Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The obstructive sleep apnea syndrome is characterized by the occurrence of cyclic snoring and frequent apneic episodes during sleep, with consequent hypoxia and hypercapnia. Obstructive sleep apnea syndrome is associated with excess daytime sleepiness, depression, and an increased incidence of ischemic cardiopathy, cardiac arrhythmias, systemic hypertension and brain infarction. Hypoglossal motoneurons, which innervate extrinsic and intrinsic muscles of the tongue, play a key role in maintaining the patency of the upper airway and in the pathophysiology of obstructive sleep apnea syndrome. Based on data obtained by using extracellular recording techniques, there is a consensus that hypoglossal motoneurons cease to discharge during rapid eye movement sleep, because they are disfacilitated. Since other somatic motoneurons are known to be postsynaptically inhibited during rapid eye movement sleep, we sought to determine, by the use of intracellular recording techniques during cholinergically induced rapid eye movement sleep, whether postsynaptic inhibitory mechanisms act on hypoglossal motoneurons. We found that, during this state, a powerful glycinergic premotor inhibitory system acts to suppress hypoglossal motoneurons. This finding opens new avenues for the treatment of obstructive sleep apnea syndrome, and provides a foundation to explore the neural and pharmacological control of respiration-related motoneurons during rapid eye movement sleep.
 ...
PMID:Hypoglossal motoneurons are postsynaptically inhibited during carbachol-induced rapid eye movement sleep. 1061 91

Chronic obstructive pulmonary disease (COPD) is a leading cause of death, and constitutes a major medical and an increasing economic problem for acute and long term care. A low level of irreversible airway obstruction when in stable condition, hypercapnia, hypoxia, the presence of comorbid heart disease, right ventricular failure, and low serum albumin are the main factors related to risk of exacerbations. Bronchial infections, bronchospasm, left ventricular failure, pneumonia, pneumothorax and thromboembolism are described as the most frequent relapsing causes of COPD. During exacerbation, the inflammatory process, the ventilation/perfusion (V'A/Q') mismatching, an increased airflow resistance and dynamic hyperinflation (PEEPidyn) expose the respiratory muscles to the risk of fatigue, eventually leading to ventilatory pump failure and rising hypercapnia. Prevention of exacerbations and subsequent hospitalisations may be obtained with careful rehabilitation programs, a strict drug protocol, long term oxygen therapy and sometimes using home noninvasive mechanical ventilation (NMV). During exacerbation proper management of infection and lung mechanics derangement has to be adopted using an accurate assessment of severity and standardized treatment protocols. Patient history and examination and functional tests are beneficial to decide how and where to treat these patients. Mechanical ventilation (possibly noninvasive) may be required to reverse the acute episode. The aims of all these procedures remain: i) to prolong length and quality of life; ii) to save costs. Both hospital and post-discharge mortality of exacerbated COPD remain high while quality of life appears to be poor. Future studies will elucidate the relation between number and severity of exacerbations and prognosis.
 ...
PMID:Exacerbations of COPD: predictive factors, treatment and outcome. 1149 3

The obesity-hypoventilation syndrome (or alveolar hypoventilation in the obese) is a new name for an old syndrome, Pickwickian syndrome. It is defined as chronic alveolar hypoventilation (PaO(2)<70 mmHg, PaCO(2) > 45 mmHg) in obese patient with a body mass index > 30 kg/m(2) who have no other respiratory disease explaining the gas anomalies. The large majority of obese subjects are not hypercapnic, even in case of severe obesity. There are three principal causes explaining alveolar hypoventilation in obese subjects: high cost of the work of respiration, dysfunction of the respiratory centers, repeated episodes of nocturnal obstructive apnea. The obesity-hypoventilation syndrome is generally found in males aged over 50 years. Exercise-induced breathlessness is a constant finding. Diagnosis is often made after an episode of severe respiratory failure. Associated diseases favored by obesity are frequent: diabetes, high blood pressure, heart disease. By definition, there is a hypoxemia-hypercapnia syndrome persisting after an acute episode. Spirography usually demonstrates moderate volume restriction. Pulmonary hypertension is frequent but not constant. Obesity-hypoventilation syndrome must be distinguished from obstructive sleep apnea, although the two conditions are often associated. Obstructive sleep apnea may be absent in certain patients with obesity-hypoventilation syndrome (we have had several cases) and inversely, obesity is not observed in certain patients with obstructive apnea. It should be recalled that the term Pickwickian syndrome designates obesity-hypoventilation syndrome (with or without obstructive apnea) and not obstructive sleep apnea syndrome.
 ...
PMID:[Alveolar hypoventilation in the obese: the obesity-hypoventilation syndrome]. 1208 46

Chronic obstructive pulmonary disease (COPD) often leads to massive oedema and the development of what is usually called cor pulmonale. The mechanisms by which patients with COPD retain salt and water are not completely understood. Several abnormalities have been found including reduced renal blood flow with relatively preserved glomerular filtration rate and elevated levels of renin, aldosterone, arginine vasopressin and atrial natriuretic peptide. Generally, these abnormalities worsen with the severity of COPD and are most marked during the oedematous phases. Cardiac output is remarkably normal, suggesting that "cor pulmonale" is not primarily a cardiac disorder but rather a condition of volume overload due to activation of sodium-retaining mechanisms. The stimulus for this activation could be underfilling of the arterial system (reduced effective circulating volume) secondary to a fall in total peripheral vascular resistance. The latter is caused by hypercapnia-induced dilation of the precapillary sphincters. Apparently, the massive sodium retention by the kidney is not able to restore the circulating volume and a vicious cycle ensues ultimately leading to a clinical picture which resembles right-sided heart failure. Predictably, only blockade of the effects of carbon dioxide at the level of the precapillary sphincters would be able to halt this process.
 ...
PMID:Fluid homeostasis in chronic obstructive lung disease. 1462 Nov 5

Acute confusional syndrome, or delirium, is a transitory mental state characterized by the fluctuating alteration of awareness and attention levels. We present the case of a patient with acute confusional syndrome associated with obstructive sleep apnea syndrome (OSAS) aggravated by metabolic acidosis induced by oral acetazolamide treatment.A 70-year-old man with no history of neurological disease was referred with a clinical picture consistent with acute confusional syndrome presenting between midnight and dawn. During the admission examination infectious, toxic, and neurologic causes, or those related to metabolic or heart disease were ruled out. Arterial blood gases measured during one of the nighttime episodes of acute confusional syndrome showed mild hypoxia and hypercapnia with mixed acidosis. Signs and symptoms suggestive of OSAS had been developing over the months prior to admission, with snoring, sleep apnea, and moderate daytime drowsiness. Polysomnography demonstrated severe OSAS with an apnea-hypopnea index of 38. Mean arterial oxygen saturation was 83%; time oxygen saturation remained below 90% was 44%. The attending physician ordered the withdrawal of oral acetazolamide, which was considered the cause of the metabolic component of acidosis. Treatment with continuous positive airway pressure was initiated at 9 cm H2O, after a titration polysomnographic study. The patient continued to improve.OSAS, for which very effective treatment is available, should be included among diseases that may trigger acute confusional syndrome.
 ...
PMID:[Acute confusional syndrome associated with obstructive sleep apnea aggravated by acidosis secondary to oral acetazolamide treatment]. 1516 96

Hypercapnic cerebrovascular reactivity is decreased in obstructive sleep apnoea and congestive heart disease perhaps as a result of repeated apnoeas. To test the hypothesis that repeated apnoeas blunt cerebrovascular reactivity to hypercapnia, we studied breath hold divers and determined cerebrovascular reactivity by measuring changes in middle cerebral artery velocity (MCAV, cm s(-1)) per mmHg change in end-tidal partial pressure of CO2(PET,CO2 ) in response to two hyperoxic hypercapnia rebreathing manoeuvres (modified Read protocol) in elite breath-hold divers (BHD, n=7) and non-divers (ND, n=7). In addition, ventilation and central (beat-to-beat stroke volume measurement with Modelflow technique) haemodynamics were determined. Ventilatory responses to hypercapnia were blunted in BHD versus ND largely due to lower breathing frequency. Cerebrovascular reactivity did not differ between groups (3.7 +/- 1.4 versus 3.4 +/- 1.3% mmHg(-1) in BHD and ND, respectively; P=0.90) and the same was found for cerebral vascular resistance and MCAV recovery to baseline after termination of the CO2 challenge. Cardiovascular parameters were not changed significantly during rebreathing in either group, except for a small increase in mean arterial pressure for both groups. Our findings indicate that the regulation of the cerebral circulation in response to hypercapnia is intact in elite breath-hold divers, potentially as a protective mechanism against the chronic intermittent cerebral hypoxia and/or hypercapnia that occurs during breath-hold diving. These data also suggest that factors other than repeated apnoeas contribute to the blunting of cerebrovascular reactivity in conditions like sleep apnoea.
 ...
PMID:Cerebrovascular reactivity to hypercapnia is unimpaired in breath-hold divers. 1741 71

Rigid spine syndrome (RSS) is a group of childhood-onset muscle disorders characterized by marked limitation of flexion of the spine. Various cardiac changes have been documented in case reports. This study reports on a cardiac evaluation of nine patients with the "vacuolar variant" of RSS. Noninvasive cardiac evaluation entailed creatine kinase levels, full-inspiration chest roentgenograms, standard 12-lead ECG, and 24-h ambulatory ECG recording, as well as M-mode and two-dimensional echocardiography with Doppler study. Heart auscultation was abnormal in five patients. Creatine kinase MB fraction was normal in all patients. Chest roentgenogram showed scoliosis (five of nine), kyphosis (one of nine), severe anterior-posterior flattening of the chest cavity (two of nine), elevated hemidiaphragm (one of nine), caved-in appearance of upper lobes (two of nine), and symmetry of lung volumes (one of nine). Twelve-lead ECG abnormalities indicated right-sided heart disease (three of nine). Echocardiogram showed mitral valve prolapse (five of nine) with regurgitation (three of five) and evidence of pulmonary hypertension (three of nine). Ambulatory ECG recorded paroxysmal tachyarrhythmias in hypoxic or hypercapnic patients (three of nine). There was no correlation between any cardiac abnormalities and patient weakness. Mitral prolapse/regurgitation may have a developmental association with this congenital myopathy. Findings of cor pulmonale were due to the restrictive chest wall defect and respiratory muscle weakness. Paroxysmal tachyarrhythmias were due to hypoxia or hypercapnia. There was no evidence of a primary cardiomyopathy.
 ...
PMID:Rigid spine syndrome: a noninvasive cardiac evaluation. 1782 62

During acute episodes of hypoxia, chemoreceptor-mediated sympathetic activity increases heart rate, cardiac output, peripheral resistance and systemic arterial pressure. However, different intermittent hypoxia paradigms produce remarkably divergent effects on systemic arterial pressure in the post-hypoxic steady state. The hypertensive effects of obstructive sleep apnea (OSA) vs. the depressor effects of therapeutic hypoxia exemplify this divergence. OSA, a condition afflicting 15-25% of American men and 5-10% of women, has been implicated in the pathogenesis of systemic hypertension and is a major risk factor for heart disease and stroke. OSA imposes a series of brief, intense episodes of hypoxia and hypercapnia, leading to persistent, maladaptive chemoreflex-mediated activation of the sympathetic nervous system which culminates in hypertension. Conversely, extensive evidence in animals and humans has shown controlled intermittent hypoxia conditioning programs to be safe, efficacious modalities for prevention and treatment of hypertension. This article reviews the pertinent literature in an attempt to reconcile the divergent effects of intermittent hypoxia therapy and obstructive sleep apnea on hypertension. Special emphasis is placed on research conducted in the nations of the former Soviet Union, where intermittent hypoxia conditioning programs are being applied therapeutically to treat hypertension in patients. Also reviewed is evidence regarding mechanisms of the pro- and anti-hypertensive effects of intermittent hypoxia.
 ...
PMID:Intermittent hypoxia: cause of or therapy for systemic hypertension? 1840 45

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) describe the phenomenon of sudden worsening in airway function and respiratory symptoms in patients with COPD. These exacerbations can range from self-limited diseases to episodes of florid respiratory failure requiring mechanical ventilation. The average patient with COPD experiences two such episodes annually, and they account for significant consumption of health care resources. Although bacterial infections are the most common causes of AECOPD, viral infections and environmental stresses are also implicated. AECOPD episodes can be triggered or complicated by other comorbidities, such as heart disease, other lung diseases (e.g., pulmonary emboli, aspiration, pneumothorax), or systemic processes. Pharmacologic management includes bronchodilators, corticosteroids, and antibiotics in most patients. Oxygen, physical therapy, mucolytics, and airway clearance devices may be useful in selected patients. In hypercapneic respiratory failure, noninvasive positive pressure ventilation may allow time for other therapies to work and thus avoid endotracheal intubation. If the patient requires invasive mechanical ventilation, the focus should be on avoiding ventilator-induced lung injury and minimizing intrinsic positive end-expiratory pressure. These may require limiting ventilation and "permissive hypercapnia." Although mild episodes of AECOPD are generally reversible, more severe forms of respiratory failure are associated with a substantial mortality and a prolonged period of disability in survivors.
 ...
PMID:Acute exacerbations and respiratory failure in chronic obstructive pulmonary disease. 1845 67

Few patients with cyanotic congenital heart disease reach adulthood without a cardiac operation. The prognosis for ''unrepaired'' pulmonary atresia with ventricular septal defect is approximately 8% in the 1st decade of age. Consequently, the number of adults with this particular heart disease (unrepaired) who are expected to need a non-cardiac surgery is extremely low. General anesthesia may aggravate the preexisting right to left shunt and lead to persistent severe hypoxemia. The goal of anesthetic management should be to maintain intravascular volume. Systemic and pulmonary vascular resistance changes, such as might occur due to acidosis, hypothermia, hypercarbia or excessive airway pressures, should be avoided. Maintenance of preload, contractility and sinus rhythm is of major importance. The complex pathophysiology of such heart disease, in addition to the circumstances of emergency operation, exacerbate the total anesthetic risk. We present here a rare case of an acute appendectomy with successful outcome in an adult with pulmonary atresia and ventricular septal defect.
 ...
PMID:Appendectomy for an adult with cyanotic congenital heart disease. 1919 May 64


<< Previous 1 2 3 Next >>