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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

201Tl myocardial perfusion imaging during adenosine infusion was performed in consecutive 55 patients with suspected coronary artery disease. Adenosine was infused intravenously at a rate of 0.14 mg/kg/min for 6 minutes and a dose of 111 MBq of 201Tl was administered in a separate vein at the end of third minute of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and apical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201Tl uptake were assessed semi-quantitatively. Adenosine infusion caused a slight reduction in systolic blood pressure and an increase in heart rate. The rate pressure products increased slightly (9314 +/- 2377 vs. 10360 +/- 2148, p < 0.001). Chest pain (24%) and headache (13%) were the frequent side effects. The second-degree atrioventricular block was developed in 11 of 55 (20%) patients. All symptoms and hemodynamic changes were well tolerated and disappeared within 1 or 2 minutes after discontinuing adenosine infusion. The sensitivity and specificity for the detection of patients with coronary artery disease were 100% (31/31) and 88% (7/8), respectively. 201Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease.
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PMID:[Thallium-201 myocardial perfusion imaging during adenosine-induced coronary vasodilation in patients with ischemic heart disease]. 145 59

A 35-year-old man was hospitalized after a sudden onset of transient syncopal attack without accompanying complaints of headache or nausea. He was slightly disorientated but neurologically normal. He had a blood pressure of 150/90mmHg and a pulse rate of 40/min. An ECG showed marked sinus brady-cardia with ventricular escaped rhythm followed by advanced atrioventricular (AV) block. Some components of conducted ventricular beats showed aberration. There was no significant ST or T wave abnormality in normally captured QRS components except for prominent T in leads II, III and aVF. At first, we thought that he might require temporary pacing because of Adams-Stokes attack. However, after administration of atropine sulfate, the ECG returned to normal sinus rhythm with heart rate of 88/min. Then he began to complain of headache followed by a convulsive seizure. A CT scan and angiogram revealed a ruptured aneurysm at the top of the basilar artery, which was successfully clipped. A wide spectrum of ECG changes can be demonstrated in practically all patients with subarachnoid hemorrhage (SAH). Prolonged QT interval, ST-T changes, U wave, sinus tachycardia, or ventricular premature complex are the common abnormalities probably caused by increased circulating catecholamine. As bradyarrhythmia in patients with SAH is an uncommon finding, its mechanism has not yet been defined. Transient sinus bradycardia with advanced AV block in this patient might have been caused not by elevated intracranial pressure (Cushing phenomenon) but by drastic discharge of the parasympathetic nerve. This case serves to illustrate the vigilance required in determining whether abnormalities of cardiac rhythm are instrumental in causing neurological symptoms and signs or a disorder of cerebral function.
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PMID:[A case of subarachnoid hemorrhage with sick sinus and advanced AV block]. 151 79

Adenosine thallium-201 myocardial scintigraphy is a promising test for coronary artery disease detection, but its safety has not been reported in large patient cohorts. Accordingly, the tolerance and safety profile of adenosine infusion were analyzed in 607 patients (351 men, 256 women, mean age 63 +/- 11 years) undergoing this test either because of suspected coronary artery disease (Group I, n = 482) or for risk stratification early (5.2 +/- 2.8 days) after myocardial infarction (Group II, n = 125). Adenosine increased the heart rate from 74.5 +/- 14.0 to 91.8 +/- 15.9 beats/min (p less than 0.001) and decreased systolic blood pressure from 137.8 +/- 26.8 to 120.7 +/- 26.1 mm Hg (p less than 0.001). Side effects were frequent and similar in both groups. Flushing occurred in 35%, chest pain in 34%, headache in 21% and dyspnea in 19% of patients. Only 35.6% of Group I patients with chest pain during adenosine infusion had concomitant transient perfusion abnormalities, compared with 60.7% of Group II patients (p less than 0.05). First- and second-degree AV block occurred in 9.6% and 3.6% of patients, respectively, and ischemic ST changes in 12.5% of cases. Concomitance of chest pain and ischemic ST depression was uncommon (6%) but, when present, predicted perfusion abnormalities in 73% of patients. Most side effects ceased rapidly after stopping the adenosine infusion. The side effects were severe in only 1.6% of patients and in only six patients (1%) was it necessary to discontinue the infusion. No serious adverse reactions such as acute myocardial infarction or death occurred.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Tolerance and safety of pharmacologic coronary vasodilation with adenosine in association with thallium-201 scintigraphy in patients with suspected coronary artery disease. 186 36

The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of adenosine in the treatment of episodes of paroxysmal supraventricular trachycardia (PSVT) are reviewed. Adenosine is an endogenous adenine nucleoside that markedly decreases heart rate and prolongs atrioventricular (AV)-nodal conduction. Adenosine is rapidly cleared from plasma by the cellular elements of the blood and by vascular endothelial cells and subjected to enzymatic metabolism. The drug has a half-life of 0.6 to 10 seconds. In noncomparative clinical trials, adenosine terminated 85% to 100% of induced or spontaneous episodes of PSVT involving the AV node in the reentrant circuit. In patients with arrhythmias that do not involve the AV node in the reentrant circuit, adenosine produces AV block and does not restore sinus rhythm. Prospective, randomized trials comparing adenosine with verapamil in adults have not yet been performed. The adverse effects of adenosine include flushing, dyspnea, headache, cough, chest pain, sinus bradycardia, atrial fibrillation, ventricular arrhythmias, and various degrees of AV block. Because of the short half-life of adenosine, these effects are transient and well tolerated. The initial dose of adenosine in treating acute PSVT is 6 mg given by rapid i.v. bolus injection, followed in one to two minutes by up to two additional 12-mg boluses if necessary. Adenosine has been found to be effective in terminating PSVT and thus offers an alternative to verapamil. Prospective, randomized trials comparing adenosine with verapamil are needed to definitively establish adenosine's role in the therapy of PSVT.
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PMID:Adenosine in the episodic treatment of paroxysmal supraventricular tachycardia. 218 71

Pharmacological coronary vasodilation induced by dipyridamole is often used in association with thallium-201 myocardial scintigraphy to evaluate the presence and prognostic significance of coronary artery disease. Because dipyridamole acts by blocking the cellular uptake of adenosine, we investigated the usefulness of direct intravenous administration of adenosine, a physiological substance with an exceedingly short (less than 2 seconds) plasma half-life, to induce maximal controlled coronary vasodilation in conjunction with 201Tl scintigraphy. We studied 89 patients (44 men and 45 women; mean age, 64 +/- 10 years [SD]) who were unable to perform an exercise test and were referred for evaluation of suspected coronary artery disease. The intravenous infusion of adenosine began at an initial rate of 50 micrograms/kg/min and was increased by stepwise increments every minute to a maximal rate of 140 micrograms/kg/min. 201Tl was injected intravenously after 1 minute at the highest infusion rate, followed by immediate and delayed (4 hour) tomographic imaging. At the highest infusion rate, adenosine induced a significant (p less than 0.001) decrease in systolic (8.7 +/- 19.3 mm Hg) and diastolic (6.7 +/- 9.4 mm Hg) blood pressures as well as a significant (p = 0.0001) increase in heart rate (14.5 +/- 11.0 beats/min). Side effects occurred in 83% of the patients but resolved spontaneously within 1 or 2 minutes after discontinuing the adenosine infusion. Chest, throat, or jaw pain were the most frequent symptoms and occurred in 57% of the patients. Headache (35%) and flush (29%) were also common. Ischemic electrocardiographic changes occurred in 12% of the patients, and transient first-degree atrioventricular block occurred in 10%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Diagnosis of coronary artery disease by controlled coronary vasodilation with adenosine and thallium-201 scintigraphy in patients unable to exercise. 236 18

In an open multicenter trial (uncontrolled study) in 4,247 patients (49.1% male, 50.9% female; aged 17-89 years) with mild, moderate, or severe hypertension, the antihypertensive efficacy and in particular the tolerability of verapamil slow-release (SR) 240 mg (Isoptin RR) were studied. The dosage of the drug was adjusted to the therapeutic response; in 88.7% of the patients it was titrated according to the study protocol: 63.2% received constantly one SR tablet throughout the 6-week treatment period; in 15.6% the dosage was increased to one and a half tablet after 2 weeks, and in 9.9% to one tablet b.i.d. after a further 2 weeks. Monotherapy with verapamil SR 240 mg normalized diastolic blood pressure (less than or equal to 90 mm Hg) in 90% of the patients with mild hypertension, 77% of those with moderate, and 61% of those with severe hypertension. It was evident that blood pressure reduction was more pronounced the higher the baseline value. Cardiac and extracardiac tolerability of verapamil SR 240 mg was good. Mean heart rate was slightly reduced, none of the patients developed a second- or third-degree atrioventricular block. Side effects were reported by 480 of the 4,247 patients (11.3%). As expected, constipation (4.03%) was the predominant adverse reaction, followed by dizziness (3.65%), headache (1.54%), and other (less than 1%). In 217 patients (5.1%) therapy was discontinued prematurely, in 139 (3.27%) because of side effects.
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PMID:Efficacy and safety of verapamil SR 240 mg in essential hypertension: results of a multicentric phase IV study. 247 86

The diagnostic and therapeutic potential of intravenous adenosine was studied in 64 patients during 92 episodes of regular sustained tachycardia. In 40 patients who had narrow complex tachycardias (QRS less than 0.12 s) adenosine (2.5-25 mg) restored sinus rhythm in 25 with junctional tachycardias (46 of 48 episodes) and produced atrioventricular block to reveal atrial or sinus tachycardia in 15. In 24 patients with broad complex tachycardias (QRS greater than or equal to 0.12 s) adenosine terminated the tachycardias in six patients and revealed atrial or sinus arrhythmias in four. The tachycardias persisted in 14 patients despite doses up to 20 mg, but adenosine allowed the diagnosis of ventricular tachycardia with retrograde atrial activation in two patients by producing transient ventriculoatrial dissociation. Diagnosis based on adenosine induced atrioventricular nodal block was correct in all patients with narrow complex tachycardias and in 92% of those with broad complex tachycardias, compared with correct electrocardiographic diagnoses in 90% and 75% respectively. Adenosine gave diagnostic information additional to the electrocardiogram in 25%. The response to adenosine in broad complex tachycardias identified those of supraventricular origin with 90% sensitivity, 93% specificity, and 92% predictive accuracy. Adenosine restored sinus rhythm in all patients with junctional reentrant tachycardias, but in 10 (35%) the arrhythmias recurred within two minutes. Symptomatic side effects (dyspnoea, chest pain, flushing, headache) were reported by 40 (63%) patients and, although transient, were severe in 23 (36%). There were ventricular pauses of over 2 s in 16% of patients, the longest pause being 6.1 s. Adenosine is of value in the diagnosis and treatment of narrow and broad complex tachycardias, but its use is limited by symptomatic side effects, a tenfold range in minimal effective dosage, occasional action at sites other than the atrioventricular node, and early recurrence or arrhythmia.
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PMID:Value and limitations of adenosine in the diagnosis and treatment of narrow and broad complex tachycardias. 278 11

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

Lyme disease typically begins with a unique skin lesion, erythema chronicum migrans (ECM) (stage 1). Patients with this lesion may also have headache, meningeal irritation, mild encephalopathy, multiple annular secondary lesions, malar or urticarial rash, generalized lymphadenopathy and splenomegaly, migratory musculoskeletal pain, hepatitis, sore throat, non-productive cough, conjunctivitis, periorbital edema, or testicular swelling. After a few weeks to months (stage 2), about 15% of patients develop frank neurologic abnormalities, including meningitis, encephalitis, cranial neuritis (including bilateral facial palsy), motor or sensory radiculoneuritis, mononeuritis multiplex, or myelitis. At this time, about 8% of patients develop cardiac involvement--AV block, acute myopericarditis, cardiomegaly, or pancarditis. Throughout this stage, many patients continue to experience migratory musculoskeletal pain in joints, tendons, bursae, muscle, or bone. Months to years after disease onset (stage 3), about 60% of patients develop frank arthritis, which may be intermittent or chronic. Recently evidence suggests that Lyme disease may also be associated with chronic neurologic or skin involvement. Thus, Lyme disease occurs in stages with different clinical manifestations at each stage, but the course of the illness in each patient is highly variable.
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PMID:Clinical manifestations of Lyme disease. 355 39

Diprafenone is a new antiarrhythmic drug with a dominant local anaesthetic action and an additional beta-sympathicolytic activity. In this study, the results of long-term treatment (8 months on average) obtained from 27 patients with chronic ventricular arrhythmias are reported. Before diprafenone, all patients were treated unsuccessfully with flecainide, propafenone, sotalol, combined sotalol/flecainide and sotalol/propafenone, and another two to six antiarrhythmic agents. Following diprafenone (300-600 mg/24 h), a substantial reduction in arrhythmic activity (greater than or equal to 80%; Lown classification less than or equal to II) was achieved in 21 cases. In 12 patients, side effects (fatigue, headache, blurred vision, dizziness and heartburn) were apparent. Diprafenone had to be discontinued in five patients, because of these side effects. At dosages greater than or equal to 450 mg/24 h, the PQ interval was significantly lengthened, and QRS duration prolonged. In one patient, an AV block III degree developed. In another case, SGOT and SGPT increased significantly; this increase was reversed after the drug was discontinued. Despite these side effects, further clinical evaluation of the compound seems promising, as the antiarrhythmic potency of diprafenone is very strong and superior to that of propafenone with respect to the required doses.
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PMID:[Treatment of chronic ventricular arrhythmias with the new class Ic anti-arrhythmia agent diprafenon--results of long-term therapy]. 367 63


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