Relief of right ventricular (RV) outflow tract obstruction in tetralogy of Fallot or similar physiology often results in pulmonary regurgitation (PR). The resultant chronic volume overload can lead to RV dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias and sudden death. Although pulmonary valve replacement (PVR) can lead to improvement in the functional class and a sub...

The flow-resistive characteristics of a variety of commercially available expiratory positive-pressure valve systems used to provide continuous positive airway pressure (CPAP) and positive end-expiratory pressure were evaluated. One flow-resistor and seven threshold-resistor expiratory pressure valve systems were set at 5, 10, 15, 20, and 25 cm H2O of expiratory pressure, and sinusoidal exhaled...

Heat exchangers are the critical components of refrigeration and liquefaction processes. Selection of appropriate operational conditions for cryogenic recuperative heat exchanger and expansion valve operating in Joule-Thomson cooling system results in improving the performance and efficiency. In the current study, a straightforward procedure is introduced to design an efficient Joule-Thomson co...

UNLABELLED Percutaneous balloon aortic valvuloplasty (BAV) was a rare procedure in catheterization laboratories because of its limited prognostic impact. The recent advent of transcatheter aortic valve implantation (TAVI) has led to a resurgence of BAV, opening the way to a new indication as a bridge to TAVI. Herein, we reported an 83-year-old man with critical aortic valve stenosis and pulmona...

Clinical and morphological findings are described in 2 adults with combined valvular pulmonary and aortic stenosis with atrial septal defect, an extremely rare combination of lesions. The direction of the shunt via the atrial septal defect in this combination appears to be dependent on the relative degree of outflow obstruction on the right side compared with the left side of the heart. In 1 pa...

AIMS In experimental studies the recovery of pressure distal to stenotic valve orifices has been well described. We evaluated the extent, determinants, and clinical importance of pressure recovery in patients with aortic valve stenosis. METHODS AND RESULTS The study was performed in 37 patients with aortic valve stenosis, in whom cardiac catheterization was performed and left ventricular and ...

joule-thomson cooling systems are used in refrigeration processes such as cryogenic gas liquefaction. although extensive studies have been carried out by researchers, most of them include cryogenic heat exchangers and their associated fields. in the current study, an attempt was made to indicate the effect of using inappropriate operational conditions in a cryogenic joule-thomson cooling system...