The medical history of CSH patients might show hypertension, diabetes, coronary artery disease, and neurodegenerative disorders (Parkinson and Alzheimer). Physical exams might be normal except for the clinical manifestations of the previously mentioned disorders.

Symptomatic CSH mainly present with the following:

Signs and Symptoms

• Presyncope or syncope.
• Unexplained falls.
• Visual changes before consciousness loss (i.e., darkening visual field).

Physical Examination

• Hypotension.
• Pallor.
• Bradycardia.
• Bruises related to fall injury.

It is very important to determine the cause of falls or syncope in the elderly, as it is very likely to miss an important and critical condition (severe aortic stenosis, arrhythmias) or neurologic conditions (seizure or stroke). Such a miss can lead to critical results, especially if the patient has recurrent episodes of syncope while driving, during sea activities (swimming and diving), parachuting, or running heavy machinery. On the other hand, CSH can be asymptomatic and only happens during a carotid massage. It is worthy to re-mention that CSH diagnostic criteria during carotid massage might happen without symptoms.

It was mentioned in the medical literature; that in rare cases of the head and neck tumors, there has been a hyper-response of the carotid sinus to the tumor burden pressing over baroreceptors (the management depends on the primary tumor, stage, age, and prognosis).[9]

Approach syncope by getting the vital signs and assessing for orthostatic hypotension and getting the history of dehydration-induced by coughing, micturition, or by exercise i.e., hypertrophic cardiomyopathy and aortic stenosis. A family history of sudden cardiac death, medical and surgical history (postprandial syncope after gastrointestinal surgery), complete blood count, basic metabolic panel, and fingerstick glucose (hypoglycemia causes unconsciousness) should be obtained. It is also important to have an electrocardiogram (ECG) and, in certain cases, an echocardiogram. Performing a neurologic exam to screen for transient ischemic attack (TIA) or strokes is needed. Tilt table test is also helpful for the diagnosis of vasovagal syncope and orthostatic hypotension. Performing a brain CT-scan or electroencephalogram EEG if the presentation suggests neurologic etiology is helpful as well.

Other diagnostic options can be used (i.e., Holter monitor and cardiac electrophysiologic study). However, the best method to diagnose CSH is via monitored carotid massage (but again, other causes of syncope must be ruled out, and history helps to choose the proper diagnostic option). Non-accidental falls in the elderly following a sudden loss of consciousness must be approached wisely to avoid misdiagnosing and event recurrence.

Massage Technique: With the patient in the supine position, use the second and third fingers over the carotid sinus, which is located anterior to the sternocleidomastoid muscle at the level of the upper border of the thyroid cartilage. First, massage the right carotid sinus as there are a bunch of receptors, and there is greater response than the left, massage for 5 to 10 seconds with a circular motion. If there is no response, switch to left carotid sinus unless it is contraindicated, and if there is asystole for 3 seconds or more and/or a drop in systolic blood pressure 50 mmHg or more, the test is considered positive regardless of symptoms evolution. If the test is not diagnostic may repeat the test with the patient in the upright position or using a tilt-table (prepared emergency equipment and skillful staff must be at the scene of the carotid massage).[10][11]

Contraindications to carotid sinus massage:

• Absolute contraindications are stroke, transient ischemic attack (TIA), and myocardial infarction in the previous three months.
• Relative contraindications include arrhythmia (ventricular tachycardia or ventricular fibrillation) and bruit over the carotid artery, in case of bruit presence an echo-doppler should be done, if showing stenosis of 70% or more, then it is a contraindication for carotid massage (it is acceptable to do a carotid massage with a stenosis level of 50 to 69%).[11][12]

General approach: Educating the patient about CSH and what might trigger an event (explain the events, cardioinhibitory or vasopressor); i.e., avoid tight collar dressing, chiropractic activities around the neck, or manipulation around the carotid sinus besides the control of associated medical conditions (for example hypertension, diabetes, etc.).

• Asymptomatic patients who fulfill the criteria for CSH diagnosis without developing an event need no further evaluation (this finding is when approaching syncope diagnosis for a reason other than CSH).
• Asymptomatic patients who develop an event during monitored carotid massage (supervised) and otherwise asymptomatic need no further treatment except for avoiding triggers and controlling other medical issues.
• Symptomatic patients treatment depend on the CSH subtype:

1. Vasopressor subtype maintaining a proper status of hydration and salt intake up to 6 gm/day if not contraindicated (hypertension and congestive heart failure) is enough to control most of the cases, if still symptomatic adding fludrocortisone (mineralocorticoid) or midodrine (alpha-adrenergic agonist) if not contraindicated as hypertension is usually existed in CSH population, adjusting the medication dosage and timing is important in avoiding hypertension and CSH events.[13][14]
2. The cardioinhibitory subtype, the use of a dual-chamber pacemaker, is the cornerstone of the management, the reason beyond using a dual-chamber pacer is because that in some cases there is a complete block at the AV node and dual-chamber pacemaker can overcome this via stimulating both the atria and the ventricles. It is also wise to use a pacemaker in the mixed subtype. However, in this case, an event development is still possible because of the vasopressor component in the mixed type, but the incidence of events is decreased with pacemaker placement, especially if the vasopressor is managed properly.[15][16]

• There is an association between sick sinus syndrome (SSS) and CSH, and they coexist in 26% of cases, hereby, pacemaker placement is both beneficial for the two cases.[17]
• Surgical or radiologic denervation of the carotid sinus was previously used to treat CSH. However, they are not used anymore because of their complications.

CSH can manifest as a syncopal attack that makes it a challenging task to approach it properly, especially when the historical carotid stimulation is not clear in the presentation (in case of sudden neck movement or a rush in blood pressure i.e. the patients will not always mention a carotid stimulation). Here are the most conditions that mimic CSH:

• Vasovagal syncope (preceded by prodromal symptoms and usually evoked via pain, or the scene of blood).
• Situational syncope (evoked via cough, defecation, and micturition ("a sudden increase in intraabdominal pressure").
• Orthostatic hypotension (change in blood pressure between standing and laying down).
• Cardiogenic syncope.
• Arrhythmias (Electrocardiogram and Holter monitor help in diagnosing).
• Myocardial infarction (ECG and cardiac enzymes).
• Massive pulmonary embolism.
• Severe Aortic stenosis.
• Seizures.
• Hypertrophic cardiomyopathy.
• Transient ischemic stroke.
• Loss of consciousness due to metabolic and toxic conditions (i.e., hypoglycemia).
• Medication adverse effect.

Hence, a proper wide approach not ignoring critical conditions should take place in the diagnosis process, each syncope case must be scanned and examined well, with the proper diagnostic plan and management. Anyway, some of the syncopal cases remain undiagnosed.[18]

The mortality rate of CSH patients is the same as the general population, CSH in itself is not considered dangerous. However, syncope related injuries are what matters for these patients, non-accidental falls or loss of consciousness in serious occasions can result in multiple fractures or intracranial bleeding, especially since many elderly patients are on anticoagulants or/and antiplatelet medication which can result in fatal consequences.[19]

The major complication is non-accidental falls, which might be serious due to the CSH elderly population (taking anticoagulants, osteoporosis, poor candidates for surgical intervention, or high risk for postsurgical complications). Another issue to consider is while performing carotid massage for diagnosis, ignoring good carotid evaluation (excluding bruits and carotid artery stenosis) may evoke a stroke.[20]

Educating the patient about the nature of the disease and its consequences is essential in the management plan, avoid wearing tight collar clothing and minimizing pressure application near the sinus node (i.e., while shaving) is helpful.

It is also mandatory to avoid actions that need full consciousness (driving, running heavy machinery, and performing sea activities i.e., diving or swimming). For driving, it depends on each state's laws, and physicians must report concerning these laws. However, the patient can retain these activities if proper treatment is achieved (pacemaker placement which can eliminate the cardioinhibitory CSH subtype, in this case, the patient can drive after one week of the pacemaker placement), for the vasodepressor subtype stabilizing the blood pressure might help in returning to the previous activities.[21]

CSH is a cause of syncope in the elderly. Physicians must approach syncope wisely. Ruling out life-threatening conditions first is a priority, after that, a monitored carotid massage is allowed (if not contraindicated), management of CSH is directed toward education about the condition and its consequences in the first place not ignoring the patients' activities requiring a full consciousness, treating the symptomatic patient helps continue daily life activities i.e., driving (after a symptom-free period post-management concerning each state's law and the case conditions). The interdisciplinary collaboration between the healthcare team to approach patients presenting with syncope and the highly skilled hands are needed at healthcare facilities to give suitable care because determining the etiology behind syncope helps in decreasing morbidity and mortality rates.