The newcastle protocol for carotid sinus massage

To the Editor: Syncope and unexplained falls are common causes for attendance at the emergency room.1, 2 There is an overlap between syncope and falls in older people.3 Increasingly, the complete investigation of older people with these conditions occurs in the setting of specialist syncope and falls clinics. We operate such a clinic at our hospital. This is a multidisciplinary service involving geriatricians, cardiologists, physiotherapists, occupational therapists, and nurse specialists. Annually, we receive 3000 new referrals and are frequently asked to provide guidelines for carotid sinus massage (CSM). To date no detailed guidelines are available. We include here the protocol and guidelines developed in our unit to help standardize the procedure for CSM and promote discussion. CSM should be considered in older patients presenting with loss of consciousness, unexplained falls, and presyncope,5 where history, examination, and cardiovascular and neurological investigations have not identified a cause. Myocardial infarct, transient ischaemic attack, or stroke in the 3 months prior to attendance are absolute contraindications. Others include a history of ventricular fibrillation or ventricular tachycardia and a history of previous adverse reaction to CSM. If carotid bruits are present, a carotid doppler ultrasound of the neck is warranted. If this shows significant stenosis or atheroma, the risks and benefits of the procedure should be explained to the patient. We have a policy, if proceeding to CSM in this group, of only doing the CSM supine. The patient should lie supine for a minimum of 5 minutes, connected to an electrocardiogram (ECG) and noninvasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda, or Portapres) on a footplate type tilt-table. Record the baseline readings: the systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (the relative risk [RR] interval on baseline ECG, at 25 mm/sec) pre-CSM. By convention, CSM on the right (R) side in the supine position is done first.7 Two people are required to perform this procedure—one to perform CSM and the other to record the ECG and BP readings. Identify the carotid sinus. It is located between the superior border of the thyroid cartilage and the angle of the mandible. At this anatomical position and at the site of maximal carotid pulsation, firm longitudinal carotid sinus massage can be carried out for 5 seconds;8 simple pressure over the carotid sinus will not reliably reproduce a response. Start the ECG machine. This will allow measurement of the RR interval pre-CSM. By saying “ON” the person supervising the ECG can mark when CSM has commenced. Carry out longitudinal carotid sinus massage for 5 seconds. Indicate you have stopped by saying “OFF” in order that this can be recorded on the ECG tracing. The ECG should be continued until the baseline heart rate has returned. Record the nadir SBP and DBP, which generally occurs within 15 seconds of stopping. Massage should be discontinued if asystole openface> 3 seconds occurs. If asystole is prolonged, administer a frappe/blow to the anterior chest wall. Record if the patient experiences either a presyncopal or syncopal episode. Ascertain if these symptoms were the same as the symptoms of which they complained of. Before repeating the procedure, in the left supine, the right erect, and left erect position, ensure that the patient is asymptomatic and that the SBP, DBP, and heart rate (HR) have returned to the pre-CSM baseline levels. If supine CSM is negative, the procedure should be repeated in the 70°, head-up, tilt position; there is an additional 30% diagnostic rate when CSM is performed upright (Figure 1).9 At the end of the procedure, the patient should be returned to the supine position for at least 10 minutes and then prepared for discharge. 6.2 seconds of asystole in a patient with cardioinhibitory carotid sinus hypersensitivity in the right supine position. Complications post CSM are rare.4, 6 If patients experience symptoms that suggest a neurological complication, the procedure should be abandoned, the patient placed in the supine position, and measures taken to ensure that BP is returned as quickly as possible to baseline levels. Aspirin 300 mg should be administered, if not contraindicated, and the patient admitted to the hospital for observation overnight. CSM may need to be repeated at another visit if it has been previously negative or if there is a strong clinical suspicion of the diagnosis or if investigations for recurrent syncope have been negative. CSM post–pacemaker insertion is only necessary if symptoms persist or recur.