Syncope

What we will discuss? Background information Evaluation of syncope Treatment of certain causes of syncope Useful, practical items

Definition Sudden and brief loss of consciousness Associated with loss of postural tone Recovery is spontaneous A symptom and not a disease

Scope of the problem Occurs in 3-37% of general population 6% annual incidence amongst elderly residents of long-term care institutions 3.5% of all ER visits 1-6% of all hospital admissions

Is it syncope? Presyncope Dizziness Vertigo Drop attacks Seizures Cardiac arrest

Pathophysiology Sudden decrease in or brief cessation of cerebral blood flow and nutrient delivery (seen in all forms) Mechanisms: - Decrease in cardiac output, including loss of preload, mechanical outflow obstruction, and arrhythmias - Loss of vascular resistance, often by neurocardiogenic reflex mechanisms - Focal or generalized decrease in cerebral perfusion caused by cerebrovascular disease - Causes in which cerebral blood flow is essentially normal, such as hypoglycemia, hypoxia, and seizures

Neurocardiogenic reflex mechanisms

Causes of Syncope

More causes of syncope

Causes of Syncope Kapoor, W. N. N Engl J Med 2000;343:1856-1862

Diagnosing the cause History is key Presence of structural heart disease Physical exam EKG The findings from this initial assessment will guide your evaluation.

Historical aspects Number of episodes Associated symptoms/Prodrome Preceding events Witnessed appearance Recovery or postevent period PMHx/Family hx/Medications

More on history Number of episodes - Single episode or multiple episodes over many years vs. multiple episodes over a short period time Associated symptoms/Prodrome - Dyspnea, angina, focal neurologic abnormalities - Nausea, warmth, pallor, lightheadedness, diaphoresis Preceding events - Coughing, eating, drinking cold liquid, urinating, defecating, exertion Recovery or postevent period - Persistence of nausea, pallor, diaphoresis - Significant neurologic changes or confusion

Other historical features Age - Young vs. elderly Position - Supine vs. standing Duration of symptoms - Brief vs. prolonged Injury - Tongue biting - Important to determine if syncope places individuals or others at risk

Preexisting medical conditions Psychiatric illness Diabetes mellitus - Orthostatic hypotension secondary to autonomic neuropathy HTN - Antihypertensive medications can result in syncope Presence of heart disease

Importance of heart disease Only independent predictor of cardiac cause of syncope (sensitivity 95%, specificity 45%) Most important factor for predicting risk of death and likelihood of arrhythmias Increased risk of death regardless of the cause of syncope

Obtaining information from Cardiology Can page EKG tech (800-308-5890) Make copies of old EKG’s, echo reports, cath reports, clinic SF600’s (before CHCS-II) If you are in the Cardiology clinic, can obtain this information from front desk area, record/storage room (code to door is 7843)

Physical examination Vital signs Heart rate, Orthostatics, RR Cardiac exam Systolic murmurs and physiologic maneuvers Neuro exam Focal signs, mental status Carotid sinus massage

Carotid sinus massage Each carotid palpated and auscultated for presence of bruits (test not performed in those with evidence of carotid artery disease) Pressure applied to one carotid sinus for 2-3 secs with vigorous/circular movements Done with simultaneous EKG monitoring Positive test if there is pause for > 3 secs Use cautiously in elderly patients

EKG findings Sinus bradycardia AV nodal disease (2nd or 3rd degree heart block) Bundle branch and/or fascicular block Prolonged QT interval Presence of EKG findings does not prove causality unless findings are captured during actual event/symptoms.

Other EKG findings

Prolonged QT syndrome www.torsades.org

Diagnostic Tests Basic laboratory tests - Leads to specific cause in 2-3% of patients Echocardiogram Stress testing Ambulatory monitoring or continuous-loop event monitor Electrophysiologic studies Tilt table testing Neurologic testing Psychiatric evaluation

Echocardiogram May diagnose underlying structural heart disease (LV dysfunction, hypertrophic cardiomyopathy, significant aortic stenosis)

Stress testing Frequently obtained in patients with cardiac disease Useful in patients with exertion-related syncope or exercise-induced arrhythmias

Testing for arrhythmias Symptoms occurring with arrhythmias occur in 4% of patients in studies using Holter monitoring. Event recorders require the patient to activate the unit to have the rhythm stored at the time of symptoms. Intermittent loop recorders can store several minutes of recording if the unit has the ability. Event recorders and Holter monitors can be ordered via CHCS

Ordering monitoring devices Ordered in CHCS Under consult procedure to cardiology - Holter or event monitor Specify in consult amount of time for event monitor (# of weeks) Make sure you have a correct address on patient because event monitor is mailed to them.

Implantable loop recorders Placed in subcutaneous pocket, usually in left pectoral region Can store about 45 minutes of retrospective electrocardiographic recording Can record automatically or be activated by the patient after an event Usually reserved for recurrent syncope in whom diagnosis remains uncertain Diagnostic yield between 25-40% during a period 8-10 months

Monitoring devices

Electrophysiologic studies Yield depends on whether there is structural heart disease or abnormal findings on EKG Among patients with heart disease, ~ 21% have inducible ventricular tachycardia and 34% have bradycardia (14% with multiple diagnoses) In patients with abnormal EKG’s, ~ 3% have inducible ventricular tachycardia and 19% have bradycardia Poor sensitivy/specificity for bradyarrhythmias

Tilt table testing Used for diagnosis of neurocardiogenic or vasovagal syncope Positive test is one where a hypotensive episode is provoked that reproduces a patient’s symptoms Specificity of negative test on passive tilt at angles between 60-70 degrees is close to 90% Sensitivity of test is uncertain because of no gold standard

Tilt table test protocol Variety of protocols have been described Angle of tilt (60-90 degrees) Duration of tilt (10-60 minutes) Patient monitored in supine position for five minutes, then placed in head-up tilt position Second tilt can be performed with isoproterenol infusion if patient asymptomatic during first tilt (nitrates are another agent used) Carotid massage can be performed with test

Indications for Tilt-Table Testing Indications for Tilt-Table Testing Grubb, B. P. N Engl J Med 2005;352:1004-1010 Grubb, B. P. N Engl J Med 2005;352:1004-1010

Demonstration of the Use of a Tilt Table Grubb, B. P. N Engl J Med 2005;352:1004-1010

Neurologic testing EEG Head CT scan MRI Carotid doppler ultrasound - May be helpful to rule out seizures/epilepsy - Provides diagnostic information in < 2% of cases of syncope Head CT scan MRI Carotid doppler ultrasound CT angiography

Psychiatric evaluation Generalized anxiety disorder, panic disorder, and major depression may cause syncope by predisposing patients to neurally mediated reactions. Fainting is a known manifestation of somatization disorder. Alcohol and drug dependence/abuse may also lead to syncope.

Useful hints on the wards Fall precautions - Protocol: yellow armband, bed alarm, side rails up, offer toileting q2 while awake/qhs/qAM, frequent reorientation PRN Seizure precautions Telemetry monitoring - Speak to in person or call using hotline phones to telemetry tech for any events - Also a telemetry chart that you can look at

Treatment Neurocardiogenic - Avoidance of predisposing factors - Patient should be instructed to lie down at onset of prodromal symptoms - Isometric contractions of arm and leg muscles, intense hand gripping - Increased fluid and salt intake - Tilt training (standing for 10-30 minutes each day against a wall) - Pharmacologic agents (beta-blockers, fludrocortisone, midodrine, SSRI’s) - Permanent cardiac pacing

Treatment Orthostatic hypotension - Volume replacement in those with intravascular volume depletion - Discontinuing or reducing doses of drugs - In cases of autonomic failure, increasing intake of salt and fluid, use of waist-high support stockings and abdominal binders - Fludrocortisone or midodrine

Treatment Neurologic causes - Antiseizure medications for seizure disorder - Surgical intervention for severe carotid artery disease Psychiatric causes - Psychiatric referral - Medications (antidepressive, anxiolytic)

Treatment for cardiac causes Ventricular arrhythmias - Antiarrhythmic therapy, ICD placement, radiofrequency ablation, electrophysiologic guided surgery Bradycardia due to conduction abnormalities - Pacemaker placement (sinus node dysfunction, high grade AV block,) Severe aortic stenosis - Aortic valve replacment Hypertrophic cardiomyopathy - Beta blockers or CCB’s, RV pacing, myomectomy, mitral valve replacment

Pacemakers/ICD                                                               

References Kapoor W. N. Primary Care: Syncope. N Engl J Med 2000; 343:1856 1862, Dec 21, 2000. Grubb B. P. Neurocardiogenic Syncope. N Engl J Med 2005; 352:1004-1010, Mar 10, 2005. Olshansky B. Evaluation of the patient with syncope. UpToDate 2005. Olshansky B. Pathogenesis and etiology of syncope. UpToDate 2005. Olshansky B. Mangement of the patient with syncope. UpToDate 2005. MedStudy

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