Comparison of hemodynamics during hyperthermal immersion and exercise testing in apparently healthy females aged 50-60 years.
BACKGROUND
Owing to excessive worries regarding adverse cardiac events, hyperthermal balneotherapy for patients with coronary artery disease is underprescribed. However, very few cardiac events occur in similar heat stress during Finnish sauna bathing. Exercise testing has proven to be a safe diagnostic procedure even in survivors of myocardial infarction.


METHODS
We compared the effects of hyperthermal immersion and exercise testing on cardiac hemodynamics in 21 apparently healthy women aged 50-60 years. The maximal symptom-limited bicycle exercise test was performed according to the modified protocol of Wasserman. Hyperthermal immersion was carried out in 40 degrees C water and was completed by increasing the core temperature by about 2 degrees C. The left ventricular function was evaluated using continuous measurement of thoracic electric bioimpedance during both tests. The blood pressure, index of contractility and heart rate were measured directly, whereas the cardiac index, left cardiac work index and systemic vascular resistance index were calculated.


RESULTS
The hemodynamic response, as assessed at continuous non-invasive monitoring, showed substantial differences between hyperthermal immersion and exercise testing. Overall, we found a significantly lower hemodynamic load during hyperthermal immersion in comparison with exercise testing. Entering the bath, there was a significant decrease in the left cardiac work, contractility and blood pressure. We recorded a slight increase in the heart rate towards peak hyperthermal immersion. However, other modulators such as the mean arterial pressure, index of contractility, cardiac index and left cardiac work index decreased even below resting values.


CONCLUSIONS
Excessive hyperthermal immersion induced a lower hemodynamic load in apparently healthy women than standard maximal exercise testing.
Second Department of Internal Medicine, School of Medicine and Teaching Hospital, Comenius University, Bratislava, Slovakia. jan.lietava@faneba.sk
Jan
J
Lietava
Branislav
B
Vohnout
Denis
D
Valent
Juraj
J
Celko
D000704:Analysis of Variance; D001795:Blood Pressure Determination; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006358:Hot Temperature; D006801:Humans; D007101:Immersion; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors; D018709:Statistics, Nonparametric