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

Ten years ago a clinical method of recording the electrical activity of the His bundle in man with transvenously inserted electrodes was described. His bundle recording has permitted the breakdown of the P-R interval into three conduction intervals, i.e., intraatrial (P-A), A-V nodal (A-H), and His-Purkinje system (H-V). His bundle studies have demonstrated our inability to accurately predict from the surface electrocardiogram the exact location of most A-V blocks. First- and second-degree A-V block can occur in the atrium, A-V node or His-Purkinje system, and third-degree A-V block in the A-V node or His-Purkinje system. However, Mobitz type II block almost always occurs below the A-V node. Intraventricular conduction defects, especially of the so-called bifascicular block, have a high incidence of H-V time prolongation, indicating additional disease of the third fascicle or the main His bundle. The prognostic value of a prolonged H-V time in patients with and without chronic conduction defects remains controversial, with some agreement that patients with unexplained syncope or dizziness, normal sinus rhythm and 1:1 conduction, who show prolonged H-V times, should probably be paced permanently. No long-term studies exist regarding the value of the H-V time in predicting death or A-V block in patients with conduction defects secondary to acute myocardial infarction, congenital heart disease or after cardiac surgery. Electrophysiological studies have been extremely useful in the diagnosis and management of patients with accessory pathways and in the evaluation of ventricular and supraventricular arrhythmias. The most valuable test in diagnosing sinus node dysfunction is the sinus node recovery time. A clearly abnormal test in a patient with unexplained syncope or dizziness predicts an almost one hundred per cent relief of symptoms with permanent pacing.
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PMID:Diagnostic and prognostic value of intracardiac electrophysiological studies. Ten years of experience. 38 29

Idiopathic hypertrophic subaortic stenosis (IHSS) occurs more commonly in the elderly than is generally believed, and is often unsuspected. In 26 patients above the age of 60, the diagnosis was recognized in only 7 (27 percent) prior to echocardiography. Symptoms included dyspnea in 17, chest pain in 16, and dizziness or syncope in 8 patients. In 10 patients, establishing the correct diagnosis led to therapy with propranolol, with or without discontinuation of digitalis; in 7 of these, the chest pain was significantly reduced. An accurate diagnosis is particularly important because drugs that are useful in other forms of heart disease may have adverse effects in IHSS. Echocardiography is the diagnostic procedure of choice and is indicated in the presence of an unexplained systolic murmur, especially when it is associated with chest pain, syncope or left ventricular hypertrophy.
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PMID:Unsuspected hypertrophic subaortic stenosis in the elderly diagnosed by echocardiography. 57 Sep 83

The case of a 22-year-old white male without known heart disease who presented with activity related lightheadedness at age 19 and dizziness and fatigue at age 21 is described. Standard electrocardiograms (ECG's) revealed intermittent complete trifascicular block. Rapid progression of symptoms over the succeeding eight months resulted in increasing incapacity. Holter monitoring demonstrated that symptoms were related to development of second and higher degrees of A-V block. Normal A-H interval and markedly prolonged H-Q interval on His bundle electrograms indicated that block was infranodal and localized to bundle branch system. Conduction problems aside, clinical and laboratory evaluation, including echocardiograms and cardiac catheterization, were unremarkable. Progression of bilateral bundle branch disease in a young patient without other demonstrable heart lesions and a negative family background conforms with criteria for Lenegre's disease. To our knowledge, this represents the youngest reported patient with this entity. Possible electrophysiologic basis of block and of exercise induced improvement in A-V conduction also are considered.
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PMID:Lenegre's disease in youth. 91 Jun 82

This report details our total experience with documented chronic His bundle block in 24 patients. Ten patients had second-degree block (eight with 2:1 block and two with type-1 block), and 14 patients had complete heart block. There were 16 women (67 percent) and eight men (33 percent) with ages ranging from 17 to 87 years. Diagnoses were as follows: hypertensive cardiovascular disease, nine patients (38 percent); arteriosclerotic heart disease, six patients (25 percent); aortic valvular disease, three patients (13 percent); primary conduction disease, two patients (8 percent); primary myocardial disease, two patients (8 percent); congenital heart block, one patient (4 percent); and traumatic heart block, one patient (4 percent). Pacing was instituted in 20 patients because of the following; congestive heart failure, seven patients; syncope, seven patients; fatigue, four patients; and recurrent dizziness, two patients. Permanent pacing was indicated within ten days of initial diagnosis in 13 patients, from 20 to 80 days in four patients, and later than 100 days in three patients. An additional two asymptomatic patients were treated with prophylactic pacing.
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PMID:The clinical spectrum of chronic His bundle block. 100 Oct 51

Two patients (aged 46 and 49 years) are presented who gave a history of several years' duration of unsteadiness, dizziness, and syncopal attacks on standing. Both had orthostatic hypotension which was associated with the development of a unifocal paroxysmal ventricular tachycardia. There was no evidence of organic heart disease. In one of the patients the symptoms usually developed when standing after working in a crouched position. He responded to treatment with beta-adrenergic blockade. The other patient developed her symptoms on standing, after exercise or other stress. The paroxysmal ventricular tachycardia, which occurred in the upright position only, was accompanied by a marked rise in plasma adrenaline. In this patient one contributory factor was a low blood volume and she responded to plasma volume expansion. We wish to draw attention to the common neurological symptoms with which paroxysmal ventricular tachycardia may present. We suggest that paroxysmal ventricular tachycardia may result from ventricular sensitivity to circulating adrenaline and not due to aberrant innervation of the heart as has been suggested previously.
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PMID:Orthostatic hypotension associated with paroxysmal ventricular tachycardia. 115 42

Out of a pacemaker population of 392 patients, 90 (23%) have been found to have sinoatrial syndrome. Their ages ranged from 22 to 86 years, and averaged 66 for men and 70 for women. The male-to-female ratio was 1:1.6. Before pacemaker implantation, syncopal attacks had occurred in 54%, dizziness without syncope in 31% and tachyarrhythmias in 57%. Atrial or paroxysmal supraventricular tachycardia had been recorded in 33%, atrial fibrillation or flutter in 28%, and ventricular tachycardia in 11%. First and/or second degree AV block was found in 36%. Coronary heart disease was present in 61% and 20% had had myocardial infarction. Cardiomyopathy and previous carditis were other associated heart diseases. Sinoatrial syndrome was the only manifestation of heart disease in 20%. Follow-up time after pacemaker implantation ranged from 3 months to 7 years, mean 23 months. Syncopal attacks were stopped in 48 of 49 patients, dizziness was relieved in all 28 patients and tachyarrhythmias were controlled by combined drug treatment in 43 of 51 patients. Nineteen patients died during the follow-up, most of them of cerebrovascular events or myocardial infarction. Associated coronary heart disease was especially frequent in this group. The death of one patient was caused by a run-away pacemaker. Other pacing failures were due to electrode movement or premature battery exhaustion. There was no mortality associated with pacemaker implantations or replacements. These results strongly support the view that pacemaker treatment most effectively controls symptoms of sinoatrial syndrome when drug treatment fails.
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PMID:Treatment of sinoatrial syndrome with permanent cardiac pacing in 90 patients. 119 8

Holter electrocardiographic monitoring in 55 symptomatic patients with syncope, palpitations or dizziness uncovered significant arrhythmias in 30 patients (55 percent). By providing an observation period of at least 24 hours including a period of sleep, the procedure aided detection and diagnosis in both symptomatic and asymptomatic patients of transient arrhythmias or conduction abnormalities not documented by routine electrocardiograms. Bradyarrhythmias accounted for the majority of arrhythmias recorded in 21 or 30 symptomatic patients (70 percent); 15 had sinus bradycardia (35 to 55 beats/min) alone and 6 also had long episodes of sinus arrest of up to 5 seconds. Two had sinus bradycardia with periods of atrioventricular block with Wenckebach phenomenon. Five patients had a tachycardia-bradycardia syndrome; three had other episodic arrhythmias and one had pacemaker failure. In 15 (60 percent) of the 25 patients without arrhythmias, monitoring did not document the cause of symptoms. Holter monitoring is of considerable value in assessing the efficacy and adequacy of drug treatment, especially in patients with known heart disease, and in detecting pacemaker malfunction. However, very long periods of monitoring may be needed to make a diagnosis in those with only sporadic symptoms.
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PMID:Value of Holter monitoring in assessing cardiac arrhythmias in symptomatic patients. 124 26

Clinical, ECG, and electrophysiologic data from 47 patients who had episodes of sustained or nonsustained monomorphic VT with no evidence of structural heart disease were reviewed. According to the QRS configuration during tachycardia, four groups were distinguished. Nine patients had a right bundle branch block configuration and superior frontal plane QRS axis (group 1). Nine patients had a right bundle branch block configuration but an intermediate or right QRS axis (group 2). Group 3 consisted of five patients with a left bundle branch block configuration and a left axis deviation, and in group 4 there were 24 patients who had a left bundle branch block configuration with an intermediate or right frontal axis. Patients in group 1 had dizziness during tachycardia less frequently, but they needed cardioversion to terminate their arrhythmias more often. They experienced tachycardia during exercise less often, and tachycardia was not initiated during exercise testing. They had fewer ventricular premature beats according to the Holter recording. During the electrophysiologic study, VT was induced and terminated by pacing more often in this group. Patients with idiopathic VT with a right bundle branch block configuration and a superior axis seem to be a unique group of patients with idiopathic VT, and reentry seems to be the most likely arrhythmia mechanism in this group. The other ECG configurations share the same clinical and electrophysiologic characteristics, which suggest that the underlying arrhythmia mechanism is the same.
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PMID:The electrocardiographic, clinical, and electrophysiologic spectrum of idiopathic monomorphic ventricular tachycardia. 151 3

Three cases of symptomatic bradycardia due to topical ocular timolol administration are reported. Two patients had syncope related to atrioventricular block, and the other one complained of dizziness due to sinus bradycardia. Heart disease was not present in any case, although a right bundle branch block was observed in one patients. A normal sinus rhythm resumed in all patients after discontinuation of timolol.
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PMID:[Bradyarrhythmias secondary to the use of ophthalmic timolol. A report of 3 cases]. 154 65

The follow-up and characteristics of 20 patients with ventricular tachycardia (VT) and no detectable heart disease is reported. These were 16 men and four women with a mean age of 44 years. Symptoms were present in 18 patients (eight had syncope and ten palpitations or dizziness), VT was sustained in 11 patients and a left bundle branch block morphology with inferior axis was found in 17 patients. In three patients, VT had a right bundle branch block morphology and left-axis deviation. The VT was inducible in 13 patients during the electrophysiological testing (EP) and was sustained in five patients. Medical treatment was introduced in 19 patients. During a mean follow-up of 10 years from the onset of the symptoms and 6 years from the EP testing, one patient died suddenly. He had stopped taking amiodarone 5 months before. In seven patients symptoms recurred and were due to discontinuation of therapy in two cases and inefficacy of previous effective treatment in five patients. After modification of the treatment (three cases), implantation of a pacemaker (one case) and catheter ablation (one case), all patients became asymptomatic. Eleven patients became asymptomatic with the first administered antiarrhythmic therapy. One patient continues to be asymptomatic in spite of discontinuation of his medical therapy. We conclude that patients with VT and no detectable heart disease have a good long-term prognosis and that appropriate therapy can be found in almost all patients.
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PMID:Ten-years follow-up of 20 patients with idiopathic ventricular tachycardia. 170 11


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