Cardiovascular responses to face immersion and apnea during steady state muscle exercise: A heart catheterization study on humans

Abstract

The cardiovascular adjustments to face immersion and apnea (FIA) in human beings during steady-state muscle exercise (163 and 98 watt) have been investigated. Using a triple lumen flow directed catheter inserted into the pulmonary artery we were able to measure cardiac output (CO) by thermodilution technique, pulmonary arterial pressure (PPA) right atrial pressure (PRA) and left ventricular filling pressure (PAD). Phasic arterial blood pressure (BP) was measured via a cannula in the radial artery. A 12 lead ECG was recorded continuously. FIA caused an immediate rise in BP (median 61%), the highest level being 25.33 kPa. CO during the last half of FIA was reduced by 49% (range 46-59, n = 7) systemic vascular resistance increased by median 200% (range 111-280). Myocardial oxygen demand determined by the heart rate pressure double product fell from median 33.6 to 16.8 (163 W) and 28.5 to 19.1 (98 W) given as beats/min X kPa X 10(2). Mean reduction was by 42%. PPA and PRA immediately increased and remained constant until a further pronounced increase was seen towards the end of FIA when pulmonary vascular resistance (PVR) went up. PACO2 and PAO2 at the end of 30 sec FIA (163 W) was 10.0 and 5.6 kPa, respectively, values which expectedly would cause pulmonary vasoconstriction. Our findings demonstrate that humans are able to make principally the same cardiovascular adjustments to diving as aquatic mammals, although the response patterns are slower and less efficient.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationships between the extent of apnea-induced bradycardia and the vascular response in the arm and leg during dynamic two-legged knee extension exercise

“…Apnea reportedly increases MAP in exercising humans (2,4,7,26,27,33,35). In the present study, we found that MAP was greatly increased during apnea in both the L and S groups, but the increase in MAP was larger in the L group than in the S group.…”

“…Acute apnea-induced bradycardia is observed in humans during exercise on land (3,4,6,7,22,25,26,27,30,33). Bjertnaes et al (7) reported that during exercise, the decrease in cardiac output (CO) induced by apnea was nearly paralleled by a reduction in heart rate (HR).…”

“…Some diving animals, such as seals, show remarkable bradycardia during voluntary diving (36). In humans, the bradycardic response seen during apnea or diving is smaller than in diving animals and varies a great deal from individual to individual (5,21,24,31,32).Acute apnea-induced bradycardia is observed in humans during exercise on land (3,4,6,7,22,25,26,27,30,33). Bjertnaes et al (7) reported that during exercise, the decrease in cardiac output (CO) induced by apnea was nearly paralleled by a reduction in heart rate (HR).…”

“…Bjertnaes et al (7) suggested that, for these people, the strong bradycardia could lead to a large reduction in CO. Moreover, total vascular conductance (TVC) would need to be reduced to maintain or increase arterial blood pressure.…”

Effects of Voluntary Apnea on Haemodynamic Responses during Groundwork Techniques of Judo

“…According to these authors, the cardiovascular modifications observed result from a vagale inhibitor and a sympathetic stimulation. Those are responsible for a tachycardia with secondary rise in the cardiac flow and the systolo-diastolic blood pressure [8] [9]. However, the review of literature does not give a report on a similar work concerning the judo.…”