Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Potassium and magnesium deficiencies are common in patients with heart disease. These are often coexistent and pathophysiologically related. Potassium deficiency cannot be treated without correction of concomitant magnesium deficiency. Correlations between serum levels and body stores are very poor for both ions. Therefore diagnosis and treatment of these conditions based on serum levels alone are erroneous. There is some evidence that it is primarily the intracellular depletion of these ions which is arrhythmogenic. Magnesium infusion has been proved effective in treatment of torsade de pointes ventricular tachycardia and arrhythmias induced by digoxin-intoxication, and is recommended in these conditions. Whether it is effective in other forms of arrhythmia is not yet elucidated.
 ...
PMID:[Heart rate disorders in potassium and magnesium deficiency]. 141 69

Globally, among mortality and morbidity indices for man, ischemic heart disease (IHD) ranks at the top of the list. In the industrialized world, IHD is the leading killer and accounts for approximately 35% of all deaths each year. This most common cause of death results from insufficient coronary blood flow. IHD is a general term used to describe a pathophysiologic state in which cardiac output is inadequate as a consequence of coronary blood flow deficits brought about when the latter cannot deliver enough O2 to meet the needs of the myocardium. This review is concerned with the etiology of IHD, special forms of IHD such as angina pectoris and variant angina, as well as sudden death ischemia heart disease. The diverse conditions that cause IHD are discussed. Important etiologic factors such as the pathogenesis of atherosclerotic obstruction as well as localized coronary vasospasm are reviewed. Implications of dietary and metabolic alterations in electrolytes are a special focus of this view. Evidence implicating Mg2+-K+ and Mg2+-Ca2+ alterations in the pathogenesis of IHD is reviewed. Special attention is devoted to the role of Mg in vascular tone, coronary blood flow and in clinical management of IHD. It is concluded that judicious use of Mg salts in IHD could be expected to reduce myocardial oxygen demand and influence the myocardial oxygen supply/demand ratio in a favorable manner.
Magnesium 1988
PMID:Ischemic heart disease and magnesium. 329 17

Tricyclic antidepressant drugs are known to cause often electrocardiographic abnormalities and to induce sometimes cardiac rhythm disturbances. We report a case of a patient on antidepressant therapy (Desipramine Hydrochloride, 50 mg/die, and Dothiepin Hydrochloride, 150 mg/die), without any underlaying heart disease, admitted to our Coronary Care Unit for recurrent syncopal episodes. An ECG on admission showed Sinus Tachycardia with Ectopic Ventricular Beats and recurrent runs of Torsade de Pointes, a distinctive form of Ventricular Tachycardia. Lignocaine i.v. was only transiently effective. Both Isoprenaline and Atropine Sulphate i.v. were uneffective. Ventricular Fibrillation occurred and cardioversion was achieved by a single DC shock. Amiodarone i.v. and electrical overdrive only temporarily suppressed ventricular arrhythmias. Magnesium Sulphate i.v. (bolus + infusion) induced a definitive suppression of Torsades de Pointes. One day later no more arrhythmias were present.
 ...
PMID:[Torsade de pointes caused by tricyclic antidepressive agents. Description of a clinical case]. 355 44

A nondigitalized patient without heart disease, but with ulcerative colitis on parenteral hyperalimentation, developed ventricular tachycardia in association with hypomagnesemia. Magnesium infusions were successful in suppressing the arrhythmia, but because of ongoing fecal losses, hypomagnesemia and ventricular tachycardia recurred each time the infusion was stopped. After total colectomy, the patient remained normomagnesemic and free of arrhythmias. The few previous descriptions of arrhythmias attributed to hypomagnesemia in nondigitalized patients are reviewed. The importance of recognizing hypomagnesemia as an easily reversible cause of arrhythmias is stressed.
 ...
PMID:Hypomagnesemia and ventricular tachycardia: a complication of ulcerative colitis and parenteral hyperalimentation in a nondigitalized noncardiac patient. 679 55

1 The hypothesis that magnesium deficiency, linked to the magnesium content of drinking water, induces major tone increases in coronary arteries and enhances their responses to vasoactive agents to an extent sufficient to explain sudden death associated with ischaemic heart disease was examined in an in vitro preparation. 2 The spontaneous tone of cattle coronary arteries was not increased during a 30 min exposure to Mg2+-deficient Krebs until the mineral was omitted entirely from the bathing medium, and even then the observed increase was small. Only in strips maintained under extremely deficient conditions for a prolonged period, namely Mg2+ concentration of 0.2 mM and 0.0 mM for 3 h, was tone substantially greater than in controls in standard (1.2 mM) Mg2+-Krebs. 3 Responses to acetylcholine and to noradrenaline were not increased in Mg2+-free Krebs but those to potassium and to 5-hydroxytryptamine were enlarged over the lower parts of their concentration-response curves. Responses to potassium and to 5-hydroxytryptamine were also examined in Krebs containing very low concentration of Mg2+ (0.4 and 0.2 mM) and only modest increases in contraction size were detected. Increases in the Mg2+ concentration of the Krebs (to 4.8 mM) depressed responses to potassium and 5-hydroxytryptamine. 4 It is concluded that Mg2+ deficiency must be nearly complete (0.4-0.0 mM) to induce even moderate tone increases in coronary vessels, or to sensitize them to agonist responses, and that there is no reason to link marginally subnormal Mg2+ levels, occasionally reported in humans with heart disease, to marked changes in coronary dynamics.
 ...
PMID:The effect of magnesium deficiency and excess on bovine coronary artery tone and responses to agonists. 685 Jan 65

The importance of metals in normal and pathologic cardiovascular function has been recognized. Significant derangements in myocardial Ca2+, Mg2+, and Cu2+ have been reported in ischemic heart injury. We studied 3 groups of hearts: 1) fifteen specimens obtained from patients who had no heart disease, 2) nine specimens from patients who had expired from cyanotic congenital heart disease, and 3) ten specimens from patients who had expired from acute rheumatic heart disease with carditis and severe heart failure. None of the patients had undergone cardiac surgery. Left ventricular lateral wall Mg2+, Ca2+, Cu2+, and Zn2+ contents were measured by atomic absorption spectrometry. The results showed a significant decrease in myocardial Mg2- (Group I 177.06 +/- 32.71; Group II 155.66 +/- 14.79; Group III 149.00 +/- 13.29, p less than 0.05 and p less than 0.01, respectively), and Cu2+ contents (Group I 3.22 +/- 0.37; Group II 2.94 +/- 0.22; Group III 2.56 +/- 0.32, p less than 0.02 and p less than 0.001, respectively), and a rise in myocardial Ca2+ content (Group I 36.06 +/- 10.72; Group II 43.22 +/- 7.01; Group III 46.30 +/- 4.85, p = not significant, and p less than 0.01, respectively). The myocardial Zn2+ content did not change significantly (Group I 26.53 +/- 3.99; Group II 26.00 +/- 4.15; Group III 26.40 +/- 3.53). The myocardial Mg2+/Ca2+ ratio was reduced markedly in both groups (Group I 5.328 +/- 1.879; Group II 3.685 +/- 0.735; Group III 3.135 +/- 0.291, p less than 0.001 for both Groups II and III vs Group I). The latter results correlated closely with the myocardial Mg2+/Ca2+ ratios reported in experimental models in peri-infarction zones. Thus, the myocardium of patients who had expired from cyanotic congenital heart disease and acute rheumatic carditis is jeopardized by ischemia, with metal contents similar to the border areas in myocardial infarction.
 ...
PMID:Myocardial metal content in patients who expired from cyanotic congenital heart disease and acute rheumatic heart disease. 717 80

Magnesium has been reported to have a dilatatory effect on cerebral arteries. Reduction of extracellular Mg+2 has been shown to be directly correlated with the intensity of cerebral spasm. A neuroprotective effect of magnesium in stroke has also been hypothesized. The aim of our study was to examine the Mg+2 levels in serum and cerebrospinal fluid (CSF) in the early stage of stroke and to evaluate the correlation between Mg+2 levels and the development of neurological deficits. Between 1986 and 1994, 96 patients who had a stroke of 24- to 48-h duration were enrolled in the study. Serum and CSF levels of magnesium were checked on admission, 2448 h after the onset of stroke. Using a neurological score, the neurological deficit was assessed on the 1st day, 1 and 4 weeks later. Computed tomography (CT) was performed after 1 week, and the volume and location of infarction were calculated and measured. Statistical analysis was performed for cortical and subcortical patients separately, using Spearman correlation and multiple linear and logistic regression analyses. Significant correlation was found between CSF Mg+2 and the size of the infarct (P < 0.0001). There was no correlation between serum Mg+2 and CSF Mg+2 levels. Regression analysis demonstrated an increase in the values of the Mathew Neurological Score with higher CSF Mg+2 levels. This association remained true after other factors such as age, associated heart disease, diabetes and infarction size had been taken into account by the regression model. The results confirm that there is a relationship between a low Mg+2 concentration in CSF during the first 48 h after onset of ischaemic stroke and the intensity of the neurological deficit. The therapeutic consequence of this finding may have some importance.
 ...
PMID:Cerebrospinal fluid magnesium level as a prognostic factor in ischaemic stroke. 975 95

Orotic acid (OA), a naturally occurring substance, is a key intermediate in the biosynthetic pathway of pyrimidines. Previous investigations in the heart suggest that orotate can protect recently infarcted hearts against a further ischemic stress and may be beneficial in certain types of experimental cardiomyopathy. At the Hamburg symposium on magnesium orotate, a number of studies of this form of metabolic supplementation were presented that indicate orotic acid and its magnesium salt have a modest beneficial effect on the myocardium under conditions of stress ranging from myocardial infarction to severe physical exercise. The following conclusions can be drawn: (1) Orotic acid can improve the energy status of the recently infarcted myocardium (rat hearts). (2) Orotic acid may improve myocardial purine and pyrimidine levels by stimulating hepatic release of uridine into the bloodstream, which in turn augments depleted myocardial pyrimidines and purines (rat heart). (3) Orotic acid improves the tolerance of the recently infarcted heart to global ischemia (rats). (4) Magnesium orotate may reduce the severity of chronic myocardial dysfunction and structural damage in cardiomyopathy (cardiomyopathic hamsters). (5) Magnesium orotate may improve exercise tolerance in patients with coronary artery disease and in trained athletes (humans). (6) Magnesium orotate has only a weak inotropic effect, if any, on normal hearts (rats). (7) Further clinical testing is indicated to determine if the effects described could be of significant clinical benefit in the treatment of heart disease.
 ...
PMID:Metabolic supplementation with orotic acid and magnesium orotate. 979 88

Numerous experimental, epidemiological and clinical studies have pointed out a relevant role for magnesium deficiency in the development of many cardiovascular diseases. Some pharmacological treatments may interfere with magnesium turnover, and magnesium deficiency may alter the pharmacokinetics and pharmacodynamics of some cardiovascular drugs. Loop and thiazide-like diuretics increase magnesiuresis, and total bodily magnesium deficiency may appear during prolonged treatment with diuretically active doses of these drugs. The potassium retaining agents, such as amiloride, triamterene and spironolactone, tend to retain magnesium but they are not magnesium-retaining substances to the extent to which they are potassium-retaining diuretics. The interaction between magnesium and digitalis is complex. Magnesium, acting as an indirect antagonist of digoxin at the sarcolemma Na(+)-K(+)-ATPase pump, reduces cardiac arrhythmias due to digoxin poisoning. Recent controlled studies have shown that treatment with magnesium significantly reduces the frequency and complexity of ventricular arrhythmias in digoxin-treated patients with congestive heart failure without digoxin toxicity. Magnesium improves the efficacy of digoxin in slowing the ventricular response in atrial fibrillation. Digoxin reduces tubular magnesium reabsorption, and in patients with congestive heart failure this interaction may be cumulative with other causes of magnesium deficiency (diuretics, diet, poor intestinal absorption). The complex and potentially life-threatening interactions between magnesium and some cardiovascular drugs suggest that magnesium status should be carefully monitored in patients receiving such drugs. Therapy with magnesium is rapidly acting, has a safe toxic-therapeutic ratio, is easy to administer and titrate. The correction of magnesium deficit should therefore always be considered for patients with cardiopathy.
 ...
PMID:Magnesium and cardiovascular drugs: interactions and therapeutic role. 1052 23

There is a great deal of information presently available documenting a cardiomyopathic condition in insulin-deficient models of diabetes. Less information is available documenting a similar status in non insulin-dependent models of diabetes. We have studied the functional integrity of the myofibrils isolated from hearts of JCR:LA rats. The JCR:LA rat is hyperinsulinemic, hyperlipidemic, glucose intolerant and obese. As such, it carries many of the characteristics found in humans with non insulin-dependent diabetes mellitus. These animals also have many indications of heart disease. However, it is not clear if the hearts suffer from vascular complications or are cardiomyopathic in nature. We examined Mg2+-dependent myofibrillar ATPase in hearts of JCR:LA-cp/cp rats and their corresponding control animals (+/?) and found no significant differences (P> 0.05). This is in striking contrast to the depression in this activity exhibited by cardiac myofibrils isolated from insulin-deficient models of diabetes. Our data demonstrate that myofibrillar functional integrity is normal in JCR:LA-cp rats and suggest that these hearts are not in a cardiomyopathic state. Insulin status may be critical in generating a cardiomyopathic condition in diabetes.
 ...
PMID:Mg2+-dependent ATPase activity in cardiac myofibrils from the insulin-resistant JCR:LA-cp rat. 1190 Mar 75


1 2 Next >>