a 46 year old man had been undergone aortic valve replacement (avr) due to mechanical aortic valve endocarditis two month ago. he was referred to imam khomeini hospital because of dyspnea since two weeks ago. echocardiography showed the false aneurysm, with an area of flow beyond the lumen of the aorta. this patient underwent reoperation, the previously implanted aortic valve was removed, metic...

OBJECTIVES The goal of this study was to compare long-term survival and valve-related complications between bioprosthetic and mechanical heart valves. BACKGROUND Different heart valves may have different patient outcomes. METHODS Five hundred seventy-five patients undergoing single aortic valve replacement (AVR) or mitral valve replacement (MVR) at 13 VA medical centers were randomized to r...

INTRODUCTION Mechanical valves in the tricuspid position may be prone to thrombosis with even brief lapses in anticoagulation. The management of patients with a history of recurrent mechanical tricuspid valve thrombosis who require noncardiac surgery is complex. CASE PRESENTATION A 43-year-old Pakistani woman with a mechanical tricuspid valve and a history of multiple episodes of mechanical v...

Direct pump control of hydraulic systems is more energy efficient than throttle valve based methods to control hydraulic systems. This requires variable displacement pumps that are responsive and capable of electronic control. Such Electronic Displacement Controlled (EDC) pumps tend to be significantly larger, heavier and more expensive than fixed displacement counterparts. In addition, achieva...

Abstract Study of mechanical properties rock under hydro-mechanical coupling. The MTS815 mechanics system is used to perform triaxial compression tests water-saturated sandstones different confining pressures and pore water pressures. results show that the peak deviation stress its corresponding axial strain, residual stress, initial dilation deformation modulus sandstone are related pressure p...

surgery for heart diseases during pregnancy, especially necessitating cardiopulmonary bypass, is believed to trigger maternal and fetal risks and should be performed only when medical therapy has been unsuccessful to alleviate the cardiac decompensation. a 33-year-old pregnant woman in her 33rd week of gestation was admitted to our hospital. she had rheumatic mitral valvular stenosis and had un...

Valvular heart disease is a major public health issue. The prevalence of valvular heart disease is expected to increase due to an aging population. Valve dysfunction manifests as valve stenosis, regurgitation, or both, due to various etiologies. Valve repair and replacement are the main treatment options for severe valve dysfunction. Valve replacement is achieved by using either a mechanical or...