Key Points
- To continuously assess phasic coronary blood flow and arterial blood pressure dynamics during spontaneous daily behaviors and sleep in unrestrained non-human primates.
- Monitored N=4 unrestrained adult baboons continuously for 48 hours using radiotelemetry following recovery from surgical instrumentation.
- Implanted Doppler ultrasonic flow probes on the left circumflex coronary artery and miniature pressure gauges in the thoracic aorta to record hemodynamics during eating, sleeping, ambulation, and excitement.
- Applied electrical stimulation to the carotid sinus nerves in one baboon to investigate autonomic neural modulation of coronary resistance.
- Coronary blood flow reached its minimum and coronary resistance reached its maximum during nocturnal sleep, whereas maximal flow and minimal resistance occurred during stress and excitement.
- Flow increases and resistance decreases generally correlated with elevated blood pressure, heart rate, and myocardial oxygen demand, but periodic vasodilations occurred during nocturnal sleep independent of hemodynamic changes.
- Carotid sinus nerve stimulation decreased coronary resistance in parallel with reductions in arterial pressure and heart rate, confirming neural regulation alongside metabolic control.
Structured PICO
PPopulation4 unrestrained adult baboons instrumented with Doppler ultrasonic flow probes on the left circumflex coronary artery and miniature pressure gauges in the thoracic aorta
IInterventionContinuous monitoring of coronary blood flow and arterial blood pressure via radiotelemetry for 48 hours; electrical stimulation of the carotid sinus nerves in one baboon
OOutcomeCoronary blood flow and aortic blood pressuresurrogate
This preclinical study demonstrates that primate coronary circulation is regulated by both neural and metabolic factors, as evidenced by periodic nocturnal vasodilations and responses to carotid sinus nerve stimulation.