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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Electrophysiologic studies have shown that intravenous magnesium sulfate prolongs atrioventricular (AV) nodal conduction and refractoriness and thus could play a role in the management of patients with paroxysmal AV reentrant supraventricular tachycardia (SVT). The present study evaluates the clinical and electrophysiologic effects of intravenous magnesium sulfate in patients with SVT and compares them with those of adenosine triphosphate (ATP), one of the most potent drugs in the treatment of this arrhythmia. Patients with inducible sustained SVT were treated with ATP (10 or 20 mg) and magnesium sulfate (2 g over 15 seconds) during electrophysiologic study. If the tachycardia failed to terminate by the sixth minute, an additional 2 g dose of magnesium was given. ATP (10 or 20 mg) was significantly better than magnesium for terminating induced tachycardias (14 of 14 vs 6 of 14, p less than 0.0001). Arrhythmia termination with ATP was due to anterograde AV nodal blockade in all but 1 patient who developed retrograde block over an accessory pathway with decremental conduction. Arrhythmia termination by magnesium was due to retrograde block over an accessory pathway in 3 patients (including the patient with accessory pathway exhibiting decremental conduction), anterograde AV nodal conduction block in 2 patients and premature ventricular complexes in 1 patient. During induced tachycardias, only AH intervals were prolonged by ATP, whereas magnesium significantly prolonged AH and QRS intervals. Short-lasting side effects (chest pain, flushing, nausea) occurred after both drugs were administered but were more severe after magnesium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical and electrophysiologic effects of magnesium sulfate on paroxysmal supraventricular tachycardia and comparison with adenosine triphosphate. 152 41

Adenosine has recently become widely available for the treatment of paroxysmal supraventricular tachycardia. In order to evaluate its role in the management of arrhythmias, we have reviewed the literature on the cellular mechanisms, metabolism, potential for adverse effects, and clinical experience of the efficacy and safety of intravenous adenosine. Adenosine produces transient atrioventricular nodal block when injected as an intravenous bolus. This is of therapeutic value in the conversion to sinus rhythm of the majority of paroxysmal supraventricular tachycardias, which involve the atrioventricular node in a re-entrant circuit. The mean success rate was 93% from over 600 reported episodes. Compared with other antiarrhythmic agents, adenosine is remarkable for its rapid metabolism and brevity of action, with a half-life of a few seconds. It commonly produces subjective symptoms, particularly chest discomfort, dyspnea, and flushing, which are of short duration only. No serious adverse effect has been reported. Arrhythmias may recur within minutes in a minority of patients. Comparative studies have shown that adenosine is as effective as verapamil in the treatment of supraventricular tachycardia, and has less potential for adverse effects. Patients with supraventricular tachycardia should initially be treated using vagotonic physical maneuvers. Immediate electrical cardioversion is indicated if the arrhythmia is associated with hemodynamic collapse. Adenosine is the preferred drug in those patients in whom verapamil has failed or may cause adverse effects, such as those with heart failure or wide-complex tachycardia. The safety profile of adenosine suggests that it should be the drug of first choice for the treatment of supraventricular tachycardia, but only limited comparative data to support this view are available at present.
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PMID:Adenosine and the treatment of supraventricular tachycardia. 160 47

This study prospectively assessed the electrophysiologic effects of parenteral magnesium sulfate administration on paroxysmal atrioventricular (AV) reentrant supraventricular tachycardia and the efficacy of magnesium to terminate these arrhythmias. Eleven normomagnesemic patients, seven with orthodromic reentrant supraventricular tachycardia that used an accessory AV pathway, and four with typical AV nodal reentry were examined. All patients had a history of sustained supraventricular tachycardia requiring pharmacologic therapy or electrical cardioversion for termination of tachycardia. After baseline electrophysiologic study, including documentation of sustained supraventricular tachycardia that was reproducibly induced, parenteral magnesium sulfate (a bolus of 0.3 mEq/kg of elemental magnesium infused over a 10-minute period followed by a maintenance infusion of 0.2 mEq/kg/hr) was administered during sustained supraventricular tachycardia. The serum magnesium concentration increased from (mean +/- standard deviation) 1.9 +/- 0.2 mg/dl to 4.0 +/- 0.6 mg/dl (p = 0.0001). Except for flushing and mild diaphoresis during infusion of the magnesium sulfate bolus, and dry heaves in one patient, there were no untoward effects or significant changes in systolic blood pressure. During administration of magnesium, the tachycardia cycle length increased from 319 +/- 39 msec to 348 +/- 43 msec (p = 0.0001). Slowing of the tachycardia occurred predominantly in the antegrade limb of the circuit at the level of the AV node with the AH interval increasing from 171 +/- 66 msec to 197 +/- 68 msec (p = 0.0001), whereas there was no significant change in the HV interval (43 +/- 3 msec to 43 +/- 4 msec, p = NS) or the VA interval (106 +/- 43 msec to 110 +/- 47 msec, p = NS) during tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prospective evaluation of parenteral magnesium sulfate in the treatment of patients with reentrant AV supraventricular tachycardia. 230 Dec 20

One hundred and seventeen episodes of supraventricular tachycardia in 50 children, including 28 infants, were treated with intravenous adenosine. Adenosine was prepared in a sterile solution of 0.9% saline (1 mg/ml) and given in incremental doses of 0.05 mg/kg every two minutes to a maximum of 0.25 mg/kg. Ninety of the 117 episodes were terminated. This included 88 of the 102 episodes of junctional tachycardia (79 of the 92 episodes of atrioventricular reentry tachycardia, seven of the eight episodes of atrioventricular nodal reentry tachycardia, and both of the episodes of long R-P' tachycardia). Only one of four episodes of His bundle tachycardia and one of the eight episodes of ectopic atrial tachycardia were terminated. None of the three episodes of atrial flutter were terminated. Side effects were frequent but mild and included transient complete atrioventricular block (less than 6 s), sinus bradycardia (less than 40 s), ventricular extrasystoles, flushing, nausea, headache, and respiratory disturbance. Reinitiation (within 5 s) of supraventricular tachycardia occurred in 13 of the terminated episodes. Although reinitiation limited its clinical efficacy in some patients, intravenous adenosine offered a safe and efficient method of rapid termination of most episodes of supraventricular tachycardia and in some cases facilitated diagnosis of the mechanism.
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PMID:Efficacy and safety of adenosine in the treatment of supraventricular tachycardia in infants and children. 278 12

The anti-arrhythmic effects of intravenous magnesium sulfate, on bouts of supraventricular tachycardia (SVT) secondary to reentry phenomenon, are evaluated in twelve patients undergoing an electrophysiological testing, because of paroxysmal SVT, the pathway of which is an intranodal reentry (eight patients) or includes an atrio-ventricular accessory route (orthodromic SVT: four patients). At the completion of the basic testing, a stable SVT is induced and an intravenous bolus of 3 grams of magnesium sulfate is administered in three minutes. The length of the SVT cycle is significantly increased from 349 +/- 71 ms to 394 +/- 70 ms (p 0.001). The injection of magnesium relieves the SVT in less than five minutes in three patients (intranodal reentry: two cases; accessory pathway: one case), or an efficacy of 25 p. cent. No incident is reported following administration of the product; but the functional tolerance may be considered as poor, mainly consisting of flushing sensations of brief duration. This study demonstrates the antiarrhythmic properties of intravenous magnesium sulfate during bouts of SVT; however, its efficacy appears moderate at the dose mentioned.
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PMID:[Anti-arrhythmic effects of intravenous magnesium sulfate in paroxysmal supraventricular tachycardia]. 322 27

Previous studies have demonstrated the efficacy of bepridil, a new calcium antagonist, in the treatment of ventricular extrasystoles and tachycardia. The electrophysiological properties of bepridil especially the lengthening of the atrial effective refractory period, would also suggest an antiarrhythmic effect at the supraventricular level. This effect was studied on 33 episodes of paroxysmal supraventricular tachycardia (SVT) occurring in 23 patients (6 men and 17 women, mean age 58.1 years; range 18 to 88 years). Bepridil was given intravenously over 5 minutes at a dose of 3 mg/kg. The duration of SVT before administration was less than 1 hour in 10 cases, between 1 and 2 hours in 8 cases and over 2 hours in 15 cases. Sinus rhythm was successfully restored in 25 cases: within 1 to 5 minutes in 19 cases, 6 to 10 minutes in 3 cases and 11 to 30 minutes in 3 cases. In 24 of the 25 cases sinus rhythm was restored without a prolonged pause (over 2 sec) after the termination of SVT; in 3 cases intermediary atrial fibrillation lasting 1, 3 and 9 minutes was observed. There were no side-effects in 26 cases; transient flushing was noted in 5 cases and vagal symptoms in 2 cases. Haemodynamic tolerance judged by blood pressure measurements excellent in all cases. The correlations between plasma concentrations of bepridil and success or failure were poor. In conclusion, bepridil is a valuable alternative to adenosine triphosphate which may induce an exaggerated vagal response and to verapamil whose negative inotropic effects may sometimes be a serious disadvantage in the reduction of paroxysmal SVT.
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PMID:[Bepridil in the treatment of supraventricular paroxysmal tachycardias]. 393 62

We questioned 113 patients with subsequently diagnosed sustained ventricular tachycardia (VT) regarding the symptoms that prompted their seeking hospital treatment, eliciting the following: 15% of patients had lost consciousness, 15% had near syncope, 35% had mild lightheadedness and 35% had no cerebral symptoms. Patients with preexisting congestive heart failure or a VT rate of 200 beats per minute or greater more often lost consciousness. Other symptoms included palpitations in 57% of patients, chest pain in 27%, dyspnea in 25%, weakness in 6%, nausea or diaphoresis in 3% each and flushing in 2%. In approximately 50% of patients who had mild lightheadedness or no cerebral symptoms, their condition was incorrectly diagnosed as supraventricular tachycardia based on the absence of severe symptoms during the tachycardia. In some patients, VT may be associated with mild or atypical symptoms. The differentiation of supraventricular from ventricular tachycardia should be based on electrocardiographic criteria and should not be influenced by the nature or severity of a patient's symptoms. The severity of cerebral symptoms is at least partially related to the VT rate and a patient's underlying heart disease.
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PMID:Clinical symptoms in patients with sustained ventricular tachycardia. 399 9

The efficacy and electrophysiologic effects of adenosine and verapamil in termination of paroxysmal supraventricular tachycardia (SVT) were compared in 18 patients (age 18-48 years, mean 33 +/- 9 years) with recurrent sustained and inducible SVT. Ten patients had atrioventricular nodal reentrant tachycardia (AVNRT) and 8 had atrioventricular reentrant tachycardia involving a retrograde accessory pathway (cycle length of SVT 280-360 msec; mean 315 +/- 20 msec). Each patient served as his own control. After induction of SVT, adenosine was administered first (6 mg i.v. bolus). If the tachycardia was not terminated, a bolus of 12 mg was given. Ten minutes later, verapamil (5 mg i.v. over 30 sec) was administered after reinduction of SVT. If the tachycardia was not terminated, a 5 mg dose was repeated every 5 minutes upto 20 mg. Adenosine terminated the SVT in 16 cases (6 mg - 7 patients, 12 mg - 9 patients). Verapamil was effective in 11 patients (5 mg - 6 patients, 10 mg - 4 patients, 15 mg - 1 patient, 20 mg - nil). The overall efficacy of adenosine (89%) was significantly greater than that of verapamil (61%; p < 0.05). Adenosine terminated the tachycardia more quickly than verapamil (mean 24 +/- 11 sec versus 142 +/- 40 sec; p < 0.01). Termination of tachycardia by both drugs was related to antegrade block of the atrioventricular node in all patients except one with AVNRT in whom adenosine blocked the retrograde fast pathway. Ventricular premature beats were seen transiently in 5 patients following adenosine. Transient side effects such as flushing, burning and chest pain were frequently observed with adenosine and correlated with the termination of tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparative clinical and electrophysiologic effects of adenosine and verapamil on termination of paroxysmal supraventricular tachycardia. 782 34

Adenosine is a purine nucleoside that impairs conduction through the AV node and is thus effective in terminating tachycardias involving the AV node. Gaining acceptance as the drug of choice for neonatal supraventricular tachycardia (SVT), it is given IV as a rapid bolus with an initial dose of 0.05 mg/kg and can be increased in increments of 0.05 mg/kg every one to two minutes until termination of SVT (to a maximum of 0.25 mg/kg). Because of its half-life of 0.6 to 10 seconds, adenosine will not prevent reinitiation of SVT, therefore other medications should be considered if prophylaxis is required. An advantage of the short half-life is the transient nature of adverse effects, which can include flushing, nondistressing alterations in respiratory pattern, irritability, sinus bradycardia, and varying degrees of AV block. Administration to critically ill infants, including those requiring mechanical ventilation, has been reported. The infant's blood pressure, electrocardiogram, respiratory status, and capillary refill should be monitored before, during, and after adenosine administration.
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PMID:Adenosine administration for neonatal SVT. 835 Aug 44

This study was conducted to evaluate the clinical efficacy of intravenous (i.v.) magnesium sulphate 2 gm bolus in sustained supraventricular tachycardia (SVT) and atrial flutter-fibrillation with fast ventricular rate of more than 160/min (AF-FVR) and to compare it with i.v. verapamil 5 mg. In this randomised controlled trial, 68 cases of SVT and 86 cases of AF-FVR were studied. Patients with evidence of renal dysfunction and systolic blood pressure less then 90 mm Hg were excluded. Response was considered when the heart rate fell to less than 100/min. In SVT, 33.3% (11 out of 33) responded to magnesium sulphate which was significantly less than verapamil (23 out of 35, 65.7%) p = 0.007. Similarly, in AF-FVR, response was more with verapamil (25 out of 45, 55.6%) than magnesium sulphate (8 out of 41, 19.5%) p < 0.0001. Response to magnesium sulphate was better in patients with IHD. There were no significant side effects, except flushing and sense of warmth with i.v. magnesium sulphate. Serum magnesium rose significantly after i.v. magnesium bolus. Though magnesium sulphate is a weaker antiarrhythmic drug than verapamil, further studies are needed to identify subgroups of supraventricular tachyarrhythmias which would respond to magnesium sulphate.
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PMID:Efficacy of intravenous magnesium sulphate in supraventricular tachyarrhythmias. 877 69


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