PURPOSE To evaluate changes at the anterior chamber angle during Valsalva maneuver in eyes suspected to have a primary adult glaucoma. METHODS Seventy-six consecutive patients underwent recording of applanation tonometry, measurement of the anterior chamber angle recess, angle opening distance, angle recess area, scleral spur-iris root distance, iris thickness, iridociliary angle, ciliary bod...

Measurements of cerebral spinal fluid pressure, arterial pressure, and internal carotid artery blood flow were obtained in a series of patients during a Valsalva maneuver. During straining (phase II), an 11% reduction in mean arterial pressure was associated with a 21% decrease in internal carotid flow from control values; and following release (phase IV), the 19% increase in mean arterial pres...

When a natural gas pipeline ruptures, the adjacent automatic line control valves (ALCVs) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ALCV action. If the DPS is not properly adjusted, the ALCV may mistakenly close or it may not take any action at proper time. This study focused on...

The purpose of this study was to investigate the influence of the Valsalva maneuver (VM) on cardiac hemodynamics in patients with patent foramen ovale (PFO). Sixty-five patients who were highly suspected to have PFO were included. The changes in E, A, E/A ratio of mitral valve blood flow, E, A, E/A ratio of tricuspid valve blood flow, left ventricular end-diastolic volume, area and right atrial...

[Purpose] The purpose of this study was to compare the effect of childbirth delivery method on vaginal pressure and abdominal thickness during the Valsalva maneuver (VAL). [Subjects] Thirty healthy female volunteers (26-39 years of age) were selected for this research. Their delivery histories were: nulliparous 10, vaginal delivery 10, and Cesarean delivery 10. None of the participants had a hi...

Protective Effects of Acetazolamide and Hyperbaric Oxygenation on Experimentally Induced Syncope • The protective effects of acetazolamide and hyperbaric oxygenation on experimentally induced syncope were evaluated in seven healthy male subjects. Syncope was induced by vigorous hyperventilation and Valsalva maneuver. Each subject performed these procedures three times in each of the following c...

Introduction: Valsalva retinopathy is a unilateral or bilateral condition that occurs when increased intra-thoracic or intra-abdominal pressure transmitted to the eye causes a sharp rise in the intraocular venous pressure, and rupture of superficial retinal capillaries. The patient often gives a history of a recent strenuous physical act, which could have increased the intra-thoracic pressure. ...

BACKGROUND Hypertension is an important risk factor for sudden cardiac death, of which the incidence increases with increases in blood pressure. Prolonged QT dispersion has been identified to indicate increased risk of life-threatening ventricular arrhythmia and sudden cardiac death. In this study, QT dispersion was investigated in hypertensive patients during the strain phase of the Valsalva m...