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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Survivors of out-of-hospital ventricular fibrillation (VF) are at high risk for recurrent VF, probably reflecting continued myocardial electrical instability. In this study 12-lead ECGs of 125 VF survivors with coronary heart disease were examined and compared to those of 98 ambulatory post-MI patients. The study was part of an effort to define clinical identifiers of patients likely to develop sudden cardiac death. Ventricular fibrillation survivors were commonly had premature ventricular complexes (PVCs):30% versus 13% (P less than 0.01). In addition, ECGs of VF survivors showed a significantly greater prevalence of ST-segment depression (46% versus 10%), T wave flattening (52% versus 26%), and QTc prolongation (35% versus 18%). It is proposed that these repolarization abnormalities represent asynchronous repolarization, which together with frequent PVCs, may set the stage for re-entrant ventricular dysrhythmias and ultimately VF. It is also possible that repolarization abnormalities together with premature ventricular contractions might serve as markers of patients with coronary heart disease who are at increased risk for sudden cardiac death.
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PMID:Repolarization abnormalities in survivors of out-of-hospital ventricular fibrillation. 7 73

Coronary haemodynamic and metabolic effects of propranolol and glyceryl trinitrate were studied in 12 patients with coronary artery disease and 5 without coronary heart disease, at rest and during tachycardia stress. Propranolol-associated reductions in indices of myocardial oxygen demand, left ventricle work, tension time, and left ventricle oxygen utilisation (LVVO2) were reversed when heart rate was controlled by atrial pacing. Adding glyceryl trinitrate at rest also restored heart rate but decreased the left ventricular work index and tension time index as coronary resistance declined paradoxically. Tachycardia-related increases in tension time index and LVVO2 were unchanged after propranolol, and ischaemia (angina, ST depression, and reduced lactate extraction) was not altered in most of the patients. During tachycardia, the addition of glyceryl trinitrate decreased the tension time index and LVVO2; angina recurred in only 4 patients, and ST depression and lactate extraction improved. Similar haemodynamic changes occurred in the patients with normal coronary arteries. In contrast with propranolol administered alone, propranolol plus glyceryl trinitrate enhances tachycardia tolerance and prevents tachycardia-induced manifestations of ischaemia. This action is attributed to glyceryl trinitrate-associated improvement in the adequacy of myocardial perfusion.
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PMID:Coronary and myocardial metabolic effects of combined glyceryl trinitrate and propranolol administration. Observations in patients with and without coronary disease. 10 30

The influence of therapeutic digitalisation on ST depression due to myocardial ischemia was investigated in 11 patients, average age 53.6 years, with coronary heart disease, compared with the effectiveness of nitroglycerine. Therapeutic digitalis led to an average increase of ischaemic ST depression from -0.53 to -0.73 mV. The mean pulmonary arterial and pulmonary capillary pressure decreased slightly, the frequency of pectanginous attacks increased. Independent of the digitalis effect nitroglycerine had an opposing action on these parameters. In decompensated patients with coronary heart disease (n = 4) both digitalis and nitroglycerine produced a shift of the left ventricular function curve as an expression of improved cardiac action. This could not be observed in patients with compensated ventricular function (n = 7). In sufficient ventricular function digitalis led to a further increase of myocardial ischaemic ST depression. In ventricular insufficiency no uniform behaviour was apparent. ST depression induced by digitalis could be reversibly influenced by nitroglycerine.
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PMID:[The action of nitroglycerine on digitalis induced ST depression in patients with coronary disease (author's transl)]. 10 65

A seven-year follow-up in 1973 of a prospective cardiovascular study of 1820 initially, healthy, middle-aged Chinese men of 40-59 years of age identified 1745 (95.9%) known survivors, 49 (2.7%) interim deaths, and 26 (1.4) who could not be traced. Of the survivors, 1462 (83.8%) were re-examined, 292 (16.7%) had another treadmill test of maximal exercise, and 283 (16.2%) failed to return for re-examination. On the basis of interim surveillance of hospital admissions, questionnaires and re-examination, a greater incidence of noncardiovascular events (338 or 18.6%) than evidence of cardiovascular disease (220 or 12.1%) was found while the majority (1021 or 56.1%) remained healthy. Total mortality was 0.29 for men under 50 and 0.76 per 100 person-years for men of 50 or more years of age. Only nine, or 18.4% of the deaths were due to cardiovascular causes, and unexpectedly for this population sample, only three were attributed to stroke. When cardiovascular morbidity was related to presence of ST depression after maximal exercise, to hypertension at rest by WHO criteria, to both findings, or to absence of either on initial intake examination, incidence increased from 2.3% for NEITHER group, to 5.7% for ST group, to 11.9% for HT group, and to 25.0% for BOTH groups. Re-examination revealed more evidence of cardiovascular disease than did surveillance of hospital admissions. Additional to effects of aging and mild adiposity, longitudinal changes in blood pressure and ST depression, increasing in the NEITHER group, but less frequent in the other groups, showed some evidence of regression toward the mean, as well as emerging disease and the confounding effects of uncontrolled treatment of hypertension in many. The potential for prediction of subsequent cardiovascular morbidity or mortality appeared stronger for hypertension than for postexertional ST depression, although the two were additive in this population, which is more prone to hypertension and stroke but now is developing clinical manifestations of coronary heart disease more frequently.
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PMID:Seven-year follow-up of cardiovascular study and maximal exercise of Chinese men. 12 87

The assess whether the magnitude of exercise induced ST segment depression improves the predictive values of symptom limited exercise tests, and helps in the recognition of patients with more severe coronary heart disease, 90 consecutive patients with positive treadmill tests who also underwent selective coronary arteriography were reviewed. The predictive value improved progressively with the increasing ST depression and was most reliable in a select group of patients with normal electrocardiographic baseline who were not receiving digitalis (73% with ST depression greater than or equal to 1 mm to 100% with ST depression greater than or equal to 4 mm). The incidence of 2 and 3 vessel disease increased from 61% with ST depression greater than or equal to 1 mm in the overall population to 100% with ST depression greater than or equal to 4 mm in the select group, and the incidence of left main trunk lesions increased, respectively from 6 to 30%. The prediction of 2 and 3 vessels disease was found to be significantly greater when patients were dichotomized into those with ST depression greater than or equal to 4 mm compared to less than 4 mm. It is concluded that the magnitude of ST segment depression definitely improves the predictive values of exercise tests as well as the ability to recognize the patients with more severe disease. However, the markedly positive exercise tests cannot be utilized to accurately predict the presence of 2 or 3 vessel disease in individual cases unless ST depression attains 4 mm or more in patients with normal electrocardiographic baseline who are not taking digitalis. In this group, the ability to predict left main trunk lesion is approximately 30%.
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PMID:The magnitude of exercise-induced ST segment depression and the predictive value of exercise testing. 26 78

The value of the exercise stress test in the evaluation of clinically healthy subjects and patients with coronary heart disease is not limited to the isolated interpretation of abnormalities of the S-T segment. Other measurable parameters which are of diagnostic and prognostic importance include: (1) a decrease in systolic blood pressure during exercise; (2) the appearance of complex ventricular arrhythmias of low exercise heart rates; (3) the appearance of inverted U waves during or after exercise; (4) the patient's maximal exercise capacity; and (5) new auscultatory findings postexercise. The reliability of the exercise test as a diagnostic tool is futher enhanced by proper patient selection and careful attention to exercise techniques. Subjects with labile ST-T wave changes during standing hyperventilation, fixed ST-T changes at rest, and intraventricular conduction defects are not ideal candidates for "diagnostic" stress testing and the examining physician must rely more heavily on nonelectrocardiographic findings. The criteria used to define an abnormal S-T response will vary according to the lead system used. However, in both symptomatic and asymptomatic subjects the appearance of marked degrees of S-T depression at low exercise heart rates significantly increases the probability of finding advanced coronary disease, particularly if the S-T depression is seen in multiple monitoring leads and is of prolonged duration postexercise.
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PMID:Role of exercise stress testing in healthy subjects and patients with coronary heart disease. Controversies in cardiology--I. 35 20

In the case of coronary heart disease the behaviour of the ST segment proved to be of major diagnostic importance for the recognition of hypoxidotic processes in the myocardium. Isolated consideration of the T-wave does not provide any characteristic information. The so-called ischaemic reaction is characterized by a typical jump of polar vectors from the left to the right side, which are moved rearwards without usually leaving the right-hand quadrant at the front. The angles of elevation are in a horizontal position or directed slightly upwards. This change of the direction can but need not include an increased magnitude. It is possible to observe the development of ischaemia as exercise is increased, with the polar vectors increasing or unchanging in magnitude and being moved rightwards, rearwards, and upwards. This characteristic movement invariably starts at the J point, involving additional portions of the ST segment as ischaemia is developed during increasing exercise. The J point depression should be considered to be only a "normal" response to exercise, provided the variations relate to the J point or 20 ms away from the latter.
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PMID:[Detection of the ischemic reaction of the myocardium by means of the polar coordinates of the ST segment in the corrected orthogonal ECG]. 39 78

The electrocardiogram on exercise with a graduated load on the bicycle ergometer has proved of value as a screening method for coronary heart disease and arrhythmias. A horizontal or descending ST junction depression of 0.1 mv in the left precordial lead is considered a significant ischemic reaction. The present paper reports the practical performance and evaluation of findings of the method. The prognostic significance of a pathological ECG on exercise with regard to the occurrence of a coronary heart disease and the progression of the disease are pointed out.
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PMID:[The ECG on exercise (author's transl)]. 40 32

The significance of asymptomatic episodes of ischemic type S-T segment depression was studied in 20 patients with coronary heart disease. Continuous 10 hour electrocardiographic recordings accompanied by detailed daily diaries of activity and symptoms were obtained periodically during a mean time of 16 months. All patients had ischemic type S-T depression associated with angina pectoris during treadmill exercise. Measurements of heart rate, S-T depression and exercise level at the onset of angina obtained during repeated controlled exercise tests at the start of each study period were compared with the measurements recorded during daily activity. After 2,826 hours of recording, 411 transient epidsodes of ischemic type S-T depression were noted during usual daily activity. Only 101 (25 percent) of these episodes were associated with angina. The remaining episodes were unrelated to other symptoms or to posture. All occurred at heart rates significantly lower than those observed at the onset of angina during exercise testing. Of these episodes of asymptomatic S-T depression, 72 percent occurred only at rest or during very light activity such as slow walking or sitting. Nitroglycerin administered hourly significantly reduced the frequency of these episodes, thus supporting the concept that they represent painless ischemia. Because the episodes of asymptomatic ischemic type S-T depression occurred more frequently than angina during usual daily activity and were evident at heart rates and activity levels well below those expected to evoke ischemia, they may be caused by factors other than those that cause angina.
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PMID:Transient asymptomatic S-T segment depression during daily activity. 40 3

Rest and exercise ECGs are the most widely used "noninvasive" tests for detecting coronary heart disease, but their sensitivity and specificity are suboptimal. Therefore, the diagnostic value of myocardial perfusion scanning using thallous chloride Tl 201 during rest and stress electrocardiography was examined in 95 patients with a chest discomfort syndrome. Overall, thallous chloride Tl 201 perfusion scanning had a sensitivity of 75% and a specificity of 91% for coronary heart disease compared with 56% sensitivity and 86% specificity with exercise-induced ST segment depression on the ECG. Combining rest and stress ECGs resulted in a sensitivity of 71%. In patients with coronary heart disease, perfusion scanning had a sensitivity of 93% for asynergy compared with 58% for exercise-induced ECG ST depression. Rest and stress myocardial perfusion scanning with thallous chloride Tl 201 provides improved sensitivity with good specificity in the diagnosis of coronary heart disease compared with exercise electrocardiography alone.
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PMID:Extent and severity of coronary heart disease. Determinations by thallous chloride Tl 201 myocardial perfusion scanning and comparison with stress electrocardiography. 44 66


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