Assessment of the influence of spinal cord stimulation on left ventricular function in patients with severe angina pectoris: an echocardiographic study

Abstract

Patients with severe, widespread coronary atherosclerosis and patients who have undergone several coronary artery bypass operations are often poor candidates for coronary bypass surgery (CABG). Spinal cord stimulation (SCS) has been shown to have an anti-anginal effect that is probably associated with an anti-ischaemic effect. In the present investigation, 15 patients with severe angina (mean age 64 years, range 49-71) were studied. All patients had a history of intractable angina pectoris despite optimal medical treatment and previous coronary bypass operation. The patients had multi-vessel disease and graft occlusion or graft stenosis on postoperative coronary angiograms. Left ventricular function was assessed echocardiographically at rest and during provocation with adenosine infusion in a control session without treatment and during treatment with SCS. The recovery time was at least 3 h. The decrease in the ejection fraction during adenosine infusion was more pronounced in the control situation (44 to 37%; P < 0.05) than during SCS (48 to 44%; ns), and the time to echocardiographic signs of dysfunction and to anginal pain during adenosine infusion was significantly prolonged during SCS (P < 0.001). In addition, the recovery time for these parameters was shorter during SCS (P < 0.001). It is concluded that the deterioration in left ventricular function during adenosine provocation was less pronounced with SCS than without. This possible anti-ischaemic effect is in agreement with results from earlier studies.