Hemodynamic responses to magnetic stimulation of carotid sinus in normotensive rabbits

OBJECTIVES:Carotid baroreflex plays a crucial role in regulating arterial pressure. Based on this knowledge, electrical stimulation of carotid sinus was designed for treating resistant hypertension. However, the clinical implication of electrical stimulation of carotid sinus is largely restrained due to obvious invasiveness. This study aimed to evaluate the efficacy of magnetic stimulation of carotid sinus (MSCS), a noninvasive strategy, for lowering blood pressure in rabbits. METHODS:MSCS with graded intensities and frequencies were systematically attempted in normotensive rabbits. Blood pressure was recorded dynamically. Sinoaortic denervation and plasma hormone level analyses were performed. RESULTS:When the right carotid sinus was stimulated at 1 Hz frequency, a dose–effect relationship was observed between stimulation intensity (100–250% motor threshold) and mean arterial pressure (MAP) decrement (3.6 ± 1.0 to 10.4 ± 2.3 mmHg). When stimulation intensity was fixed at 200% motor threshold, the median reduction of MAP in 1-Hz group [10.8 (8.6–14.9) mmHg] was significantly higher than that in other frequency groups (all P