BACKGROUND Sustained ventricular tachycardia (VT) and fibrillation (VF) occur in up to 20% of patients with acute myocardial infarction (MI) and have been associated with a poor prognosis. The relationships among the type of arrhythmia (VT versus VF or both), time of VT/VF occurrence, use of thrombolytic agents, and eventual outcome are unclear. METHODS AND RESULTS In the GUSTO-I study, we ex...

Although sodium channels have been reported to be inactive after 5-10 minutes of ventricular fibrillation (VF), their state during early VF is unknown. In 12 open-chest dogs, a floating glass microelectrode was used to record intracellular action potentials from the right ventricle during pacing and during electrically induced VF. Before any drug was administered, an initial episode of VF was c...

PURPOSE We used the Swedish interactive threshold algorithms (SITA) standard strategy of Humphrey perimetry, to analyze the pattern of visual field (VF) defects and evaluate the quantitative correlation between the tumor volume and severity of VF defects in patients with pituitary macroadenoma. METHODS We reviewed 50 patients with pituitary macroadenoma who received VF test and 11 patients we...

OBJECTIVES This study mapped human ventricular fibrillation (VF) to define mechanistic differences between episodes requiring defibrillation versus those that spontaneously terminate. BACKGROUND VF is a leading cause of mortality; yet, episodes may also self-terminate. We hypothesized that the initial maintenance of human VF is dependent upon the formation and stability of VF rotors. METHOD...

OBJECTIVES The purpose of this study was to determine if the defibrillation threshold (DFT) is lower during the first few cycles of ventricular fibrillation (VF) than after 10 s of VF and, if so, if the effect is caused by local or global factors. BACKGROUND The DFT may be low very early during VF because: (1) for the first few cycles VF arises from a localized region close to a defibrillatio...

OBJECTIVES We sought to demonstrate the mode of spontaneous onset of ventricular fibrillation (VF) in patients with Brugada syndrome. BACKGROUND The electrophysiologic mechanisms of VF in Brugada syndrome have not been fully investigated. METHODS Nineteen patients (all male, mean age 47 +/- 12 years) with Brugada syndrome were treated with an implantable cardioverter defibrillator (ICD). Th...

It is unknown whether ventricular fibrillation (VF) studied in experimental models represents in vivo human VF. First, we examined closed chest in vivo VF induced at defibrillation threshold testing (DFT) in four patients with ischemic cardiomyopathy pretransplantation. We examined VF in these same four hearts in an ex vivo human Langendorff posttransplantation. VF from DFT was compared with VF...