Safety and efficacy aspects of pulsed field ablation catheters as a function of electrode proximity to blood and energy delivery method.

Background: Pulsed field ablation (PFA) is a promising technology based on electroporation. It is unclear if different catheter designs imply efficacy and safety differences.

Objective: To vary geometry, blood exposure, and energy delivery methods among 3 representative catheter designs, and then compare lesion transmurality, extra-atrial safety, and embolic risk.

Determinants of Subcutaneous Implantable Cardioverter-Defibrillator Efficacy: A Computer Modeling Study.

Objectives: This study determined the impact of subcutaneous implantable cardioverter-defibrillator (S-ICD) coil and generator position on defibrillation threshold (DFT).

Background: S-ICD implantation can occasionally result in unacceptably high DFT. Implant position characteristics associated with high DFTs in S-ICD patients have not been fully elucidated.

Subcutaneous bioimpedance recording: assessment of a method for hemodynamic monitoring by implanted devices.

Background: Diagnostic evaluation of patients with suspected symptomatic arrhythmias is limited by inability to assess the hemodynamic impact of a detected rhythm.

Objective: To address this limitation, we utilized closely spaced subcutaneous electrodes, small enough to incorporate within an implantable monitor, to detect blood flow-induced pectoral muscle bioimpedance (Z) changes in a swine model of hemorrhage-induced hypotension.

Methods: In seven anesthetized and ventilated adult pigs, small ring electrodes (current electrodes 5 cm apart; voltage electrodes 3.

Cardiac resynchronization therapy optimization by finger plethysmography.

Objectives: We tested a simple noninvasive method for cardiac resynchronization therapy (CRT) optimization using standard finger photoplethysmography (FPPG).

Background: CRT can increase left ventricular cardiac output in patients with heart failure and ventricular conduction delay. Optimal therapy delivery depends on an appropriate AV delay.

Monitoring lung edema using the pacemaker pulse and skin electrodes.

Previous clinical studies have shown that impedance measurements using right ventricular (RV) leads can monitor congestion due to heart failure. We previously reported on a three-fold advantage of bipolar left ventricular (LV) leads, which are near the lung, over RV leads in detecting pulmonary edema with impedance. A combined system of internal and external electrodes is now investigated using computer models, for use with conventional cardiac resynchronization (CRT) systems with unipolar LV leads.

Determinants of radial artery pulse wave analysis in asymptomatic individuals.

Background: Noninvasive techniques to evaluate arterial stiffness include noninvasive radial artery pulse contour analysis. Diastolic pulse contour analysis provides a separate assessment of large (C1) and small artery (C2) elasticity. Analysis of the systolic pulse contour identifies two pressure peaks (P1 and P2) that relate to incident and reflected waves.

Improved lung edema monitoring with coronary vein pacing leads: a simulation study.

This computer simulation study compared the ability of left ventricular coronary vein (LV) pacemaker leads against right ventricular (RV) and right atrial (RA) leads to monitor lung edema using electrical impedance measurements. MRI images were used to construct electrical models of the thorax. Four lead configurations were tested with increases of pulmonary edema, intravascular fluids and heart dilation.