Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Left ventricular function was studied at rest and during post-extrasystolic potentiation in 18 patients with chronic obstructive lung disease. The contractility indices used were obtained from pressures recorded in the isovolumetric period (left ventricular end-diastolic pressure, Vmax., VECmax., dP/dtmax.) and from volume variations during ejection (end-diastolic volume, ejection fraction, VCF). Left ventricular diastolic compliance was also evaluated. All patients were hypoxic (PaO2 = 58 +/- 7 torr); six of them had cor pulmonale (group B); the remaining 12 patients constituted group A. Left ventricular function of groups A and B was similar; we conclude that right cardiac failure, in cor pulmonale, is not secondary to left ventricular failure. However, left ventricular dysfunction exists; the left ventricle is hypertrophied (probably resulting from chronic hypoxia). Pump function is altered (abnormal ventricular function points are found), but left ventricular kinetics is normal or exaggerated (ejection fraction and VCF are increased). Isovolumetric phase contractility indices are diminished; however, they may increase normally during post-extrasystolic potentiation. Left ventricular compliance is abnormal due to left and right ventricular hypertrophy and to paradoxical movement of the interventricular septum which impedes diastolic expansion of the left ventricle. These changes are responsible for decreased left ventricular output. There seems to exist an impairment of left ventricular function related to both intrinsic (secondary to hypoxia, hypercapnia, left ventricular hypertrophy) and extrinsic factors (right ventricula hypertrophy deviating interventricular septum, lowering of left ventricular preload).
 ...
PMID:[Left ventricular function in chronic obstructive lung disease (author's transl)]. 15 43

For over 15 years, upper respiratory tract obstruction due to adenotonsillar hypertrophy has been known to cause hypoxia, hypercapnia, increased pulmonary vascular resistance and thereby cor pulmonale and congestive heart failure. This is now an uncommon but not rare entity and three recent cases prompted this report. The typical patient is dyspneic with retractions, cyanosis, occasional periods of apnea and somnolence. Edema and hepatomegaly and at times splenomegaly are common. X-rays show cardiomegaly, which on electrocardiogram is found to involved mainly the right ventricle. The strict definition of cor pulmonale is right ventricular hypertrophy secondary to lung disease or abnormal pulmonary function, a definition that may logically be stretched to include abnormal respiratory function secondary to upper airway pathology. The mechanisms by which this occurs are generally agreed upon. Hypoxia has been demonstrated to cause pulmonary vasoconstriction. Acidosis and hypercapnia are thought by some to have the same effect. Pressure across the pulmonary vascular bed is also increased, as predicted by Poiseuille's law, by the high rate of blood flow required to maintain tissue oxygenation with poorly oxygenated blood. Conditions producing hypoxia of hypercapnia or both lead to hypertrophy and eventually to dilatation of the right ventricle. Three cases of children who underwent cardiac catheterization while suffering from cor pulmonale due to adenotonsillar hypertrophy are reported. Right ventricular pressure averaged 44/5, PAO2 72, pH 7.32, and PACO2 52. All were clinically improved following adenotonsillectomy. Cardiac catheterization was repeated in one case, with right ventricular pressure dropping from 44/5 to 21/2, pulmonary vascular resistance from eight units to three, and PACO2 from 62 to 44.
 ...
PMID:Cardiac and pulmonary failure secondary to adenotonsillar hypertrophy. 95 48

Cor pulmonale is right ventricular enlargement secondary to pulmonary hypertension. Although most often caused by parenchymal lung disease, derangements of the ventilatory drive, the respiratory pumping mechanism, or the pulmonary vascular bed may also result in right ventricular hypertrophy and dilatation. Arterial hypoxemia (and resultant polycythemia), hypercapnia, and respiratory acidosis all contribute to the increased afterload on the right ventricle. Diagnosis is often difficult, since pulmonary vascular disease, pulmonary hypertension, and cor pulmonale have few specific manifestations, especially early in their evolution. Treatment is primarily directed at the underlying pulmonary or ventilatory disorder, rather than at the right ventricular failure per se. Supplemental oxygen is essential to avoid hypoxia; corticosteroids, anticoagulants, vasodilators, and other specific therapies are used as indicated to treat the underlying pulmonary disorders. When medical therapies fail, lung or heart-lung transplantation has become a possibility for selected patients.
 ...
PMID:Chronic cor pulmonale. Etiology and management. 239 36

The effects of chronic respiratory failure (hypoxia and hypercapnia) on the contractile properties of cardiac muscle are not established. A study was performed of the isometric contractile properties of isolated papillary muscle removed from rats exposed in a normobaric environmental chamber to 28 days of hypoxia (fractional inspired oxygen (FIO2) 10%, fractional inspired carbon dioxide (FICO2) less than 1%), hypercapnia (FIO2 21%, FICO2 5%), and hypoxia with hypercapnia (FIO2 10%, FICO2 5%). Rats exposed to both hypoxia and hypoxia with hypercapnia developed selective right ventricular hypertrophy. Exposure to hypercapnia alone did not alter right ventricular weight. No change in right ventricular papillary muscle contractility per unit muscle mass was observed as measured by maximum active tension, maximum rate of rise or fall of tension, or time to peak tension. Rat cardiac muscle adapts successfully to the altered acid-base environment and increased work load associated with prolonged exposure to hypoxia and mild hypercapnia.
 ...
PMID:Contractility of papillary muscle from rats exposed to 28 days of hypoxia, hypercapnia, and hypoxia with hypercapnia. 259 23

To determine the relative contribution of sudden death as a cause of late inpatient mortality in newborns after prolonged mechanical ventilation, we reviewed the charts of 348 patients who received ventilation assistance and who were admitted to the neonatal intensive care unit during a 26-month period. The overall mortality rate for these patients was 25%, with 88% (77/88) of these deaths occurring within 30 days of birth. Eleven infants died after more than 60 days of mechanical ventilation. Seven of these late deaths were sudden, unexpected in-hospital deaths. Sudden deaths occurred at a mean (uncorrected) age of 12 months (range, 4 to 27 months), during periods when infants appeared to be stable or clinically improving, were unrelated to recent respiratory exacerbations, and occurred despite prompt resuscitative efforts. Four infants still required mechanical ventilation, and 4 had tracheostomies at the time of death. All of the infants had chronic hypercarbia (greater than 50 mm Hg) and an elevated serum bicarbonate level (greater than 30 mmol/L), but not hyponatremia, hypochloremia (less than 80 mmol/L), or alkalemia. Left and right ventricular hypertrophy, multiple drug therapy, recurrent cyanotic episodes, and frequent unexplained fevers were common. In comparison with 17 bronchopulmonary dysplasia survivors who required longer than 60 days of ventilation therapy, the late deaths group more frequently had left ventricular hypertrophy and received prolonged combination theophylline anhydrous and beta-adrenergic agonist therapy. We report that sudden death can occur in infants with severe bronchopulmonary dysplasia despite in-hospital cardiopulmonary monitoring and the rapid institution of cardiopulmonary resuscitation, and is a significant cause of late mortality in infants who receive ventilation therapy for longer than 2 months.
 ...
PMID:Late sudden unexpected deaths in hospitalized infants with bronchopulmonary dysplasia. 274 53

The histories and the results of the postmortem examinations of 507 patients with chronic pulmonary heart disease were studied. In 62.6% of them left ventricular hypertrophy was found. As probable causes for this left ventricular hypertrophy are suggested: arterial hypertension, ischemic heart disease, hypoxemia, hypercapnia, heart failure, diabetes mellitus. The weight measurement correlations between the left and the right heart ventricles were studied in: "normal hearts", hearts with right ventricular, hypertrophy only, hypertrophy of both ventricles, left ventricular hypertrophy only. A correlation between the mass increase and the wall thickness of the ventricles was established. In the patients with chronic pulmonary heart disease and hypertrophy of both ventricles the mass and the wall thickness of the ventricles increase simultaneously. The possible pathogenetic mechanisms of the left ventricular involvement in patients with chronic pulmonary heart disease are discussed.
 ...
PMID:[Left heart ventricle in chronic cor pulmonale patients. Etiological, pathomorphological and organ weight measurement studies]. 296 38

Blood gas and haemodynamic changes caused by chronic respiratory insufficiency affect the right ventricle and produce chronic cor pulmonale. Equally important but less well known modifications affect the left ventricle and the general circulation and are the subject of the present report. Hypoxemia, hypercapnia and acidosis caused by severe hypoxia create functional disturbances in both ventricles that are manifested in a volume overload that added to other major malfunctions provoke congestive heart failure. The coronary circulation is affected by metabolic factors, perfusion alterations, right ventricular hypertrophy and concomitant coronary lesions. Advanced respiratory insufficiency caused by poorly compensated respiratory acidosis and metabolic acidosis reduces cardiac output and frequency so that tissue perfusion is compromised. Furthermore alterations in transmembrane electrolytic concentrations produce repeated multifocal ventricular arrhythmias that expose the patient to the risk of sudden death. Cardiac failure is reflected in other organs like the kidney and the central nervous system and also contributes to tissue and cerebral hypoxia. The later depresses the respiratory centres and develops into often irreversible coma. A better knowledge of these elements may contribute to the development of appropriate treatment.
 ...
PMID:[General cardiocirculatory effects in chronic respiratory insufficiency]. 354 42

Left ventricular function was studied at rest and during post-extrasystolic potentiation (PESP) in 18 patients with chronic obstructive lung disease. The contractility indices were obtained from pressures recorded in the osovolumetric period and from volume variations during ejection. All patients were hypoxic; six of them had cor pulmonale (group B); the remaining 12 patients constituted group A. Left ventricular function was similar in both groups; it is concluded that right heart failure in cor pulmonale is not secondary to left ventricular failure. Left ventricle was hypertrophied and pump function altered, but left ventricular kinetics was normal or increased. Isovolumetric phase contractility indices were decreased; they may increase during PESP. Left ventricular compliance was altered due to left and right ventricular hypertrophy and to paradoxical movement of interventricular septum which impeded diastolic expansion of left ventricle. The impairment of left ventricular function seems to be related to both intrinsic (hypoxia, hypercapnia, hypertrophy) and extrinsic factors (right ventricular hypertrophy with deviation of interventricular septum, lowering of left ventricular preload).
 ...
PMID:Left ventricular function in chronic obstructive pulmonary disease. 645 29

This report describes a young woman with unexplained chronic hypoventilation that was greatly exacerbated during sleep. Treatment with nocturnal O2 during a 2-yr period was associated with stable cardiovascular function but severe morning headaches and lethargy, presumably related to nightly bouts of hypercapnia and acidosis during sleep. A subsequent 2-yr period in which ventilation was assisted during sleep by means of a rocking bed, but supplementary O2 was not used, was associated with disappearance of the headaches and improved psychosocial function, but with the insidious development of signs of pulmonary hypertension and right ventricular hypertrophy. This patient's clinical course demonstrates the separate adverse effects of intermittent hypoxemia and hypercapnia and emphasizes the importance of preventing both hypoxemia and hypercapnia during sleep.
 ...
PMID:Idiopathic hypoventilation syndrome: importance of preventing nocturnal hypoxemia and hypercapnia. 735 98

Young rats are thought to be more tolerant to hyperoxia. We propose that this may not be proven and depends on how tolerance is defined. We assessed oxygen tolerance in Sprague-Dawley rats from birth to maturity by comparing survival, lung water, antioxidant enzyme activity, lung morphometrics, heart weight, and arterial blood gases in newborn and 27-, 44-, 48-, and 96-day-old rats exposed to 100% O2 or room air for 22 days. Some 96-day-old rats (rest group) received only 50% O2 between 48 and 72 h. Mortality after 5 days of O2 was 0% in newborn and 27-day-old rats and 27% in 44-day-old rats but was > 80% in 48- and 96-day-old rats. Between 5 and 22 days, the death rate was 100% in newborns, 25% in 27-day-old rats, and 0% in 44- to 96-day-old rats. Death occurred when lung water was > 84% except in newborns, which tolerated high lung water for the first 7 days. In chronically exposed 44- and 96-day-old rats, lung water returned to normal. Enzyme activity increased with O2 at all ages but did not relate to survival. In 96-day-old rats, the initial increase was suppressed on day 3. All chronically O2-exposed rats had minimal nonvascular parenchymal changes but developed right ventricular hypertrophy and increased alveolar ductal artery muscularization and lost alveolar capillaries. The most mature rats were least affected. In O2, there was pulmonary insufficiency the first 3 days, followed by recovery, and later hypercarbia and decreased arterial PO2. We conclude that young rats, 0-44 days old, are more O2 tolerant for 5 days. More mature animals, surviving 5 days, are more tolerant to chronic exposure.
 ...
PMID:Comparative age-related acute and chronic pulmonary oxygen tolerance in rats. 789 11


1 2 3 Next >>