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

Five patients with bidirectional tachycardia due to digitalis toxicity associated with severe organic heart disease were studied. The origin of the abnormal rhythm was established with the aid of His bundle recordings in three cases and by indirect clues in the others two. In three cases the origin of bidirectional tachycardia was suprahisian while in two patients it was infrahisian. In one patient the transition from junctional to ventricular tachycardia could be observed. Bidirectional tachycardia appears to be a complex arrhythmia in which similar electrocardiographic configuration can be due to different mechanism. Digitalis toxicity was often a causal factor.
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PMID:Bidirectional tachycardia a study of five cases. 108 15

Recently disorders of sinus node function have found increasing interest in clinical medicine thanks to new diagnostic and therapeutic developments. This paper represents a comprehensive review of these conditions, combined under the name "Sick Sinus Syndrome" (SSS). Besides a detailed analysis of 63 cases seen at our institution, the results of other groups are compared and extensively discussed. The clinical picture of the SSS is characterized by a wide variety of bradycardiac and tachycardic atrial arrhythmias, occurring separately or in combination. These can be classified in three subgroups: Patients with exclusive sinus bradycardia; patients with sinoatrial exit block or transient episodes of sinus arrest with or without AV escape rhythms; and finally patients with the bradycardia/tachycardia-syndrome, which are complicated by additional atrial tachyarrhythmias. The symptomatology of the SSS is multiform and extends from symptomless cases and those with only general signs of reduced cardiac function to patients with recurrent severe syncopal attacks which may lead to cerebral damage and even death. Besides the typical history, the diagnosis of the SSS primarily rests upon the ECG, especially the long term ECG recorded continuously on a 24 hrs. tape (Holter technique). Also the exercise ECG is of some value, characteristically showing an inadequate increase in the sinus rate, sometimes with AV escape systoles and -rhythms. In addition various provocative tests have been devised which are of help to differentiate between a pathologic and a normal sinus node function. Among these the determination of the sinus node recovery time following overdrive atrial pacing has gained wide acceptance. In most cases the exact etiology of the SSS is not known. In addition to coronary and inflammatory heart diseases a primarily degenerative lesion of the sinus node, comparable to cases with "primary heart block" are discussed. There is also a remarkably frequent past history diththeria. Rarer causes of the condition represent cases with cardiomyopathy, thyreotoxic heart disease, collagen and other disorders and also a familial manifestation of the SSS has been described. Therapeutically, pharmacologic treatment with vagolytic, beta-adrenergic or the common antiarrhythmic drugs is often unsuccessful, especially in the treatment of the Brady-Tachy-Syndrome. Digitalis glycosides, however, are frequently of some value, as they represent an effective prophylactic agent against atrial tachyarrhythmias without prolonging the sinus node recovery time or reducing significantly the sinus rate. While a few patients do not require any treatment, an artificial cardiac pacemaker has to be inserted in most cases. Atrial stimulation may be superior to ventricular on-demand pacing in some patients, and also a special system for the treatment of the SSS combined with significant AV block (binodal disease) has been designed, the bifocal sequential pacemaker.
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PMID:[Sinus node syndrome]. 109 30

Digitalis intoxication is among the most common serious adverse drug reactions in clinical medicine. While the recent development of a radioimmunoassay to accurately measure serum concentrations of digoxin has been of assistance, digitalis intoxication remains a difficult diagnosis to make with certainty. The difficulty in diagnosing digitalis intoxication arises from the nonspecificity of its associated signs and symptoms. The most common symptoms include fatigue, weakness, nausea, and anorexia. These symptoms can occur with many illnesses other than digitalis intoxication. Similarly, the electrocardiographic disturbances caused by cardiac glycosides may be nondiagnostic. The arrhythmias commonly associated with digitalis toxicity are often nonspecific and can be a reflection of the patient's underlying heart disease. The measurement of serum digoxin levels is useful, but studies have demonstrated overlap of the levels between groups with and without toxicity. Due to the modulation of the cardiac effects of digitalis glycosides by such clinical variables as underlying myocardial or renal disease, electrolyte and acid-base imbalances, and other factors, the correlation of toxicity with particular serum digoxin concentrations may vary. Because of the inherent difficulties in confirming the diagnosis of digitalis intoxication in some cases, digoxin-specific Fab antibodies may play a role as a diagnostic tool. Certainly, digoxin-specific Fab antibodies play a significant part in the treatment of digitalis intoxication. Fab antibodies have been successfully used to reverse the effects of digoxin, digitoxin, and oleander poisoning. These antibodies are useful in the treatment of acute and chronic digitalis intoxication in all age groups, including geriatric and pediatric populations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Recognition and management of digitalis intoxication: implications for emergency medicine. 199 19

The sodium and potassium concentrations of the red blood cells and plasma were investigated in 93 children with cardiac disease, most of them with congenital heart defect, and in 48 healthy children of the same age. The red blood cell sodium and potassium concentrations were constant within a narrow range in normal subjects, but varied profoundly in pathological conditions. Digitalis treatment caused RBC Na+ and plasma K+ levels to increase and the RBC K+ level to decrease by blocking the Na+-K+ pump. The highest RBC Na+ concentration was observed in critically ill patients with congestive heart failure treated with digoxin. An augmented RBC sodium value was found in heart malformations with left to right shunt and in congestive cardiomyopathy that was not treated, whereas in patients with right to left shunt lower RBC sodium, higher RBC potassium and plasma potassium values were registered without any treatment. In cases of hyperkinetic circulation without any congenital heart defect the value of RBC sodium was definitely low. A low sodium and a high potassium level of the RBC were found after total correcting heart surgery. It is concluded that measurement of changes in sodium and potassium concentrations of the red blood cells is not a reliable method for assessment of the efficacy of digitalis treatment. The results point to the accompanying phenomena at a cellular level in heart disease.
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PMID:Sodium and potassium concentrations in red blood cells and plasma in children with congenital heart defect. 342 57

Clinical studies were carried out during digoxin maintenance therapy to clarify three questions concerning digitalis therapy: optimal time for blood sample collection for serum digoxin concentration (SDC), the overlapping range of SDC levels in which some patients may be intoxicated while others are not, and both resistance and sensitivity of atrial fibrillation (AF) to digitalis. The SDC curve after a single dose of digoxin or beta-methyldigoxin shows the appropriate sampling time to be at least 12 hours after the administration. The optimal time is 24 hours. The overlapping SDC range was 1.7-2.7 ng/ml. There were significant differences in CTR and ventricular rates in AF between intoxicated and non-intoxicated groups. This suggests that susceptibility to digitalis increases with the severity of underlying heart disease. Precipitating factors such as CTR should be taken into consideration, if the SDC is in the overlapping level. Digitalis resistance occurs in 6.7% of 105 patients with AF, and more frequently in hypertensive heart disease than others. Digitalis sensitivity occurs more often in the elderly and in patients with dilated cardiomyopathy. But it is not necessary to attain higher therapeutic levels for AF than for sinus rhythm. Clearly optimal digitalis therapy for AF can be best accomplished when precise clinical findings, SDC and EKG recordings are carefully monitored and used to correct treatment.
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PMID:The problems of digitalis therapy from the viewpoint of serum concentration with special reference to the sampling time, to the overlapping range of serum concentration where intoxicated and non-intoxicated patients are located and to atrial fibrillation. 377 29

Sixty-three patients with life-threatening digitalis intoxication were treated with purified fragments of digoxin-specific antibodies (Fab) obtained from sheep. Twenty-eight patients developed toxicity as the result of digitalis ingestion in a suicide attempt, 5 ingested a large amount of digoxin accidentally and 30 developed toxicity in the course of treatment for underlying heart disease. The dosage of digoxin-specific Fab was calculated to be equimolar to the amount of cardiac glycoside in the patient's body. Digitalis toxicity was completely reversed in most cases, with onset of effect usually within 30 minutes of administration of Fab fragments. Unbound and, therefore, active digoxin serum concentrations decreased to undetectable levels within minutes after administration of the fragments. In all patients who had elevated serum potassium concentrations caused by massive digitalis toxicity, treatment with the Fab fragments reversed the hyperkalemia. There were no obvious adverse reactions to treatment. Potentially life-threatening digitalis intoxication can be rapidly and safely reversed by treatment with purified digoxin-specific Fab fragments.
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PMID:Treatment of 63 severely digitalis-toxic patients with digoxin-specific antibody fragments. 388 48

Atrial fibrillation occurred in 16 (10%) of 167 patients with idiopathic hypertrophic subaortic stenosis. The clinical and haemodynamic findings in these 16 patients are presented. Atrial fibrillation appeared late in the course of the disease, and its occurrence did not seem to be related to the severity of left ventricular outflow obstruction or to the amount of associated mitral regurgitation. In each patient the onset of the arrhythmia was accompanied by severe clinical deterioration, which often necessitated urgent medical treatment. Digitalis was administered to all 16 patients with subsequent clinical improvement in 15. Electrical cardioversion was uniformly successful in restoring sinus rhythm, but atrial fibrillation usually recurred. In each of 8 patients catheterized during atrial fibrillation, cardiac output was strikingly low (average, 1.9 l./min./m.(2)), whereas it was normal in 10 of 13 patients studied in sinus rhythm. The duration of follow-up from the onset of atrial fibrillation has averaged 5 years, and 3 of the 16 patients have died of causes related to their heart disease. Four have suffered cerebral emboli. Only 5 patients are now in stable sinus rhythm; in general, they are less symptomatic than the patients in whom atrial fibrillation has recurred.The unusually severe clinical deterioration at the onset of atrial fibrillation and the low cardiac output measured during catheterization are thought to be related to the loss of the important contribution to ventricular filling of atrial systole in patients with poorly compliant ventricles, and to the effect of an irregular ventricular rhythm on the variable nature of the outflow obstruction.
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PMID:Atrial fibrillation in patients with idiopathic hypertrophic subaortic stenosis. 552 80

Supraventricular tachycardia is one of the most frequent arrhythmias in childhood. It may accompany congenital heart disease. W.P. W. syndrome, or a normal state of health. A re-entry circuit is the most commonly observed electrophysiological mechanism. Persistence is followed by decompensation. Drug management is based on digitalis, ATP, amiodarone, and verapamil. Atrial and ventricular pacing and surgery are alternatives when other means fail. Persistent tachycardia (i.e. its presence over long periods) is much less frequent that the paroxysmal form, and its aetiology is generally unknown. Even here, the clinical picture is substantially related to decompensation. Digitalis + amiodarone is the best treatment, though the arrhythmia may resolve spontaneously.
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PMID:[Supraventricular tachycardia in children]. 665 30

It is well known that the incidence of cardiac arrhythmia is particularly high in patients with chronic respiratory insufficiency (CRI). This study examines the prevalence, incidence and prognostic clinical importance of arrhythmia occurring during the course of CRI on the basis of data taken from the literature and the authors' personal experience using dynamic electrocardiographic diagnosis (24-hour Holter monitoring). The majority of arrhythmias observed in these patients appeared to take the form of premature ventricular and/or supraventricular beats and less frequently of atrial fibrillation and/or attacks of supraventricular paroxysmal tachycardia. Cardiac rhythm alterations were observed using Holter monitoring in 70-90% of patients. No cardiac rhythm disorder is specific to this pathological condition. The aim of this study was to formulate, as far as was possible, a rational therapeutic approach which took account of the electrogenesis of arrhythmic phenomena, variations in the type of arrhythmia and the hemodynamic conditions under which they occur. The etiopathogenesis of arrhythmias within the framework of CRI is relatively complex and probably multifactorial since there are a number of concomitant pathological conditions able to trigger off arrhythmogenic processes both inducing the onset of reflux circuits and enhancing cardiac automatism centres. Many studies correlate the presence of arrhythmia with hypoxemia, hypercapnia and both respiratory and metabolic alkalosis. Even the combined effect of hypoxia with respiratory acidosis and the integrity or otherwise of cardiac function (chronic pulmonary heart, right ventricular hypertrophy, ischemic cardiopathy) have a notable pro-arrhythmic effect. Hypokalemia induced by both respiratory alkalosis and by drugs used during the course of CRI (eg diuretics and/or steroids) may induce a marked dispersion of refractory periods of the various fibrocells thus encouraging the onset of arrhythmia. With regard to drugs, it has been observed that both digitalis and theophylline and beta-2 stimulants if frequently used during the course of CRI may possibly induce arrhythmia. It is therefore important to underline that they should be used with particular caution. As far as concerns the use of beta-2 adrenergic compounds, it is advised that they be administered using an aerosol rather than systemic route. Digitalis has limited indications; the molecules of the methylxanthine classes require careful pharmacological dose monitoring. Arrhythmic therapy should also be seen in terms of prophylaxis and the correction of predisposing and decisive factors such as hypoxemia, hypercapnia, hemoglobin and electrolyte levels, and alterations in blood pH following the obstruction of small airways.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Respiratory insufficiency and cardiac arrhythmia: the rationale of treatment]. 833 38

Obesity can result in alterations in cardiac structure and function even in the absence of systemic hypertension and underlying organic heart disease. Increased total blood volume creates a high cardiac output state that may cause ventricular dilatation and ultimately eccentric hypertrophy of the left (and possibly the right) ventricle. Eccentric left ventricular (LV) hypertrophy produces diastolic dysfunction. Systolic dysfunction may ensue due to excessive wall stress if wall thickening fails to keep pace with dilatation. This disorder is referred to as obesity cardiomyopathy. The presence of systemic hypertension in obese individuals facilitates development of LV dilatation and hypertrophy. Congestive heart failure may occur in such individuals, and may be attributable to LV diastolic dysfunction or to combined LV diastolic and systolic dysfunction. The sleep apnea/obesity hypoventilation syndrome occurs in 5% of morbidly obese individuals and is potentially life-threatening. Treatment of obesity cardiomyopathy consists of weight loss, salt restriction, and diuretics. Digitalis and vasodilators may be useful in selected cases. Central obesity is probably a risk factor for the development of coronary heart disease. Alterations in lipid and insulin metabolism may facilitate development of coronary heart disease in obese patients.
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PMID:Obesity and the heart. 836 92


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