Annals of clinical research最新文献

Digitised M-mode echocardiography was used to study the diastolic left ventricular function in ten patients with constrictive pericarditis. Each patient was matched for heart rate and stroke volume with a control patient who had normal left ventricular end-diastolic pressure and coronary arteries. All 20 patients underwent right and left cardiac catheterisation. In patients with constrictive pericarditis compared with controls, the median (range) left ventricular peak diameter lengthening rate, normalised for end-diastolic dimension, was 4.5 (2.5-8.0) s-1 and 2.9 (1.6-4.1) (p less than 0.01), and the rapid filling period fraction of diastole was 0.28 (0.18-0.37) and 0.37 (0.21-0.58) (p less than 0.05), while the mitral valve E-F slope was 20.1 (10.5-39.2) cm/s and 11.8 (7.6-14.5) (p less than 0.05), respectively. Thus, the early rate of left ventricular diameter lengthening is increased in constrictive pericarditis independent of heart rate and stroke volume, while the actual duration of the rapid filling period is decreased. These results, obtained noninvasively, extend the findings of previous invasive studies. The method may help in the difficult clinical diagnosis of constrictive pericarditis, although there is some overlap with the normal control range.

For over a hundred years Finnish sauna has been documented as a physiotherapeutic method in respiratory diseases. Physiological changes of ventilation remain small (about 10%) in the sauna. Heat load, sauna air and sympathetic stimulation generally do not cause problems to the lungs. Electron microscopic studies have not shown irreversible damages to the airway epithelium. Sauna takers should avoid bathing during acute respiratory infections. Sympathomimetic drugs may provoke tachycardia and arrhythmias in the sauna.

Finns have used the sauna for centuries to clean themselves, to maintain their health and even to help in treating a variety of ills. Up to this century the sauna was widely used as a place for childbirth. But the main reason for a sauna is the pleasure of sauna bathing and the craving for the feeling after the sauna. The longevity and effects of the sauna in Finland are linked to the view of the sauna as a holy place; participants have to behave in the sauna as they would in the church. The use of the vihta or vasta (a sauna whisk made of birch branches) has been an essential part of sauna bathing. Beating with the vihta promotes sweating and stimulates the warm skin. Many curative and magical effects have been attributed to the practice. Seldom has the sauna been thought to cause any disease.

Findings of virus infection were prospectively studied in 133 episodes of obstructive respiratory difficulty in 90 children aged 2 to 15 years. A viral infection was confirmed in 16 episodes (12%). In a further 11% of cases serological evidence of a recent viral infection was found. Respiratory syncytial virus (RSV) accounted for half of the positive viral results. Skin prick tests were performed after the second episode of bronchial obstruction. Of the 79 children tested, 57% had at least one positive result to house dust mite allergen and/or to one of the four seasonal allergens studied. Reactivity to birch pollen was most common. There was no significant correlation between the frequency of episodes in children with birch, timothy grass and mugwort pollens or with Cladosporium herbarum allergies and counts of the respective pollens or spores in the air. Blood eosinophilia was found in 34% of cases immediately after the episodes, but no seasonal variation occurred. It was impossible to differentiate the episodes initiated by viruses from those initiated by seasonal allergens. Thus exposure to seasonal allergens is a less common precipitant of respiratory difficulties from bronchial obstruction than are virus infections.

With the aid of a special questionnaire 16 healthy persons were divided to morning or evening types of personalities. Their arterial blood pressure was registered ambulatorily for 24 hours in order to elucidate the difference of blood pressure reactions between the groups. The average maximum blood pressure occurred 3.5 hours later in evening types than in morning types. Individually there were very small differences and it seems that the blood pressure level is more affected by physical activity than by morningness or eveningness.

It is proposed that the failure of current antihypertensive treatment to reduce the incidence of coronary heart disease in patients with hypertension is due to severe, possibly irreversible restriction of coronary vascular reserve in the deeper layers of the left ventricle. Contrary to the heart, the brain can maintain a normal oxidative metabolism when the blood pressure is lowered, by extracting more oxygen from the blood. The brain is thus better suited than the heart to take advantage of the beneficial effect of antihypertensive treatment in terms of protection against hypertensive organ damage. This hypothesis is supported by studies of cerebral and coronary autoregulation and the J-shaped relation between death from myocardial infarction and treated diastolic blood pressure now reported from a number of studies.

For over a decade it has been known that clonidine and alpha-methyldopa lower blood pressure by activating central and peripheral alpha-2-adrenoceptors and prazosin likewise by antagonizing alpha-1-adrenoceptors. During the 1980s, the number of therapeutic indications for drugs which act via these classes of alpha-adrenoceptors has expanded greatly, particularly the non-cardiovascular applications of drugs acting on alpha-2-adrenoceptors. Novel alpha-2-agonists such as detomidine and medetomidine have been introduced into veterinary medicine as sedative/analgesics. It is possible that these and other compounds with better alpha-2-adrenoceptor selectivity than clonidine may be used in human medicine to ease symptoms of anxiety in drug- and alcohol-related withdrawal syndromes, and as preanaesthetic agents. Several novel alpha-2-adrenoceptor antagonists, such as idazoxan and atipamezole, have been developed with improved selectivity compared to the traditional antagonist at these receptors, yohimbine. At present none of these new compounds are registered for use, but several are undergoing clinical trials for a variety of therapeutic applications such as depression (idazoxan), arousal of animals sedated with alpha-2-agonists (atipamezole), and adult-onset diabetes (DG-5128). The established use of yohimbine in the treatment of male sexual impotence has been reconfirmed and several of the above compounds may be evaluated in the future to treat this disorder.

Alcohol-related minor accidents such as sprains and burns are common in sauna, but more serious accidents also take place--head contusions, heat stroke after passing out in sauna and drownings while swimming. The exact number of these accidents is not known, but in Finland (population 4.8 million) the consumption of alcohol has been estimated to be a contributing factor in some 20 to 25 sauna-related deaths every year. The scientific information on the interaction of sauna and alcohol on human physiology is totally lacking. Thus our discussion on the physiological and medical consequences of this interaction relies merely on presumptions. Ingestion of large amounts of alcohol while sauna bathing may affect the body's ability to maintain blood pressure. In particular, the risk of an orthostatic hypotensive reaction is increased with concomitant faintings and accidents. Alcohol intoxication and particularly the hangover phase exposes a person to cardiac arrhythmias, and sauna may further increase the arrhythmia-risk due to enhanced adrenergic activity. Sauna bathing and heavy drinking, and also sauna bathing during hangover phase undoubtedly create real health risks.