Introduction: It is well-documented that right-sided heart dysfunction and significant tricuspid valve regurgitation (TVR) have adverse effects on patient outcomes after left-sided heart valve surgery. Therefore, the evaluation of right ventriclular (RV) function and TR severity in patients who had undergone mitral valve replacement (MVR), associated with/without concomitant su...

Verapamil was administered intravenously to 30 open-chest dogs and the electrophysiologic and hemodynamic effects of the drug were correlated with the corresponding plasma concentrations. At concentrations below 152 ng/ml, verapamil prolonged the A-H interval, abolished ventriculoatrial conduction, but did not significantly change sinus rate, cardiac output, left ventricular dp/dt, of systemic ...

The hot gases produced by the internal combustion engines passes through the exhaust valve and causes high temperatures in the exhaust valve and its seat. To avoid damaging the exhaust valve, heat must be transferred from the valve to its seat during the contact they make at the opening and closing cycle. Heat transfer rate from the exhaust valve to its seat is a function of many factors. One o...

introduction: rheumatic heart disease still remains one of the leading causes of congestive heart failure and death owing to valvular pathologies, in developing countries. valve replacement still remains the treatment of choice in such patients.the aim of this study wasto analyze the postoperative outcome of  double valve replacement (mitral and aortic ) in patients of rheumatic heart disease. ...

infective endocarditis is one of the most severe complications of parenteral drug abuse. the outstanding clinical feature of infective endocarditis in intravenous drug abusers is the high incidence of right-sided valve infection, and the tricuspid valve is involved in 60% to 70% of the cases. we herein report a case of isolated pulmonic valve infective endocarditis with a native pulmonary valve.

the patient was a 19 year-old woman with the diagnosis of resistant hypertension, although she was under treatment of three classes of anti-hypertensive drugs (beta blocker, angiotensin receptor blocker, diuretic) for more than one year. in physical examination there was only a significant difference between the systolic blood pressure of upper and lower extremities (200 vs. 120 mmhg), without ...

Pressure control valve (PCV) is implemented in internal combustion engine to regulate crankcase pressure. In this study, the performance of a diaphragm PCV valve is investigated numerically and experimentally. Firstly, numerical simulation is carried out using commercial code to predict the flow and pressure distribution inside the valve. Furthermore, downstream and upstream pressure of the val...

This paper presents a failure analysis on a failed intake valve in a gasoline engine. During an endurance test, an intake valve was broken and caused some damages on the piston. Material examinations (by a light microscope and also a scanning electron microscope) were conducted on the fracture surface of the intake valve shaft. Results showed that no pores or defects could be observed and the m...

The main purpose of this paper is to study various configurations of a magnetorheological (MR) damper valve and to evaluate their performance indices typically dynamic range, valve ratio, inductive time constant and pressure drop. It is known that these performance indices (PI) of the damper depend upon the magnetic circuit design of the valve. Hence, nine valve configurations are considered fo...

prolapsed mitral valve syndrome is a common, benign disorder with prevalence of %0.3-6 in population. this syndrome also is known as barlows syndrome and flaapy mitral valve syndrome. prolapsed mitral valve is the dropping of one or two mitral valve leaflet(s) into the left atrium during ventricular systole. this malformation leads to incomplete closing of mitral valve and regurgitates the bloo...