Annals of clinical research最新文献

In connection with a mass screening of the Bergen population 93 patients with essential hypertension and 48 normotensive controls were studied in 1965-66. Blood pressure (BP) was recorded intraarterially, cardiac output (CO), by dilution method, heart rate (HR) by ECG and oxygen consumption (VO2) by Douglas bag/Scholander technique. Studies were performed during rest and 50, 100 and 150 watt steady state exercise. The most important initial findings were: Although CO and HR were higher in the youngest hypertensive group (17-29 yrs) than in normotensive age matched controls VO2 was also increased and no true luxury perfusion was demonstrated. Exercise stroke index (SI) did not increase to the same level as in normotensives and total peripheral resistance index (TPRI) during exercise was increased. Cross-sectional data showed a reduction in SI and CI and an increase in TPRI with increasing age - at rest as well as during exercise. 10-year follow-up: 28 subjects initially below 40 years were completely untreated. During the first 10 years there was a fall in CI and SI of approximately 15% and TPRI increased by 20%. The same changes were seen at rest as well as during exercise. Resting blood pressure was practically unchanged. Nearly all patients greater than 40 yrs were treated. 20-year follow-up: Between the 10 year and 20 year follow-up DAP rose to 100 mmHg or more in most of the subjects less than 40 yrs and treatment had to be started. Generally diuretics, betablockers or a combination of the 2 were used. Before the 20 year follow-up, treatment was withdrawn for 2 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Cutaneous circulation increases greatly in sauna in order to prevent body heating. Blood pressure tends to fall but this is prevented by increased cardiac output by means of faster heart rate and by decreased blood flow to the visceral organs. Cooling in cold air, shower, water or rolling in snow causes rapid cutaneous vasoconstriction, which leads to elevation of arterial blood pressure and increase of central venous blood volume. The effects of both heat and cold are mediated via the sympathetic nervous system. The circulatory responses to sauna are related to the intensity and duration of the heat exposure. An ordinary sauna bath increases cardiac workload about as much as moderate or vigorous walking. Habituation to sauna decreases the sympathetic stimulation and cardiovascular responses. Sudden cooling, for example diving in cold water, causes a severe transitory volume load and pressure load to the heart and increases the possibility of cardiac arrhythmias. The risk of cardiovascular complications in correctly practiced sauna bathing is very small and it is confined to subjects predisposed to the risk because of manifest or latent cardiovascular abnormalities.

Sauna and sports go well together. Top Finnish athletes have discovered this, taking a sauna almost twice a week. Why do they do this? In the sauna, an athlete cleanses his body, refreshes his mind, recovers more rapidly, and relaxes. Sauna bathing is not a way of adapting before competitions in a hot climate, or of losing weight rapidly, although one might expect the sauna to be ideal for these purposes. An athlete does not look to the sauna to help his performance, the sauna itself is reward enough.

The aim of the study was to analyze rhythm disturbances and clinical course in 18 patients aged 20-52 years with mitral valve prolapse. The patients were followed up for a mean of three years (range: 1-11 years). We analyzed clinical signs, resting ECG 24 hour ECG, exercise ECG, echocardiograms and the effects of antiarrhythmic treatment. One patient developed marked mitral incompetence. Supraventricular arrhythmias occurred in three patients and ventricular extrasystoles in all 18 patients (class I in 2, II in 6, III in 4, IV in 3, V in 3, according to Lown). Five patients required combined antiarrhythmic treatment. Course of pregnancy and births in two patients with mitral valve prolapse syndrome and class IV arrhythmias were uncomplicated for both the mothers and their babies. Great clinical variability of mitral valve prolapse syndrome ranging from an asymptomatic form to ventricular fibrillation is emphasized.

Finnish sauna is heated by the radiation energy of an electrical or wood burning stove resulting in high air temperature, 80-100 degrees C, and low air humidity levels, 50-60 g/kg of air. Sauna bathing is divided into several 5-20 min sessions and between the sessions several minutes are spent at normal room temperature. Finnish sauna presents a heat load of 300-600 W/m2 of skin surface area. This increases mean skin temperature to 40-41 degrees C, causes strong heat sensations and starts thermoregulatory mechanisms. Evaporative heat transfer by sweating is the only effective channel dissipating heat from the body in sauna. Sweating is usually 0.6-1 kg/h and represents a heat loss of about 200 W/m2. The body cannot compensate for the heat load of sauna and the temperature of viscera begins to increase. A 30-minute stay in a sauna with a temperature of 80 degrees C increases rectal temperature by about 0.9 degrees C in adults whereas in children less intensive sauna (10 min at 70 degrees C) increases rectal temperature by 1.5 degrees C. The subjective feelings after Finnish sauna are usually described in positive terms such as "calm" and "pleasant".