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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eleven patients with short P-R intervals and narrow QRS complexes had ventricular tachycardia due to organic heart disease: mitral valve prolapse with mitral insufficiency (2 patients); alcoholic (?) cardiomyopathy (2 patients); and coronary artery disease (7 patients). Intracardiac studies showed short A-H intervals during sinus rhythm in all cases. The onset of ventricular fibrillation (which, to our knowledge, has not been observed in patients having short P-R and A-H intervals coexisting with narrow QRS complexes) was documented in 4 cases. Only 1 patient (with quinidine syncope) had been premedicated. In the 3 other patients the episodes of ventricular fibrillation appeared during bouts of atrial fibrillation with rapid ventricular rates which could have been an exprerssion of the "enhanced A-V conduction" that had been manifested in sinus beats by short P-R and A-H intervals. In clinical settings and physiological conditions proven to be hemodynamically unstable (such as transient ischemia or acute myocardial infarction) these rapid ventricular rates could have led to ventricular fibrillation; directly because of the R-on-T phenomenon, and/or indirectly due to decreased coronary perfusion. Ventricular tachycardia and ventricular fibrillation due to organic heart disease probably occur more often than suggested by the few reported cases in the literature. Its significance, however, has to be clarified by further prospective studies.
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PMID:Ventricular tachycardia and ventricular fibrillation in patients with short P-R intervals and narrow QRS complexes. 9 18

Uncontrolled hypertension increases the workload of the left ventricle causing the development of hypertrophy and an increase in myocardial oxygen consumption that may precipitate ischemia because of inadequate oxygen delivery related to accelerated coronary atherosclerosis. Control of the hypertension should prevent the further development of hypertrophy, delay the development of fibrosis and possibly also slow the rate of development of atherosclerosis. Furthermore, when myocardial function is impaired because of hypertrophy or other myocardial diseases, the level of blood pressure becomes an important determinant of left ventricular performance. Regardless of the level of arterial pressure, vasodilator drugs that lower arterial pressure may result in marked improvement in left ventricular performance and relief of symptoms of left ventricular failure. Therefore, control of blood pressure in the presence of heart disease may involve treatment of normotensive patients to bring them into a lower normotensive range as well as the more traditional treatment of hypertensives to bring them into the normotensive range. Although this scenario is consistent with conventional wisdom and clinical experience, intricacies of the relationship between hypertension, hypertrophy, myocardial oxygen delivery, atherosclerosis and intramyocardial blood flow distribution remain poorly understood. Until these aspects of the natural history of heart disease are better worked out therapy will remain largely empirical.
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PMID:Heart disease in the hypertensive patient. 14 Feb 80

Myocardial ischemia occurs when there is an imbalance between myocardial oxygen demand and supply, and it is usually entirely or predominantly subendocardial. Animal experiments have shown that relative subendocardial ischemia (a reduced inner:outer flow ratio) can be predicted quite accurately from the ratio of two pressure-time areas:DPTI, the area between diastolic aortic and left ventricular pressures, and SPTI, the area beneath the systolic left ventricular pressure curve. Although the importance of relating supply and demand is obvious, care is needed in applying the results of these animal experiments to man. Recent work has shown that the critical DPTI:SPTI ratio below which subendocardial ischemia occurs is about 0.4 to 0.5 rather than 0.7 to 0.8, as originally reported. On the other hand, the critical ratio may be raised to an unknown extent by myocardial edema or hypertrophy, or by thickened or narrowed coronary arteries. Furthermore, the critical ratio is not independent of absolute coronary diastolic pressure: It is much lower than 0.4 when coronary pressures are high, perhaps because intramyocardial diastolic pressures are much higher than once thought. Further work is required to allow an important physiologic concept to be used in making decisions about patients with heart disease.
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PMID:The myocardial supply:demand ratio--a critical review. 14 25

Insulin accelerates the entry of glucose and amino acids into muscle cells by acting upon the 'carrier-facilitated' transport mechanism. For glucose this process is passive and leads to equilibration of intracellular and extracellular concentrations. In heart muscle, glucose transport is a rate-limiting step for glucose uptake. During hypoxia and ischemia the heart turns to anaerobic glycolysis for energy production and therefore, maximal glucose transport becomes important. Insulin is necessary to insure proper protein synthesis, probably at the level of membrane-bound polyribosomes. However, during myocardial hypoxia, insulin alone cannot restore the associated depression in protein synthesis. Although insulin hyperpolarizes the cell, a change in the ratio of intracellular to extracellular activities of potassium is not its primary mode of action. An insulin-induced configurational change in the plasma membrane could simultaneously account for the effects of insulin on sodium and potassium permeability and the action on facilitated transport. Intracellular levels of cyclic adenylate may be reduced by insulin in adipose tissue because of inhibition of adenyl cyclase or stimulation of phosphodiesterase. However, at this time there is little evidence that insulin alters cyclic AMP levels in the heart. Insulin secretion is depressed in patients with heart disease in proportion to the reduction of cardiac index sustained. Since the ischemic heart is dependent upon glucose as the major fuel, insulin lack may deprive the heart of adequate substrate.
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PMID:Insulin: fundamental mechanism of action and the heart. 18 67

Eighteen infants carrying pulmonary stenosis with a complete interventricular wall whose most frequent clinical data are: precocius cyanosis, congestive cardiac insufficiency and in 25% of them hypoxic crises are presented. Complementary explorations of this entity are not definitive, but clinical diagnosis described with evolutional cardiomegaly at the expense of the right cavities and pulmonary ischemia forces authors to think that there is a severe obstruction of the infumdibulum with complete interventricular septum. The different parameters which have been proposed to evaluate severity of the stenosis are discussed and compared, finding among them significative differences. Authors consider the concept of the right diminutive ventricle, finding in these cases the electrocardiographic pattern rS in V1 and observing a great mortality both spontaneous and postsurgical. The high mortality of this heart disease, both in its' natural evolution as well as after surgery is to be pointed out as in most published series.
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PMID:[Critical pulmonary stenosis in infants (author's transl)]. 50 75

Eighteen patients with idiopathic optic neuropathy lacked symptoms and signs of cardiovascular and cerebrovascular disease, especially when compared to three groups of patients with sudden visual loss caused by retinal infarction, transient ischemia, and cerebral infarction. Many patients in the latter groups had hypertension, carotid bruits, heart disease, transient ischemic attack, and stroke. But among the patients with ischemic optic neuropathy, hypertension was the only evidence of cardiovascular disease, affecting 44% of the patients. We argue that, in many cases, ischemic optic neuropathy represents a direct and early complication of hypertension arterial disease affecting small arterioles supplying the anterior part of the optic nerve. The pathologic process may thus be similar or identical to lacunar infarction of the brain.
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PMID:Ischemic optic neuropathy as a possible early complication of vascular hypertension. 51 8

50 patients, 20 without heart disease and 30 with coronary heart disease (CHD), were studied by kinetocardiography (KCG), before and after administration of isoproterenol (initial dose 2 microgram/min, maximum dose 6 microgram/min). In the control subjects the KCG was unaffected by the drug. In contrast, in most of the patients with CHD isoproterenol induced the appearance or the increase of paradoxical systolic bulges, which are regarded as the expression of ventricular dyskinesia resulting from isoproterenol-induced transient regional ischemia. This test is recommended as a valuable noninvasive method for the diagnosis of ischemic ventricular dyskinesia.
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PMID:The kinetocardiogram during the isoproterenol test for the assessment of coronary heart disease. 58 10

The electrocardiogram was monitored in 51 patients during fiberoptic bronchoscopic procedures and was compared to recordings made before premedication. Sixteen of the patients had heart disease. During the bronchoscopic procedure, the heart rate increased by 154 "/- 5 percent (+/- SE). The frequency of atrial ectopic beats was minimally increased, by an average 0.15 +/- 0.12 beats per minute (not significant). Ventricular ectopic beats became less frequent during the bronchoscopic procedure (-0.17 +/- 0.41 beats per minute; not significant), and there was no ventricular tachycardia. Frequent ventricular ectopic beats were seen mainly during bronchoscopic procedures in patients with coronary heart disease, but even in this group, ventricular ectopic beats became less frequent than at rest (-1.13 +/- 1.46 beats per minute; not significant). The nearly uniform sinus tachycardia that was observed was well tolerated but could predispose coronary patients to ischemia; however, the fiberoptic bronchoscopic procedure per se does not enhance prior ectopy.
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PMID:Arrhythmias from fiberoptic bronchoscopy. 67 41

1). In 1001 patients with acute myocardial infarction 403 cases were found (40.2%) showing possible relapse. A study was made of 125 cases (12.5%) with positive diagnosis of acute myocardial infarction relapse, and among them, 12 were found to be occurring for the third time. Is possible for the real frequency of the iterative infarction to be even higher, because many cases were dismissed (27.7%) for lacking of conclusive electrocardiographic data pointing to myocardial transmural infarction. 2). Investigations were conducted about the evolutive condition of the danger factors in the coronary profile as well in the male as in the female group. Besides, a comparative study was made about symptoms, complications, morbidity and mortality. Clinical, enzimatic and electrocardiographic proofs were found, in every case, of a new myocardial transmural necrosis which was in evolution, with waves of injury and ischemia. Thirty eight deaths were registered in hospitals (30.4%) and in 25 of these, a necropsic study was conducted. 3). This illness is more frequent among men than among women, in a 3.5 to 1 proportion. The recurrent myocardial necrosis tends to be more frequently present during the first year following the first episode. In women, the first myocardial infarction as well as the iterative infarction occur at an older age than in men. 4). The influence of personality and stress is a very important factor of danger in the iterative infarction. Familiar antecedents of ischemic cardiopathy constitute a danger factor in patients presenting a single episode of myocardial infarction; nevertheless they don't seem to have a determining influence in this group of relapsing infarction. Although this study confirms with statistics that smoking has a decisive influence in the first myocardial infarction, neither frequency nor mortality of the relapsing infarction are in any way modified by the diminishing or suppression of the smoking habit.
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PMID:[Myocardial reinfarction in male and female]. 69 61

Intending to find out which is the prevalence of mitral valvular prolapse in cases of ischemic cardiopathy with "normal" coronariography, a review was made of the coronary-ventriculographic studies at the I.N.C. archives, which showed as clinical diagnosis that of ischemic cardiopathy with "normal" coronaries. In the present studies we record 47 cases showing chest angina and/or electrocardiographic changes in rest or effort tests, compatible with myocardic ischemia and coronariography undoubtedly normal. We found 30 cases (63.8%) showing strong evidence of mitral prolapse in the left cineventriculography taken in right-front oblique position.
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PMID:[Prolapse of the mitral valve]. 70 34


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