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)

In recent years, data has become available to support the concept that a selective lengthening of the cardiac action potential (a Class III antiarrhythmic action) by whatever mechanism with an attendant increase in the effective refractory period constitutes a distinct antiarrhythmic mechanism. Such an action is exemplified clinically by hypocalemia and hypothyroidism and pharmacologically by amiodarone, sotalol and bretylium, all of which have other associated features. The N-acetylation of procainamide leads to the pharmacologically active compound, N-acetylprocainamide (NAPA). The loss of propensity to block depolarization with the preservation of the effect on repolarization in the case of NAPA makes the compound a class III antiarrhythmic agent. The process of N-acetylation has also led to longer elimination half-life and predominantly renal excretion with linear kinetics but with the preservation of the antiarrhythmic properties of the parent compound. The electrophysiologic data are consistent with the results of studies which have demonstrated that NAPA has the potential to suppress premature ventricular contractions and prevent spontaneously occurring as well inducible ventricular tachycardia in patients with heart disease. The effects on atria indicate that the drug has the potential to electively reverse atrial flutter and fibrillation to normal rhythm and maintain stability of sinus rhythm. The overall experimental and clinical data warrant further evaluation of NAPA as an antiarrhythmic agent.
 ...
PMID:Arrhythmia control by selective lengthening of cardiac repolarization: role of N-acetylprocainamide, active metabolite of procainamide. 243 67

Fifty patients with supraventricular tachycardia (SVT) underwent clinical electrophysiological studies (EPS), endomyocardial biopsies and cardiac catheterizations. EPS revealed AV nodal reentrant tachycardia (AVNRT) in seven patients, AV reentrant tachycardia utilizing concealed AV bypass tracts (AVR-CBT) in nine patients, AV reentrant tachycardia utilizing AV bypass tracts with ventricular preexcitation (manifest WPW) in 13 patients, sinus nodal or intra-atrial reentrant tachycardia (SNRT or IART) in three patients, atrial flutter (AF) in nine patients, automatic atrial tachycardia (AAT) in five patients, and multifocal atrial tachycardia (MAT) in four patients. According to the clinical observations, three patients with AVNRT (43%), six with AVR-CBT (67%), six with manifest WPW (46%), two with SNRT or IART (67%), eight with AF (89%), two with AAT (40%), and two with MAT (50%) showed other accompanying clinical abnormalities. In all patients who were studied histologically, changes in the myocardium were seen; myocarditic changes, postmyocarditic changes and nonspecific abnormalities were present in six (12%), 15 (30%), and nine (18%) respectively. Myocardial changes were observed in four out of seven cases with AVNRT (57%), in six out of nine with AVR-CBT (67%), in five out of 13 with manifest WPW (38%), in two out of three with SNRT or IART (67%), in six out of nine with AF (67%), in all five cases of AAT (100%), and in two out of four with MAT (50%). Nineteen out of 32 without clinical abnormalities except for arrhythmias (59%) had myocardial changes (six had myocarditic changes, ten had postmyocarditic changes, and three had nonspecific abnormalities). On the other hand, nine out of 21 with myocarditic or postmyocarditic changes were accompanied with various arrhythmias other than SVT (two had SSS, five had AV block or rBBB, and two had VT). Elevated LVEDP was present in 36% of the group with normal myocardium and in 53% of the group with myocardial changes. However, the low EF was shown in no patients with normal myocardium but in 21% of the group with myocardial changes. The low CI was also shown in only 9% of the group with normal myocardium but in 28% of the group with myocardial changes. These results suggest that patients with SVT may exhibit several histopathological changes in the myocardium, even in the absence of any clinical organic heart disease.
 ...
PMID:Clinical, electrophysiological, and histopathological observations in supraventricular tachycardia. 245 68

Our study group included 12 patients (4 males, 8 females), mean age 60 yr, with symptomatic or threatening tachyarrhythmias (Lown classes IV A, B, V); 2 patients were suffering from mitral valve prolapse syndrome, 2 from ischemic heart disease; 4 from cardiac insufficiency caused by hypertensive or ischemic heart disease; 4 had no evident clinical signs of cardiopathy. Patients suffering from: cardiac insufficiency (F.C. III e IV NYHA); II and III degree BAV; atrial flutter and fibrillation; long QT syndrome; acute ischemic heart disease were excluded from the study. During short-term treatment, patients received placebo for four days and subsequently flecainide 200 mg daily for four days. During medium-term treatment patients received flecainide 200 mg daily (for six months). Several Holter/24-hour monitorings were performed for evaluation of therapy. No significant reduction in the number of ectopic ventricular beats (B.E.V.) was found with placebo whereas reductions of B.E.V. number (97% and 95%, respectively) were found during short and medium-term treatment with flecainide. Flecainide produced: changes in Lown class: from IV A, B and V to II and I; a marked reduction of subjective symptoms (dyspnea, giddiness syncope, precordial pain); ECG changes: increases in: PR: 5-25%; QRS: 11-12%; QT: 11-22%. Flecainide produced no pro-arrhythmic effects or changes in echocardiographic ventricular function index. Flecainide can be considered one of the most effective new antiarrhythmic drugs.
 ...
PMID:[Short- and medium-term treatment of ventricular hyperkinetic arrhythmia with flecainide]. 252 12

The aim of this paper was to study atrial natriuretic factor, plasma renin activity and antidiuretic hormone values during paroxysmal atrial arrhythmias with different ventricular rates before and after pharmacological cardioversion and during chronic atrial flutter-fibrillation. The study was carried out: 1) during acute arrhythmias (atrial flutter-fibrillation or supraventricular tachycardia) and after restoration of normal sinus rhythm in 2 patients without heart disease, in 13 with chronic heart disease and in 6 with acute myocardial infarction; 2) during chronic atrial flutter-fibrillation in 5 patients with chronic ischemic heart disease, without congestive heart failure. Atrial natriuretic factor, aldosterone, plasma renin activity and antidiuretic hormone values were measured by radio-immunoassay. During paroxysmal atrial arrhythmias atrial natriuretic factor levels were higher than normal in all patients, particularly in those with supraventricular tachycardia. Most of the aldosterone measurements were above the normal range. As far as plasma renin activity and antidiuretic hormone values are concerned, levels higher than the normal range were found in the patients with severe hemodynamic impairment. Central venous pressure was above normal in all patients except in the 2 without heart disease, and there was a positive correlation between atrial natriuretic factor and central venous pressure values. After restoration of normal sinus rhythm atrial natriuretic factor values returned to normal except in acute myocardial infarction patients, in 1 chronic ischemic heart disease patient with congestive heart failure and in 3 patients with mitral valve disease. In all patients with chronic atrial flutter-fibrillation and in 5 patients with acute atrial flutter-fibrillation and low rate, above normal atrial natriuretic factor values were found with normal central venous pressure values. Atrial distension due to high central venous pressure values, lack of atrial contraction and rhythmic detension of the atrial stretch receptors, may be considered the major stimuli responsible for atrial natriuretic factor release during acute paroxysmal atrial arrhythmias and atrial flutter-fibrillation with low ventricular rate, respectively.
 ...
PMID:[Atrial natriuretic factor in acute atrial hyperkinetic arrhythmia and chronic atrial fibrillo-flutter]. 252 75

Although electrophysiologic testing accurately delineates abnormalities in patients with fixed cardiac-conduction defects, its sensitivity in identifying transient rhythm disturbances is unknown. We prospectively studied 21 patients who had electrocardiographically documented intermittent atrioventricular block (n = 13) or sinus pauses (n = 8) causing syncope, but whose cardiac rhythm had reverted to normal by the time of referral. There were 14 men and 7 women, with a mean age (+/- SD) of 63 +/- 13 years. Fourteen patients had organic heart disease, and 8 were taking cardioactive medications. Electrophysiologic testing was performed before the implantation of a permanent pacemaker. Only three of the eight patients with documented sinus pauses had abnormalities during their tests that suggested the correct diagnosis (sensitivity, 37.5 percent), including a prolonged sinus-node recovery time in one and carotid-sinus hypersensitivity in two. Three of the eight patients had abnormalities detected that were unrelated to syncope, including atrial flutter, dual atrioventricular nodal pathways, and sustained monomorphic ventricular tachycardia. Of the 13 patients with documented atrioventricular block, only 2 had abnormalities suggesting the correct diagnosis (sensitivity, 15.4 percent). Additional observations unrelated to syncope among these 13 patients included abnormal sinus-node function, atrial flutter, and atrial fibrillation causing hypotension. These preliminary observations suggest that a negative electrophysiologic test in a patient with a normal cardiac rhythm who has experienced syncope does not exclude a transient bradyarrhythmia as a cause of the syncope. Furthermore, electrophysiologic testing may sometimes reveal unrelated rhythm disturbances that may mistakenly be designated as the cause of the syncope.
 ...
PMID:The diagnostic sensitivity of electrophysiologic testing in patients with syncope caused by transient bradycardia. 232 41

Thirty nine cases, in which sudden cardiac death (SCD) was suspected, were studied to evaluate the mechanism and the prediction of SCD in arrhythmia-patients using electrophysiological studies (EPS). The 39 cases (28 male and 11 female) were located by surveying 2098 patients who underwent EPS for the evaluation of arrhythmias. Age at time of EPS ranged from 4 to 86 years, average 50.5 years. Time from EPS to death was 2 to 163 months, average 27.9 months. Underlying heart disease was: dilated cardiomyopathy in 11, old myocardial infarction in 5, ischemic heart disease in 5, hypertensive heart disease in 5, valvular heart disease in 3, hypertrophic cardiomyopathy in 2, arrhythmogenic right ventricular dysplasia in 1, myocarditis in 1, sarcoidosis in 1, cor pulmonale in 1, and no obvious heart disease in 4. Fifteen had a permanent pacemaker implanted. SCD in cases without a permanent pacemaker (24 cases): 2 had chronic complete A-V block (one BH block, one HV block), 1 had advanced A-V block (HV block), 3 had bundle branch block with first degree HV block, 9 had ventricular tachycardia (VT), 3 had sick sinus syndrome (SSS), 3 had paroxysmal atrial flutter, 1 had WPW syndrome and paroxysmal atrial fibrillation, 1 had paroxysmal atrial tachycardia, and 3 had premature ventricular beats and first degree HV block. SCD in cases with permanent pacemaker (15 cases): 5 had SSS, and 10 had A-V block. In 3 of the 5 with SSS and 7 of the 10 with A-V block, VT was found before pacemaker implantation. In our study, brady and tachyarrhythmias coexisted in 25 cases (64%).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Mechanism and prediction of sudden cardiac death in arrhythmia patients using electrophysiological studies. 263 27

251 untreated patients with mild to moderate hypertension were included in a multicenter study aimed 1) to detect arrhythmias (24-H Holter recording) and 2) to assess the efficacy of sotalol on blood pressure and possible arrhythmias. Patients with coronary heart disease or previously documented arrhythmias were excluded. Atrial arrhythmias such as premature beats, fibrillation, flutter and paroxysmal atrial tachycardia were detected in 16% of patients. Monomorphic ventricular premature contractions (VPCs) (Lown I and II) were detected in 41% of patients and polymorphic VPCs or duplets/triplets (Lown III and IV) in 14%. A correlation seems to exist between the level of hypertensive cardiopathy, judged on electrocardiographic data (Tarazi classification), age of patients and severity of arrhythmias. Sotalol was administered during 2 months at a mean dose of 160 mg per day. The treatment was effective on blood pressure and arrhythmias (82% improvement of severe VPCs) and the drug was well tolerated. It was difficult to conclude if these good results are due to the betablocking properties or specific class II antiarrhythmic effects of sotalol or to the combined activity.
 ...
PMID:[Cardiac arrhythmia in moderate arterial hypertension. Epidemiologic survey of 251 cases. Effect of sotalol]. 264 67

Primary surgical treatment of many tachyarrhythmias in children is now possible. In those with life-threatening arrhythmias not responsive to any form of medical treatment, the choice for surgery is clear. These arrhythmias include atrial fibrillation with the Wolff-Parkinson-White syndrome, PJRT, or atrial ectopic tachycardia with severe congestive cardiomyopathy, incessant ventricular tachycardia in infancy, and recurrent sustained ventricular tachycardia in postoperative congenital heart disease. In the majority of patients, however, surgical treatment remains an option to be weighed carefully against chronic medical treatment. Surgery is now possible with very low mortality for infants and children with Kent bundles, atrial ectopic tachycardia, and the permanent form of junctional reciprocating tachycardia. The mortality, morbidity, and likelihood of eventual resolution of the arrhythmia with each type of management plan should be considered. With possible direct surgical ablation of atrial flutter and newer forms of catheter treatment of arrhythmias, the future looks promising.
 ...
PMID:Surgical treatment of arrhythmias in children. 265 77

The large frequency of arrhythmias and conduction disorders in the course of Steinert's myotonic dystrophy is well known; most of the time, the muscle disease is already known when the heart disease is discovered. The authors report three cases of young subjects (2, 31 and 35 years) in whom an atrial flutter without obvious etiology preceded by several years (14, 2.5 and 2 years) the diagnosis of muscular disease. On this occasion, the characteristics of the heart involvement in Steinert's disease are reminded: large frequency of atrial and also ventricular rhythm disorders, distalic conduction disorders. Our cases emphasize the importance of diagnosing Steinert's disease by clinical examination, electromyography and neuro-muscular biopsy in front of a rhythm disorder--especially atrial flutter--or an interventricular conduction disorders occurring, without obvious etiology, in a young subject.
 ...
PMID:[Auricular flutter preceding by several years the discovery of Steinert's disease. 3 cases]. 266 Jul 34

Here we report on a study of 181 episodes of spontaneous atrial flutter (AF) (mean atrial cycle length 250 +/- 32 msec) treated by transesophageal atrial pacing (TAP) in 138 patients (92 men and 46 women; mean age 59.5 +/- 12.6 years). TAP was effective in 163 episodes (90%); sinus rhythm resumption was immediate in 36 (19.9%) and followed a short period of atrial fibrillation in 64 (35.3%); in 63 episodes (34.8%) a stable atrial fibrillation was obtained. TAP was unsuccessful in 18 cases (10%). All the patients tolerated the procedure well. A statistical elaboration with the Fisher exact test did not evidence a correlation between efficacy and age, sex, atrial cycle length, or underlying heart disease but showed a significant correlation between efficacy and AF duration of less than 1 day (p less than 0.05) and absence of antiarrhythmic pharmacologic pretreatment (p less than 0.01). These data strongly support the immediate first-choice use of TAP in AF therapy.
 ...
PMID:Transesophageal atrial pacing: a first-choice technique in atrial flutter therapy. 272 54


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