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

Facioscapulohumeral muscular dystrophy is an autosomal dominant disorder with an incidence of 3 to 10 cases per million. The only type of cardiac involvement ascribed to this neuromuscular disorder is a unique form of heart disease--permanent atrial paralysis. However, reported cases of facioscapulohumeral muscular dystrophy probably represented instead what is now recognized as phenotypically similar Emery-Dreifuss dystrophy. Cardiac involvement, therefore, has not been convincingly reported in facioscapulohumeral muscular dystrophy, but because of the clinical similarity of that disorder to Emery-Dreifuss dystrophy and its genetic variants, a prospective investigation of the electrophysiologic properties of the atria and atrioventricular (AV) node and infranodal conduction was undertaken in 30 rigorously documented cases of facioscapulohumeral muscular dystrophy. All patients had a 12 lead surface electrocardiogram (ECG), 22 had a 24 h ambulatory ECG, 15 patients had two-dimensional echocardiographic/Doppler studies and 10 patients underwent 12 intracardiac electrophysiologic investigations. Left atrial, right atrial or biatrial P wave abnormalities were present in 60% of the surface ECGs. Evidence of abnormal AV node or infranodal conduction was present on intracardiac electrophysiologic study or surface ECG in 27% of patients. Atrial flutter or fibrillation was induced by single atrial extra stimuli in 10 of the 12 intracardiac electrophysiologic studies. Sinus node function was abnormal in three patients. This investigation provides the first secure evidence of cardiac involvement in facioscapulohumeral muscular dystrophy. The involvement is represented by relatively high susceptibility to induced atrial flutter or fibrillation during electrophysiologic study, together with less frequent evidence of abnormal sinus node function and abnormal AV node or infranodal conduction.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Facioscapulohumeral muscular dystrophy: evidence for selective, genetic electrophysiologic cardiac involvement. 229 71

The potential ability of electrophysiologic abnormalities to predict recurrence of atrial flutter was evaluated. Twenty-five patients with chronic atrial flutter resistant to combined digitalis and quinidine therapy were studied electrophysiologically after restoration of sinus rhythm by overdrive pacing or by eventual direct current cardioversion. Recurrence of atrial flutter was observed in 12 patients during a mean follow-up period of 17 months (range 3 to 50). Electrophysiologic testing included programmed high right atrial stimulation at a paced drive cycle length of 600 ms and incremental pacing up to 200-ms paced intervals. When coupling intervals of 90% of the drive cycle length were compared to coupling intervals of 48% of the drive cycle length, the increase in S1A1 interval, defined as the interval between the stimulus artifact and the atrial activation near the atrioventricular junction, was greater in patients with subsequent recurrence of atrial flutter (47 +/- 11 vs 21 +/- 18 ms). Stepwise logistic regression analysis identified the S1A1 increase to be the sole independent predictor of recurrence (p = 0.0082) while previous episodes of atrial flutter or the presence of organic heart disease were identified as dependent variables. Reclassification showed a 91% sensitivity and a 92% specificity. Correct classification was achieved in 92% of patients. The initiation of atrial dysrhythmia had no predictive value. The assessment of the S1A1 interval by programmed atrial stimulation appears helpful in delineating the patient risk of recurrent atrial flutter after termination by overdrive pacing.
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PMID:Electrophysiologic determinants of recurrent atrial flutter after successful termination by overdrive pacing. 230 85

The coexistence of bradycardia and a tachyarrhythmia may preclude effective pharmacologic treatment of 1 arrhythmia without paradoxic aggravation of the other. This study evaluated the potential relation between the 2 types of arrhythmias and the effect of conventional modes and rates of pacing for bradycardia on the frequency of the associated tachyarrhythmias. Twenty-one young patients, aged 2 to 19 (mean 11) years with congenital heart disease and a tachyarrhythmia occurring in the setting of chronic bradycardia were studied. The effects of pacing were evaluated by comparison of the number of episodes of clinical tachycardia during the 12-month intervals before and after pacemaker implantation. During these intervals, antiarrhythmic drug therapy was not altered. Patients were analyzed as independent groups, based on the type of tachyarrhythmia: supraventricular (n = 5), atrial flutter (n = 9) and ventricular (n = 7). The modes of chronic pacing were AAI (n = 4), DDD (n = 6) and VVI (n = 11). The prevention of bradycardia by pacing was associated with a significant decrease in the frequency of supraventricular (p = 0.008) and ventricular (p = 0.02) tachyarrhythmias. However, the frequency of atrial flutter was not altered. Prevention of tachycardia was more frequently associated with the AAI and DDD modes of pacing compared to VVI (p = 0.08). Pacing represents an effective therapy for certain tachyarrhythmias associated with chronic bradycardia, although critical modes may be required.
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PMID:Bradycardia-mediated tachyarrhythmias in congenital heart disease and responses to chronic pacing at physiologic rates. 230 88

We reviewed our experience with 382 fetal echocardiograms. Complete studies were not possible for three pregnancies because of either fetal position or maternal obesity. Studies were performed for fetal arrhythmia (28%), maternal factors (21%), fetal anomaly (11%) and family history of congenital heart disease (40%). There was a recurrence of heart disease in two of 153 patients (1.3%). Arrhythmia was the most common finding (82 of 382 patients). Premature atrial and ventricular contractions were the most common arrhythmia, and structural defects were present in four of 58 patients (6.8%) with premature contractions. Fetal heart defects (n = 44) were identified in 40 of 382 (10%) referrals. The defects were complete atrioventricular block (13), ventricular septal defect (4), atrioventricular canal (5), cardiac mass (3), ectopia cordis (2), thoracopagus (2), hypoplastic left ventricle (2), hypoplastic right ventricle (2), atrial flutter (2), pulmonic stenosis (1), single ventricle (2), Uhl's anomaly (1), Ebstein's anomaly (1), mitral atresia (1), d-transposition of the great vessels (1), tetralogy of Fallot with absent pulmonary valve (1), and atrial septal defect and ventricular septal defect (1). There were three false positive (99% specificity) and two false negative (95% sensitivity) fetal echocardiograms. The survival rates for referred patients with heart defects was: live born and perinatal survivor, 54%; perinatal death, 31%; still birth, 11%; and termination of pregnancy, 4%. Fetal echocardiography is accurate, and the abnormalities detected appear to be more severe than those detected on newborn screening.
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PMID:Fetal echocardiography: a large clinical experience and follow-up. 231 May 91

Long-term follow-up data on young patients receiving amiodarone is lacking, especially in relation to growth and late side effects. The records of 95 young patients (mean age 12.4 years; range 3 weeks to 31.5 years) who received amiodarone were reviewed. Minimal follow-up time for those continuing to take amiodarone was 1.5 years; the mean duration of therapy was 2.3 years (maximal 6.5). The mean maintenance dosage was 7.7 (1.5 to 25) mg/kg body weight per day. Initial success (based on symptoms and 24 h electrocardiogram) was achieved in 23 of 34 patients with ventricular tachycardia, in 32 of 33 with atrial flutter and in 21 of 28 patients with supraventricular tachycardia. However, in 7 of 33 patients with atrial flutter, the arrhythmia returned after 6 months. Patient growth continued in the same percentiles achieved before amiodarone in all but eight patients, improving in six and worsening in two with severe underlying disease. Proarrhythmia occurred in three patients: one had torsade de pointes that disappeared when amiodarone administration was stopped; two with severe anatomic heart disease died suddenly during the loading period (one with atrial flutter and one with ventricular tachycardia). Side effects occurred in 28 (29%) of the 95 patients: keratopathy (in 11), abnormal thyroid function test (in 6), chemical hepatitis (in 3), rash (in 3), peripheral neuropathy (in 2), hypertension (in 1) and vomiting (in 1). All side effects disappeared when amiodarone was discontinued or the dose was reduced.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Long-term follow-up of amiodarone therapy in the young: continued efficacy, unimpaired growth, moderate side effects. 231 68

Although intraatrial reentry has been traditionally listed as a mechanism for supraventricular tachycardia, few reports describing the clinical features of this arrhythmia exist. Nineteen patients with a clinical history of sustained supraventricular tachycardia were diagnosed as having intraatrial reentrant tachycardia. Seventeen (89%) patients of the 19 had underlying structural heart disease and 17 had echocardiographic evidence of atrial enlargement; the mean left ventricular ejection fraction was 51 +/- 16%. A history of concomitant atrial fibrillation or flutter was present in 13 patients (68%). The mean atrial cycle length during tachycardia was 326 +/- 57 ms (range 260 to 460). Fourteen patients had 1:1 atrioventricular (AV) conduction during tachycardia, of whom 50% had an RP'/RR' ratio greater than 0.5. Intravenous adenosine (dose range 37.5 to 150 micrograms/kg) and verapamil (dose range 5 to 10 mg) had no effect on atrial tachycardia cycle length in 13 of 14 and 9 of 9 patients, respectively, despite induction of second degree AV block. Type 1a antiarrhythmic drugs achieved long-term suppression of intraatrial reentrant tachycardia in only 6 patients, whereas amiodarone (326 +/- 145 mg/day) was successful in 11 patients during a 32 +/- 20 month follow-up period. The remaining two patients and one patient who later developed amiodarone toxicity either progressed to (n = 1) or had (n = 2) catheter-induced high grade AV block and were treated with long-term ventricular pacing. It is concluded that intraatrial reentrant tachycardia is often associated with structural heart disease, particularly of types that cause atrial abnormalities, but left ventricular dysfunction is not a requisite finding. Other arrhythmias are frequently observed in these patients. This arrhythmia responds poorly to type 1a antiarrhythmic drugs, but is effectively treated with amiodarone. Catheter ablation of the AV junction offers a therapeutic option for patients who are refractory to medical therapy.
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PMID:Sustained intraatrial reentrant tachycardia: clinical, electrocardiographic and electrophysiologic characteristics and long-term follow-up. 232 38

The authors examined the prevalence and significance of cardiac rhythm disturbances in healthy elderly individuals. They selected 26 men with active lifestyles, aged 70-81 years, after clinical, routine blood tests, chest radiographs, echocardiography, resting and exercise electrocardiography, and Gated cardiac blood imaging evaluations. The men were submitted to continuous electrocardiographic monitoring during their daily routine. The recording time ranged from 838 to 1,432 min (average = 1,307 +/- 153 min). Clinical follow-up was done every six months. Sinus rhythm predominated in all subjects. The maximal, minimal, and average heart rate ranges (beats/min) were, respectively: during sleeping periods, 60-115 (85.8 +/- 13.2), 42-80 (56.6 +/- 8.7), 51-85 (64.0 +/- 8.8); and during awake periods, 85-150 (118.4 +/- 16.4), 50-85 (64.1 +/- 9.1), 61-90 (75.3 +/- 8.3). The longest sinus pauses were observed during sleep and ranged from 0.8 to 2.5 sec (1.25 +/- 0.34 sec). Atrial ectopic beats were observed in 20 individuals (76.9%). They were frequent in four (15.4%) and repetitive in nine (34.6%) of them. Short-lasting episodes of paroxysmal atrial tachycardia and paroxysmal atrial flutter were observed in one case each. Ventricular ectopic beats were recorded in 20 individuals (76.9%). They were frequent in 6 (23%) and multiform in 13 (50%) of them. Couplets were observed in 5 cases (19.2%) and episodes of nonsustained ventricular tachycardia were present in 3 individuals (11.5%). No symptoms were referred by any individual during recording. No clinical signs of heart disease or symptoms were noticed during the average 40 +/- 7.2 months of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Frequency and significance of cardiac rhythm disturbances in healthy elderly individuals. 234 17

In the young patient resuscitated from sudden cardiac arrest, the risks of recurrence are uncertain and so are the criteria defining therapeutic efficacy for the presumed cause of the initial event. In this study, we analyzed the outcome of 15 consecutive young patients, who were resuscitated from pulseless ventricular tachycardia or ventricular fibrillation and who were evaluated by comprehensive hemodynamic and electrophysiological testing. Patients were 11.2 +/- 2.7 (mean +/- SD) years old at the time of their event, and each was known to have some form of heart disease before sudden cardiac arrest. Ventricular tachycardia or fibrillation was inducible by programmed electrical stimulation in eight patients. Accessory atrioventricular connections, with antegrade effective refractory periods less than 220 msec, were identified in three patients. Sustained atrial flutter was the only arrhythmia inducible in two patients, and no arrhythmias were inducible in two other patients. Surgical or electrophysiological-guided medical therapy resulted in noninducibility of the ventricular arrhythmias in six patients. Surgical division of the accessory atrioventricular connections was performed in three patients, and arrhythmias were not inducible after operation. The four patients with atrial flutter or without defined arrhythmia were treated with an empiric therapy. During 37 +/- 14 months of follow-up, the nine patients with documented noninducibility of a defined cause of sudden cardiac arrest were free of recurrent events. In contrast, during 18 +/- 10 months of follow-up, two of the six patients with empiric therapy or persistent inducibility of ventricular tachycardia died suddenly, and three others had recurrence of ventricular tachycardia or fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Assessment and follow-up of pediatric survivors of sudden cardiac death. 219 20

With the purpose to call attention to the clinical utility of fulguration of the His bundle (a therapeutic procedure somewhat neglected in Italy) 3 new cases are presented. All patients had a long history of supraventricular tachyarrhythmias refractory to conventional treatment. Patients 1 and 2, in whom surgical correction of tetralogy of Fallot and mitral valve replacement, respectively, had been performed several years before, had chronic atrial tachycardia with congestive heart failure. Patient 3 suffered from persistent atrial flutter, in the absence of demonstrable organic heart disease. Three shocks of 320 J were necessary to induce complete AV block in patient 1 and 2. In patient 3, a single discharge (320 J) resulted in interruption of AV conduction. Twenty-four hours after the procedure, a rate-responsive ventricular pacemaker was implanted in all patients. The success of the procedure was confirmed 3 months later, during transitory pacemaker inhibition. Patients 1 and 3 exhibited atrial tachycardia and atrial flutter, respectively, but complete AV block was still present, with junctional escape rhythm at a rate of 40 and 45 b/min; in patient 2 atrial tachycardia with high degree AV block, and a mean ventricular rate of 75 b/min, were observed. Refinement of transcatheter ablative techniques is desirable. However, even in the present status, catheter ablation of the His bundle is an effective, low-risk procedure for patients with refractory supraventricular tachyarrhythmias.
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PMID:[Fulguration of the bundle of His. Description of 3 new cases]. 237 54

Calcium antagonists have emerged as a new class of antiarrhythmic agents for the control of certain supraventricular and ventricular arrhythmias. Electrophysiologically, these agents are heterogeneous but their main action is mediated through a depressant effect on the slow calcium channel in cardiac muscle, most readily demonstrated in isolated tissue preparations. In vivo, their actions are modulated by their reflex actions and by their interaction with the autonomic nervous system due to the noncompetitive adrenergic-blocking actions that some of the compounds exhibit. The major agents exerting antiarrhythmic actions are verapamil, diltiazem, gallopamil, tiapamil and bepridil; the dihydropyridines are devoid of electrophysiologic actions in vivo. Calcium antagonists prolong intranodal conduction time, lengthen the effective and functional refractory periods in the atrioventricular node but exert little or no effect on atrial, ventricular, His-Purkinje or bypass tract conduction or refractoriness (except in the case of bepridil, which has additional electrophysiologic properties). These effects form the basis of the clinical antiarrhythmic effects of this class of agents. The most striking action is the predictable and prompt termination of the reentrant supraventricular tachycardia by intravenous verapamil and diltiazem and the slowing of the ventricular response in atrial flutter and fibrillation. These agents may also be of value in the long-term control of ventricular response in atrial flutter and fibrillation; their role in multifocal atrial tachycardia and other ectopic tachycardias is less well defined. Calcium antagonists reverse ischemic ventricular arrhythmias caused by coronary artery spasm but exert little or no action in the usual forms of sustained ventricular tachyarrhythmias associated with severe structural heart disease. They are poor suppressants of ventricular premature complexes. Recent data have established their role in exercise-induced tachycardia occurring in the context of ischemic heart disease; they are also of value in ventricular tachycardia occurring in young patients who develop tachycardia with a right bundle branch block and left axis deviation morphology, an arrhythmia thought to be due to triggered automaticity.
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PMID:Use of calcium antagonists for cardiac arrhythmias. 243 30


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