To investigate the relation between basal coronary artery diameter and development of coronary artery spasm, the diameters of the proximal, middle and distal segments of the three major coronary artery branches, together with that of the left main trunk, were measured on a control angiogram and after ergonovine and nitrate administration in 30 patients with vasospastic angina without significant organic stenosis, and in 35 patients without ischemic heart disease. The percent change in coronary diameter after ergonovine and nitrate administration compared with the control diameter was used as an index of coronary vasoreactivity. In patients with vasospastic angina, coronary artery responses to both ergonovine and nitrate were greater in the spastic segments than in the other segments (p less than 0.05), and those of the coronary arteries without spasm were greater than those of the coronary arteries in patients without ischemic heart disease (p less than 0.01). There were no significant differences between the coronary artery diameters in the two groups after nitrate administration, and the control diameters were less in patients with vasospastic angina than in patients without ischemic heart disease. These observations indicate that a coronary vasomotion disorder, which involves increased basal coronary artery tone and hypersensitivity to vasoconstrictive stimuli, not only at a localized segment but also in the entire coronary artery tree, is present in patients with vasospastic angina. Clinically, evaluation of basal coronary artery tone may be useful for predicting the occurrence and location of coronary artery spasm.
We investigated the characteristics of decreased heart rate variability (HRV) in diabetic patients with ischemic heart disease (IHD). Twenty-one healthy control subjects, 17 diabetic patients without IHD, and 33 diabetic patients with IHD were studied. The diabetic patients with IHD were subdivided into 2 groups according to the severity of their IHD: severe or mild. HRV was evaluated in all subjects using the spectral variables of the all-frequency, low-frequency, high-frequency (AF, LF, HF) components and the LF/HF ratio were determined from Holter recordings. The AF and LF components in patients with diabetes only or diabetes and severe IHD were significantly lower than in control group, but the HF component was significantly lower only in the group of patients with diabetes and severe IHD. The LF/HF ratio did not differ significantly among the 4 groups, but was the lowest in diabetic patients without IHD. Patients with diabetes and mild IHD showed a slight decrease in HRV, but this was not significant. With regard to the circadian rhythm of HRV, the AF and LF components in patients with diabetes-only or diabetes and severe IHD were significantly decreased and showed the same pattern throughout the day. However, the HF component was decreased during more time zones in patients with diabetes and severe IHD, whereas the LF/HF ratio was lower during more time zones in the diabetes-only group. All spectral variables showed a tendency to be inversely related to the duration of diabetes in all diabetic patients. In particular, the LF/HF ratio showed a significant negative correlation. The HRV of diabetic patients was characterized by a decreased LF/HF ratio. It was concluded that, although HRV in diabetic patients with severe IHD was reduced mainly as a result of diabetic neuropathy, this was also partly due to a decline in parasympathetic tone as a result of myocardial injury.
The QRS axis of 130 consecutive patients with coronary artery disease undergoing percutaneous transluminal coronary angioplasty (PTCA) were measured before balloon inflation and just before balloon deflation. Patients were divided into two groups. Group A (103) had angina pectoris and/or non-transmural old myocardial infarction with no abnormal Q waves; group B (27) had an old transmural myocardial infarction with abnormal Q waves. In group A, the QRS axis had significantly shifted to the left in patients with left anterior descending artery (LAD) occlusion (from 68.0 +/- 42.7 degrees to 40.2 +/- 44.6 degrees, P < 0.001); however in those patients without involvement of the major septal branch, significant axis changes were not observed (from 53.6 +/- 34.1 degrees to 49.8 +/- 33.1 degrees). When the right coronary artery (RCA) was occluded in group A, the QRS axis shifted to the right significantly (from 63.2 +/- 40.0 degrees to 89.8 +/- 30.1 degrees. P < 0.01); during left circumflex artery (LCX) occlusion, no significant axis shift was observed. In group B, no significant axis shift was observed either in patients with occlusion of the LAD or the RCA. It is concluded that transient left axis deviation reflects an obstructive lesion of the proximal portion of the LAD with involvement of the major septal branch, and transient right axis deviation reflects an obstructive lesion of the RCA.
Summary:The QRS axis of 101 patients with coronary artery disease (CAD) and 57 nonnal subjects without CAD who underwent coronary arteriograms were measured before and after exercise testing. There was no improvement in the sensitivity of positive axis shifts (15 degnxs or greater) for CAD (1 8 %) when compared to the value of positive ST depression (61%). However, the specificity of positive axis shifts for CAD was significantly increased (98%) when compared to the value of positive ST depression (77 96). In addition, 39 96 of those patients with CAD (39 of 101) showed false negative ST depression, but 18% of these patients (7 of 39) showed a positive axis shift. In nonnal subjects 21 % (12 of 57) showed false positive ST depression, but all of the 21 % (12 of 12) showed negative axis shift. There was no significant difference in the increments of heart rate between positive ST depression, positive axis shift, and negative ST depression, negative axis shift. No statistical differences in the sensitivity of ST depression and an axis shift for one-, two-and threevessel diseases were noted. The specificity of left-axis shift for the left anterior descending attery lesion was 98 % and the specificity of right-axis shift for the right coronary artery and/or left circumflex artery lesion was 91 % . Therefore, the axis shift response is no more sensitive for the detection of CAD than ST depression. However, when a positive axis shift is observed, one can predict two things: the CAD and the localization of the coronary stenosis .
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