Frequency control and chirp compensation from an electro-opticalDBR laser

The variability of optical frequency modulation with electric field in an electro-optical phase section is analysed. When configured for maximum sensitivity, the electro-optical phase section was used to compensate for the chirp of the gain section: 48 ps and 8.5 GHz wide transform-limited pulses were obtained at 5 GHz     

Surgical treatment of aneurysms of the left ventricle. Immediate and long-term results. Apropos of a consecutive series of 121 cases

From 1978 to 1992, 121 cases of postinfarction left ventricular aneurysm (99 males, 22 females, mean age 60 years) were operated on. The authors insist on a high rate of clinical arhythmogenicity (31.4%) and associated mechanical complications (21%). 76% of patients were in functional NYHA class III or IV. Resection was performed in 90% of patients, plication in 10%. 58% underwent coronary artery bypass grafting (1.7 graft/patient), 16% encircling ventriculotomy, 8% mitral valve replacement and 13% closure of ventricular septal defect. Operative mortality was 14.9% (10% when other mechanical complications where excluded). 5-year survival is 67.9%. Late cardiac deaths are as follow: left ventricular failure (1.8% A/P), Sudden death (1.4% A/P), Myocardial infarction (0.6% A/P). 82% of survivals are in functional NYHA class I or II. Only functional class NYHA III or IV is predictive of late death. We conclude that postinfarction left ventricular aneurysm remains a high risk complication especially when associated with other mechanical complications. When arhythmogenicity is present we suggest rhythmologic surgery and in all cases, complete revascularization.     

The Carpentier-Edwards porcine valve in the supra annular aortic position. Results after 12 years in a series of 1108 patients

In the decision concerning the choice of valvular prosthesis, certain prostheses are considered to be standards of reference: this is the case of the Carpentier-Edwards Supra Annular 2650 porcine bioprosthesis. This study reports the results in a series of patients followed up for 12 years. Between 1983 and 1995, 1108 patients were implanted with this prosthesis for isolated aortic valve replacement. The majority of patients was elderly (mean 78.3 +/- 8.3 years). The follow-up rate was 94%, representing a total of 3 925 patient-years (average 4 +/- 3 years). The survival at 5, 10 and 12 years, operative mortality included, was 70.7%, 46% and 28%. Thromboembolic events to dehiscence represented the commonest complication (0.7% per patient-year). Structural valve degeneration (21 cases) (0.5% per patient-year) was a low risk complication up to 10 years but increased suddenly at the 11th year: age and gender were risk factors for this complication. The actuarial complication-free rate was 94% at 10 years and 82% at 12 years. Other complications were much less common (infectious endocarditis, haemorrage). The Carpentier-Edwards Supra Annular porcine bioprosthesis is associated with a low risk of complications after 10 years' follow-up, especially of valve degeneration. It remains a competitive choice in the register of valve prostheses. As with the other bioprostheses, the main indications are observed in elderly patients.