Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coronary arterial vasoconstriction, well recognized in Prinzmetal's variant angina, may participate in the pathogenesis of classic angina as well. Several recent studies in patients with obstructive coronary artery disease suggest that apparently spontaneous reductions in coronary blood flow can result in myocardial ischemia and even infarction. Evidence supporting the alpha adrenergic nervous system as a cause of such coronary vasoconstriction is reviewed, particularly the results of provocative testing with the cold pressor stimulus. Upon exposure of the skin to cold, patients with coronary artery disease demonstrate an inappropriate coronary vasoconstrictor response, often sufficient to produce angina. Normal patients, by contrast, show no change in coronary vascular resistance. In patients with a diseases coronary circulation, inappropriate vasoconstriction further restricts myocardial perfusion and appears to be little affected by beta adrenergic blocking agents or nitrates in the usual dosages. Nifedipine has proved effective in preventing coronary arterial spasm in patients with Prinzmetal's angina. Studies currently in progress suggest that it is also effective in blocking inappropriate coronary vasoconstriction in patients with typical angina. Nifedipine may thus be a useful addition to the treatment of ischemic heart disease.
 ...
PMID:Inappropriate coronary vasoconstriction in patients with coronary artery disease: a role for nifedipine? 38 63

Coronary artery spasm was induced by intravascular administration of ergonovine maleate (Ergotrate) during cardiac catheterization. In 78 patients suspected to have Prinzmetal's angina, no morbidity or death has resulted despite complete occlusive spasm in two and three coronary arteries. Typical EKG changes and akinesia of the myocardium in the distribution of the occluded vessels documented functional myocardial ischemia during spasm. The occlusive spasm is readily reversed by sublingual or intravascular nitroglycerin, and ventricular contractility returns to normal following relief of spasm. Occlusive spasm has been demonstrated in 15 patients with clinical evidence of Prinzmetal's angina. Symptoms have been effectively relieved by coronary vasodilators in 10 patients. Of the 5 patients in whom medical therapy failed, 4 were treated surgically. These 4 patients were in the intensive care unit with protracted, prolonged pain, subendocardial infarctions, and persistent failure of coronary vasodilators. Aorta-coronary bypass grafts have been combined with total cardiac denervation by autotransplantation (one patient) and total cardiac denervation by stripping of the great vessels (3 patients). Two of the patients treated by cardiac denervation died in the early postoperative period. The patient treated by autotransplantation has total relief of symptoms but persistent spasm on angiography. The angiographic demonstration of occlusive coronary spasm remains a valuable diagnostic tool to document definitively the presence of spasm. The surgical results question the value of surgical intervention in this disease.
 ...
PMID:Coronary artery spasm. medical management, surgical denervation, and autotransplantation. 40 7

Variant angina pectoris, usually not precipitated by exertion or emotional stress, often is more severe and lasts longer than classic angina. The pain tends to recur at about the same time each day. Arrhythmias, usually ventricular, occur in about 50% of cases during the peak of pain. Electrocardiograms show a characteristic ST segment elevation during pain, which is in contrast to the ST segment depression of classic angina pectoris. Pain may be due, at least in some cases, to a temporary increase in tonus of a single, large, narrowed coronary artery. Chemical changes in the myocardium and plasma catecholamine changes differ from those occurring in classic angina pectoris. The course of the disease is highly variable but the prognosis must be regarded as grave, since single large vessel disease, present in most cases, is associated with severe myocardial ischemia. Patients with variant angina pectoris should be studied early with coronary arteriography and considered for coronary artery bypass surgery if appropriate.
 ...
PMID:The variant form of angina pectoris. 76 70

A 40-year-old man with severe angina had electrocardiographic changes typical of Prinzmetal angina during his attacks of chest pain. ST segment elevations in leads II, III, and aVF occurred intermittently with elevations in leads I and aVL, and with T wave flattening in V1, suggesting myocardial ischemia in areas supplied by the right coronary artery and by the circumflex branch of the left coronary artery. However, the coronary arteries appeared normal when arteriograms were made, suggesting that a reversible event caused the attacks.
 ...
PMID:Prinzmetal angina. Normal arteries and multifocal electrocardiographic changes. 81 19

Eleven of 21 consecutive patients with Prinzmetal angina (PMA) exhibited no significant fixed stenoses of the coronary arteries. Spontaneous coronary arterial spasm was demonstrated in 3 patients. Ergonovine maleate produced near-total occlusion of a major vessel in 3 of 4 other patients with PMA, but did not provoke spasm in 10 without PMA. The current study documents spasm as the mechanism of myocardial ischemia in some patients with normal coronary arteries and provides initial and favorable diagnostic results with provocative pharmacoangiography in this entity.
 ...
PMID:Spontaneously and pharmacologically provoked coronary arterial spasm in Prinzmetal variant angina. 93 83

The findings in four young patients with the billowing mitral leaflet syndrome who presented with evidence of acute myocardial infarction are reported. Because technically adequate coronary arteriograms demonstrated patent vessels and the electrocardiograms initially showed pronounced elevation of the ST segments as occurs in Prinzmetal's angina, it is postulated that spasm of normal coronary arteries was the operative factor. Scrutiny of those cases of clinically apparent ischemic heart disease with normal coronary angiograms is suggested to establish whether there is in fact a causal relationship with the billowing mitral leaflet syndrome.
 ...
PMID:Acute myocardial infarction with normal coronary arteries: a possible manifestation of the billowing mitral leaflet syndrome. 93 21

In the light of 4 personal observations of PPPRINZMETAL's angina, a review has been conducted of the literature in the 15 years since the condition was first described. Although the formal diagnostic criteria for this form of angina simultaneously clinical, biological and electrical - anginal attacks occurring at rest, often at night, during which elevation of the ST segment is recorded which disappears at the end of the attack without any significant rise in enzyme levels (SGOT and CPK) - the frontiers of the syndrome appear to have widened since PRINZMETAL's description: - Severe proximal stenosis of the coronary arteries is not obligatory; they may be only slightly damaged or even healthy. - Prinzmetal's angina is by no means always "spontaneous" but is often induced, either by psychic factors, which explain the fixed time of the attacks, or by organic factors, e.g. cold drinks (Observation No.2). In this event it would appear safer to speak of angina or rest as opposed to angina of effort. - In contrast to what PRINZMETAL thought, effort tests may sometimes induce angina-type pain with elevation of the ST segment, and here the borderline between this syndrome and conventional angina with ST segment elevation after effort test (5% of cases) is less clear-cut. The two nosologic entities probably reflect the same physiopathological situation, i.e. acute myocardial ischemia, and may represent the same affection in different phases of development. The prognosis is equally bad. - Attacks of rinzmetal's angina are often accompanied by severe and sometimes fatal disorders of rhythm, and this influences the therapeutic approach. - The coronary spasm posited by PRINZMETAL and others before the advent of coronarography is indeed, in the majority of cases, the immediate cause of myocardial ischemia and anginal pain, without any preliminary increase in the energy requirements of the heart as in the conventional anginal attack. - A vasoactive substance present in the circulating blood at the beginning of the affection, which may be degraded and subsequently disappear and may be secreted by the pathologic coronary artery, was demonstrated in observation No. 4: this may, in conjunction with vagal hypertonia, be the causative factor in coronary spasm. Study of its pharmacodynamic properties is now in progress.
 ...
PMID:[Prinzmetal's angor. Apropos of 4 cases. Review of the literature]. 108 Aug 80

Transient abnormal Q waves were seen in two patients with Prinzmetal's angina during episodes of chest pain. The Q waves appeared recurrently while the patients had chest pain and disappeared when it subsided, indicating that Q waves suggestive of myocardial infarction can be seen with severe myocardial ischemia without actual necrosis. We describe these two patients, the various conditions in which transient abnormal Q waves have been reported and the theories offered to explain this electrophysiologic finding.
 ...
PMID:Transient Q waves in Prinzmetal's angina. 112 24

Two cases presenting with episodes of marked ST segment elevation occurring with, but most often without, anginal pain are reported. The changes were recorded through continuous ECG monitoring during Prinzmetal's angina and in the course of myocardial infarction. Such transient asymptomatic ECG abnormalities reveal silent acute myocardial ischemia and are often unrecognized. However, they may lead to severe arrhythmias or myocardial infarction, and sudden deaths occurring in the course of ischemic heart disease are likely to be explained on this basis. Transient episodes of silent ST segment elevation similar to those occurring in Prinztal's angina have been reported in various circumstances. They bring into discussion the delimitations of variant angina pectoris.
 ...
PMID:Transient ST segment elevation occurring without anginal pain. Correlations with Prinzmetal's angina. 115 52

Coronary arteriography performed in 17 patients with Prinzmetal's variant angina demonstrated high grade fixed obstructions in 9 patients (Group I) and insignificant or no fixed lesions in 8 patients (Group II). Group I consisted mostly of middle-aged or elderly men with S-T segment elevations in various sites; Group II included five younger women with S-T segment elevations in inferior electrocardiographic leads. In Group I patients, arteriography revealed a discrete high grade lesion located proximally in a major coronary artery in four patients and multivessel involvement in five patients. In Group II patients, spontaneous spasm was documented in three patients and spasm was pharmacologically provoked in two others during arteriography. The current study indicates that spasm is the responsible pathogenetic mechanism of myocardial ischemia in some patients with Prinzmetal angina and that this mechanism may be suspected from the clinical characteristics of these patients.
 ...
PMID:Clinical and arteriographic features of Prinzmetal's variant angina: documentation of etiologic factors. 126 48


1 2 3 4 5 6 7 8 9 10 Next >>