Evaluationof Syncope

Dr. Charles Nelson

November 14, 2014

Syncope: A Symptom, not a Diagnosis

• Self-limited loss of consciousness and postural tone

• Relatively rapid onset

• Variable warning symptoms

• Spontaneous, complete, and usually prompt recovery without medical or surgical intervention

Underlying mechanism: Underlying mechanism: transient global cerebral transient global cerebral

hypoperfusion.hypoperfusion.

Syncope Mimics

• Acute intoxication (e.g., alcohol)• Seizures• Sleep disorders• Somatization disorder (psychogenic pseudo-syncope)• Trauma/concussion• Hypoglycemia• Hyperventilation

Brignole M, et al. Europace, 2004;6:467-537.

Syncope: Epidemiological Data

• 40% population, presumed syncope at least once1

• 1-6% of hospital admissions2

• Approx 1% of ED visits per year3,4

• 10% of falls by elderly are believed due to syncope5

• Injuries:

• 6% major morbidity (e.g., fractures, MVA)1

• Minor injury in 29%1

1Kenny RA, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.2Kapoor W. Medicine. 1990;69:160-175.

3Brignole M, et al. Europace. 2003;5:293-298.4 Blanc J-J, et al. Eur Heart J. 2002;23:815-820.

5Campbell A, et al. Age and Ageing. 1981;10:264-270.

Syncope & Collapse: Emergency Department US Data 2006

• Emergency Department visits • Primary Diagnosis ~1.13 million• Among all listed diagnoses >1.35 million

• Hospital admission rate, ~36%

• Estimated hospital costs > $5400/hospitalization

• Treating ‘falls’ in older adults1 >$7 billion

Impact of Syncope in USA: Annual Expenditures

1. Benjamin C. Sun, MD, MPP, Jennifer A. Emond, MS, and Carlos A. Camargo, Jr., MD, DrPH “Direct medical costs of syncope-related hospitalizations in the USA Am J Cardiol 2005;95:668-671

2 Kenny RA, Kapoor WN. In: Benditt D, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.

Syncope & Collapse: Estimated Hospitalization Costs

Conservative estimates of annual cost:

• Syncope / Collapse - $2.4 billion

• Asthma - $2.8 billion

• HIV - $2.2 billion

• COPD - $1.9 billion

Causes of True Syncope

OrthostaticCardiac

Arrhythmia

StructuralCardio-

Pulmonary

1• VVS• CSS• Situational

CoughPost- micturition

2• Drug-Induced• ANS Failure

PrimarySecondary

3• Bradycardia

Sinus pause/arrestAV block

•TachycardiaVTSVT

• LongQT Synd

4 • Aortic

Stenosis• HCM• Pulmonary

Hypertension• Aortic

Dissection

Neurally-Mediated

Reflex

Unexplained Causes = Approximately 10%

60%60% 15%15% 10%10% 5%5%

Impact of Syncope on Mortality Risk

• Vasovagal Syncope has low mortality risk– But recurrences are a concern

• Syncope of presumed cardiac cause is associated with high mortality risk– Most evidence suggests that risk is

similar to that of patients without syncope but with similar severity of heart disease

Soteriades ES, Evans JC, Larson MG, et al. Incidence and prognosis of syncope. N Engl J Med. 2002;347(12):878-885. [Framingham Study Population]

Establish cause of syncope with sufficient certainty to:

• Assess prognosis confidently

• Initiate effective preventive treatment

Diagnostic Goal

• EEG, Head CT, Head MRI

carotid dopplers

• May help diagnose seizure

• Reasonable if syncope has

resulted in closed head

injury or if focal neuro

findings

Neurological Tests: Rarely Diagnostic for Syncope

Neurological Tests: Rarely Diagnostic for Syncope

Brignole M, et al. Europace. 2004;6:467-537.

Clinical Features Suggesting Cause of Syncope: ESC Syncope Task Force 2004

• Neurally-mediated Reflex Syncope– Absence of cardiac disease (except CSS)

– Long history of recurrences

– Associated with emotional event, pain, prolonged upright posture, hot

environment, head rotation

– After strenuous exertion

• Orthostatic Syncope– Associated with change to upright posture, prolonged standing, dehydration

– Recent addition of diuretic, vasodilator, etc

– History of neuropathy, diabetes, alcohol abuseCSS=carotid sinus syndrome

Neurally-Mediated Reflex Syncope (NMS)

• Vasovagal Syncope (VVS)• Carotid Sinus Syndrome (CSS)

• Situational Syncope– post-micturition– cough– swallow – defecation– blood drawing– etc.

NMS:Clinical Pathophysiology

• Neurally-mediated physiologic reflex mechanism with two

components:

– Cardioinhibitory ( HR )

– Vasodepressor ( BP )

• Both components are usually present:

– Vasodepressor may be masked in the presence of severe

bradycardia

– Pace or pre-treat with atropine in order to observe

Vasodepressor component

Orthostatic Intolerance Syndromes

Orthostatic Syncope

Orthostatic Syncope

POTSPOTS

VasovagalSyncope

VasovagalSyncopeOrthostatic

Intolerance

Orthostatic Hypotension- Etiology

• Drug-induced (very common)

– Diuretics, Vasodilators

• Primary autonomic failure

– Multiple system atrophy, Parkinsonism

• Secondary autonomic failure

– Diabetes, Alcohol, Amyloid

Clinical/ECG Features For Cardiac Syncope• Presence of severe structural heart disease

• Family history of sudden death

• Syncope during exertion or while supine

• Palpitations at time of syncope

• Heart failure / LV Dysfunction

• ECG / Monitor findings of:

– Baseline Wide QRS Complex

– Mobitz 1 second degree AVB

– Sinus bradycardia <50 bpm

– Documented Non Sustained or Sustained VT

– Preexcitation, Long QT, t wave inversion

– Bifasicular blockAdapted from ESC Syncope Guidelines– Update 2004

Syncope Due to Structural CV Disease

• Acute MI / Ischemia • Acquired coronary artery disease

– Congenital coronary artery anomalies• Hypertrophic Cardiomyopathy (HCM)• Arrhythmogenic RV Dysplasia (ARVD)• Acute aortic dissection• Acute pulmonary embolus/pulmonary hypertension• Valvular abnormalities

– Aortic stenosis– Mitral stenosis

• Atrial myxoma• Intra-cardiac thrombus (ball-valve thrombus)

Syncope Due to Cardiac Arrhythmias

• Bradyarrhythmias

– Sinus arrest, exit block

– High grade or acute complete AV block

• Tachyarrhythmias

– Atrial fibrillation/flutter with rapid ventricular rate (e.g., WPW syndrome)

– Paroxysmal SVT or VT

– Torsades de pointes (e.g., long QT syndrome)

The Initial Evaluation: 4 Key Questions

• Did the patient suffer ‘true’ Transient Loss of Consciousness (TLOC)?

• Was TLOC due to syncope or mimic?

• Is heart disease present?

• Does the medical history (including observations by witnesses) suggest a specific diagnosis?

Occasionally may need to be admitted

•No heart disease but sudden onset of palpitations shortly before syncope or high suspicion of cardiac syncope

•Other sig condition associated with though not cause of syncope

•Syncope in supine position,

•Frequent recurrent episodes, injuries

Hospital Admission for Diagnosis or Treatment

ESC Syncope Task Force 2004

Diagnostic Testing

• Exertional syncope or exertional symptoms: stress test

• Signs or symptoms CHF, murmurs: echo

• Palpitations or tachycardia preceeding event: holter or

event

• Abnormal ekg (heart block, bifasicular block): holter or

ILR

• Suspected (but uncertain) NMS: tilt test

• Pts that are orthostatic do not need tilt test

When do not need refer to specialist

• No need to refer when cause for syncope is certain,

and no evidence of significant heart disease.

• No need to refer if diagnosis is uncertain, but

episode did not result in significant injury and is not

recurrent.

When to refer to specialist

• When initial evaluation or testing indicates underlying significant

heart disease (abnormal ekg or echo)

• When need tilt testing to confirm cause of syncope

• When syncope is recurrent in spite of treatment for suspected

cause

• When cause is uncertain and syncope is recurrent

• Anytime you have a question that you cant answer or are not

sure how to proceed in evaluating the patient.

Feedback and Questions

Treatment Strategies for Orthostatic Intolerance• Patient education, injury avoidance

• Hydration

– fluids, salt, diet

– minimize caffeine/alcohol

• Sleeping with head of bed elevated

• Tilt Training, leg crossing, arm tensing

• Support hose, abdominal binders

• Drug therapies

– fludrocortisone, midodrine, erythropoietin