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)

A 45-year-old man who had been implanted with a VVI pacemaker for sinus arrest complained of syncope, dizziness and throbbing in the neck. His pacemaker function was normal, but during ventricular pacing, retrograde V-A conduction was observed. This pacer was replaced by a DVI unit which caused periodic abdominal muscular contractions. We replaced this unit with an Intermedics Cosmos DDD-M pacemaker. This type of pacemaker in a patient with V-A conduction may cause pacemaker-mediated tachycardia (PMT). However, the Cosmos has a tachycardia-termination algorithm which detects continued pacing at the ventricular tracking rate, allows it to proceed for 15 consecutive pace events, and inhibits the 16th ventricular output pulse, thus breaking the reentry loop. The Cosmos pacer has a number of features to prevent initiation of PMT, and is also able to terminate the tachycardia when it occurs because of the tachycardia-termination algorithm. This feature is valuable in DDD-M pacemakers implanted in patients with V-A conduction. Whether this algorithm will be effective in all cases remains to be determined.
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PMID:Tachycardia-termination algorithm: a valuable feature for interruption of pacemaker-mediated tachycardia. 620 Aug 58

Sixteen patients, aged 4 to 42 years, operated for congenital heart disease, presented, months or years after surgery, complete atrioventricular (11 cases) or sinoatrial block (5 cases). Six patients had transient complete atrioventricular block in the immediate postoperative period, the maximum duration of which was less than 30 days. The late postoperative period was defined as at least 6 months after surgery. The period between surgery and the implantation of a pacemaker varied from 9 months to 19 years, average 6,3 years. Analysis of long term electrocardiographic studies distinguished three types of progression: --group I: alternation of sinus rhythm and conduction defect until definitive block, sometimes presenting with syncope; --group II: sudden, severe conduction defect after a long period of sinus rhythm; --group III: progressive lengthening of the PR interval. Seven patients developed syncope; 4 had dizziness, 2 were short of breath; only 3 were asymptomatic. All underwent permanent pacing. The incidence of late conduction defects appears to be 1 to 2% of operated patients. The causes include progressive fibrosis, slow sclerosis extending over conduction pathways which are congenitally fragile. Most late blocks are of an advanced degree. Some may be responsible for unexplained sudden death. It is therefore desirable to avoid this complication by the judicious and considered implantation of a cardiac pacemaker. Some authors mention the following factors in deciding on the indications for pacing: --complete, transient atrioventricular block during the operation or the immediate postoperative period; --ECG appearances of right bundle branch block and left anterior hemiblock, or trifascicular block; --His bundle studies.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Severe postoperative heart blocks appearing late. 16 cases]. 641 89

We studied eye movements and clinical findings in 1225 patients with complaints of dizziness. Downbeat nystagmus was demonstrated in 11 patients during eye closure. Simultaneous vertical and horizontal eye recordings were examined to demonstrate vertical eye position during eye closure. Downbeat nystagmus appeared on midline position even during eye closure in six patients. An electrooculography was demonstrated in three out of above six patients. A 24-year-old woman (Case 1) complained of a single spell of vertigo. There was no remarkable finding on neurological examination. An audiogram was an abrupt type sensorineural hearing loss in both ears. A caloric test was normal. Horizontal and vertical smooth pursuit was normal. Optokinetic nystagmus showed normal response in both horizontal and vertical planes. Both eyes were elevated on eye closure. They were depressed to the midline position with mental task and downbeat nystagmus appeared. A 68-year-old man (Case 2) had a history of dizziness on walking of three-year duration. On examination neurological findings were normal. A caloric test was normal in both ears. Optokinetic nystagmus and smooth pursuit were normal in both horizontal and vertical eye recordings. He had a transient eye elevation on eye closure. Both eyes immediately came downward to midline position and downbeat nystagmus was demonstrated. His nystagmus had persisted for four years. A 68-year-old woman (Case 3) complained of positional vertigo of seven-month duration. Neurological findings were normal. A caloric test was normal. There was a conductive hearing loss on the left ear. The right ear showed a normal audiogram.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Downbeat nystagmus during eye closure]. 652 20

Young adults with nonsurgically induced complete heart block (CHB) do not necessarily have a benign prognosis and pacemaker (PM) implantation may be necessary. No one has reported long-term PM follow-up in young adults with CHB. We studied 13 patients aged 15 to 37 years (mean 24 years) at PM implantation. There were nine female and four male patients. All were functional class II or III (NYHA) before PM implantation. Syncope, dizziness, fatigue, shortness of breath, and dyspnea on exertion were the most common symptoms. Cardiac catheterization findings (11 of 13 patients) were normal in five, and additional cardiac anomalies were present in six. His bundle studies (9 of 13 patients) showed absent AH intervals in all patients, with HV intervals not identified in two, 20 to 30 msec in one, and 30 to 50 msec in six patients. Holter monitor recordings (8 of 13 patients) demonstrated CHB in all eight with intermittent second- to third-degree block in two of three patients. Two patients had occasional premature ventricular contractions. Stress exercise tests (9 of 13 patients) demonstrated increased ventricular rate response (although subnormal in some patients); symptoms developed in seven. One patient had ventricular ectopy. All 13 patients were contacted 3 months to 7 years (mean 4 years) after PM implantation. Two patients had died, but the deaths were not related to PM dysfunction. All patients who are currently alive had marked improvement in functional symptomatology and all are currently functional class I. CHB is not a benign condition in young adults and may require PM implantation, which improves symptoms and allows the patient to lead a normal life.
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PMID:Long-term follow-up of young adults following permanent pacemaker placement for complete heart block. 680 42

The effects of encainide on ventricular arrhythmia and left ventricular function were studied in 21 patients with chronic, high-grade ventricular arrhythmia using a prospective, 3-month, placebo-controlled, single-blind trial design. Encainide caused a 96% decrease in the average hourly frequency of ventricular premature complexes (VPCs) and comparable reductions in salvos of nonsustained ventricular tachycardia (VT) and episodes of sustained VT. Intracardiac electrophysiologic testing showed prolonged intraatrial and intraventricular conduction times and increased atrial, atrioventricular nodal, and ventricular refractory periods with both i.v. and oral encainide without His-Purkinje block, despite marked prolongation of HV and QRS intervals. Induced repetitive ventricular beating after ventricular extrastimuli in 15 patients showed persistent repetitive ventricular beating with chronic oral encainide in seven patients, four of whom had sustained VT within 2 months of treatment on encainide. Encainide did not reduce exercise capacity or left ventricular ejection fraction at rest or during supine exercise. Minor adverse effects of encainide in 11 of 21 patients included dose-related visual disturbances, dizziness and sinus pauses (less than 3 seconds). Major adverse effects included the new appearance of sustained VT in three of 20 patients (15%). Oral encainide effectively reduces the frequency and grade of VPCs, prolongs intracardiac conduction times, and does not impair left ventricular performance. However, it is associated with frequent minor side effects and uncommon but potentially severe major side effects (sustained VT), both of which apparently have a direct relationship to the size of the dose.
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PMID:Treatment of frequent ventricular arrhythmia with encainide: assessment using serial ambulatory electrocardiograms, intracardiac electrophysiologic studies, treadmill exercise tests, and radionuclide cineangiographic studies. 680 10

To evaluate subsidiary ventricular pacemaker function in 20 children with congenital or surgically induced complete heart block, we measured recovery times following overdrive ventricular pacing. Long-term ECG tape recordings were performed in eight of these children. Ages ranged from 1 month to 17 years. The resting R-R intervals ranged from 595 to 1,740 msec. The ventricles were paced at various cycle lengths of 400 to 1,000 msec with either transvenous electrode catheters or surgically implanted epicardial electrodes. His bundle recordings showed that the site of block did not allow separation of patients with symptoms from those without symptoms. Prolonged recovery times were present in patients with block above the His bundle recording site who had symptoms of syncope or dizziness, as well as in patients who had a wide QRS. However, some asymptomatic patient with heart block above the His bundle recording site also had long recovery times. None of the asymptomatic patients who had ECG tape recordings had paroxysmal tachycardia in more than 300 hours of recordings. However, one symptomatic patient with congenital heart block and a prolonged recovery time had brief episodes of paroxysmal ventricular tachycardia that produced no symptoms at the time of recording. The results suggest that the coexistence of prolonged recovery times and paroxysmal tachycardia may be predisposing factors to the development of symptoms in patients with complete heart block. We believe that further electrophysiologic investigation of this possibility is warranted in patients with heart block.
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PMID:Heart block in children. Evaluation of subsidiary ventricular pacemaker recovery times and ECG tape recordings. 706 26

A patient presented to hospital with sudden onset of blindness which was subsequently shown both clinically and by radionucleotide scanning to be cortical in nature. Four days before admission he had suffered 2 short episodes of aching jaw, dizziness, and profuse sweating. Myocardial infarction was confirmed by serial ECGs and cardiac enzymes. His cortical blindness was thought to be secondary to an embolus from a myocardial mural thrombus. A review of the literature revealed 5 previous patients with cortical blindness and associated myocardial infarction. In 2 of these, blindness followed within days of the myocardial infarct, but in none was it the presenting feature of a myocardial infarct.
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PMID:A case of blindness associated with myocardial infarction. 741 43

A patient presented with orthostatic dizziness and syncope caused by postural heart block. When the patient was supine, atrioventricular conduction was normal and he was asymptomatic; when he was standing he developed second degree type II block and symptoms. The left bundle-branch block on his electrocardiogram and intracardiac electrophysiological study findings suggest that this heart block occurred distal to the His bundle. Orthostatic symptoms are usually presumed to be secondary to an inappropriate distribution of intravascular volume or to autonomic nervous system abnormalities. As shown in this patient, these symptoms may be the result of orthostatic heart block. Ambulatory monitoring may be useful in patients with orthostatic neurological symptoms, particularly when conduction abnormalities are present on the electrocardiogram.
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PMID:Postural heart block. 742 77

We present our experience of percutaneous transluminal angioplasty (PTA) in the treatment of subclavian artery stenosis in two patients. One patient was a 66-year-old asymptomatic man. His left arm systolic blood pressure was 40 mmHg lower than that of his right arm. He had irregular segmental stenotic lesions (50% to 80%) at the proximal portion of the left subclavian artery. PTA was attempted via the left brachial artery. After the procedure, the stenotic lesion seemed totally dilated and his left arm systolic blood pressure was 8 mmHg lower than that of his right arm. Restenosis of the left subclavian artery was noted four months after the procedure. The second patient was a 51-year-old man with symptoms of intermittent dizziness, nausea and vertigo. His left arm systolic blood pressure was 30 mmHg lower than that of his right arm. He had 43% diameter stenotic lesion at the proximal portion of the left subclavian artery. PTA was attempted via right femoral artery. After the procedure, the stenotic lesion seemed markedly dilated and his left arm systolic blood pressure was 14 mmHg lower than that of his right arm. He is well three years post-procedure without evidence of restenosis.
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PMID:[Angioplasty for subclavian artery stenosis: report of two cases]. 754 90

The most important symptoms in bradycardia are vertigo, dizziness and syncopy due to diminished cerebral blood sypply. Cardial symptoms are cardiac insufficiency and angina pectoris. By means of ECG, especially Holter-ECG, carotid sinus massage, atropin test and invasive methods (atrial stimulation, His-bundle ECG) sinu-nodal dysfunction, carotid sinus syndrome, bradyarrhythmia absoluta and AV-block can be diagnosed. Pharmacological treatment is only useful in acute situations. For symptomatic bradyarrhythmias the implantation of a Pacemaker is the therapy of choice. Individual treatment of the various types of bradyarrhythmia and the patients special needs is possible through the evolution of pacemaker technology.
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PMID:[Differential diagnosis and therapy of bradycardic arrhythmias]. 782 27


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