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)

A thorough cardiovascular evaluation is necessary to detect potentially lethal abnormalities that may predispose children and adolescents to sports-related sudden death. Hypertrophic cardiomyopathy and anomalous origin of the left coronary artery from the right sinus of Valsalva are the two most common cardiac abnormalities associated with sudden death during childhood. Other conditions potentially associated with sudden death are Marfan's syndrome, aortic valve stenosis, primary pulmonary hypertension, and arrhythmias. A detailed medical evaluation is indicated for subjects who have a history of nonvasodepressor syncope, exercise-related syncope or presyncope, angina pectoris, or known congenital or acquired heart disease. In addition, a family history of premature sudden unexpected syncope or death, hypertrophic cardiomyopathy, premature atherosclerotic heart disease, severe arrhythmias, or Marfan's syndrome or premature aortic aneurysms is an indication for a thorough cardiovascular evaluation before participation in sports.
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PMID:Cardiovascular evaluation of the child and adolescent before participation in sports. 406 61

Patients who are at increased risk of sudden death generally have significant underlying organic heart disease, but this is not always the case. The majority of patients at risk include those with the idiopathic long QT syndrome, the Wolff-Parkinson-White disorder, mitral valve prolapse, coronary heart disease, and cardiomyopathy. A history of syncope or presyncope and/or frequent or repetitive runs of ventricular ectopic beats are common prodromal findings in patients with a potentially life-threatening problem. Potential candidates for implantable antiarrhythmic devices include high-risk patients in whom an effective antiarrhythmic agent cannot be identified or those who cannot tolerate indicated antiarrhythmic agents because of adverse side effects.
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PMID:Early identification of patients who may require electrical control treatment. 620 6

We performed M-mode echocardiography on 100 subjects with idiopathic mitral valve prolapse (IMVP) and on 100 normal control subjects to determine if differences exist between the two groups in cardiac chamber size, left ventricular performance or left ventricular mass. Subjects with IMVP demonstrated significantly greater left ventricular mass than normal control subjects. There were no significant differences in fractional shortening of the left ventricle or left ventricular end-diastolic volume. There was no significant difference in left ventricular mass between asymptomatic subjects with IMVP and those with chest pain, palpitations, syncope or presyncope. Subjects with and without mitral regurgitation showed no significant difference in mass. The results indicate that subjects with IMVP demonstrate subtle left ventricular hypertrophy which does not appear to be caused by underlying organic heart disease, mitral regurgitation or sustained hypercontractility. This suggests that myocardial involvement is an integral part of the IMVP syndrome.
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PMID:Increased left ventricular mass in idiopathic mitral valve prolapse. 621 84

This study delineates the clinical spectrum of 15 patients with polymorphic ventricular tachycardia and normal QT intervals in the absence of apparent structural heart disease, adverse drug effects, or electrolyte disturbances. Patients presented with either palpitations (n = 2), presyncope (n = 5), syncope (n = 4), no symptoms (n = 1), or aborted sudden death (n = 3). Mean age was 41 years (range 20 to 64), and mean follow-up 38 months (range 4 to 109). Left ventricular function was normal as determined by either echocardiogram (n = 9) or left ventriculography (n = 9). Episodes of polymorphic ventricular tachycardia (VT) were analyzed in terms of the preceding interval, and the relation of the initiating coupling interval to the QT interval (coupling interval/QT interval = polymorphic VT index). The mean QT for the group as a whole was 0.41 +/- 0.02 second. Patients could be separated into 3 distinct groups. Four patients had polymorphic VT reproducibly induced by exercise and initiated by late-coupled beats (mean polymorphic VT index 1.27 +/- 0.21). Isoproterenol induced polymorphic VT in 3 of 4 patients, and all 4 responded to chronic beta blockade. Two patients had polymorphic VT during episodes of coronary artery spasm, and both responded to calcium channel blockade. Polymorphic VT unrelated to exertion or coronary vasospasm occurred in 9 patients. Tachycardia onset was initiated by closely coupled beats (mean polymorphic VT index 0.95 +/- 0.16), and was preceded by a pause in 4 patients, and no pause in 5 patients. Sudden death occurred in 5 of 9 patients with the shortest polymorphic VT indexes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sudden cardiac death and polymorphous ventricular tachycardia in patients with normal QT intervals and normal systolic cardiac function. 790 Jun 61

Orthostatic stress during tilt table testing (TTT) is used to examine patients who may have vasodepressor syncope. This response is thought to be mediated by activation of left ventricular mechanoreceptors. Isoproterenol, by increasing the rate of discharge of these mechanoreceptors, has been proposed to increase the sensitivity of TTT without decreasing its specificity. This mechanism is not, however, totally consistent with recent observations of vasodepressor responses after cardiac transplantation in patients with denervated hearts. These reports and data showing that not all sympathomimetic agents increase the sensitivity of TTT suggest that more than one mechanism may be responsible for a positive TTT result. Therefore we hypothesized that patients with positive TTT results tests not requiring isoproterenol (iso-independent) would have a different clinical and therapeutic response than patients who required isoproterenol (iso-dependent). One hundred sixty-one consecutive patients who underwent TTT for the evaluation of unexplained syncope were included in the study. TTT was performed without and during isoproterenol infusion. A positive TTT result was defined as syncope or presyncope with a sudden decrease in systolic blood pressure and reproduction of the patient's clinical symptoms. Patients with a positive TTT result underwent a second test after 1 to 2 weeks of therapy with an oral beta-blocking agent; if the result remained positive, TTT was performed again with other agents until a satisfactory therapeutic response was obtained. Sixty-six (41%) of 161 patients had a positive result; 18 (27%) were iso-independent, and 48 (73%) were iso-dependent. There were no significant differences in age, gender, or presence of underlying heart disease between these two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential therapeutic responses of patients with isoproterenol-dependent and isoproterenol-independent vasodepressor syncope. 798 91

In 17 patients (aged 78 +/- 9 years) with symptomatic atrial fibrillation and a slow ventricular response not related to drugs, a resting electrocardiogram and 24-hour Holter recording were obtained before and 5 to 6 days after administration of slow-release theophylline (700 mg/day), and successively every 3 months during the long-term phase. Fourteen patients had organic heart disease, and 13 complained of syncope or presyncope, and 4 of asthenia and easy fatigability. At the steady-state evaluation, theophylline significantly increased resting heart rate (HR) by 42%, mean 24-hour HR by 31% and minimal 24-hour HR by 34%. Cardiac pauses > 2,500 ms disappeared or markedly decreased. The daily number of wide QRS complexes increased. Serum theophylline level was 13 +/- 5 ng/ml. During the follow-up period (20 +/- 18 months), the mean daily theophylline dosage was 450 mg and the mean serum theophylline level 9 ng/ml. Seven patients died: 1 because of heart failure, and 6 because of noncardiac death. One patient complained of a syncopal episode during 1 visit. The drug markedly reduced asthenia and easy fatigability. During the long-term phase, HR increased spontaneously in 3 patients, and the treatment was interrupted. In 2 patients, theophylline had to be discontinued because of gastric intolerance. During long-term therapy, HR was similar to that observed at the steady-state evaluation, despite the reduction in daily dosage. The data suggest that theophylline is an effective therapy in most patients with symptomatic atrial fibrillation and a slow ventricular response.
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PMID:Long-term effects of theophylline in atrial fibrillation with a slow ventricular response. 823 3

Seventy-six consecutive patients were evaluated to assess whether the response to head-up tilt test was related to the type of clinical presentation in patients with syncope of unknown origin and free from heart disease. The syncopal attacks were clinically characterized in a prospective fashion before the tilt test. In 44 patients (group I) syncope had been preceded by autonomic symptoms or was associated with recent or static sustained orthostatism. In 32 patients (group II), syncope had been sudden, without prodromal or autonomic symptoms. Mean age was 49 +/- 17 years in group I patients and 47 +/- 17 years in group II patients (NS). The degree of tilt was 75 degrees. During 30 min no drugs were administered, and then isoproterenol was infused for an additional 20 min (1-5 micrograms/min until a maximal heart rate of 140 bpm was achieved). Tilt test was considered as positive when the patient developed syncope or presyncope with hypotension. Tilt test was positive in 33 patients from group I (75%) and 12 from group II (37.5%)(p = 0.001). The positive response developed within the 30 initial min of the test (without isoproterenol infusion) in 19 of 33 patients from group I (57%) and in 3 of 12 patients from group II (25%) (p = 0.053). It is concluded that the response to tilt test is related to the clinical features of syncopal attacks.
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PMID:[An analysis of the responses to the tilt-table test depending on the clinical characteristics of the syncopal episodes in patients without apparent cardiopathy]. 846 5

A 26-year-old man underwent an electrophysiological study for evaluation of a history of congenital heart disease, presyncope, and wide complex tachycardia. During the study the patient developed sustained atrial fibrillation with a rapid ventricular response. A 17-year-old man with a history of sick sinus syndrome developed sustained atrial fibrillation. Both patients failed four attempts at external cardioversion with a maximum delivered energy of 360 J. Low energy cardioversion was successful in both patients using biphasic waveforms and internal transvenous defibrillation electrodes. Internal cardioversion using a transvenous electrode system can be successful in patients with atrial fibrillation refractory to external cardioversion.
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PMID:Internal cardioversion in two patients with atrial fibrillation refractory to external cardioversion. 873 59

Based on a retrospective study, we report the clinical and electrophysiological characteristics of 62 cases of effort-induced atrio-ventricular block (AVB). The diagnosis of effort-induced AVB was established by stress test and/or Holter ECG. This series consisted of 18 women and 44 men with a mean age of 64 +/- 13 years. AVB presented in the form of poor adaptation to effort in 41 patients (66%), fainting and/or presyncope suggestive of Stokes-Adams attacks in 20 patients (32%), associated with poor adaptation to effort, except in 5 patients. 48 patients (77%) did not have any underlying heart disease. The ECG was normal in 25 patients (40%) or abnormal, demonstrating a 1st degree AVB and/or an intraventricular conduction disorder. On electrophysiological investigation, the AVB was type II (Mobitz II) in 48 patients (77%), generally 2/1. The block was infranodal, either in or below the His bundle, in 56 patients (90%). When it was situated above the His bundle, it was organic and degenerative, situated at the AV node, at the node-His junction, or even proximally in the His bundle. Effort-induced AVB implies DDD atrioventricular stimulation. The presence of this anomaly should be investigated in patients with poor adaptation to effort, but also when the clinical picture is dominated by Stokes-Adam attacks.
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PMID:[Effort-induced atrioventricular block. Apropos of 62 cases]. 874 58

The purpose of the study was to report the prevalence of inducible supraventricular tachyarrhythmias (SVTA) in 827 consecutive patients aged 17 to 90 years who did not have spontaneous documented SVTA and who had unexplained presyncope and/or syncope. The electrophysiologic study (EPS) included programmed atrial and ventricular stimulation up to two extrastimuli at three cycle lengths, and the study of sino-atrial and AV conduction. The results were as follows. EPS was normal in 386 patients. Inducible junctional tachycardia or atrial flutter and fibrillation was the only finding in 187 patients (23%). In the remaining patients we found ventricular tachycardia in 103 (12%), heart block in 67 (8%), sick sinus syndrome in 56 (7%) and increased vagal tone in 28 (3%). The presence of an underlying heart disease (47%) and salvos of atrial premature beats on Holter monitoring (39%) were significantly correlated with the induction of SVTA. However, the comparison with similar groups without syncope indicates that only the induction of SVTA in patients with hypertrophic cardiomyopathy and mitral valve prolapse was significantly correlated with the history of syncope. In patients without heart disease or with prior myocardial infarction or decreased left ventricular function, the induction of SVTA, which is not associated with hypotension in the supine position, could require an induction after head-up tilting, because of the lack of specificity of programmed stimulation in these patients. Programmed atrial stimulation should be systematically performed in patients with unexplained syncope, in particular in those with hypertropic cardiomyopathy and mitral valve prolapse, who require a specific treatment, if a SVTA is induced. In other patients the results of programmed atrial stimulation should be interpreted cautiously.
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PMID:Significance and prevalence of inducible atrial tachyarrhythmias in patients undergoing electrophysiologic study for presyncope or syncope. 877 79


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