Female-Specific Echocardiography-Derived Cardiac Responses To The Cold Pressor Test

Area of Science:

• Cardiovascular Physiology
• Human Physiology
• Exercise Physiology

Background:

• Previous research indicated heterogeneous vascular resistance (VR) responses to the cold pressor test (CPT) in females.
• Cardiac output (CO) is a critical determinant of the pressor response.
• Understanding cardiac contributions to the CPT is essential for interpreting female physiological responses.

Purpose of the Study:

• To prospectively examine cardiac contributions to the CPT in females.
• To test the hypothesis that females exhibit heterogeneous cardiac and vascular responses to the CPT.
• To compare cardiac and vascular responses between sexes during the CPT.

Main Methods:

• Nineteen healthy females and nine males underwent a 3-minute CPT.
• Continuous measurements included mean arterial pressure (MAP), cardiac output (CO), stroke volume (SV), heart rate (HR), and femoral vascular resistance (FVR).
• Echocardiography, electrocardiogram, finger photoplethysmography, and duplex ultrasound were utilized for data acquisition.

Main Results:

• No significant sex differences were observed in changes (Δ) of MAP, HR, CO, or %FVR during CPT.
• Females exhibited smaller ΔSV compared to males (p=0.03).
• Female ΔSV responses were heterogeneous, with subgroups showing increases (SVINC) or decreases (SVDEC) in SV, impacting ΔCO and total peripheral resistance (TPR).

Conclusions:

• Female stroke volume responses during the CPT are heterogeneous.
• These heterogeneous SV responses are associated with compensatory changes in cardiac output and total peripheral resistance.
• Despite heterogeneous cardiac responses, the overall pressor response magnitude to the CPT is not different between sexes.