The stability control of nominal frequency and terminal voltage in an interconnected power system (IPS) is always a challenging task for researchers. load variation or any disturbance affects the active reactive demands, which badly influence normal working IPS. In order to maintain at rated values, controllers are installed generating stations keep these parameters within prescribed limits by ...

OBJECTIVES This prospective-randomized study investigated the effect of aortic valve design and patient-prosthesis mismatch (PPM) on coronary flow reserve (CFR) after mechanical or biological aortic valve replacement (AVR) in patients with aortic stenosis (AS). BACKGROUND Coronary flow reserve may be an important parameter of long-term survival after AVR in patients with AS. Reduced CFR may c...

This review summarizes the major long-term (> or =10 to 15 years) patient outcomes after insertion of many Food and Drug Administration approved prosthetic heart valves (PHV). Mechanical PHV was associated with a better survival (p < 0.02) at 15 years after aortic valve replacement (AVR) than with a bioprosthesis in the Department of Veterans Affairs (DVA) trial. In both the DVA and the Edinbur...

BACKGROUND Electrocardiogram (ECG) in patients with acute pulmonary embolism (APE) presents many abnormalities. There are no data concerning prognostic significance of ST-elevation (STE) in lead aVR in patients with APE. AIM To assess the prevalence of STE in aVR in patients with APE and its correlation with clinical course as well as other ECG parameters recorded at admission. METHODS The ...

BACKGROUND To evaluate the perioperative risk of redo aortic valve replacement (AVR). MATERIALS AND METHODS Sixty-three patients (53 males, 10 females) underwent redo AVR from 2001-2005. Forty-one bioprostheses had to be replaced for degeneration and/or paravalvular leakage, and 18 mechanical prostheses were changed because of thrombosis and/or paravalvular leakage. Four patients with a bicus...

OBJECTIVE The Hancock II (HII) is a second-generation porcine bioprosthesis introduced into clinical use in 1982. This study aimed to evaluate very long-term outcomes for the HII valve in a large patient population. METHODS Between May 1983 and November 1993, 517 consecutive patients (pts) (309 male, mean age: 64+/-9 years) underwent valve replacement (VR) surgery with HII, with 302 (58.4%) i...

Numerous indirect methods for apical vertebral rotation (AVR) measurement have been reported and none of them seems to be as accurate as computed tomography evaluation. The aim of this study was to compare spinal rotation changes during innovative technique of intraoperative computed tomography (ICT) evaluation with indirect methods such as Perdriolle and clinical evaluation with scoliometer. W...

BACKGROUND Mitral regurgitation (MR) is common in those with severe aortic regurgitation (AR) and can predispose to atrial fibrillation, heart failure, and a need for mitral valve surgery during aortic valve replacement (AVR). However, little data exist as to its clinical and prognostic implications. METHODS AND RESULTS Search of our echocardiographic data base between 1993 and 2007 yielded 7...

We retrospectively studied 252 operated and 47 unoperated patients with isolated aortic valve disease. Aortic valve replacement (AVR) was recommended to all patients based on clinical and hemodynamic data. Preoperative hemodynamic and angiographic data were similar in operated and unoperated cohorts. Seventy-one percent of patients received a Bjork-Shiley prosthesis. Operative mortality was 7% ...