Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two female patients had received therapeutic irradiation of the left side of the chest for adenocarcinoma of the left breast and 18 and 23 years later, respectively, developed atrioventricular block. Both patients had early and late cutaneous reactions, as well as fibrosis of the left lung, lymphedema of the left arm, and pathologic rib fractures but had no signs of recurrence of the carcinoma. One patient developed signs of congestive heart failure while the electrocardiogram revealed second and third degree atrioventricular block; subsequent pacemaker implantation relieved the congestive heart failure. In the second patient, fatigue was the only symptom leading to the diagnosis of transient second and third degree atrioventricular block; this symptom subsided after pacemaker implantation. Based on reports of radiation-induced cardiac damage, it is assumed that the heart block in these two patients might have been due to postirradiation fibrosis of the atrioventricular node, either direct or mediated by fibro-occlusive changes in the coronary vessels.
 ...
PMID:Complete heart block following therapeutic irradiation of the left side of the chest. 83 2

Serial measurements of heart rate and oxygen uptake were obtained before and during maximal upright graded bicycle stress testing in 16 patients, 10 to 77 years old (mean 46 years), with sinus node dysfunction; five had permanent and two had temporary demand ventricular pacemakers. In 15 patients, including those with pacemakers, maximal exercise was performed before and after the intravenous administration of 1 mg atropine. Maximal exercise was terminated because of cerebral symptoms in seven (three had effort-induced tachyarrhythmias and one had autonomic insufficiency), fatigue in five (one had effort-induced heart block), heart failure in three and angina pectoris in one. With maximal exercise, patients with sinus node dysfunction were unable to obtain maximal heart rates or oxygen uptakes comparable to age- and sex-matched control subjects. Additionally, maximal oxygen uptake did not differ significantly between patients with or without pacemakers even when ventricular pacing rates were increased (two instances). The administration of atropine increased the resting heart rate, but the maximal heart rate and oxygen uptake achieved during maximal exercise did not differ significantly from those obtained before the administration of atropine in the patient and control groups. Physically active patients with sinus node dysfunction have diminished exercise capacity due in part to cardiac arrhythmia, latent or overt cardiac failure, or autonomic dysfunction.
 ...
PMID:Graded exercise testing in patients with sinus node dysfunction. 84 52

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.
 ...
PMID:The clinical spectrum of chronic His bundle block. 100 Oct 51

In the first 4 hours after occlusion of the anterior septal coronary artery, 18 dogs developed bundle branch block, heart block, or both. The hearts were then excised, and preparations were dissected to expose the His bundle and the bundle branches, which were superfused with modified Tyrode's solution at 37 degrees C. In the His bundle and the most proximal bundle branches, resting potentials were reduced and diminutive action potentials had slow upstrokes, often with notches or steps. Action potentials were generated by fibers that had resting potentials between--40 and --50 mv. Conduction was impaired; conduction velocities less than 0.01 m/sec were sometimes observed. In more severely affected cells, refractoriness outlasted repolarization. Encroachment on the prolonged refractory period resulted in further diminution of action potentials and continuous rather than intermittent block. More commonly, the response to rapid rate took the form of intermittent block with progressive conduction delay in the series of conducted beats, culminating in a blocked beat (Wenckebach sequence). There was a fatigue factor that accumulated at short cycle lengths and depressed the action potential. Automaticity was not enhanced, but pacemaker function was abnormal. The threshold potential shifted erratically, and pacemaker potentials sometimes were intermittently diminished, resulting in intermittent failure to propagate. During prolonged superfusion, there was a tendency to recover with a drift of the maximum diastolic potentials toward more negative levels. None of these changes were found in ten hearts excised from dogs in which the coronary artery had not been ligated.
 ...
PMID:Disorders of cellular electrophysiology produced by ischemia of the canine His bundle. 111

The interaction between verapamil and beta-blockers may involve negative chronotropic, inotropic, and dromotropic effects. Three randomized, double-blind, crossover trials evaluated standardized submaximal exercise hemodynamics after oral verapamil (120 mg) and beta-blocker, alone and in combination, in groups of eight healthy men. The beta-blockers were propranolol (80 mg), metoprolol (100 mg), and pindolol (5 mg). During submaximal exercise, each beta-blocker produced similar reductions in heart rate. Likewise, each verapamil and beta-blocker combination caused greater decreases in heart rate and prolongation of PR interval than did either drug alone. Only the verapamil and propranolol combination produced greater reduction of systolic blood pressure and prolongation of rate-adjusted PR interval. All verapamil and beta-blocker combinations caused frequent adverse events, predominantly exercise fatigue and resting first-degree heart block. Although the verapamil and metoprolol or pindolol combinations produced lesser negative dromotropic or inotropic effects compared with verapamil and propranolol, coadministration of verapamil and any beta-blocker should be performed cautiously.
 ...
PMID:Interaction between oral verapamil and beta-blockers during submaximal exercise: relevance of ancillary properties. 201 27

Adverse effects of beta-adrenergic receptor blocking drugs can be divided into two categories: 1) those that result from known pharmacological consequences of beta-adrenergic receptor blockade; and 2) other reactions that do not appear to result from beta-adrenergic receptor blockade. Adverse effects of the first type include bronchospasm, heart failure, prolonged hypoglycemia, bradycardia, heart block, intermittent claudication, and Raynaud's phenomenon. Neurological reactions include depression, fatigue, and nightmares. It is not yet proven whether the beta 1-selective adrenergic blockers or those with partial agonist activity reduce the overall frequency of adverse reactions seen with propranolol. Patient age does not appear, in itself, to be associated with more beta-blocker side effects. Side effects of the second category are rare. They include an unusual oculomucocutaneous reaction and the possibility of oncogenesis. There are also many drugs that interact with beta-blockers, which may increase toxicity. Finally, there are specific patient characteristics where one beta-blocker may be more effective and safer than another.
 ...
PMID:Beta-adrenergic receptor blockers. Adverse effects and drug interactions. 289 72

While deficient exercise performance of sick children results from hypoactivity and detraining, it can also be caused by specific pathophysiological factors. These can affect one or more components of physical fitness. A low maximal aerobic power will result from a low maximal stroke volume, as in aortic stenosis or cardiomyopathy; a low maximal heart rate, as in congenital complete heart block or intake of beta-blockers; a low O2 content of the arterial blood, as in anemia or advanced cystic fibrosis; and a high O2 content of mixed-venous blood, as in muscle atrophy or severe malnutrition. A high O2 cost of locomotion, as in advanced obesity or cerebral palsy, will cause the patient to exert at a high percentage of his maximal aerobic power and thus fatigue easily. A subnormal muscle strength, as in progressive muscular dystrophy or juvenile rheumatoid arthritis, is sometimes the primary factor that limits the walking ability or other daily functions. Recent data suggest that local muscle endurance, as assessed by the Wingate anaerobic test, is particularly deficient in some neuromuscular diseases. Examples are muscular dystrophies and spastic cerebral palsy. The ratio of peak anaerobic power to peak aerobic power seems lower in such patients than in able-bodied controls.
 ...
PMID:Pathophysiological factors which limit the exercise capacity of the sick child. 372 7

To define the long-term natural history of congenital complete heart block, we followed 27 patients prospectively by means of frequent ambulatory electrocardiographic (ECG) recordings for a mean (+/- SD) of 8 +/- 3 years. During that time, 8 of the 13 patients with a mean daytime heart rate below 50 bpm (Group A) had cardiac complications such as sudden death, syncope, presyncope, or excessive fatigue. Six of the eight patients had additional ECG findings that suggested an instability of the junctional escape mechanism. These findings included nocturnal junctional exit block (three patients), little or no change in the junctional rate with physical activity (three patients), and associated tachyarrhythmias (three patients). None of the 14 patients with a mean daytime heart rate of 50 bpm or more (Group B) had an adverse clinical outcome, and 5 of the 13 patients in Group A also remained well. Among the five patients in stable condition in Group A, three had no evidence of an unstable junctional mechanism. We conclude that patients with a mean daytime junctional rate below 50 bpm and other evidence of an unstable junctional escape mechanism should probably undergo prophylactic pacemaker implantation. Since junctional exit block and tachyarrhythmias sometimes appear first during follow-up, the method of risk stratification employed in this study depends on serial ambulatory ECG recordings.
 ...
PMID:Use of ambulatory electrocardiographic monitoring to identify high-risk patients with congenital complete heart block. 382 27

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.
 ...
PMID:Long-term follow-up of young adults following permanent pacemaker placement for complete heart block. 680 42

With advancing age of the population and with echocardiographic means of diagnosis, amyloid disease of the heart is of increasing clinical interest. Advanced age, restrictive myocardiopathy, arrhythmias, and conduction disorders are familiar features of this disease. A 92 year old man with past history of hemiblock followed by complete heart block and transvenous pacemaker was admitted to the hospital because of increasing fatigue and the abrupt development of dyspnea. Examination revealed paradoxic pulse, markedly elevated central venous pressure, and echocardiographically demonstrated large pericardial effusion. Shortly after admission signs of tamponade developed; 1,000 ml of pericardial fluid was removed with prompt relief of dyspnea dna disappearance of paradoxic pulse and return of central venous pressure to normal. However, dyspnea soon recurred and subsequent hemodynamic measurements indicated increased right ventricular and left ventricular filling pressures. Echocardiography revealed no recurrent effusion or ventricular hypokinesis. Left ventricular ejection fraction by radionuclide ventriculogram was 64 percent. Echocardiography revealed ventricular wall thickening, normal chamber size, and glittering, sparkling myocardial echoes. On postmortem examination, there was extensive myocardial amyloidosis. There was no evidence of constrictive pericarditis or recurrent effusion. The unique aspect of this case was the combined presence of restrictive myocardiopathy and pericardial tamponade. To our knowledge, no previous case of tamponade due to amyloid heart disease had been reported.
 ...
PMID:Pericardial tamponade, a new complication of amyloid heart disease. 709 Nov 68


1 2 3 4 Next >>