A significant number of patients with cardiac syndrome X(CSX) present frequent episodes of severe chest pain, refractory to maximal multi-drug therapy. A few, small, uncontrolled data suggested that spinal cord stimulation(SCS) may have favourable clinical benefits in these patients. Methods and results: We studied 10 CSX patients who were being treated by SCS for refractory angina pectoris for 17± 16 months(median 8). Patients were randomized to either continue or withdraw SCS for a period of 3 weeks and were then crossed over to the other condition for a further 3- week period. During each 3- week period patients kept a detailed diary of angina episodes occurring in the last 2 weeks of each phase. Furthermore, at the end of each 3- week period, angina status was also assessed by Seattle Angina Questionnaire(SAQ), a 0- 100 visual analogue scale(VAS), and patients underwent 24- h Holter monitoring(HM) and echocardiographic dobutamine stress test(DST). Compared with the withdrawal phase, SCS reduced the number(P=0.01), duration(P=0.022), and severity(P=0.011) of angina episodes, and nitrate consumption(P=0.042). SAQ scores(P≤ 0.013 for all) and VAS(P< 0.001) were also improved, the number of episodes of ST-segment depression on HM was decreased(P=0.014), and time to angina(P=0.045) and to 1 mm ST-segment depression(P=0.04) during DST were both prolonged by SCS. Conclusions: Our data point out that SCS may be an effective form of treatment in patients with CSX suffering from frequent angina episodes significantly impairing quality of life(QOL) and refractory to maximally tolerated drug therapy. A few numbers of patients with cardiac syndrome X (CSX) present frequent episodes of severe chest pain, refractory to maximal multi-drug therapy. A few, small, uncontrolled data suggested that spinal cord stimulation (SCS) may have favourable clinical benefits in these Patients. Methods and results: We studied 10 CSX patients who were being treated by SCS for refractory angina pectoris for 17 ± 16 months (median 8). Patients were randomized to either continue or withdraw SCS for a period of 3 weeks and were then crossed over to the other condition for a further 3- week period. each, 3-week period kept a detailed diary of angina episodes occurring in the last 2 weeks of each phase. status was also assessed by Seattle Angina Questionnaire (SAQ), a 0-100 visual analogue scale (VAS), and patients underwent 24-h Holter monitoring (HM) and echocardiographic dobutamine stress test (DST). Compared with the withdrawal phas (P = 0.022), and severity (P = 0.011) of angina episodes, and nitrate consumption (P = 0.042). SAQ scores (P≤ 0.013 for all) and VAS (P <0.001) were also improved, the number of episodes of ST-segment depression on HM was decreased (P = 0.014), and time to angina (P = during DST were both prolonged by SCS. Conclusions: Our data point out that SCS may be an effective form of treatment in patients with CSX suffering from frequent angina episodes significantly impairing quality of life (QOL) and refractory to maximally tolerated drug therapy.