From the Guidelines
The appropriate monitoring protocol after alcohol septal ablation involves close observation in a cardiac intensive care unit for at least 24 hours post-procedure, with continuous cardiac monitoring to detect potential complications such as complete heart block, which occurs in 15% to 50% of patients 1.
Monitoring Protocol
The monitoring protocol should include:
- Continuous cardiac monitoring for at least 24 hours post-procedure to detect potential complications such as complete heart block
- Daily electrocardiograms to assess for conduction abnormalities
- Cardiac biomarkers (troponin, CK-MB) should be measured at baseline and every 8-12 hours for the first 24-48 hours to quantify the extent of the induced infarct
- Echocardiography should be performed within 24 hours post-procedure and again prior to discharge to assess septal thickness, left ventricular outflow tract gradient reduction, and to rule out complications such as ventricular septal defects or mitral regurgitation
Post-Discharge Follow-Up
After discharge, patients should be evaluated at 1,3,6, and 12 months with:
- Clinical assessment
- ECG
- Echocardiography Long-term annual follow-up is recommended to monitor for potential late complications and to assess the durability of gradient reduction.
Medications
Patients should continue their pre-procedure medications for hypertrophic cardiomyopathy, typically including beta-blockers or calcium channel blockers, with dosages adjusted based on symptoms and hemodynamic response.
Antiplatelet Therapy
Antiplatelet therapy with aspirin 81-325 mg daily is typically recommended for at least 3-6 months post-procedure. This comprehensive monitoring approach is necessary because the full hemodynamic benefits of alcohol septal ablation may take 3-6 months to manifest as remodeling occurs, and complications can develop both immediately and in the months following the procedure, as noted in the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1.
From the Research
Monitoring Protocol After Alcohol Septal Ablation
To monitor post alcohol septal ablation, the following protocols can be considered:
- Continuous implantable cardiac monitoring (ICM) to capture clinically actionable arrhythmic events, including atrial fibrillation and complete heart block 2
- Holter ECG monitoring to detect ventricular arrhythmias and other heart rhythm disturbances 3
- Implantable loop recorder or pacemaker to monitor for sustained ventricular tachycardia or ventricular fibrillation 4
- Echocardiography and cardiovascular magnetic resonance imaging to assess segmental thickness and predict outcomes after alcohol septal ablation 5
Key Considerations
When monitoring patients after alcohol septal ablation, the following key considerations should be taken into account:
- The risk of arrhythmic events, including complete heart block and atrial and ventricular arrhythmias, is high in the first 3 months after the procedure 2
- The incidence of sustained ventricular tachycardia or ventricular fibrillation is low, but can occur within 30 days after the procedure 4
- The procedure can reduce the risk of sudden cardiac death and the number of risk factors for sudden cardiac death 6
- Patient selection is crucial, and non-invasive tools such as echocardiography and cardiovascular magnetic resonance imaging can be used to select patients who are likely to benefit from the procedure 5
Arrhythmic Events
The following arrhythmic events can occur after alcohol septal ablation:
- Atrial fibrillation: the cumulative rate of ICM-detected first atrial fibrillation event at 18 months was 37% 2
- Complete heart block: the cumulative rate of ICM-detected complete heart block at 18 months was 19% 2
- Ventricular arrhythmias: sustained ventricular tachycardia or ventricular fibrillation can occur within 30 days after the procedure, but the incidence is low 4