Chapter 62. Catheter Ablation

• • Treatment of supraventricular tachycardia (SVT).

  • • Life-threatening arrhythmia unresponsive to medications.

    • Younger children with arrhythmia refractory to antiarrhythmic medications.

    • Older children with recurrent SVT.

    • Older children with SVT associated with preexcitation.

  • Treatment of ventricular tachycardia.

  • • Younger children with life-threatening ventricular tachycardia refractory to medications.

    • Older children with recurrent ventricular tachycardia refractory to medications.

    • Older children with recurrent ventricular tachycardia who are unable to tolerate medications due to side effects, or who choose to have procedure.

Absolute

• • Lack of vascular access.

Relative

• • Infants with arrhythmia controlled by medications.

  • Patients with multiorgan system disease.

  • Patients with hemodynamic instability unable to tolerate procedure or anesthesia.

• • Cardiac catheterization laboratory.

  • Biplane fluoroscopy.

  • Monitoring for continuous heart rate, blood pressure, oxygen saturation.

  • Respiratory monitoring and support.

  • Vascular access.

  • Anesthesia.

  • Resuscitation equipment, including medications and cardiac defibrillator.

  • Electrode catheters, ablation catheters, energy delivery generator.

• • Hemodynamically unstable arrhythmias.

  • Bleeding.

  • Infection.

  • Vascular injury, including coronary artery damage.

  • Pneumothorax.

  • Cardiac perforation.

  • Thromboembolism.

  • Stroke.

  • Radiation exposure.

  • Cardiac valve injury.

  • Conduction system injury, including complete heart block; may necessitate implantation of permanent pacemaker.

  • Risk of injuring the normal conduction system is highest for right septal ablation sites.

  • Cardiac arrest.

• • Not all arrhythmias are amenable to catheter ablation.

  • Highest success rates are for SVT due to accessory connections or for atrioventricular nodal reentry tachycardia.

  • Automatic atrial tachycardias, especially due to a single automatic focus, are amenable to ablation, with slightly lower success rates than above.

  • Ablation of ventricular tachycardias: Lower success rate than SVT.

  • Primary electrical disorders, such as long QT syndrome, are not amenable to catheter ablation.

  • Availability of noncontact mapping systems and “global positioning” systems reduces fluoroscopy time.

  • Neonatal SVT often improves substantially during first 18 months of life and frequently recurs later, such as ages 5–8 and 10–13 years.

  • Delaying intervention until child is older and larger may be indicated.

• • Patient should not have any oral intake for at least 4 hours before the study.

  • Antiarrhythmic medications are generally withdrawn for at least 5 half-lives prior to ablation.

  • 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.

• • Accessory connections...