Changes in cerebral perfusion during third-generation implantable cardioverter defibrillator testing

Area of Science:

• Cardiology
• Neuroscience
• Biomedical Engineering

Background:

• Implantable cardioverter-defibrillators (ICDs) offer tiered therapy for ventricular arrhythmias.
• Current ICD programming lacks consideration for hemodynamic effects of dysrhythmias.
• Intelligent ICDs require assessment of hemodynamic consequences and end-organ perfusion.

Purpose of the Study:

• To evaluate quantitative electroencephalography (QEEG) and transcranial Doppler (TCD) for measuring cerebral perfusion during ICD testing.
• To determine if QEEG and TCD can predict tolerance or intolerance to programmed ICD therapy.
• To assess the utility of these techniques for evaluating hemodynamic sensors in future ICDs.

Main Methods:

• QEEG and TCD were used to monitor cerebral perfusion in patients undergoing ICD testing.
• Cerebrovasomotor reactivity (CVR) was assessed during hypotensive episodes and ventricular tachycardia.
• Near-infrared spectroscopy measured transcranial oxyhemoglobin saturation during ventricular tachycardia.

Main Results:

• Impaired CVR and changes in EEG (loss of alpha power, increased delta power) predicted intolerance to ICD therapy in 25/91 hypotensive episodes.
• Intact CVR prevented cerebral ischemia and predicted tolerance to programmed ICD therapy.
• These effects were more pronounced in the erect posture and during ventricular tachycardia.

Conclusions:

• QEEG and TCD are sensitive indicators of cerebral perfusion during ICD testing and programming.
• These techniques can predict patient tolerance to programmed ICD therapy.
• QEEG and TCD can serve as benchmarks for evaluating hemodynamic sensors in next-generation ICDs.