Frequency Of ST Segment Depression Research Articles

Comparison of Clinical Efficacy of Ticagrelor and Clopidogrel for Treatment of Coronary Heart Disease with Myocardial Ischemia

Objective: To compare clinical efficacy of ticagrelor and clopidogrel for treatment of coronary heart disease with myocardial ischemia to provide references for later phase of clinical treatment. Methods: Ninety-six coronary heart disease patients with myocardial ischemia admitted to our hospital from July 20 to July 2019 were recruited as subjects. They were randomly divided into study group and control group according to parity of case number, with 48 patients in each group. Control group was given treatment with clopidogrel, while patients in study group were given treatment with ticagrelor. Clinical efficacy was compared between the both groups. Results: Comparison showed that total effective rate of clinical treatment was higher in study group when compared to control group (P<0.05). Frequency of ST segment depression, duration of ST segment depression, systolic blood pressure, diastolic blood pressure, heart rate and other clinical indicators in study group were superior to control group (P<0.05). Whole blood viscosity at low shear rate, whole blood viscosity at high shear rate, plasma viscosity shear rate, total cholesterol, triglyceride and other haemorheological parameters in study group were superior to control group (P<0.05). Conclusion: Application of ticagrelor has higher clinical efficacy than clopidogreal for coronary heart disease patients with myocardial ischemia. Clinical indicators and haemorheological parameters of myocardial ischemia patients were significantly improved. It should be promoted for application.

051 Reducing particulate air pollution exposure in patients with coronary heart disease: improved cardiovascular health

Introduction Particulate air pollution is a major public health concern and is associated with cardiovascular disease. In healthy volunteers, reducing particulate air pollution exposure attenuates exercise-induced increases in blood pressure and improves heart rate variability. In this study, we investigated the benefit of reducing exposure in patients with coronary heart disease. Methods In an open-label randomised crossover trial, 98 patients with coronary heart disease walked on a predefined city centre route in Beijing in the presence and absence of a highly efficient facemask. Personal exposure to air pollution and exercise was assessed continuously using portable monitors and GPS tracking respectively. Blood pressure was measured using ambulatory blood pressure monitoring. Continuous 12-lead electrocardiography was carried out using a Holter monitor. Subjects9 symptoms were assessed using a simple questionnaire. Results The mask intervention was well tolerated and reduced general symptoms, perceived effort of work and perception of pollution (p 3 ; PM 2.5 ) and particle number (4.19±1.29 vs 4.39±1.45×10 4 particles/cm 3 ) were slightly lower during the mask visit, but based on efficacy studies, we predict the mask reduced the exposure further to 2 μg/m 3 and 1200 particles/cm 3 respectively. During the 2-h walk, exercise performed was identical on both visits. When subjects wore a facemask, mean arterial pressure was lower (93±10 vs 96±10 mm Hg; p=0.025) and heart rate was similar (p>0.05). During the 2-h walk, heart rate variability was increased (HF-power 54 (27 to 108) vs 40 (20 to 69) ms 2 , p=0.005; HF/LF ratio 0.418 (0.258 to 0.712) vs 0.328 (0.207 to 0.573), p=0.004; RMSSD 16.7 (13.2 to 22.5) vs 14.8 (10.9 to 19.6) ms, p=0.007) when a facemask was worn. There were no differences in overall 24-h blood pressure, heart rate or heart rate variability. Maximal ST segment depression throughout the 24-h period was reduced when subjects wore a mask (−142 (−179 to −110) vs −156 (−202 to −123) μV; p=0.046) although there was no difference in the frequency of ST segment depression (>1 mm) episodes or symptoms of angina. Conclusions In patients with coronary heart disease, wearing a facemask reduces symptoms and is associated with objective improvements in myocardial ischaemia, blood pressure and heart rate variability. This simple well-tolerated intervention has the potential to reduce the incidence of cardiovascular events in patients with coronary heart disease living in industrialised or urban environments.

Differences in the Frequency of ST Segment Depression During Upright and Supine Exercise

Differences in the Frequency of ST Segment Depression During Upright and Supine Exercise

Differences in the frequency of ST segment depression during upright and supine exercise: Assessment in normals and in patients with coronary artery disease

Increased utilization of ambulatory ST segment monitoring mandates an appreciation of nonischemic variables that may influence the ST segment. While a greater frequency of ST segment depression has been reported with supine vs upright exercise, the relative false positive rate in both positions is not known. Thus, we compared the frequency of exercise ECG abnormalities during upright and supine bicycle exercise in two groups—17 normals and 46 patients with coronary artery disease. Exercise was performed in combination with radionuclide ventriculographic imaging. Peak exercise heart rate, peak systolic blood pressure, and exercise duration time were all slightly higher in the upright vs supine position ( p < 0.05). Nevertheless, the frequency of positive ST segment responses was more common in the supine position, both in the patients with coronary artery disease (54% vs 30%, p < 0.05) and in the normal subjects (29% vs 6%, p = NS). The corresponding radionuclide ventriculographic responses, however, were normal during upright and supine exercise in 6 of the 11 CAD patients and in all five of the normal subjects with an abnormal ST segment response during supine exercise only. The frequency of exercise-induced chest pain was also similar in the two positions. Thus, we theorize that nonischemic factors may govern some positive ST segment responses in the supine position. This finding is of relevance for understanding the potential sources of physiologic false positive ST segment responses for ambulatory ST segment monitoring.

Should we treat silent ischaemic?

24-hour ambulatory monitoring of the ST segment in patients with angina has shown that ST segment depression may be accompanied by angina pectoris, but it occurs equally often without any symptoms. Approximately half of all episodes of ST segment depression are accompanied by chest pain. Doubt has been expressed as to the significance of ST segment changes that occur in the absence of chest pain, but haemodynamic studies and nuclear imaging have shown that such changes are accompanied by alterations in left ventricular filling pressure. Ambulatory pulmonary artery monitoring has also shown that silent ST segment depression is accompanied by a significant increase in pulmonary artery diastolic pressure, and this does not differ from painful episodes of ST segment depression. Studies using ambulatory monitoring have shown that antianginal drugs are capable of reducing the frequency of ST segment depression accompanied by pain. We have recently performed studies investigating the use of antianginal medications; i.e. beta-blocking drugs with and without sympathomimetic activity, alpha-beta-blocking drugs, calcium antagonists and nitrates in the treatment of both painful and painless ST segment depression. These studies have shown that the effect of these drugs on painless episodes is similar to their effect on painful episodes of myocardial ischaemia. Although the prognostic implications of silent ischaemia and the importance of these therapeutic findings are unknown, it is well known that approximately one-quarter of all myocardial infarctions occur without chest pain. Moreover, recent investigations in unstable angina show that silent myocardial ischaemia is an important predictor of future coronary events.

Should We Treat Silent Ischaemia?

Twenty-four hour ambulatory monitoring of ST segments in patients with angina has shown that ST-segment depression may occur accompanied by angina pectoris or equally frequently in the absence of symptoms. Approximately one-third of all episodes of ST-segment depression are accompanied by chest pain. Doubt has been expressed as to the significance of ST-segment changes occurring in the absence of chest pain, but haemodynamic studies and nuclear imaging have shown that such changes are accompanied by alterations in left ventricular filling pressure. Ambulatory pulmonary artery monitoring has also shown that silent ST-segment depression is accompanied by a significant increase in pulmonary artery diastolic pressure and that these do not differ from painful episodes of ST-segment depression. Studies using ambulatory monitoring have demonstrated that antianginal drugs, angioplasty, and surgery are capable of reducing not only the frequency of ST-segment depression accompanied by pain, but also painless ST-segment changes. Further studies are necessary to determine whether prognosis is improved by treating these silent episodes of myocardial ischaemia.

Favorable Effects of Acebutolol on Exercise Performance and Angina in Men with Coronary Artery Disease

Acebutolol, a relatively cardioselective beta-adrenergic blocking drug, was administered to 20 men with coronary artery disease and angina. A three month double-blind cross-over (placebo and acebutolol) design was used following a 12-week placebo phase and a six-week dose-titration phase. During the cross-over phase, acebutolol (400 mg in 19 men and 300 mg in one, orally three times per day) increased the duration of treadmill exercise (placebo, 6.8 +/- 0.5) min [average +/- SEM]; acebutolol, 8.1 +/- 0.6 min; P less than 0.05) and decreased the frequency of ST segment depression during exercise (placebo, 12 or 20 men; acebutolol, 6 of 20 men). The heart rate x systolic blood pressure product (x 10(-2)) was decreased both at rest (placebo, 105.0 +/- 4.0; acebutolol, 84.0 +/- 3.0; P less than 0.01) and during exercise (placebo, 199.0 +/- 10.0; acebutolol, 144.0 +/- 8.0; P less than 0.01). Acebutolol treatment decreased the frequency of angina (diary cards) (placebo, 9.0 +/- 2.4 episodes per week; acebutolol, 6.4 +/- 2.2 episodes per week; P less than 0.05) and decreased the consumption of nitroglycerin (placebo, 9.0 +/- 4.4 tablets per week; acebutolol, 7.4 +/- 4.0 tablets per week; P less than 0.05). Results suggest that acebutolol increases exercise performance and decreases the occurrence of angina in men with coronary disease.