[Hydrodynamics of disk artificial heart valves with different design characteristics]. / Gidrodinamika diskovykh iskusstvennykh klapanov serdtsa s razlichnymi konstruktivnymi kharakteristikami.

Bench tests for 38 models of artificial heart valves (AHV) with different design parameters allowed us to decide in favour of the valves with reduced eccentricity (compared to the serial AHV of the EMAHV type) according to its resistance in the constant flow. Out of the compatibility checks of the design parameters tested it was concluded that the disk did not make the complete calculated angle when rotated. The dependence of AHV resistance on the disk rotation angle showed that there is no necessity to increase that angle more than 70 degrees for the mitral valve and more than 75 degrees for the aortic AHV.

[Clinical characteristics of the Soviet low-profile heart valve prostheses EMIKS and LIKS]. / Klinicheskaia kharakteristika otechestvennykh nizkoprofil'nykh protezov klapanov serdtsa EMIKSA i LIKS.

The present work is devoted to the clinical assessment of the Soviet-made cardiac valve prostheses 'EMIKS' and 'LIKS'. From 1983 to May 1, 1988, 632 prostheses were implanted to 508 patients. A group of 348 patients were assessed: 139 after mitral (M) replacement, 130 after aortal (A) replacement, and 79 after mitral-aortal (M+A) replacement. Hospital mortality rate was: in M group--4.3 per cent, in A group--5.3 per cent, in M+A group--8.8 per cent. Survival rate on the fifth postoperative year was: in M group--89.5 +/- 9.2 per cent, in a group--90.0 +/- 4.2 per cent, in M+A group--91.0 +/- 6.2 per cent, the stability of the good results being 85.5 +/- 7.2, 79.5 +/- 6.2, and 75.0 +/- 9.1 per cent, respectively. At year 5 of the follow-up, patient numbers without thromboembolic complications amounted to 95.0 +/- 4.7 per cent in M group, 95.5 +/- 4.2 per cent in A group, and 85.0 +/- 9.1 in M+A group. 95.1 per cent patients belong to functional classes I and II. In mitral replacement, the mean 'EMIKS' gradient was 4.2 +/- 0.58 mm Hg, the 'LIKS' one--4.58 +/- 0.62 mm Hg. Intravascular hemolysis was not observed. The 'EMIKS' and 'LIKS' prostheses match the models produced in other countries. No significant differences between the two models were found.

[A method of determining the kinematic parameters of artificial/disk heart valves]. / Metod opredeleniia kinematicheskikh parametrov diskovykh iskusstvennykh klapanov serdtsa.

The described method makes it possible to determine the kinematic parameters of the artificial cardial disk valves in treadmill tests. This method is more convenient and accurate than those proposed earlier. The article presents design formulae and graphs for determining the above parameters. The evaluation of the accuracy of measurements shows their fitness for analysing the present clinical and experimental models of the artificial cardiac disk valves.

[Analysis of the causes of potential wear and breakdown of elements of artificial heart valves of the disk type]. / Analiz prichin vozmozhnogo iznosa i razrusheniia élementov iskusstvennykh klapanov serdtsa diskovogo tipa.

The reliability analysis of the artificial cardiac valve and experiments made it possible to establish that the ACV reliability is ensured by the physical and mechanical properties of the material, technology observance and thorough control over each operation during the manufacturing process. The accelerated testing of the new MX disk valve made in the USSR showed a satisfactory degree of the disk wear and the absence of breaks-down after 400 million working cycles which is equivalent to ten-years' work in a human body.