CHANGES IN LEFT-VENTRICULAR ACTIVITY DURING APNEA AND FACE IMMERSION

  • 1 January 1977
    • journal article
    • research article
    • Vol. 4  (1) , 27-37
Abstract
Apneic face immersion in water was analyzed with respect to its effects on heart rate and ventricular function in a group of highly trained teenaged swimmers of both sexes. Both parameters were studied on a beat-by-beat basis throughout the maneuvers and analysis of the systolic time intervals has provided a noninvasive tool for studying changes in ventricular function. The pre-ejection period of systole is lengthened, while left ventricular ejection time shows little change with apnea, face wetting (27.degree. C), or a combination of these. This decrease in ventricular function lags behind the previously well-recognized decrease in heart rate, a difference which is particularly obvious when face immersion is performed in the postexercise state. This suggests ventricular function changes are regulated separately from heart rate changes and may be a secondary effect. Analysis of the face immersion reflex on a beat-by-beat basis has also revealed a more rapid development of bradycardia with colder (15.degree. C) water. A model was developed to describe the face immersion reflex in the light of these findings and previous information.