Improved implantable cardioverter-defibrillator shock efficacy using programmable pulse width.

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Devices

Background:

• Implantable cardioverter-defibrillator (ICD) shock waveforms are defined by tilt or pulse width.
• Current ICD programming often relies on fixed tilt, but fixed pulse width may enhance shock efficacy.
• Optimizing ICD shock waveforms is crucial for successful treatment of life-threatening arrhythmias.

Purpose of the Study:

• To compare shock energies and success rates between fixed pulse width and fixed tilt waveforms.
• To evaluate the efficacy of different ICD/CRT-D shock waveform programming strategies for spontaneous ventricular tachycardia/fibrillation (VT/VF).

Main Methods:

• Retrospective analysis of US patients with single-coil ICD/CRT-D devices who received shock therapy.
• Comparison of shock success rates and energies when devices were programmed to both 65% fixed tilt and fixed pulse width modes.
• Data extracted from the Merlin.net patient remote care network for patient demographics, programming, and shock episodes.

Main Results:

• Fixed pulse width significantly increased first-shock success rates compared to fixed tilt (100.0% vs. 87.5%, P<0.001).
• A higher percentage of patients achieved 100% first-shock success with fixed pulse width (69.3% vs. 46.2%, P<0.001).
• Comparable shock energies were delivered between the two waveform types (33.0 J vs. 32.9 J, P=0.53).

Conclusions:

• Reprogramming ICD shock waveforms from fixed tilt to fixed pulse width significantly improves intra-patient shock success.
• Fixed pulse width represents a superior programming strategy for enhancing defibrillation efficacy in ICD/CRT-D devices.