Cardiac Output during Breath-holding in Man

Abstract

Paulev, P. & Wetterqvist, H. Cardiac Output during Breath-holding in Man. Scand. J. clin. Lab. Invest. 22, 115-123, 1968.

Cardiac output was measured with the indicator dilution technique in eight healthy subjects. Four of the subjects held their breath with relatively high intrapulmonic pressures (Valsalva manoeuvres). During breath-holding their cardiac output was 20-40 per cent lower than the control values. In contrast, cardiac output was unchanged or increased in four other subjects, who held their breath with intrapulmonic pressures around zero. The changes in cardiac output were always in accordance with the simultaneously recorded alterations in the arterial blood pressure. The arterial oxygen tension and pH decreased, while the arterial carbon dioxide tension increased with the duration of the breath-hold. The results showed a small stroke volume during Valsalva manoeuvres, and a slightly altered stroke volume during apnoea.

Key Words:

• Arterial carbon dioxide
• arterial oxygen tension
• arterial pH
• blood pressure
• breath-holding
• carbon dioxide
• cardiac output
• indicator dilution technique
• intrapulmonic pressure
• oxygen tension
• Valsalva manoeuvre