II. Indications
-
Atrial Tachycardia
- Ablation indicated in symptomatic Atrial Tachycardia refractory to medical therapy (e.g. Beta Blocker)
- Also indicated in Tachycardia-mediated Cardiomyopathy
- Atrioventricular Nodal Reentrant Tachycardia (AVNRT)
- Ablation indicated in most AVNRT cases (Most common indication for catheter ablation)
-
Atrioventricular Reciprocating Tachycardia (AVRT)
- Includes Wolff-Parkinson-White Syndrome (WPW)
- Ablation indicated in episodic Tachycardia and signs of accessory pathway conduction (delta wave)
-
Atrial Flutter
- Ablation indicated in most cases of Atrial Flutter
-
Atrial Fibrillation and very symptomatic (esp. in young patients)
- Ablation indicated in normal left atrial size and symptomatic and refractory Atrial Fibrillation
III. Contraindications: Atrial Fibrillation Ablation
- Ejection fraction <35%
- Left atrial size >5.5 cm
- Mechanical Mitral Valve
- Age over 75 years old
IV. Efficacy
-
Atrial Tachycardia
- Success rate: 86 to 100%
- Complication rate: 8% or less
- Atrioventricular Nodal Reentrant Tachycardia (AVNRT)
- Success rate: 96%
- Complication rate: 1% or less
-
Atrioventricular Reciprocating Tachycardia (AVRT)
- Success rate: 95%
- Complication rate: 2 to 4%
-
Atrial Flutter
- Higher efficacy and lower complication rate than Atrial Fibrillation Ablation
- Success rate: 88-100%
- Complication rate: 2.5 to 3.5%
-
Atrial Fibrillation
- Lower efficacy and higher complication rate than Atrial Flutter Ablation
- Best success is with normal left atrial size and paroxysmal Atrial Fibrillation
- Ablation is preferred for WPW and Atrial Fibrillation
- Success rate: 60-80%
- Complication rate: 6-10%
V. Complications
-
General risks (applies to all ablation procedures)
- Radiation exposure (fluoroscopy): 1.4 mSV to 50 mSv depending on length of procedure
- Electrophysiology study alone: 3.2 mSv
- Atrial Tachycardia Ablation: 4.4 mSv
- Atrioventricular nodal reentrant Tachycardia (AVNRT) ablation: 4.8 mSv
- Atrial Flutter Ablation: 12.1 mSv
- Atrioventricular Reciprocating Tachycardia (AVRT) ablation: 12.8 mSv
- Atrial Fibrillation Ablation: 16.6 mSv
- Cardiac perforation with tamponade
- Due to myocardial perforation by guidewire, dilator or thermal energy
- Occurs in up to 0.2 to 5% of patients
- Typically occurs during procedure or prior to hospital discharge
- However, presentation may be delayed as long as 2 weeks after procedure
- Obtain Bedside Ultrasound
- Maintain high index of suspicion in cardiopulmonary symptoms (e.g. Dyspnea) after ablation
- Atrial Perforation (esp. with Atrioesophageal fistula)
- Rare (<0.25% of cases)
- Complications
- Atrioesophageal fistula
- Esophageal Perforation
- Presentations at 1 to 6 weeks after ablation (mean 2 weeks)
- Fever
- Chest Pain
- Dyspnea
- Nausea or Vomiting
- Odynophagia
- Hematemesis or melana
- Air emboli resulting in neurologic deficits
- Evaluation
- CT Chest with contrast
- Avoid endoscopy (risk of air emboli)
- Complete atrioventricular nodal block (complete Heart Block)
- Requires emergent Pacemaker placement
- Pneumothorax
- Rare complication (typical access is via femoral vein)
- Femoral Vein access complications
- Myocardial Infarction
- Rare with ablation and Troponin Is not typically recommended unless ischemic EKG
- Single Troponin Is more likely to be falsely positive due to the ablation Thermal Injury
- Esophagitis
- Occurs in up to 20% of cases
- Esophagus lies behind left atrium and is susceptible to Thermal Injury
- Radiation exposure (fluoroscopy): 1.4 mSV to 50 mSv depending on length of procedure
-
Atrial Flutter
- Ablation is at isthmus in right atrium and is a lower risk procedure
- Thromboembolic events
- Myocardial Infarction
-
Atrial Fibrillation
- Ablation site is high risk due to proximity of major structures
- Recurrent Atrial Fibrillation (repeat procedure required in up to 20% of cases)
- Complications (as high as 6% complication rate)
- Pulmonary vein stenosis
- Cerebrovascular Accident
- Cardiac perforation
- Atrial-esophageal fistula (rare)
- Thromboembolic events
VI. Technique
- Typical Catheter Ablation Procedure
- Ablation probe applied in same pattern as MAZE procedure
- Ablation circumferentially around each set of pulmonary veins
- Also ablate a line between the two pulmonary veins within the left atrium
- Ablation circumferentially around superior and inferior vena cava entry within the right atrium
- Other procedures: AV Nodal ablation with Pacemaker placement indications
- Older patients with Tachycardia induced Cardiomyopathy
- Refractory rapid ventricular rate despite maximal medical therapy
-
Anticoagulation
- Anticoagulation for one month before and several months after ablation
VII. Protocol: Refractory and symptomatic Atrial Fibrillation despite maximal therapy
-
AV Node Ablation with Pacemaker placement
- Last resort method that is rarely indicated
- Ozcan (2001) N Engl J Med 344:1043-51 [PubMed]
VIII. References
- Demeester and Swaminathan in Swadron (2022) EM:Rap 22(1): 15-6
- Gutierrez (2017) Am Fam Physician 83(1): 61-8 [PubMed]
- Scheinman (2003) Pacing Clin Electrophysiol 26(3): 789-99 [PubMed]
- Shapira (2009) Am Fam Physician 80(10): 1089-94 [PubMed]