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Predictors of automatic implantable cardioverter defibrillator discharge for life-threatening ventricular arrhythmias
P A Kelly1, D S Cannom, H Garan
1Cardiac Unit, Massachusetts General Hospital, Boston, Massachusetts 02114.
Insights
Electrophysiology studies predict automatic implantable cardioverter defibrillator (AICD) discharge in patients with ventricular arrhythmias. Inducing sustained arrhythmias with few stimuli during electrophysiology testing indicates a high risk of appropriate AICD discharge.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Life-threatening ventricular arrhythmias pose a significant risk to patients.
- Automatic implantable cardioverter defibrillators (AICDs) are crucial for managing these arrhythmias.
- Predicting AICD discharge is essential for patient management and device programming.
Purpose of the Study:
- To identify clinical, angiographic, and electrophysiologic predictors of appropriate AICD discharge.
- To determine the independent predictive value of electrophysiologic variables for AICD discharge.
Main Methods:
- Analysis of data from 100 patients with ventricular arrhythmias and AICDs.
- Prospective follow-up for a median of 18 months.
- Electrophysiology studies performed both off and on antiarrhythmic drugs.
Main Results:
- 45% of patients experienced appropriate AICD discharge.
- Univariate predictors included depressed left ventricular ejection fraction and inducible sustained ventricular arrhythmias.
- Multivariate analysis identified induction of sustained ventricular arrhythmia with 1-2 extrastimuli during electrophysiology study on the discharge regimen as the sole independent predictor (p < 0.0001).
- Patients with inducible arrhythmias using 1-2 extrastimuli had an 86% probability of appropriate AICD discharge at 18 months.
Conclusions:
- Electrophysiology study findings, particularly the ease of inducing sustained ventricular arrhythmias, are highly predictive of appropriate AICD discharge.
- The number of extrastimuli required to induce arrhythmia during electrophysiology testing is a critical factor in risk stratification.
- These findings can aid in optimizing AICD programming and patient management strategies.
Abstract:
Data from 100 patients with life-threatening ventricular arrhythmias and automatic implantable cardioverter defibrillators (AICDs) were analyzed to determine if clinical, angiographic and electrophysiologic variables are predictive of AICD discharge. During a median follow-up period of 18 months, 45% of patients experienced greater than or equal to 1 device discharge during a documented ventricular arrhythmia or in association with presyncope or syncope ("appropriate" AICD discharge). Univariate predictors of appropriate AICD discharge included depressed left ventricular ejection fraction (p = 0.0007), inducible sustained ventricular arrhythmia at electrophysiologic study performed in the absence of antiarrhythmic drugs (p = 0.009), fewer number of extrastimuli required for induction at this study (p = 0.001), inducible sustained arrhythmia at electrophysiologic study performed on the discharge antiarrhythmic regimen (p = 0.0005) and fewer extrastimuli required for this induction (p less than 0.0001). Multivariate analysis identified the induction of a sustained ventricular arrhythmia by 1 or 2 extrastimuli during electrophysiologic study performed on the discharge regimen as the only independent predictor among the variables analyzed (p less than 0.0001). The probability of appropriate AICD discharge at 18 months was 86% for patients who had a sustained arrhythmia induced with 1 or 2 extrastimuli versus 15% for those requiring 3 extrastimuli for arrhythmia induction and 13% for patients without inducible sustained arrhythmias.