Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bepridil, a new calcium-channel blocking agent with an extended plasma elimination half-life of greater than 50 hours, was compared to placebo in 77 patients with confirmed coronary artery disease and chronic stable angina pectoris. The effects of bepridil were compared with those of placebo on angina frequency, nitroglycerin tablet use, the resting ECG and hemodynamics at rest and maximal exercise using a study design comprising 5 sequential 2-week single-blind treatment phases. After 2 weeks of placebo (phase 1), bepridil was given for 3 phases (2, 3 and 4) at total daily dosages of 200, 300 and 400 mg, respectively; the study was completed after a final reintroduction of placebo (phase 5). Within each phase once- and twice-daily regimens of bepridil were randomly compared. Bepridil (300 mg/day) reduced anginal frequency 68%, from 8.5 +/- 1.1 (standard error of the mean) to 2.7 +/- 0.7 attacks/week and nitroglycerin tablet use 76% (p less than 0.001). Bepridil improved exercise duration 26%, from 6.9 +/- 0.4 to 8.7 +/- 0.5 minutes (p less than 0.001) and exercise work 52%, from 2.7 +/- 0.3 to 4.1 +/- 0.4 kpm X 10(-3) (p less than 0.001) on a standardized treadmill protocol. Resting and peak exercise heart rate and blood pressure were unaffected by bepridil. The antianginal effects were similar with either once- or twice-daily treatment schedules. Minor side effects of nausea, epigastric discomfort and tremor were infrequent and there were no major side effects. The results of this large but preliminary, single-blind and short-term study suggest that bepridil is an effective and well tolerated antianginal agent when administered once daily.
Am J Cardiol 1984 Jan 01
PMID:Bepridil for chronic stable angina pectoris: results of a prospective multicenter, placebo-controlled, dose-ranging study in 77 patients. 636 86

In a clinical trial the efficacy of encainide, a newly developed class I antiarrhythmic agent, was compared with the well-known mexiletine. Nine patients with different underlying cardiac disease and chronic complex ventricular ectopies (documented by 24-h Holter monitoring, confirmed during the initial placebo period) entered the study. The dosage of encainide was increased from 25 to 75 mg three times daily and the antiarrhythmic effect monitored by repeated 24-h Holter registration and in some patients by treadmill exercise testing. During the clinical followup we noted a high incidence of so-called "minor side effects" (headache, dizziness, blurred vision, tremor, and nausea), which caused us to terminate the study. In all instances adverse effects emerged before ectopic activity was suppressed satisfactorily prohibiting further increment of dosage. These results indicate that encainide cannot be regarded as an antiarrhythmic drug of first choice in routine clinical application.
Clin Cardiol 1984 Sep
PMID:Increased incidence of side effects after encainide: a newly developed antiarrhythmic drug. 644 23

Amiodarone was administered to 154 patients who had sustained, symptomatic ventricular tachycardia (VT) (n = 118) or a cardiac arrest (n = 36) and who were refractory to conventional antiarrhythmic drugs. The loading dose was 800 mg/day for 6 weeks and the maintenance dose was 600 mg/day. Sixty-nine percent of patients continued treatment with amiodarone and had no recurrence of symptomatic VT or ventricular fibrillation (VF) over a follow-up of 6 to 52 months (mean +/- standard deviation 14.2 +/- 8.2). Six percent of the patients had a nonfatal recurrence of VT and were successfully managed by continuing amiodarone at a higher dose or by the addition of a conventional antiarrhythmic drug. One or more adverse drug reactions occurred in 51% of patients. Adverse effects forced a reduction in the dose of amiodarone in 41% and discontinuation of amiodarone in 10% of patients. The most common symptomatic adverse reactions were tremor or ataxia (35%), nausea and anorexia (8%), visual halos or blurring (6%), thyroid function abnormalities (6%) and pulmonary interstitial infiltrates (5%). Although large-dose amiodarone is highly effective in the long-term treatment of VT or VF refractory to conventional antiarrhythmic drugs, it causes significant toxicity in approximately 50% of patients. However, when the dose is adjusted based on clinical response or the development of adverse effects, 75% of patients with VT or VF can be successfully managed with amiodarone.
Am J Cardiol 1983 Nov 01
PMID:Long-term efficacy and toxicity of high-dose amiodarone therapy for ventricular tachycardia or ventricular fibrillation. 663 51

Amiodarone was used to treat cardiac arrhythmias that had been refractory to conventional medical therapy. The first 70 consecutive patients treated with amiodarone in this study had at least 6 months of follow-up (range 6 to 24, mean 11) and form the basis for this report. Sixty-six patients were treated for ventricular arrhythmias and four for supraventricular tachycardias. Amiodarone therapy consisted of a loading dose of 600 mg orally twice a day for 7 days, and 600 mg daily thereafter. Doses were reduced only if side effects occurred. Because of frequent side effects, the dose was reduced from 572 +/- 283 mg per day (mean +/- standard deviation) at 45 days to 372 +/- 174 mg per day at 6 months. With a mean follow-up of 11 months in the 54 patients who continued to take amiodarone, only 4 patients had ventricular fibrillation. Three additional patients experienced recurrent sustained ventricular tachycardia in long-term follow-up. All 70 patients had extensive clinical and laboratory evaluation in follow-up. Side effects were common, occurring in 93% of patients. Thirteen patients (19%) had to discontinue the medication because of severe side effects. Fifty-six patients had gastrointestinal side effects, most commonly constipation. All patients but 1 eventually developed corneal microdeposits, and 43 patients were symptomatic. Cardiovascular side effects were uncommon. Symptomatic pulmonary side effects occurred in seven patients, with unequivocal pulmonary toxicity occurring in five. Neurologic side effects, most commonly tremor and ataxia, occurred in 52 patients. Thyroid dysfunction occurred in 3 patients, and 32 patients had cutaneous abnormalities. Miscellaneous other side effects occurred in 32 patients. Amiodarone appears to be useful in the management of refractory arrhythmias. Because virtually all patients develop side effects when given a maintenance daily dose of 600 mg, lower maintenance doses should be used. It is unknown if the more severe side effects are dose-related. Amiodarone is difficult to administer because of its narrow toxic-therapeutic range and prolonged loading phase. More importantly, the first sign of antiarrhythmic failure may be manifest as sudden cardiac death.
J Am Coll Cardiol 1983 Dec
PMID:Toxic and therapeutic effects of amiodarone in the treatment of cardiac arrhythmias. 668 51

Pentylenetetrazol (PTZ) and sodium valproate (VPA) produce acutely in the naive rat various behavioural effects resembling signs of opiate withdrawal in the morphine-treated subject. Suggestions in the literature that these substances may activate directly some of the neural consequences of opiate and drug withdrawal prompted us to look for and examine possible aversive effects of these substances at non-toxic doses. With a sensitive two-flavour, three-trial taste aversion procedure, relatively low doses of PTZ and VPA (5 and 160 mg/kg, respectively) do indeed have aversive effects. The maximum aversions were produced by 10 and 20 mg/kg PTZ and 320 mg/kg VPA and were equivalent to those of morphine withdrawal precipitated by 0.01-0.03 mg/kg naloxone in a morphine pellet-implanted animal. Moreover, the maximum aversions with PTZ and VPA were significantly higher than the maximum aversions seen with naloxone in the drug-naive animal under the same training conditions. Thus, the data from the present study confirmed the notion that low doses of PTZ and VPA in the naive animal may activate processes activated by drug withdrawal, including those important for the motivational effect of withdrawal. However, it was also pointed out that the lowest dose VPA producing aversion was higher than that found here to produce writhes and ataxia (80 mg/kg) but the same as that required for shaking (160 mg/kg), while the PTZ aversion was at a dose lower than that known to produce a PTZ cue. Implications were discussed for using withdrawal-like phenomena as a model in the non-treated organism of clinically-relevant withdrawal effects.
 ...
PMID:Withdrawal-like effects of pentylenetetrazol and valproate in the naive organism: a model of motivation produced by opiate withdrawal? 758 68

Arbutamine is a new catecholamine designed for use as a pharmacologic stress agent. This study compared the sensitivity of arbutamine with symptom-limited exercise to induce echocardiographic signs of ischemia. Arbutamine was administered by a computerized closed-loop delivery system that controls the infusion rate of arbutamine toward a predefined rate of heart rate increase and maximum heart rate limit. Beta blockers were stopped > or = 48 hours before both tests. Stress was stopped for intolerable symptoms, or clinical, electrocardiographic or echocardiographic signs of ischemia (new or worsening wall motion abnormality), target heart rate (> or = 85% age predicted maximum heart rate), or plateau of heart rate response. Thirty-seven patients were entered into the study (35 arbutamine and exercise, 1 arbutamine only, 1 exercise only), of which 30 had angiographic evidence of coronary artery disease (> or = 50% lumen diameter narrowing). Rate-pressure product increased significantly in response to both stress modalities (p < 0.001) and was significantly greater with exercise (11,308 +/- 2,443) than with arbutamine (9,486 +/- 2,479, p < 0.001). The time to maximum heart rate was longer during arbutamine stress echocardiography than during exercise testing (17.3 +/- 9.4 versus 9.3 +/- 4.2 minutes, respectively, p < 0.001). There were more patients with interpretable echo data for arbutamine (82%) than for exercise (67%). Sensitivity for recognition of myocardial ischemia was 94% (95% confidence interval 70% to 100%) and 88% (95% confidence interval 62% to 98%), respectively. The most frequent adverse events during arbutamine (n = 36) were dyspnea (5.6%) and tremor (5.6%). Two arbutamine stress tests were discontinued due to arrhythmias: 1 patient had premature atrial and ventricular beats, and the other had premature atrial contractions and atrial fibrillation. Arrhythmias were well tolerated and resolved without sequelae. In conclusion, the sensitivity of arbutamine to induce echocardiographic signs of ischemia was similar to that of exercise despite a lower rate-pressure product. Arbutamine was well tolerated and provides a reliable alternative to exercise echocardiography.
Am J Cardiol 1997 Mar 15
PMID:Comparison of arbutamine and exercise echocardiography in diagnosing myocardial ischemia. 907 May 46

A new generation of surgical telemanipulation systems has helped to overcome the limitations of conventional endoscopic tools. These computer-enhanced instrumentation systems provide tremor filtering and motion scaling and allow dexterous manipulations in confined spaces through ports or trocars. Using these systems, total endoscopic coronary artery bypass grafting both on the arrested and on the beating heart has been performed successfully. Repair of mitral valves as well as atrial septal defects has also been performed remotely through 1 centimeter incisions. Despite some early procedural success, operating times are prolonged and a number of conversions have been reported. Currently, the use of telemanipulation systems is restricted to selected patients and limited to very few indications. Further refinements in telemanipulator technology as well as integration of image-based navigation systems may expand the use of computer-enhanced instrumentation systems in the near future.
Curr Opin Cardiol 2000 Nov
PMID:Developments in robotic cardiac surgery. 1119 19

Advances in computer and robotic technology are transforming cardiac surgery, overcoming the limitations of conventional endoscopic tools. Using minimal access through 5 millimeter ports, computer-enhanced instruments provide superhuman dexterity through tremor filtration and motion scaling, and are capable of precise manipulation in confined body cavities. Using these technologies, endoscopic beating heart coronary bypass surgery as well as complex mitral valve repairs have been performed in the last few years. However, the current world experience with robotic heart surgery is mostly anecdotal, retrospective, and noncontrolled. Results of rigorous prospective randomized studies in the United States under Food and Drug Administration approved protocols, are awaited. The use of robotic telemanipulation technology for heart surgery is restricted in the United States to patients enrolled in clinical studies in a few elite centers. Further refinement in robotic and image-guided technology for cardiac surgery may further expand the use of computer enhanced instrumentation in the near future.
Cardiol Rev
PMID:Robotic heart surgery. 1152 Apr 53

That tremor simulates atrial fibrillation and causes oral anticoagulation has not been reported. In a 69-year-old patient with diabetes, arterial hypertension and recurrent strokes, hand tremor developed since 1998. In September 2000 atrial fibrillation was diagnosed upon a routine and 24-hour ambulatory ECG. Because of the additional risk factors for stroke/embolism, phenprocoumon was begun. The diagnosis was changed to paroxysmal AF upon the following ECGs, showing sinus rhythm. Not earlier than 1 year after establishing the diagnosis,"atrial fibrillation" was identified as being due to a tremor artefact. Phenprocoumon was discontinued. Neurological investigations revealed Parkinson's disease as the cause of the tremor. Three weeks after initiation of pramipexol, the tremor artefact was no longer visible on ECG. Misinterpreting an ECG-artefact due to Parkinsons's tremor as atrial fibrillation may be followed by unnecessary diagnostic and therapeutic procedures, including long-term oral anticoagulation. Upon adequate treatment of Parkinson's disease, the tremor artefact immediately disappears from the ECG.
Acta Cardiol 2003 Oct
PMID:Oral anticoagulation for ECG tremor artefact simulating atrial fibrillation. 1460 9

Electrocardiographic (ECG) artifacts may interfere in ECG interpretation. Body movement, tremors, poor skin-electrode contact, recorder malfunction, electromagnetic interference and implantable electronic devices are the main reasons for ECG artifacts. Transcutaneous nerve and implanted spinal cord stimulators have been reported to result in ECG artifacts. With availability of newer implantable electronic devices, different ECG artifact patterns are being seen. Tremor control device is a newer implanted device used for suppression of tremors in patients with essential tremors or Parkinsonian tremors not adequately controlled by medications and where the tremor causes a significant functional incapacity. A differential pattern of ECG artifacts due to use of an implanted tremor control device is reported.
Int J Cardiol 2004 Aug
PMID:Differential electrocardiographic artifact from implanted thalamic stimulator. 1526 47


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