A 43-year—old man was admitted to the coronary care unit because of recurrent syncope. His medical history included pulmonic valve angioplasty at age 9 years, mechanical mitral valve replacement because of severe mitral regur-gitation caused by congenital atrioventricular canal, and pacemaker implantation because of complete atrioventricular block. On admission he was orthopneic, his blood pres...

The effect of chemical disinfection of the Heidbrink expiratory valve in buffered glutaraldehyde (Cidex solution) was investigated. Cidex caused stickiness and increased the opening pressure and resistance of the valve to different gas flow rates. An electrolytic type of corrosion may also have occurred. However, autoclaving of the Heidbrink valve did not appear to cause corrosion or significan...

REPLACEMENT of nonfunctioning valves is a significant recent advancement in the correction of cardiac valvular disease. The most widely used artificial device replacing the mitral valve is the Starr-Edwards ballvalve prosthesis.' Its effectiveness was shown in recent reports by the marked clinical improvement in properly selected patients.2 However, cardiologists and cardiac surgeons are faced ...

We appreciate the suggestions of Dr. Veyrat regarding our study (1) and agree that it would be of interest to trigger the computed tomographic (CT) images at the time point of maximal aortic valve opening as previously calculated with Doppler velocity-time integral. However, some technical and logistic considerations arising from the CT perspective should be taken into account. The heart rate m...

Conventional internal combustion engines use mechanical camshafts to command the opening and closing phases of the intake and exhaust valves. The lift valve profile is designed in order to reach a good compromise among various requirements of the engine operating conditions. In principle, optimality in every engine condition can be attained by camless valvetrains. In this context, electromagnet...

Echocardiographically recorded mitral valve motion was compared with phasic transmitral flow in 17 open chest dogs. The normal mitral valve opening started with the onset of mitral flow and reached its full excursion while flow was still accelerating. Complete valve opening occurred .044 sec (plus or minus .002 sem) before peak flow, during which time an average of 17.6 percent of total mitral ...

An echocardiographic study was carried out on 23 young diabetics, 19 of whom had retinopathy. Their diastolic function was analysed by comparing the timing and pattern of mitral valve opening with the pattern of left ventricular wall movement. Only six patients had all their values within the normal range. Fourteen patients had abnormalities similar to those seen in patients with cardiomyopathy...

Artificial valve replacement is a common procedure in case of heart valve disorders treatment. The main task of this prosthesis is to generate blood flow similar to flow generated by natural, human valve. Velocity distribution depends mainly on the geometry of the valve. That is why it should be analysed and modified in case to obtain the best results. The objective of this study was to numeric...

OBJECTIVE The aims of this study were to compare opening and closing angles of normally functioning mechanical aortic valves measured on dual-source computed tomography (CT) with the manufacturers' values and to compare CT-measured opening angles according to valve function. MATERIALS AND METHODS A total of 140 patients with 10 different types of mechanical aortic valves, who underwent dual-s...