BACKGROUND Much of the research performed studying the mechanism of ventricular fibrillation (VF) has been in normal ventricles rather than under a pathological condition predisposing to VF. We hypothesized that different ventricular substrates would alter the mechanism and characteristics of VF. METHODS AND RESULTS Three groups of dogs were studied: (1) control (n=8), (2) pacing-induced cong...

In this paper, the effect of a static synchronous compensator (STATCOM) influence on the frequency of islanded microgrids based on frequency control using fuzzy cooperative control is investigated. To achieve fast frequency control, instantaneous power balance between generation and consumption is inevitable, and it can be supplied through energy storage systems such as battery with a proper fr...

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 then rapidly excised and connected to a L...

Changes in ventricular fibrillation (VF) organization occurring after the onset of global ischemia are relevant to defibrillation and survival but remain poorly understood. We hypothesized that ischemia-specific dynamic instability of the action potential (AP) causes a loss of spatiotemporal periodicity of propagation and broadening of the electrocardiogram (ECG) frequency spectrum during VF in...

Partial discharges are localized electric discharges that do not bridge the electrodes. For high voltage components measurements of partial discharges are commonly used to diagnose the condition of the insulation system. Traditionally partial discharges are measured at a single frequency of the applied voltage. However the rather newly developed technique of Variable Frequency Phase Resolved Pa...

Normal “master–slave” relationship between the action potential (AP) and intracellular Ca transient (CaiT) is sometimes altered during ventricular fibrillation (VF). The nature of AP/CaiT dissociation during VF and its role in inducing wavebreaks (WBs) remain unclear. We simultaneously mapped AP (RH237) and CaiT (Rhod-2) during VF in blood-perfused pig hearts. We computed AP and CaiT dominant f...