Carotid sinus massage is recommended in the routine investigation of all older patients who have syncope, dizziness or unexplained falls. Twenty-three percent of unexplained falls are attributed to carotid sinus hypersensitivity, an abnormal response to carotid sinus massage characterized by either a significant heart rate slowing (more than three seconds asystole; cardioinhibitory type), a decrease in systolic blood pressure (more than 50 mm Hg; vasodepressor type) or a combination of both (mixed carotid sinus hypersensitivity). The massage technique involves applying longitudinal digital pressure at the bifurcation of the internal and external carotid artery for five seconds. This procedure is applied first to the right and then to the left side after 120 seconds. It is performed using a tilt table, with the patient in a supine position and tilted to 70 degrees. The risk of carotid sinus hypersensitivity increases with age. Davies and Kenny present incidence data of neurologic and cardiologic complications of carotid sinus massage in a large series of older patients evaluated for syncope or falls.

A total of 4,000 patients were evaluated using the technique described previously. Contraindications to carotid sinus massage include the presence of a carotid bruit, stroke or myocardial infarction within the previous six months, and a history of serious cardiac arrhythmia, ventricular tachycardia or ventricular fibrillation.

During the study, 11 patients had neurologic complications and no patients had a cardiac complication. Of the patients who experienced neurologic complications, 10 developed hemiparesis, three developed expressive dysphasia and one developed a hemianopia. Complications occurred within five minutes of massage in five patients, and at 10 minutes, 30 minutes and two hours after massage in the remaining patients. Computed tomographic head scan revealed new brain lesions in only two patients. A carotid Doppler ultrasound examination was performed in nine of the patients after the procedure; two patients showed greater than 70 percent contralateral diameter stenosis and another two patients showed greater than 30 percent contralateral diameter stenosis. Seven of the 11 patients had carotid sinus hypersensitivity. All had a significant vasodepressor response and one had a cardioinhibitory response. Nine patients made a full functional recovery, and seven of these patients recovered within 24 hours. Full recovery occurred in two patients within one month. Hemiparesis persisted in two patients.

The authors conclude that the incidence of neurologic complications following carotid sinus massage is low (0.28 percent) and that most patients make a full functional recovery.