Statistically Evaluation of Mechanical Heart Valve Thrombosis Using Heart Sounds

Thrombosis is a serious complication and important cause of mortality and morbidity reason for patients with mechanical heart valve. Echocardiogram of mechanical heart valves is necessary to diagnose valve thrombosis definitely. Because of the difficulty in making early diagnosis of thrombosis, and the cost of diagnosis equipment and operators, improving noninvasive, cheap and simple methods to evaluate the functionality of mechanical heart valves are quite significant. In this study, statistical features obtained from auscultation of heart sounds are proposed to evaluate mechanical heart valve thrombosis as a simple method. For this aim, heart sounds of one patient with mechanical heart valve thrombosis and five patients with normally functioning mechanical heart valve were recorded. Statistical features of these sounds, the skewness and kurtosis, were calculated and statistically evaluated using t-test. As a result, it is clearly seen that the skewness of Si sounds is the most discriminative features (p < 0.01) and it may be used fairly well in differentiating normally functioning mechanical heart valve from malfunctioning mechanical heart valve.