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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 102 patients with inducible supraventricular tachycardia (SVT), 56 women and 46 men aged 20-86 (mean, 52) years, underwent electrophysiologic study. SVTs observed at electrophysiologic study were atrial flutter or atrial fibrillation (32%), the "slow-fast" form of atrioventricular (AV) nodal reentrant tachycardia (45%), orthodromic AV reentrant tachycardia (25%), and atrial tachycardia (9%). More than 1 SVT occurred in some patients. Spontaneous symptomatic SVT frequency prior to oral flecainide varied from 3/day to 1/3 months (mean, 3/month). At electrophysiologic study and during SVT, intravenous flecainide, 2 mg/kg body weight, was given at an infusion rate of 10 mg/min up to a maximum dose of 150 mg. Patients were commenced on oral flecainide if SVT termination occurred during intravenous flecainide administration and if reinitiation was not possible after the total dose of flecainide had been given. In patients with AV nodal reentrant tachycardia and AV reentrant tachycardia further criteria for commencing oral flecainide were SVT termination by ventricular-atrial conduction block and persistent ventricular-atrial block after intravenous flecainide administration. Initial oral flecainide dosage was determined by assessing ability to reinitiate SVT after 50 mg, 100 mg, and the total dose of intravenous flecainide had been given. Eighty-nine patients (87%) remained free of symptomatic SVT over a mean follow-up period of 3.9 years (range, 3 months to 6.5 years). Two thirds were still taking the original dosage of flecainide and the rest were SVT-free on a higher dosage. Oral dosages ranged from 50 to 300 mg/day (median dosage, 100 mg twice daily) Nine patients experienced minor side effects, including, lethargy, dizziness, headache, and blurred vision. There were no deaths and no reports of major proarrhythmic events or other major adverse effects.
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PMID:Efficacy and safety of long-term oral flecainide acetate in patients with responsive supraventricular tachycardia. 860 96

The purpose of this study was to evaluate the value of esophageal programmed stimulation in children and teenagers with normal sinus rhythm ECG and normal noninvasive studies, having palpitations and syncope, and no documented tachycardias. Paroxysmal tachycardias are frequent in children and are often related to accessory connection. These tachycardias are sometimes difficult to prove. Transesophageal atrial pacing was performed at rest and during infusion of isoproterenol in 31 children or adolescents aged 9-19 years (16 +/- 3 years) with normal sinus rhythm ECG and suspected or documented episodes of paroxysmal tachycardia. Sustained tachycardia was induced in 27 patients, at rest in 13 patients, and after isoproterenol in 14 remaining patients. Atrioventricular nodal reentrant tachycardia was found as the main cause of paroxysmal tachycardia (22 cases). Six patients were followed by a vagal reaction and dizziness. These patients had spontaneous tachycardia with syncope. In three other patients, atrial fibrillation was also induced. Concealed accessory pathway reentrant tachycardia was identified in three patients. In two patients, a regular wide tachycardia with right bundle branch block morphology was induced; the diagnosis of verapamil-sensitive ventricular tachycardia was made in a second study by intracardiac study. In conclusion, atrioventricular nodal reentrant tachycardia was found as the main cause of symptoms in children with normal sinus rhythm ECG. Syncope is frequently associated and provoked by a vagal reaction. This diagnosis could be underestimated in adolescents frequently considered as hysterical because noninvasive studies are negative.
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PMID:Paroxysmal tachycardia in children and teenagers with normal sinus rhythm and without heart disease. 1122 67

A 77-year-old male patient with an intermittent 2:1 infra-Hisian block during sinus rhythm was presented with dizziness and near-syncope. During electrophysiological (EP) study, dual atrioventricular (AV) nodal pathways and retrograde fast pathway were easily induced by atrial and ventricular programmed stimulation, respectively. A typical slow-fast AV nodal reentrant echo beat also could be demonstrated by single atrial extrastimulation. Atrioventricular nodal reentrant tachycardia (AVNRT) can occasionally exhibit 2:1 AV block. Conversely, AV nodal reentry property had been rarely reported behind 2:1 infra-Hisian block. The EP presentation from this case may support the notion that tissues below the His are not part of the reentrant circuit of AVNRT.
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PMID:Inducible atrioventricular nodal reentrant echo behind organic 2:1 infra-hisian block during sinus rhythm. 1660 2

In general practice palpitations are reported in around 8 per 1,000 persons per year. The differential diagnosis includes cardiac and psychiatric causes, as well as numerous others e.g. anaemia, hyperthyroidism, prescribed medication, caffeine and recreational drugs. Factors that point towards a cardiac aetiology are male sex, irregular heartbeat, history of heart disease, event duration > 5 minutes, frequent palpitations, and palpitations which occur at work or disturb sleep. Other clues suggesting a cardiac origin are abrupt onset and termination of palpitations, positional palpitations, and accompanying symptoms such as dizziness and presyncope. Cardiac arrhythmias are the result of enhanced automaticity, triggered activity or re-entry. The latter mechanism is responsible for the majority of clinically relevant arrhythmias, such as atrial fibrillation and supraventricular tachycardias. The prevalence of supraventricular tachycardia in the general population is around 2-3 per 1,000 persons. AV nodal re-entry tachycardia (AVNRT) is the most common paroxysmal supraventricular tachycardia, accounting for nearly two-thirds of all cases. The typical clinical presentation of AVNRT is a sudden onset of palpitations (98%) and/or dizziness (78%). Patients may present at any age and are more frequently female than male.
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PMID:Palpitations: when you hear hoof beats don't forget to think zebras. 2902 Jul 30

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of reentrant paroxysmal supraventricular tachycardia that occurs in the presence of dual AV nodal physiology. Wolff-Parkinson-White (WPW) syndrome is another type of supraventricular tachycardia characterized by short PR intervals, delta waves and wide QRS complexes on the surface electrocardiogram (ECG), reflecting atrioventricular pre-excitation. Uncommonly, AV nodal reentry and accessory pathways can coexist. In this case report, we present a patient who had frequent episodes of palpitation and syncope and recently presented to the emergency department (ED) with the complaint of dizziness. We performed successful radiofrequency (RF) catheter ablation of mitral annulus posterolateral accessory pathway and AVNRT which was the cause of the second tachycardia induced during the same session.
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PMID:The coexistence of Wolff-Parkinson-White syndrome (WPW) and atrioventricular nodal reentrant tachycardia (AVNRT). 3019 Nov 96