Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

In the elderly, a transient ischemic attack (TIA) and a hypersensitive carotid sinus reflex (HCSR) often co-exist and can pose a diagnostic challenge. Seven cases are presented. HCSR is a relative condition; besides increased irritability of the receptor or target organs, susceptibility of the nerve center to ischemia probably is induced by a slow heart rate or low blood pressure in any patient with pre-existing occlusive cerebrovascular disease. Dizziness and syncope of this type represent hemodynamic TIA in contrast to thromboembolic TIA. The carotid sinus massage test is recommended for differentiating the two types of TIA; the treatments differ. At present there is no uniform management that can be applied to either TIA or HCSR routinely. Therefore, treatment should be approached on an individual basis, keeping in mind the different pathophysiologic factors operating in the specific patient.
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PMID:The problem of dizziness and syncope in old age: transient ischemic attacks versus hypersensitive carotid sinus reflex. 124 91

The ages of 6 male patients with the sick sinus syndrome ranged from 10-15 years when their symptoms began. At rest all had a heart rate of 60/min or less. Two had syncopal attacks which threatened life; 1 had only attacks of dizziness; the other 3 had no syncopal attacks but had recurrent attacks of supraventricular tachycardia ('brady-tachycardia syndrome') which were more resistant to drug therapy than is usual in childhood. They were not controlled or suppressed by digoxin when it was given. Substernal pain occurred in 2 patients who had syncope. In all patients the heart rate remained inappropriately slow after exercise and atropine. Cardiac pacemakers were used in the 2 patients with life-threatening syncope. Any patient who has dizziness or syncopal attacks and an inappropriately slow heart rate should have electrocardiograms recorded at rest and after exercise to record the heart rate and to look for abnormal P-waves.
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PMID:Sick sinus syndrome in children. 125 55

In a 14-month period mitral leaflet prolapse was diagnosed in 85 patients by echocardiography or cineangiography. Chest pain alone was the presenting complaint in 30 patients and linked with palpitation, dyspnoea, or syncope in 9. Eleven presented with major neurological disturbances (9 had transient ischaemic attacks), 10 with palpitation, 4 with undue and persistent fatigue, 2 with dyspnoea, and 2 with dizziness. Seventeen were referred not because of symptoms but because of clicks and murmurs. Overall, chest pain affected 61 patients and unless associated with coronary artery disease was not anginal. Palpitation was admitted by 42 patients; dizziness, lightheadedness, or paraesthesiae by 15, and syncope by 12. Systolic auscultatory abnormalities were noted in 69: 25 had single clicks, 3 had multiple clicks, 19 had both click(s) and murmur, and 22 had a murmur alone. Electrocardiography revealed ST segments flat for greater than 0-10 s in 21, prolonged QTc in 18, and T wave flattening or inversion in inferior limb and lateral chest leads in 14. The exercise stress test was abnormal in 13 of 27 patients. Mitral valve echograms showed definite mitral leaflet prolapse in 61, 'possible' prolapse in 14, and were normal in 8 patients with angiographic proof of mitral leaflet prolapse. Cardiac catheterization with left ventriculography showed prolapse of posterior mitral leaflet in 36, of both leaflets in 2, and left ventricular wall motion abnormalities in 16 cases. Selective coronary arteriography in 31 cases showed major vessel narrowing of larger than or equal to 80 per cent lumen diameter in 4, all with angina. This consecutive series indicates that the physical event of mitral leaflet prolapse is more common than hitherto appreciated, is priminently associated with non-anginal chest pain, palpitation, and neurological disturbances, and in 90 per cent of cases could be shown echocardiographically.
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PMID:Clinical features and investigative findings in presence of mitral leaflet prolapse. Study of 85 consecutive patients. 125 39

Heart block was noted in 60 (35 complete and 25 second-degree) of 410 patients with acute inferior wall myocardial infarction. This group with heart block was compared to a control group of 30 patients with acute inferior wall infarction without heart block. The incidences of prior myocardial infarction and hypertension, in addition to the highest level of serum creatine phosphokinase and a maximum degree of ST-segment elevation in the inferior leads, were all greater in patients with heart block, as compared to the controls. The incidences of various complications, including dizziness and syncope, transient hypotension, cardiogenic shock, and congestive heart failure, were also higher in the group with heart block, while sinus nodal distrubances and atrial arrhythmias occurred with equal frequency. The mortality in those with heart block was 28 percent compared to 13 percent for the control. It is concluded that patients with heart block complicating acute inferior myocardial infarction have a greater amount of myocardial necrosis, a higher incidence of complications, and a higher mortality. Insertion of a temporary pacemaker should be considered when specific indications are present and not routinely.
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PMID:Heart block complicating acute inferior wall myocardial infarction. 126 67

In a 16 weeks open label therapeutic trial, studies were performed on isradipine (Lomir) to evaluate its haematological and biochemical safety and hypotensive capacity in the management of adult black hypertensive patients. The mean sitting diastolic blood pressure decreased from 105.5 +/- 9.66 mm hg at the end of the washout period to 92.1 +/- 7.59 mm hg at the end of the study, p less than 0.0001; while the mean standing diastolic blood pressure was 108.0 +/- 7.10 mm hg and 93.9 +/- 8.4 mm hg at the end of the washout phase and at the completion of the therapy respectively, p less than 0.0001. The corresponding mean sitting systolic blood pressures were 155.4 +/- 9.91 mm hg and 140.6 +/- 9.47 mm hg, p less than 0.001 while the corresponding mean standing systolic blood pressures were 156.6 +/- 12.50 mm hg and 142.6 +/- 9.15 mm hg, p less than 0.001. There were negligible changes in the mean heart rate; from 79.5 +/- 9.23 beats per minute (bpm) at the end of the placebo phase to 78.2 +/- 9.15 bpm at the end of the study in the sitting position, p greater than 0.1. The corresponding mean standing values of heart rate were 82.5 +/- 11.33 and 78.6 +/- 8.76, p greater than 0.5. The haematological, biochemical and electrocardiographic parameters remained within normal limits during the study. Side effects were mild, transitory, improved with therapy and consisted of dizziness, palpitations, headache, nocturia, tiredness and fainting attacks. The study achieved 96% good-to-excellent results with respect to both efficacy and tolerability. Isradipine (Lomir) is therefore an efficacious and safe antihypertensive agent in the management of black adult patients with mild to moderate primary arterial hypertension when administered in the dose of upto 2.5 mg twice daily alone or in combination with a beta-blocker.
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PMID:Clinical studies on isradipine in the management of adult hypertensive patients at Moi University Teaching Hospital, Eldoret, Kenya. 138 77

Dosage and tolerance are critical issues in successful drug therapy for patients with Alzheimer's disease (AD). A clear distinction among patient populations and AD patient subpopulations is necessary to ensure a thorough assessment of new central nervous system-active compounds. Phase I inpatient trials, in which tolerance and safety are evaluated under double-blind conditions in the target population, provide valuable information for use in planning multicenter outpatient trials. In similar studies, even those involving the elderly, tolerance and safety outcomes in healthy volunteers are not always predictable. An early trial of the effects of velnacrine in healthy, elderly, male volunteers was followed by a trial in the target population. A group of volunteers, aged 60 to 74 years who did not have AD, received 300 mg of velnacrine each day. This dosage was well tolerated for 28 days. Diarrhea, generally of moderate severity, was the only reported adverse effect. No subjects were required to discontinue taking velnacrine. In contrast, a similar trial showed a dosage of 300 mg of velnacrine each day intolerable among patients with AD. Adverse reactions to dosages greater than 225 mg/day included dizziness, fainting, nausea and/or vomiting, headache, and severe diarrhea. A velnacrine dosage of 225 mg/day appeared to be safe and well tolerated in a small population of healthy patients with AD. Based on the inpatient experience with AD subjects, a maximum dose of 225 mg/day was adopted for outpatient studies. Although factors that may contribute to drug sensitivity in patients with AD vary beyond conclusive parameters, the observed sensitivity within the target AD group may indicate a safety/tolerance study as a worthwhile antecedent to multicenter efficacy trials.
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PMID:Alzheimer's patients should be included in phase I clinical trials to evaluate compounds for Alzheimer's disease. 141 62

Marijuana is known to cause symptoms suggestive of orthostatic hypotension such as dizziness and fainting during upright posture. We examined changes in cerebral blood velocity (CBV) and peripheral circulation during upright posture after smoking marijuana in 10 right-handed male subjects with a previous history of exposure to marijuana. The participants were physically and mentally healthy and drug-free for a minimum of 3 months before the experiment. Middle cerebral artery CBV, blood pressure and pulse rate were recorded during reclining position and standing, before and after smoking a high-potency marijuana cigarette or a placebo cigarette administered during 2 separate visits to the laboratory. The participants were questioned about dizziness during the upright position. Six of 10 subjects reported moderate to severe dizziness during standing after marijuana but not placebo. Subjects who experienced severe dizziness during standing showed marked decreases in blood pressure and CBV. Those who reported moderate dizziness showed reduction in CBV but not blood pressure. Subjects who reported mild dizziness after marijuana and after placebo smoking showed minimal changes in blood pressure and CBV. Cerebral ischemia during upright position after marijuana smoking may be caused by hypotension and impaired cerebral autoregulation.
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PMID:Middle cerebral artery velocity during upright posture after marijuana smoking. 152 42

Although the predominant location of symptomatic carotid artery occlusive disease is the carotid bifurcation, proximal common carotid artery lesions cause similar symptoms. Common carotid artery lesions occur as isolated disease or in tandem with carotid bulb disease. Restoration of carotid artery inflow from subclavian based extraanatomic bypasses should provide adequate reconstruction of these lesions. To evaluate subclavian-carotid artery bypass, a retrospective review of all patients undergoing this procedure from Jan. 1, 1977, to Feb. 20, 1989, was performed. Twenty patients (14 men, 6 women) with a mean age of 60 years were treated. Fifteen patients (75%) were admitted with transient ischemic attacks. Five (25%) had nonfocal symptoms (e.g., dizziness, syncope). Arteriographic evaluation demonstrated severe proximal occlusive disease of the common carotid artery in all cases. Reconstruction bypasses were performed to the carotid bulb (45%), internal carotid artery (30%), and external carotid artery (25%). Four patients underwent endarterectomy of the internal carotid artery in conjunction with subclavian-carotid artery bypass. Bypass conduits included saphenous vein (75%) and prosthetic grafts (25%). Asymptomatic phrenic nerve neuropraxia was identified by postoperative chest radiography in four cases, with no resultant respiratory disease. No perioperative strokes occurred. One postoperative death (5%) resulted from a myocardial infarction. Long-term results were available for 18 patients (90%), with a mean follow-up of 50 months (range, 1 to 122 months). Four patients have died of causes unrelated to carotid vascular disease. Serial duplex scans have documented graft patency in all 18 patients. A single patient returned with focal neurologic symptoms as a result of a posterior circulation infarct.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Extrathoracic carotid reconstruction: the subclavian-carotid artery bypass. 153 Aug 26


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