Zeinab Alsweady - Department of mathematical and computer science, Razi university, Iran, Kermanshah
Abdolah Chalechale - Department of computer engineering, Razi university, Iran, Kermanshah

The vital functions of the heart is pump blood through the network of arteries and veins called the cardiovascular system . for any kind of disorder that affects the heart so that adversely affect the heart and pump blood in a normal work therefore, heart disease is the No. 1 reason for death worldwide .People with cardiovascular disease or who are at high cardiovascular risk need early detection and management using counselling and medicines, as appropriate. The development of expert systems which will aid medical practitioners in delivering effective and efficient medical services to patients. On the other hand ovser three quarters of CVD deaths take place in low- and middle-income countries this will in turn reduce mortality rate in cases where a limited medical doctors are available, as it provides very rapid method of diagnosis with so much accuracy and reduces the hours spent by patients in the hospital. When a heart disease has dynamic behavior, fuzzy logic is a suitable tool that deals with this problem due to the strength of Fuzzy Logic (FL) in the provision of accurate solutions to difficult real life problems. In this paper, we presents the review of past work that has been carried out by various researchers based on fuzzy expert systems for the diagnosis of different types of heart disease. In many researches, fuzzy expert system with different models and methodologies was used for heart disease diagnosis .To predict the heart disease, several researchers combined fuzzy technique with some other technique for efficient classification purpose, since the fuzzy is efficient only if proper fuzzy rules are given in the rule base such as ANN,PCA,KNN,AIS.

fuzzy logic, expert system, heart disease, fuzzy expert system, survey