The investigators have previously shown that a frequency of 15.95-16.00 Hz protects against acute myocardial infarction in rats. In the current study the investigators would like to investigate whether this frequency enables cardiac patients with exercise-induced chest pain to exercise at higher workload and heart rate. Therefore, patients will undergo two exercise stress tests, one test after being exposed to 30 minutes of the above mentioned frequency and another test after being exposed to sham (no frequency is turned ON). The investigators will measure changes in the electrocardiogram (ECG), workload, exercise time, and subjective measure of chest pain (angina).

Several studies have shown that low frequency electromagnetic field has biological and therapeutic potential on the human body, however, to very limited extent on the heart. In the current study cardiac patients suffering from exercise-induced-angina will undergo two consecutive stress tests, one test after being exposed for 30 minutes to the magnetic field and the other test after being exposed to placebo (magnetic field not operated). The order of which the magnet will be operated will be randomly assigned for the patients so a group of patients will be exposed to the magnetic field at their first stress test and another groups of patients will be exposed to the magnetic field at their second stress test. During resting period, and while the patients are subjected to the magnetic field, a 12 lead electrocardiogram (ECG) will be monitored. Thereafter the magnetic field and frequency will be turned off and the patients will be subjected to graded exercise stress test during which they will be monitored for ECG and blood pressure changes. Similar monitoring will be documented during the recovery period following the stress test. In addition, the patients will grade their angina score as documented during the stress test. The data will be compared between the two stress tests and to document any advantageous of the magnetic field on exercise time, workload, ECG changes and/or chest pain.

Inclusion Criteria:

Patients with known exercise-induced-angina

Exclusion Criteria:

Patients that changed treatment course between the two exercise stress tests Patients that decided to drop from the second exercise stress test

Patients enrolled at the Cardiac Rehabilitation Institute, sheba Medical Center