Echocardiographic findings in five patients with pulmonary embolism were studied. Tricuspid echocardiograms showed abnormalities in valve motion, that is a monophasic triangular wave during diastole in all the patients as well as an increased dimension of the right ventricle. An "a' dip of the pulmonary valve echocardiogram was also recognised in all five. Later tricuspid echocardiograms regain...

OBJECTIVES Flow variations can affect valve-area calculation in aortic stenosis and lead to inaccuracies in the evaluation of the stenosis. Knowing that transvalvular flow varies normally within one beat, we designed this study to assess the response of the valve to intrabeat variation of flow during systole. Results were compared with flow-derived measurements. BACKGROUND Technological impro...

SUMMARY The Lillehei-Kaster (L-K) valve is a tilting disc prosthesis currently in use for heart valve replacement. We report data from phonocardiography (PHONO) and echocardiography (ECHO) in 20 patients with a normally functioning mitral valve prosthesis (MVP). The MVP is well recorded by ECHO, resembling a mitral stenosis pattern with a disc excursion of 7 to 12 mm and a mean opening and clos...

To achieve the accurate measurement of the hydraulic valve opening position, the sensor measurement circuit was designed for two and three differential solenoid coil inductance displacement sensor. Some experiments were done to detect the static and dynamic performance. Comparing the static output characteristic of the two type of the sensor. The experimental results of the actual measurement o...

Direct acting spring loaded pressure relief valve is one of the most important devices to ensure security to pipeline oil transport. However, relief valves’ manufactures generally only provide information on valve characteristics under full opening stage, which is obtained under steady state regime, therefore, valve and flow’s transient behavior are neglected. Understanding the transient behavi...

Gas fuel control valves play important roles in the of gas flow high-precision turbines. To clarify influence coupling between structure and fluid system, a thermal fluid–solid mechanism is presented based on numerical investigations carried out using dynamic mesh technique. Valve core deformation can affect outlet accuracy. At 2% valve opening, temperature contributes 93% to deformation. The e...

The ability of the echocardiogram to define mitral valve opening and closure was assessed by simultaneously recording the echocardiogram of the anterior leaflet (ECHO) with intracardiac pressures, aortic second sound, and ECG on 38 occasions in 14 patients undergoing cardiac catheterization. Hemodynamic opening and closure were defined by intersection of the pulmonary wedge and left ventricular...

There is presently considerable ambiguity and confusion relating to ventilator terminology. This can be eliminated using a simple approach, visualising mechanical ventilation as an inspiratory pump, and defining trigger, limit, and cycling in this context. The trigger is the signal that starts a breath by opening the inspiratory valve, the limit is the factor which controls the way gas flows in...

See Clinical Perspective The rationale behind the protective mechanism of CRT was initially attributed to the pathophysiology of left bundle branch block (LBBB), in which a delayed activation of left ventricle through the right ventricle and the septum results in delayed left and right ventricular contraction, delayed aortic valve opening and closure, and mitral valve opening, but has no impact...

The valvular disease usually involves two conditions: valvular stenosis and valvular insufficiency. Valvular stenosis occurs when a valve opening is smaller than normal due to stiff or fused leaflets. The narrowed opening may make the heart work very hard to pump blood through it. This can lead to heart failure. All four valves can be stenotic (hardened, restricting blood flow); the conditions ...