Long-term arrhythmia variability after monomorphic ventricular tachycardia in patients with an implantable...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Patients receiving an implantable cardioverter-defibrillator (ICD) for monomorphic ventricular tachycardia (mVT) exhibit a higher arrhythmia burden compared to other indications.
• Understanding the long-term arrhythmia profile in this specific patient group is crucial for optimizing device therapy.

Purpose of the Study:

• To investigate the long-term arrhythmia characteristics in patients with an ICD implanted for mVT.
• To assess the variability in tachycardia cycle lengths (CLs) and morphologies.
• To evaluate the impact of multiple mVT morphologies on antitachycardia pacing (ATP) efficacy and shock burden.

Main Methods:

• Follow-up of 52 patients with ICDs implanted for mVT for at least 3 months.
• Analysis of tachycardia cycle lengths (CLs) and intracardiac electrogram morphologies from device memory.
• Assessment of the response to antitachycardia pacing (ATP) for different mVT episodes.

Main Results:

• A total of 833 mVT episodes were analyzed in 41 patients.
• Fifty percent of patients (26/52) exhibited mVTs with cycle lengths different from the index mVT.
• Over half of patients (28/52) presented with at least two distinct mVT morphologies, which correlated with reduced ATP efficacy and increased shock burden.

Conclusions:

• Patients with ICDs for mVT experience a significant arrhythmia burden with considerable variability in cycle length and morphology.
• The presence of multiple mVT morphologies during follow-up is a significant predictor of decreased ATP efficacy and increased reliance on ICD shocks.