Objectives To explore the effects of Cardiac Shock Wave Therapy (CSWT) on the Microvolt-T-wave alternans (MTWA) of CAD Patients.

Methods A total of 87 patients with old myocardial infarction (OMI) were enrolled in this study who received treatment in Department of Cardiology, 1^st Affiliated Hospital of Kunming Medical University from October 2008 to January 2011, 68 male and 19 female, aged from 43 to 80 years (66.80 ± 8.41 years). The patients were divided into different group, Group A enrolled 32 cases (24 male, 8 female, 68.31 ± 8.72 years), Group B enrolled 30 cases (24 male, 6 female, 65.67 ± 8.33 years). Patients in Group A received 9 spots treatment of each ischaemia target region (-1, 0, +1 pairs), patients in Group B received 25 spots treatment of each ischaemia target region (-2, -1, 0, +1, +2 pairs), 200 shocks/spot, 3 times/week, during the first week of each month on the first, third, and fifth day for 3 months for a total of 9 therapies per patient. And 25 patients were in the control group (Group C, 20 male, 5 female, 66.24 ± 8.14 years). Group C treated with the same procedures but without the shock wave energy by using randomised single-blind method. Before the CSWT (0 month) and the follow-up of 3 months, 6 months, 12 months, all patients received time-domain way MTWA examination by Treadmill, meanwhile measuring the heart rate (HR) when the maximam MTWA occurred, MTWA/HR and the exercise time, compared the above mentioned parameters of patients in different groups to evaluate the effect of CSWT.

Results Before the CSWT there was no significant difference for each assessing parameter include MTWA, HR, MTWA/HR and Exercise time among three groups (P > 0.05). After CSWT, Compared the MTWA, HR, MTWA/HR and Exercise time in Group A and B, all the above mentioned parameters improved significantly at 3 months, 6 months, 12 months follow-up than 0 month (P < 0.05), During follow-up the Exercise time of patients in both group A and group B have continuous increased significantly, especially for the 12 months the Exercise time increased obviously than other months (P < 0.05), the rest parameters compared each two of different time subgroup within Group A and B, the differences have no statistical significance (P > 0.05); but the above mentioned parameters of Group A and B compared with Group C improved significantly (P < 0.05). The above mentioned parameters of Group C, compared each two of different time subgroup, the differences have no statistical significance (P > 0.05).

Conclusions 1. CSWT can lower the measured value of MTWA, So CSWT can lower the risk of CAD patients occurred ventricular arrhythmia and SCD, 2. can obviously improve the variable function of heart, and can significantly increase the threshold of frequency which causes TWA.