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...

OBJECTIVES This multicenter study sought to evaluate the long-term follow-up of patients ablated for idiopathic ventricular fibrillation (VF). BACKGROUND Catheter ablation of idiopathic VF that targets ventricular premature beat (VPB) triggers has been shown to prevent VF recurrences on short-term follow-up. METHODS From January 2000, 38 consecutive patients from 6 different centers underwe...

OBJECTIVE To compare the occurrence of normal visual field (VF) test results following 2 vs 3 consecutive, abnormal, reliable test results in the Ocular Hypertension Treatment Study. METHODS The Ocular Hypertension Treatment Study is a prospective, multicenter follow-up study as part of a longitudinal randomized clinical trial. Sixty-four (68 eyes) of 1636 participants developed a VF primary ...

BACKGROUND Shocks that have defibrillated spontaneous ventricular fibrillation (VF) during acute ischemia or reperfusion may seem to have failed if VF recurs before the ECG amplifier recovers after shock. This could explain why the defibrillation threshold (DFT) for spontaneous VF appears markedly higher than for electrically induced VF. METHODS AND RESULTS The DFT for electrically induced VF...

Background—A therapeutic implication of the focal-source hypothesis of ventricular fibrillation (VF) is that VF can be terminated by focal ablation. We hypothesize that -adrenergic receptor blockade converts multiple-wavelet VF to focal-source VF and that this focal source is located near the papillary muscle (PM). Methods and Results—We used optical mapping techniques to study the effects of p...