Effects of spinal cord stimulation in angina pectoris induced by pacing and possible mechanisms of action.
OBJECTIVE
To investigate the effects of spinal cord stimulation on myocardial ischaemia, coronary blood flow, and myocardial oxygen consumption in angina pectoris induced by atrial pacing.


METHODS
The heart was paced to angina during a control phase and treatment with spinal cord stimulation. Blood samples were drawn from a peripheral artery and the coronary sinus.


METHODS
Multidisciplinary pain centre, department of medicine, Ostra Hospital, and Wallenberg Research Laboratory, Sahlgrenska Hospital, Gothenburg, Sweden.


METHODS
Twenty patients with intractable angina pectoris, all with a spinal cord stimulator implanted before the study.


RESULTS
Spinal cord stimulation increased patients' tolerance to pacing (p < 0.001). At the pacing rate comparable to that producing angina during the control recording, myocardial lactate production during control session turned into extraction (p = 0.003) and, on the electrocardiogram, ST segment depression decreased, time to ST depression increased, and time to recovery from ST depression decreased (p = 0.01; p < 0.05, and p < 0.05, respectively). Spinal cord stimulation also reduced coronary sinus blood flow (p = 0.01) and myocardial oxygen consumption (p = 0.02). At the maximum pacing rate during treatment, all patients experienced anginal pain. Myocardial lactate extraction reverted to production (p < 0.01) and the magnitude and duration of ST segment depression increased to the same values as during control pacing, indicating that myocardial ischaemia during treatment with spinal cord stimulation gives rise to anginal pain.


CONCLUSIONS
Spinal cord stimulation has an anti-anginal and anti-ischaemic effect in severe coronary artery disease. These effects seem to be secondary to a decrease in myocardial oxygen consumption. Furthermore, myocardial ischemia during treatment gives rise to anginal pain. Thus, spinal cord stimulation does not deprive the patient of a warning signal.
Mannheimer
C
C
Department of Medicine, Ostra Hospital, Gothenburg, Sweden.
Eliasson
T
T
Andersson
B
B
Bergh
C H
CH
Augustinsson
L E
LE
Emanuelsson
H
H
Waagstein
F
F
D000368:Aged; D000787:Angina Pectoris / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial; D003326:Coronary Circulation / Q000502:physiology; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D013116:Spinal Cord
D007773:Lactates; D019344:Lactic Acid