome, do not generally undergo invasive electrophysiology studies. + • Patient should not have any oral intake for at least 4 hours before the study.• Sedation is administered; general anesthesia is often preferred for lengthy procedures or for younger patients.• Intravenous access is necessary, usually femoral venous, often bilaterally and multiple, in addition to internal jugular or subclavian venous access. + • Supine, with protection of airway.• Arms are positioned at sides for long procedures, to avoid potential brachial plexus injury.• Adequate padding to avoid pressure injury is needed for extremities and head.• Shielding of gonads from radiation is necessary. + • Catheters are positioned in atria, at atrioventricular nodal region, and in right ventricular apex for basic procedures.• Additional catheters are positioned in coronary sinus, coursing posteriorly to mitral valve, to record left atrial activation.• Left ventricular or esophageal recordings may be added. + • Using sterile preparation with Seldinger percutaneous entry technique into veins or an artery, electrode catheters are advanced to the heart through vascular sheaths, and positioned using fluoroscopy.• Catheters are connected to recording equipment and filter box to allow electrogram display and recording; real-time and review mode of tracings available.• Catheter positioning is optimized based on size of electrograms recorded, pacing capture thresholds, and anatomic positioning.• For diagnostic purposes, pacing may initiate reentrant cardiac arrhythmias, allowing interpretation of mechanism of tachycardia.• Mapping may be performed to precisely localize critical part of tachycardia circuit, or origin of automatic arrhythmia; performed in ... Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth