Continuous Recording of Direct Arterial Pressure and Electrocardiogram in Unrestricted Man

Abstract

(Johnson et al., 1969). This is a further demonstration of the biochemical consequences of imbalance between levels of emotional and physical activity. It provides some additional encouragement for those investigating the place of "exercise therapy" in the prevention and treatment of cardiovascular disease.In addition, this study indicates that sudden exposure to intense heat, as in sauna baths, Turkish baths, and presumably the "coffee baths" becoming fashionable in Japan, may contain an element of risk in those prone to coronary insufficiency. This group includes a number of middle-aged men with tiredness, lethargy, and "fibrositis" in the chest and shoulder who will seek out the most gruelling of these artificial environments and stay in longest to "sweat it out of their system." Apart from descriptions such as "my heart was thumping" and "I thought my heart was going to stop" appearing in recent articles on the subject (Observer, 1971), sudden syncopal attacks just on standing to leave the sauna are not uncommon.If any recommendations can be made on the basis of the limited number of subjects in this study perhaps a cautious approach for the middle-aged and elderly sauna novice might be indicated. The cooler, lower levels away from the heater should be tried in the high temperature saunas being promoted in Britain with a time limit of five minutes. However, at the lower temperature of 60-70'C more common in Finnish saunas, Eisalo's (1956) work has shown that a more leisurely approach can be used without apparently undue strain on the cardiovascular system. The recumbent posture customary in these Finnish saunas also helps adequate coronary artery perfusion, rather than sitting or standing in the smaller units found in Britain. For many healthy people the sense of relaxation and wellbeing induced by a sauna will continue to outweigh the potential dangers of the circulatory gymnastics involved. On the basis of these experiments, however, it appears to be neither healthgiving nor heroic to prolong a sauna bath past the point where a person feels he has had enough.

The effects of acute and chronic dihydropyridine calcium antagonist therapy on baroreflex sensitivity: a re-analysis using the sequence method

“…Blood pressure was measured directly and continuously from the brachial artery on a portable analogue tape recorder as previously described by us. 11 No complications of the intra-arterial technique were encountered in these patients. All patients gave informed consent to these investigations, which were approved by the hospital Ethics Committee.…”

Self-measurement of blood pressure

“…Lability increases as the blood pressure level rises, though less than when expressed as a percentage of the mean pressure; it also increases with increasing age (9,12). Clinical physiologists have shown that blood pressure becomes more vari-4868 -155-able as the sensitivity of the baroreflexes declines in hypertensive subjects (4,5) and, strangely, the variations in heart rate decline as the blood pressure variability increases (7,13). However, when it is realized that the baroreflex influences the blood pressure in large measure by moderating cardiac function, it can be appreciated that, as the baroreflex sensitivity declines, the heart rate will increase and its variability will decrease.…”

Effect of labetalol on continuous ambulatory blood pressure.

“…Secondary hypertension and cardiac and renal complications were excluded by routine investigations. We used a transducer-perfusion unit initially developed at Oxford (Bevan et al, 1969;Littler et al, 1972) and later perfected and in constant use at Northwick Park Hospital for the past 7 years for measuring ambulatory BP (Millar-Craig et al, 1978b Mean values were plotted on a 24-h axis to obtain circadian curves, and the points making up these curves were then compared before and after treatment. To standardize the activity/inactivity cycle of each patient, the exact time of waking was carefully recorded and these curves normalized around this time so that events about the waking hour could be carefully compared.…”