A system for detection of frequency power for diagnosing of coronary artery disease, comprising: - an acoustic sensor adapted to be placed on the chest of a patient, and to generate acoustic signals S A; - at least one memory adapted to store said acoustic signals S A from the acoustic sensor; - a control unit adapted to receive said acoustic signals S A; wherein said control unit further comprises: - an identification unit adapted to identify diastolic or systolic periods in a predetermined time period of the stored acoustic signals S A, and to generate a period signal Sp indicating said identified periods; - a filtering unit adapted to apply at least one filter to said identified periods and to generate a low frequency band signal S LFB indicating low frequency bands of said identified periods, wherein said low frequency band is between 5-70 Hz; - a calculation unit adapted to estimate the power in said low frequency band of said identified periods, and that said calculation unit is adapted to normalize said estimated power over another, higher frequency band, said calculation unit is further adapted to calculate a low frequency power measure based upon said estimated and normalized power and to generate a low frequency power measure signal S LFP indicating said low frequency power measure, wherein said system further comprising a risk determining unit adapted to determine a risk of coronary artery disease by comparing said low frequency power measure with at least one reference value for CAD, and generating a risk-of-CAD-signal S CAD indicating the result of said comparison. - an acoustic sensor adapted to be placed on the chest of a patient, and to generate acoustic signals S A; - at least one memory adapted to store said acoustic signals S A from the acoustic sensor; - a control unit adapted to receive said acoustic signals S A; wherein said control unit further comprises: - an identification unit adapted to identify diastolic or systolic periods in a predetermined time period of the stored acoustic signals S A, and to generate a period signal Sp indicating said identified periods; - a filtering unit adapted to apply at least one filter to said identified periods and to generate a low frequency band signal S LFB indicating low frequency bands of said identified periods, wherein said low frequency band is between 5-70 Hz; - a calculation unit adapted to estimate the power in said low frequency band of said identified periods, and that said calculation unit is adapted to normalize said estimated power over another, higher frequency band, said calculation unit is further adapted to calculate a low frequency power measure based upon said estimated and normalized power and to generate a low frequency power measure signal S LFP indicating said low frequency power measure, wherein said system further comprising a risk determining unit adapted to determine a risk of coronary artery disease by comparing said low frequency power measure with at least one reference value for CAD, and generating a risk-of-CAD-signal S CAD indicating the result of said comparison. - an identification unit adapted to identify diastolic or systolic periods in a predetermined time period of the stored acoustic signals S A, and to generate a period signal Sp indicating said identified periods; - a filtering unit adapted to apply at least one filter to said identified periods and to generate a low frequency band signal S LFB indicating low frequency bands of said identified periods, wherein said low frequency band is between 5-70 Hz; - a calculation unit adapted to estimate the power in said low frequency band of said identified periods, and that said calculation unit is adapted to normalize said estimated power over another, higher frequency band, said calculation unit is further adapted to calculate a low frequency power measure based upon said estimated and normalized power and to generate a low frequency power measure signal S LFP indicating said low frequency power measure, wherein said system further comprising a risk determining unit adapted to determine a risk of coronary artery disease by comparing said low frequency power measure with at least one reference value for CAD, and generating a risk-of-CAD-signal S CAD indicating the result of said comparison.