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)

Verapamil and norverapamil trough plasma levels were measured in 22 children, aged from 15 days to 17 years, under chronic oral treatment with the drug (mean daily dose +/- SD: 4.9 +/- 1.4 mg/kg) for supraventricular tachyarrhythmias (n = 20) or hypertrophic cardiomyopathy (n = 2). Overall, 67 determinations were available (1 to 11 per patient) and the mean concentration values (+/- SD) were 43.3 +/- 36.4 ng/ml for verapamil and 41.7 +/- 28.9 ng/ml for norverapamil. Verapamil and norverapamil trough concentrations were correlated with the daily dose (p < 0.05) but a wide intersubject variability was present at any given dose and the regression line did not pass through the origin of axes (x-axis intercept: 1.2 mg/kg for verapamil, 0.9 mg/kg for norverapamil). To study the influence of age on drug kinetics, verapamil plasma concentrations corrected by daily dose/kg ([V]/D) and norverapamil to verapamil concentration ratios (N/V) (taken as an index of metabolic clearance) were divided according to age quartiles. The median [V]/D was higher in the first and in the fourth age quartile than in the other two age groups. On the contrary, median N/V ratio increased with age, suggesting that drug metabolism was improving during the first year of life. Four children developed typical adverse reactions to the drug (bradycardia, AV block, hypotension). In one case verapamil plasma levels were definitely high (294 ng/ml). In the other three cases, concomitant factors (such as very young age and heart disease) seem to have contributed to drug toxicity.
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PMID:Verapamil and norverapamil plasma levels in infants and children during chronic oral treatment. 772 79

In a 4 1/2 year period fetal, echocardiographic studies were performed on 1600 fetuses. In 55 with arrhythmia, 44 had supraventricular ectopic beats, resolved in all, and none had heart disease. Sustained arrhythmias occurred in 11 fetuses. Atrial flutter was present in 3 all with heart disease (Ebstein disease, right atrial tumour and WPW diagnosed after birth). Another 3 fetuses had supraventricular tachycardia (SVT), all with a normal heart. In the bradycardia group, 2 had complete heart block (CHB) associated with AVSD; 2 sinus bradycardia and one had non conducted atrial ectopic beats. Digoxin was the first choice drug for tachyarrhythmia therapy; association with Verapamil, Flecainide, Quinidine and Procainamide was used in 4 of the 6. One fetus with CHB received Orciprenaline with no results. Atrial flutter resolved or improved; in SVT 2 fetuses converted to sinus rhythm and one died in utero. All fetuses with CHB died in cardiac failure. Mortality was 27% (3 cases) in utero and global 36%. In our experience most fetal arrhythmias (90%) were transitory ectopic beats or non lasting bradycardia in normal heart and did not trigger other kinds of arrhythmias. In sustained arrhythmias, heart failure and heart disease had a negative effect on prognosis.
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PMID:[Fetal arrhythmia. A case load of 4 years and a half]. 777 Dec 7

Atrial fibrillation is one of the most common arrhythmias, leading at least in a subset of patients to severe symptoms (palpitations, weakness, syncope), and to hemodynamic impairment especially in the clinical setting of left ventricular dysfunction. Thus, in many cases restauration of sinus rhythm is indicated because of the negative effects of reduced cardiac output. Quinidine has been the first line drug for many years and has been proven to be highly effective especially when combined with Verapamil. But there is growing concern about using quinidine and other class I-anti-arrhythmic agents because of some hints in clinical trials for increased longterm mortality on these drugs. This study was undertaken to test the efficacy of Sotalol, a beta-blocker with additional strong class-III antiarrhythmic action, compared to a fixed combination of Quinidine and Verapamil for conversion of chronic atrial fibrillation and maintenance of sinus rhythm after medical or electrical cardioversion. To avoid early proarrhythmic effects, potassium values in the range of "high"-normal values (> 4.3 mval/L) were tried to be obtained. 82 patients were randomly assigned to receive either Sotalol or Quinidine/Verapamil. There was no difference between the groups as far as the underlying heart disease, duration of atrial fibrillation (mean 219 days) and other clinical features including echocardiographic parameters were concerned. The dose of the drug was weight-related individually adjusted, and the drug was continued thereafter. If sinus rhythm could not be established at that time, electric cardioversion was performed and the drug was continued in lower dosage thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Sotalol and quinidine/verapamil (Cordichin) in chronic atrial fibrillation--conversion and 12-month follow-up--a randomized comparison]. 784 39

The mechanism of ventricular tachycardia (VT) that occurs in the absence of structural heart disease ("idiopathic" VT) is unknown, but may involve triggered activity or reentry through calcium channel-mediated conduction pathways. It has been suggested that termination of VT by adenosine is specific to ventricular arrhythmias caused by cyclic adenosine monophosphate-mediated triggered activity. The effects of vagotonic maneuvers, and intravenous adenosine (up to 0.25 mg/kg in incremental doses) and verapamil (0.145 mg/kg) administered to 9 patients with "idiopathic" VT were studied during electrophysiologic study. Seven patients had inducible fascicular VT and 2 had incessant right ventricular outflow tract tachycardia. Vagal maneuvers did not have any effect on any VT. Adenosine interrupted both right ventricular outflow tract tachycardias for a period (2 to 15 seconds) that was dependent on the dose of adenosine, but had no effect on VT in any patient with fascicular VT. Verapamil produced stuttering termination of right ventricular outflow tract tachycardia with no preceding change in RR interval in patients with this arrhythmia. Administration of verapamil to patients with fascicular VT was followed by gradual slowing of the arrhythmia (cycle length increased from 397 +/- 45 to 506 +/- 86 ms; p < 0.01) in all 7 patients and by termination of VT in 6. In conclusion, the differential response of fascicular and right ventricular outflow tract tachycardias to both adenosine and verapamil suggests that: (1) These 2 forms of idiopathic VT have different mechanisms. (2) Fascicular VT is unlikely to be due to cyclic adenosine monophosphate-mediated triggered activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of intravenous adenosine on verapamil-sensitive "idiopathic" ventricular tachycardia. 816 Jun 12

To assess the efficacy and safety of current pharmacologic therapy for supraventricular tachycardia (SVT) in infants, we reviewed 112 infants treated between July 1985 and March 1993. The SVT mechanism was determined by esophageal electrophysiologic study and involved an accessory pathway in 86, atrioventricular (AV) node reentry in 10, atrial muscle reentry in 11, and an ectopic atrial tachycardia in 5 patients. Of six infants not treated, none had clinical recurrences of SVT. Of the 106 patients treated, 70% remained free of tachycardia while receiving digoxin, propranolol, or both. Class I antiarrhythmic agents were necessary for 13 patients, and class III agents were required for another 13 infants. Verapamil was used in one infant with AV node reentry tachycardia. Nine infants with complex clinical presentations were believed to have failed medical management and underwent radiofrequency ablation. Five patients died, four of complications related to structural heart disease and one shortly after radiofrequency ablation was performed. No deaths appeared to be related to antiarrhythmic medications. No drug-related side effects requiring medication change occurred, and no proarrhythmia was observed. Thus medical therapy appears to be effective and safe in infants with SVT. Radiofrequency ablation should be reserved for rare infants who fail aggressive medical regimens or when the situation is complicated by ventricular dysfunction, severe symptoms, or complex congenital heart disease.
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PMID:Efficacy and risks of medical therapy for supraventricular tachycardia in neonates and infants. 855 21

Verapamil-sensitive ventricular tachycardia (VT) is a well-recognized clinical entity that some authorities believe may result from triggered activity. Despite its uniform response to verapamil, however, there is evidence that this uncommon form of VT may not be as homogeneous as first believed. Standard intracardiac electrophysiologic techniques were used to study verapamil-sensitive VT in 32 patients (aged 38 years +/- 20 years) without evidence of structural heart disease. More than half of these patients (69%) exhibited VT with a right bundle branch block-type QRS pattern, with the remainder (31%) displaying VT with a left bundle branch block pattern. In 31% of the patients the VT could be induced by fixed-cycle length atrial pacing, whereas in 59% of patients fixed-cycle length ventricular pacing was necessary. A critical range of cycle lengths for VT induction was required in 66% of the patients. Ventricular tachycardia was initiated with single atrial premature extrastimuli in 16% of patients, single ventricular extrastimuli in 50% of patients, and double ventricular premature extrastimuli in 9% of patients. Ventricular tachycardia displaying cycle-length alternans was observed in 28% of patients. In only 19% of patients was it possible to entrain VT during pacing from the right ventricular apex. Isoproterenol infusion was required for tachycardia induction in 50% of patients, 44% of whom had VT with a left bundle branch block QRS pattern, with the remaining 56% exhibiting VT with a right bundle branch block pattern. Beta-adrenergic blockers suppressed 53% of verapamil-sensitive VT in patients tested, whereas adenosine terminated VT in 50% of patients, with 81% of these patients exhibiting either a left bundle branch block QRS pattern or isoproterenol dependence. Ventricular tachycardia exhibiting a left bundle branch block pattern was more likely to be isoproterenol dependent (p <0.05) and adenosine sensitive (p <0.001). However, verapamil-sensitive, catecholamine-dependent VT was no more likely to be adenosine sensitive than the catecholamine-independent form of the arrhythmia (p >0.5). Verapamil-sensitive VT exhibits properties expected of both a reentrant and triggered arrhythmia, and it is inconsistently dependent on both exogenous catecholamines for induction and intravenous adenosine for termination. Verapamil-sensitive VT encompasses a heterogeneous group of tachycardias that may result from multiple cellular electrophysiologic mechanisms.
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PMID:Spectrum of electrophysiologic and electropharmacologic characteristics of verapamil-sensitive ventricular tachycardia in patients without structural heart disease. 864 47

Of the traditional antiarrhythmic agents administered in the treatment of ventricular tachycardias, those belonging to Class III are most commonly used. However, some ventricular tachycardias displaying special clinical, electrocardiographic and/or electrophysiologic characteristics have been successfully treated with calcium antagonists. Otherwise, Class IV antiarrhythmic agents are primarily used in the treatment of supraventricular tachyarrhythmias. It is reasonable to suspect that calcium-dependent phenomena underlie ventricular tachyarrhythmias in a number of patients. Verapamil-sensitive sustained left ventricular tachycardias represent a typical example. Sufficient response to calcium antagonists has also been demonstrated for exercise-induced ventricular tachycardias and repetitive monomorphic ventricular tachycardias. Characteristically, these arrhythmias occur in young patients with no structural heart disease. The long-term prognosis of these patients is in fact very good, but because of intrusive symptoms, pharmacological or nonpharmacological (radiofrequency ablation) treatment is often indicated. Through correct diagnosis and implementation of a short- and long-term therapy with calcium antagonists, and excellent alternative to the potentially harmful therapy with Class I and Class III antiarrhythmic agents can be offered.
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PMID:[Calcium antagonists in treatment of ventricular tachycardia]. 871 44

Exercise-induced ventricular tachycardia (VT) without demonstrable heart disease was studied in pediatric patients. The study population consisted of 17 patients aged 5-14 years (average 9.1 years), who demonstrated reproducible VT during or immediately after exercise testing using a treadmill. The main reasons for the exercise testing were episodes of exercise-related syncope in two patients, exercise-related palpitation in seven and evaluation of sporadic ventricular premature contraction (VPC) in eight. Of the eight patients in the asymptomatic group, two developed sustained VT and the other six had non-sustained VT. Of the nine patients in the symptomatic group, six developed sustained VT. Verapamil produced a good response in seven of 14 patients, and propranolol in six. None of the patients died during the follow-up period, an average of 59.6 months. In four patients, both VT and VPC disappeared, not only on exercise testing, but also on Holter electro-cardiograms, so the anti-arrhythmic agents were discontinued. One patient had syncope and convulsion caused by rapid bidirectional VT in the follow-up period. It was concluded that the prognosis of exercise-induced VT without demonstrable heart disease in children is relatively benign, but careful follow-up is required.
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PMID:Exercise-induced ventricular tachycardia without demonstrable heart disease in childhood. 894 10

Heart rate variability on 24-hour electrocardiographic recording was assessed in 23 patients without structural heart disease before and after 2 months of oral treatment with verapamil prescribed for paroxysmal atrioventricular nodal reentrant tachycardia. Verapamil had no significant effect on overall heart rate variability in the frequency domain, but it increased ultra low frequency power and decreased the low-frequency/high-frequency ratio, deemed to be a marker of sympathetic activity.
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PMID:Effect of verapamil on heart rate variability in subjects with normal hearts. 935 62

Repetitive monomorphic ventricular tachycardia (RMVT) is defined by the presence of numerous monomorphic isolated, premature ventricular complexes, couplets, and runs of unsustained ventricular tachycardia having the same morphology in patients without structural heart disease. Patients with RMVT mostly demonstrate the typical left bundle branch block morphology with normal or rightward axis during tachycardia. At our institution, 20 patients with RMVT have been systematically studied: a syncope had occurred in 35% of our patients, in three cases a syncope was the first manifestation of the RMVT. Of our RMVT patients, 25% developed sustained episodes (> 3 min) of ventricular tachycardia as documented by Holter ECG. The salvos of ventricular tachycardia are generally short in RMVT. This behavior and the typical exercise dependence differentiates RMVT from paroxysmal sustained idiopathic ventricular tachycardia. Exercise testing is mandatory for correct diagnosis of RMVT. In our institution, 85-90% of RMVT patients demonstrated runs of ventricular tachycardia or sustained ventricular tachycardia while on a treadmill (exercise test) or during isoproterenol infusion. RMVT was inducible by programmed electrical right ventricular stimulation in only 13% of our patients. Therefore, in patients with suspected RMVT programmed electrophysiological stimulation is only useful to differentiate a ventricular tachycardia from a supraventricular tachycardia with bundle brunch block or in patients with unexplained syncope. The prognosis is considered generally good; in our patients no life threatening ventricular tachyarrhythmias were observed during a follow-up of up to 4 years. Verapamil and beta-adrenoceptor antagonists generally offer symptomatic improvement. In some cases treatment with a class III antiarrhythmic agent is necessary. While drug-refractory paroxysmal sustained idiopathic ventricular tachycardia can be abladed with both immediate and long-term success, catheter ablation of RMVT is only rarely indicated.
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PMID:[Repetitive monomorphic ventricular tachycardia (Gallavardin type): clinical and electrophysiological characteristics in 20 patients]. 965 50


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