Cardiovascular Responses to Natural and Auditory Evoked Slow Waves Predict Post-Sleep Cardiac Function

The importance of sleep as a key component of cardiovascular health has been increasingly recognized. Our previous research demonstrated that auditory-enhanced slow waves increase cardiac function, but the underlying mechanisms behind these beneficial effects remain uncertain. In this study, we examined the influence of two types of slow waves on cardiovascular functions. 18 healthy middle-aged men participated in a three-night sleep lab experiment under three conditions: two auditory slow wave enhancement conditions and one SHAM control. We found that the strength of heart rate and blood pressure responses occurring concurrently with slow waves predicts post-sleep cardiac function in men as measured through transthoracic echocardiography. Furthermore, we observed that highly synchronized type I slow waves, compared to lower-amplitude type II slow waves, are primarily associated with increased cardiovascular responses (transient increase in heart rate and blood pressure). While auditory stimulation enhances both types of slow waves, they display distinct temporal dynamics, suggesting different underlying brain and body microstates. These distinct slow wave types may affect cardiovascular function differently, indicating that targeted slow wave stimulation could be a strategic approach to enhancing cardiac function. Trial Registration: This study was registered under clinicaltrials.gov (NCT04166916).