Jack M. Rogers

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Endocardial mapping has suggested that Purkinje fibers may play a role in the maintenance of long-duration ventricular fibrillation (LDVF). To determine the influence of Purkinje fibers on LDVF, we chemically ablated the Purkinje system with Lugol solution and recorded endocardial and transmural activation during LDVF. Dog hearts were isolated and perfused,(More)
We developed a new method for fabricating plunge needle electrodes for use in cardiac mapping. The needles have 12 electrodes with 1-mm spacing, are 0.5 mm in diameter, and are fabricated from fiberglass reinforced epoxy. They are stiff enough to be easily inserted into beating hearts and durable enough to be reused many times. We found that these new(More)
Optical mapping of electrical activity from the surface of the heart is a powerful tool for studying complex arrhythmias. However, a limitation of traditional optical mapping is that the mapped region is restricted to the field of view of the sensor, which makes it difficult to track electrical waves as they drift in and out of view. To address this, we(More)
Functional reentry has been hypothesized to be an underlying mechanism of ventricular fibrillation (VF); however, its contribution to activation patterns during fully developed VF is unclear. We applied new quantitative pattern analysis techniques to mapping data acquired from a 21 x 24 unipolar electrode array (2-mm spacing) located on the ventricular(More)
We tested whether the interventions typically required for optical mapping affect activation patterns during ventricular fibrillation (VF). A 21 x 24 unipolar electrode array (1.5 mm spacing) was sutured to the left ventricular epicardium of 16 anesthetized pigs, and four episodes of electrically induced VF (30-s duration) were recorded. The hearts were(More)
Much of the research into the mechanisms of ventricular fibrillation (VF) employs high-resolution mapping of electrical activation and recovery patterns. We previously developed a method for analyzing electrically mapped VF patterns that was based on identifying individual VF wavefronts. We now introduce a related method designed to take into account the(More)
During ventricular fibrillation (VF), electrical activation waves are fragmented, and the heart cannot contract in synchrony. It has been proposed that VF waves emanate from stable periodic sources (often called "mother rotors"). The objective of the present study was to determine if stable rotors are consistently present on the epicardial surface of hearts(More)
It has been hypothesized that during ventricular fibrillation (VF), the fastest activating region, the dominant domain, contains a stable reentrant circuit called a mother rotor. This hypothesis postulates that the mother rotor spawns wavefronts that propagate to maintain VF elsewhere and implies that the ratio of wavefronts propagating off a region to(More)
Action potential propagation simulations with physiologic membrane currents and macroscopic tissue dimensions are computationally expensive. We, therefore, analyzed distributed computing schemes to reduce execution time in workstation clusters by parallelizing solutions with message passing. Four schemes were considered in two-dimensional monodomain(More)