Hospitallized patients with new onset or previously diagnosed heart failure will be recruited to the study. Control group will include healthy people with no medical records or chronic treatment at the same age range. After signing an informed constent form, full medical history and blood samples will be collected. A second blood sample will be collected 8 weeks later, assuming the patient was discharged and not hospitalized since than. The blood samples will be analyzed by Bnai Zion Medical Center Immunology labs for the above semaphorins levels in the heart failure group and control group. Statistical analysis will then commence for possible correlatoion with different clinical parameters.