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

A reproducible tourniquet-shock has been produced in hind limbs of dogs by unilateral and bilateral extremity ischemia. The following parameters have been measured for analysing the function of the cardiovascular system: mean aortic pressure, heart rate, cardiac output, intraventricular pressure and left ventricular pressure. From these data the stroke volume, stroke work, total peripheral resistance and the parameters of heart contractility dp/dtmax, dp/dtmax:IP and t-dp/dtmax were derived. During the ischemic period all circulatory parameters did not change in comparison to the controls. A tourniquet-shock developed upon recirculation of the ischemically stressed extremity which was more pronounced after bilateral than after unilateral hind leg ischemia. After release of the tourniquet all animals with unilateral tourniquet survived an observation period of 5 hours duration, whereas 6 out of 8 dogs with bilateral tourniquet died of heart failure. Upon release of the tourniquet, the cardiac output raised up to 140% of the normal value: the abruptly decreasing aortic pressure was fully compensated by a tachycardia from 100 to 190 (beats/minute). The parameters dp/dtmax:IP and t-dp/dtmax indicated a distinct increase of the left ventricular contractility in the early tourniquet-syndrom. Already after 30 minutes an increasing circulatory depression developed indicative of the decrease in aortic pressure, and enddiastolic pressure. At the same time an increase of heart rate and total peripheral resistance occurred. The parameters of left ventricular contractility did not change markedly during the course of shock except for the final stage.
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PMID:[Hemodynamics and myocardial contractility in experimental tourniquet-shock]. 126 40

In summary, although exercise is, as is every other procedure, imperfect with regard to sensitivity and specificity, it provides an invalualbe adjunct in the evaluation of patients with coronary disease. The test is simple, inexpensive, safe and rapidly performed and is an invaluable aid in screening patients with possible coronary disease. It is used in an asymptomatic population for industrial purposes, is useful in assessing the etiology of otherwise undiagnosed chest pain, helpful in evaluating the overall severity of ischemia [and therefore in culling-out those patients that might benefit from coronary angiography], is useful in following the course of patients with proven coronary disease [including those with acute myocardial infarction], and has found a place in the follow-up evaluation of individuals having aortocoronary bypass surgery. As a screening procedure, the treadmill test aids in seeking out that group of patients with coronary disease with potentially malignant lesions, i.e. main left coronary lesions, triple-vessel disease and [to a lesser extent] severe proximal left anterior descending coronary disease. Hence, the finding of marked depth of ST depression, prolonged duration of ischemia associated with deep ST segments, serious exercise-induced ventricular arrhythmias and hypotension produced during mild-to-moderate exercise might each be an indication of extensive coronary angiography. In many cases exercise testing is superior to coronary angiography, being a simpler, safer screening procedure, and a more functional test in documenting the presence or absence of coronary insufficiency.
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PMID:Interpretation and limitations in stress testing. 127 86

The present study indicates that: (a) local administration of low concentrations of an analog of vasopressin, 1-deamino-[2-phenylalanine, 8-arginine]-vasopressin (DPAVP), constricts venules in the rat splanchnic terminal vascular bed of normal animals, unlike that seen for catecholamines; (b) maximal concentrations of DPAVP narrow but do not occlude both arterioles and venules: (c) microscopic muscular venules (31-39 mu i.d.) do not narrow more than 20% in response to the vasopressin analog DPAVP; and (d) terminal arterioles (17-23 mu i.d.) do not narrow more than 50% in response to DPAVP. Systemic administration of DPAVP to rats subjected to hemorrhage or bowel ischemia shock more than doubles survival rates over control rats receiving Ringer solution. Infusion of DPAVP produces a dose-dependent effect on arterial blood pressure, microscopic capacitance vessels, large arterioles and small arteries. In addition, i.v. administration of DPAVP: (a) returns arterial hematocrit towards normal after shock; and (b) regenerates and sustains vasomotion and venular tone, decreases microvascular hyperreactivity characteristic of shock syndromes, restores constricted arteriolar lumen sizes towards normal, predisposes to a splanchnic microbed virtually free of stasis, petechiae and leukocytic sticking, and restores capillary perfusion and outflow to near-normal. Further, DPAVP effectively restores the early reticuloendothelial system (RES) phagocytic depression, characteristic of shock syndromes, to normal; the latter eventuating in RES hyper-phagocytic activity. These findings indicate it is possible to synthesize vasoactive molecules which: (a) exert selective microvascular and RES phagocytic effects; and (b) are highly beneficial in the therapy of low-flow states, at least in rats.
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PMID:DPAVP: a vasopressin analog with selective microvascular and RES actions for the treatment of circulatory shock in rats. 127 38

Nicorandil is a potent coronary vasodilator. To assess its long-term antianginal effect, we designed a randomized, parallel double-blind trial of 6 weeks' duration comparing nicorandil (10 or 20 mg b.i.d.) with propranolol (40 or 80 mg t.i.d.). The study comprised 77 men with stable angina, no maintenance medication at entry, and an exercise test positive for angina and ST-segment depression. The therapy was started with 10 mg nicorandil b.i.d. or 40 mg propranolol t.i.d. After 3 weeks, the dosage could be doubled according to clinical criteria. Four men receiving nicorandil and one receiving propranolol were withdrawn with side effects; in three cases, the data were not complete. Thus, comparative data were obtained in 69 patients; in 51 of these (26 receiving nicorandil and 25 receiving propranolol), the dosage was increased to the higher level. Blood pressure and heart rate were unaltered by nicorandil and lowered by propranolol. The number of anginal attacks decreased relative to baseline on nicorandil and propranolol (p < 0.002), but total exercise duration was not influenced by either drug. The exercise test performed 2 h after either pill ingestion showed a decrease and a delay in occurrence of myocardial ischemia. The test performed 12 h after medication exhibited reduced ischemia, whereas only propranolol resulted in delayed ST-segment depression. The double product of heart rate and systolic blood pressure was affected only slightly by nicorandil and reduced significantly by propranolol (p < 0.001). Thus, nicorandil medication affords similar improvement as propranolol in patients with angina pectoris, but the mode of action appears to be different.
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PMID:Efficacy of nicorandil versus propranolol in mild stable angina pectoris of effort: a long-term, double-blind, randomized study. 128 78

In a randomized, cross-over, double-blind study, the effects of nifedipine were compared with those of diltiazem in 20 patients with severe stable angina pectoris and multivessel coronary artery disease treated with nitrates and beta-blockers. The comparison was performed by bicycle ergometry, clinical evaluation, and ambulatory 24-h ECG monitoring for 7-8 weeks. As compared with placebo, both nifedipine and diltiazem significantly reduced the daily number of anginal attacks and nitroglycerin consumption; prolonged exercise duration, time to 1-mm ST segment depression, and to onset of angina; and reduced the sum of ST segment depressions at maximal identical load in ergometry. In ambulatory ECG monitoring, only nifedipine significantly diminished the duration of asymptomatic ST segment depression as compared with placebo. Antianginal and antiischemic effects of nifedipine and diltiazem were similar. Both nifedipine and diltiazem significantly increased the effects of treatment with nitrates and beta-blockers. Administration of nifedipine was safer because at night diltiazem caused significant bradycardia despite careful titration of optimum doses of the drug. Although the maximum well-tolerated doses of conventional medication suppressed anginal symptoms in some patients, they did not abolish ischemia either at ergometry or in daily life.
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PMID:Effects of nifedipine and diltiazem on myocardial ischemia in patients with severe stable angina pectoris treated with nitrates and beta-blockers. 128 86

Ischemic hepatic failure is often accompanied by systemic circulatory failure. In hepatic graft failure, this circulatory derangement is reported to be cured by retransplantation. This suggests that ischemic liver might release some substance which causes circulatory depression. In the present study, the role of platelet activating factor (PAF) in systemic circulatory failure after liver ischemia was investigated. Partial hepatic ischemia was induced in ten dogs by clamping the afferent vessels to almost 70% of the liver for 60 minutes, and non-ischemic lobes were resected after declamping. Five were pretreated with 3 mg/kg of PAF antagonist (CV6209) i.v. (PAF antagonist group), and the others were pretreated with saline (control group). The mean arterial pressure markedly decreased after declamping in control group (89 +/- 25mmHg 25 min after declamping), but it did not fall in PAF antagonist group (155 +/- 221mmHg). Three died from either shock or hepatic failure within a week in control group, but none died in PAF antagonist group. In conclusion, ischemic liver was suggested to release PAF and depress systemic circulation. And a PAF antagonist was expected to be an effective drug for the circulatory derangement caused by ischemic liver.
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PMID:[Experimental study on platelet activating factor and systemic circulatory failure caused by ischemic liver]. 128 60

The clinical implications of isolated late recovery ST depression were tested in patients with scintigraphically defined ischemia (coronary artery disease [CAD], n = 18) compared with patients without ischemia (n = 25). Spontaneous (78.4 versus 12.0%, P < 0.008) and exercise-induced angina (44.4 versus 0%, P < 0.0001) were more frequently seen in patients with CAD. Histories of unstable angina (33.3%), prior myocardial infarction (27.8%), ST elevated angina (22.2%) and significant stenosis in the left anterior descending artery (17 of 18, 94.4%) were almost exclusively seen in the CAD group. There was no significant difference between the two groups in capacity for exercise, maximum deviation of ST level or TV2 amplitude. Balloon angioplasty abolished late recovery ST changes in 63.6% of CAD patients. These results suggest that isolated late recovery ST depression, when accompanied with typical chest pain, may be considered as an indicator of myocardial ischemia, but this phenomenon is difficult to distinguish electrocardiographically.
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PMID:Isolated post exercise delayed ST depression as a sign of severe ischemia: the influence of percutaneous transluminal coronary angioplasty. 128 36

Using Langendorff's perfusion model of isolated rat heart, the effect of period of ischemia, ischemia-reperfusion and changes in perfusate pH on the function of calcium uptake of cardiac sarcoplasmic reticulum (SR) was observed. The initial rate and capacity of calcium uptake by SR decreased significantly after 25 min ischemia, and were further worsened when ischemia was prolonged to 40 min. When hearts were subjected to 15 min reperfusion after 25 min ischemia, calcium uptake capacity and initial rate decreased even more in comparison with that of 40 min ischemia. In addition, the calcium dependent ATPase activity of SR was also markedly inhibited. Reperfusion with acid (pH 6.8) or alkaline (pH 8.0) made no significant difference on the aforementioned reperfusion induced changes. The results indicated that myocardial ischemia depressed the calcium transport activity of SR, and this depression was further aggravated with prolonging ischemia. Reperfusion after ischemia exacerbated the ischemic injury. Reperfusion with either acid or alkaline Krebs-Henseleit solution could not improve the calcium uptake function of SR, implying that the pH change does not seem to be an important factor in inducing the SR dysfunction during ischemia-reperfusion.
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PMID:[Alteration of calcium uptake and Ca(2+)-ATPase activity of cardiac sarcoplasmic reticulum in rat during ischemia-reperfusion]. 129 51

Working capacity after myocardial infarction depends on the physical and cardiovascular status, psychological repercussions and conditions of work. The latter two are much more important than the first two factors. Cardiovascular functional status is readily assessed by the large number of available investigations which leave little unknown. Exercise stress testing during the second week is the most cost-efficient investigation, providing reliable and sufficiently quantifiable data about the possible sequellae of cardiac failure on effort, ischemia and arrhythmias: an idea of the patient's functional capacity and circulatory responses (athletic, hyperkinetic) may also be obtained allowing adjustment of treatment to improve exercise capacity which goes much further than the statistical hope of prolonging survival. However, it would be naive to think that a satisfactory exercise stress test guarantees the patients' capacity to return to work. Psychological and sociological factors are more important by far. The dominant trait of the post-infarction psychological syndrome must be identified (anxiety, depression, negation): the positive and negative influences of the family, social and professional environment must be evaluated. A good knowledge of the patient's working conditions is essential to go against a number of taboos hindering the return to work (stress, stairs, restaurant meals, etc...). Finally, the medico-legal relationship between the infarct and work should not be neglected: the management of myocardial infarction when an occupational disease must respect the legislative and judicial texts which do not always correspond with everyday clinical practice. There is a lack of structures for cardiac function testing for assessing physical aptitude: we suggest that in the context of the proposed hospital reforms, departmental heads should consider setting up such units which would have a specific task respecting the spirit of these reforms. Nevertheless, cardiologists should pay more attention to the convalescent phase of infarction. This is the time when many social catastrophes can be avoided.
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PMID:[Return to work after myocardial infarction: evaluation and decision]. 130 47

Six patients (2 males and 4 females, mean age of 46 years) with X syndrome were reported in this paper. All patients presented with typical exertional angina pectoris. In 4 patients the angina had a variable threshold of onset, it often occurred at rest and occasionally nocturnally. The electrocardiogram during chest pain showed ST segment depression of more than 0.05-0.1 mV in all 6 patients. The treadmill or bicycle ergometer exercise test was positive in 4 cases (ST segment depression > 0.1 mV), equivocal in 1 (ST segment < 0.1 mV) in whom the 201Tl exercise myocardial perfusion scan showed sign of ischemia, and negative in 1 in whom atrial pacing at heart rate of 135 beats/min induced angina and ST segment depression of 0.1-0.15 mV. Echocardiograms and X ray chest films revealed no sign of ventricular hypertrophy or enlargement. The 201Tl exercise myocardial perfusion scan was performed in 5 patients, which showed signs of ischemia in 4 patients and suspected to have ischemia in 1. Left ventriculograms and coronary angiograms were normal in all 6 patients. Ergonovine provoking test (total dose of 0.4 mg) was negative in 5 patients, it was not performed in 1 in whom there was no evidence of coronary artery spasm by angiogram during appearance of electrocardiographic ischemic changes and chest pain. Left ventricular endomyocardial biopsy was performed in 1 patient, which showed significant smooth muscle cell proliferation in the medial layer of a small artery with diameter of 62.5 mu which produced narrowing of the lumen.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[X syndrome--report of six cases]. 130 21


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