Alpha males: muscle sympathetic discharge on beat‐to‐beat forearm vascular conductance

19 healthy young men (initial study) and 7 healthy males (follow-up study)

Continuous recording of multi-unit muscle sympathetic nerve activity (MSNA) using microneurography and brachial artery duplex Doppler ultrasound for 20-35 min; follow-up study included infusion with phentolamine (co-infused with angiotensin II)

Cardiac cycles without a MSNA burst; saline control condition for the infusion study

Beat-to-beat changes in forearm vascular conductance (FVC) and central cardiovascular variables (total vascular conductance, cardiac output, mean arterial pressure) over 15 cardiac cycles following each identified eventsurrogate