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Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
An 82-year-old male was found unresponsive by his son. EMS found the patient with a pulse of
70 and BP was 160/98. The patient had a history of HTN and HCTZ.
Upon his arrival at the Emergency Department, physical exam revealed a facial contusion and
that the patient is unable to move his left wrist. ECG indicated SR, LBBB, and PVCs. X-ray
confirmed a left wrist fracture. What are the next Rx. steps?
Key Learning Points:
1. Less than 50% of patients will have a clear etiology for a syncope spell.
2. While many causes of syncope are benign, potential life threats including cardiac causes
must be considered.
3. Risk stratification aids in disposition of patient can be effectively stratified based on age,
medical history, physical examination and ECG.
4. ACEP Clinical Policy on Syncope discusses workup, risk stratification and disposition.
5. When to admit:
a) History CHF, ventricular arrhythmias
b) Scenario consistent with ACS
c) Evidence of CHF or valvular heart disease
d) Abnormal ECG
6. Consider admission if:
a) Age > 60
b) Hx CAD, congenital heart disease
c) Family history of sudden death
d) Exertional syncope
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 2 of 9
Definition
♦ Transient loss of consciousness
♦ Loss of postural tone
♦ Spontaneous and full recovery
♦ Absence of prolonged confusion
Epidemiology1,2
♦ 6% of hospital admits
♦ Up to 3% of ED visits
♦ Experienced by 12-40% of young adults (less than 40)
♦ 6% annual incidence in those over 75 years old
Natural History
Mortality
Sudden Death
60
50
40
%
30
20
10
0
1
2
3
4
5
0
1
2
3
4
Year of follow-up
Cardiogenic
Undetermined
Noncardiac
Kapoor:
Kapoor: Medicine, 1990
Etiology of Syncope3
♦ Noncardiac Causes
Vasodepressor (vasovagal, neurocardiogenic) (10-29%)
Situational (e.g., micturition)
Psychogenic
Orthostatic (4-12%)
Drug induced (2-9%)
Carotid sinus sensitivity
Seizure (exclude by most syncope studies)
Neuralgias – trigeminal, glossopharyngeal
Neurologic – TIA, strokes, migraines (rare)
5
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 3 of 9
Cardiac Causes - Obstruction to flow (3-11%)
Subaortic stenosis
Aortic valve stenosis
Mitral valve stenosis
Myxoma (rare)
Pulmonic valve stenosis
Pulmonary emboli
Pulmonary hypertension
AMI
Pericardial tamponade
Aortic dissection
Cardiac Causes – Arrhythmias (5-30%)
♦ Tachyarrhythmias
Supraventricular tachycardia
Ventricular tachycardia
♦ Bradyarrhythmias
Atrial ventricular block
Sick sinus syndrome
Pacemaker malfunction
Age-Dependent Causes of Syncope – Mayo Clinic data4
Mayo Clinic: 1996-1998 (n=1,291)
≥65 years
n=684
<65 years
n=607
3%
10%
18%
17%
19%
24%
43%
23%
30%
13%
Cardiogenic
Vasovagal
CHS
Undetermined
Cardiac etiology becomes more frequent as the patient ages.
Other
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 4 of 9
Syncope In Children
♦ Syncope in children is generally a benign event.
♦ There are a few rare, but serious, causes of syncope in children. These include:
Hypertrophic cardiomyopathy
Anomalous origin of left coronary artery
Myocarditis
Long QT Syndrome
Cystic medial necrosis
Wolff-Parkinson-White Syndrome
♦ The only population-based study of syncope in children looked at 151 patients age 1-22 years
with syncope, with the following findings:
1987 to 1991
(n = 151)
Simple faint
Vasodepressor/vasovagal
Hysteria/psychogenic
Breathholding
Concurrent infectious disease
Possible epilepsy
Syncope
Orthostatic
Hyperventilation
Hypoglycemia
Unknown
Other
No.
%
44
61
3
6
3
3
6
2
1
3
6
22
29
40
2
4
2
2
4
1
1
2
4
15
Driscoll DJ, et al: J Am Coll Cardiol 29; 1997 5
Of these patients, one ultimately was found to have long QT Syndrome.
♦ Based on the above data and a number of case reports of sudden death:
Obtain a family history for sudden death/syncope
Beware of exercise-induced syncope in children
Consider obtaining an ECG even in pediatric patients with syncope
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 5 of 9
♦ Drug-Induced Syncope
Appears relatively common – felt to be responsible for 13% of 70 syncope cases referred
to Duke University’s Syncope Clinic.6
♦ Drug to be considered:
Beta-blockers
Nitrates
Calcium –channel blockers
Ace inhibitors
Phenothiazines
Antiarrhythmics
Diuretics
Digoxin
Insulin
Drugs of abuse
The Economic Burden of Syncope:7
♦ The overall cost per hospital admission was estimated to be about $5,300 in 1996
♦ One study found to be $17,000 of “unnecessary” testing to diagnose vasodepressor syncope
♦ Overall, cost in United States estimated to be in excess of $1 billion
Signs and Symptoms:
Seizure versus syncope
Though often not an issue, there are many cases when it is difficult to be sure whether a
“spell” was syncope or a seizure.
One study compared 41 seizure patients with 53 “non seizure” patients. They found the
following associations:8
Seizure
Frothing at mouth
Tongue biting
Disorientation (postictal)
Age < 45 years
LOC over 5 minutes
Not a Seizure
Sweating prior to episode
Nausea prior to episode
Orientated after event
Age > 45 years
In a separate study on tongue biting, this was found only in the seizure patients (99%
specifically), but it’s absence did not exclude the possibility of a seizure (24% sensitivity).9
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 6 of 9
Features of Major Causes of Syncope are Outlined Below:
Feature
Suggested Diagnosis
Postexertional on standing < 2 min.
Structural heart disease
Stress related
Vasodepressor
Situational
Micturition syncope
No prodrome
Cardiac – esp. arrhythmia
Congestive Heart Failure:
An ominous finding in syncope patients.
In a study of 491 patients with severe congestive heart failure, 12% had syncope over a one-year
period. Of those diagnosed with a cardiac etiology, 49% were dead within a year of the event.
Likewise, 39% of those with noncardiac syncope died within 12 months, compared to 12% of the
nonsyncope group.10
Orthostatic Hypotension
♦ Generally defined as a drop in blood pressure of > 20 mmHg on standing
♦ Beware! Orthostatic hypotension is present in about 40% of patients over 70 years old.
♦ Up to 23% of patients younger than 60 have orthostatic blood pressure drops.
♦ If you are able to reproduce the patient’s symptoms on standing, this is helpful (regardless of
the measurements).11
Diagnostic Testing
ECG
♦ The ECG will be diagnostic in 2-12% of syncope cases.2
♦ What to look for:12
VT (3 or more beats)
Sinus pulse (> 2 seconds)
Bradycardia – with symptoms
SVT with symptoms or hypotension
Atrial fibrillation – especially slow ventricular response
Second or third degree heart block
Pacemaker malfunction
Blood Work:
♦ Generally not helpful.
♦ One study found no abnormal lab findings other than those which would be readily identified
on physical exam (hypoglycemia, profound anemia).7
Testing beyond the ED:
♦ Holter monitor
Helpful in a small minority of patients.
In one series (of 1500 patients), 2% had an arrhythmia associated with near syncope
while wearing the monitor.13
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 7 of 9
♦ Tilt Table Testing
A test for autonomic instability.
A positive test indicates a predisposition for vasodepressor syncope.
Isoproterenol, a sympathomimetic can be used in low doses to increase the sensitivity
of the test.
Patients can have false positive results from 25-80% of the time.
♦ Electrophysiologic Studies (EPS)
An invasive procedure that involves meticulous mapping of the heart’s conduction
system, studies of conduction times, and can test the heart’s susceptibility to ventricular
arrhythmias.
EPS is abnormal in 18-68% of patients with syncope of unknown cause. However,
abnormal finding on EPS does not guarantee that that was what causes a patient’s
syncope!
The Dilemma of Syncope
♦ Who needs admission for inpatient testing?
♦ Who can be safely discharged for an outpatient workup?
The key may be shifting from searching to establish a diagnosis, which we will only find in 50%
of our ED patients at best12 to risk stratifying patients for likelihood of an adverse event.
Identify low-risk patients who need minimal testing and have a low likelihood of an
adverse event.
Identify high-risk patients in whom a more aggressive approach is indicated.
♦ Risk Stratification in Syncope12
Syncope Patients in ED
Derivation cohort N = 252
Validation cohort N = 374
Outcome arrhythmias and mortality at 1 year.
Factors Associated with Mortality
1) Abnormal ECG
2) Ventricular arrhythmias
3) Presence of CHF
4) Age over 45 years
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 8 of 9
Mortality at one year based on number of risk factors:
Risk Stratification Mortality at 1 Year
1.0
1.0
0.9
0.9
0.8
0.8
0.7
Derivation
cohort
0.6
Validation
0.5
cohort
0.7
0.6
0.5
0.4
0.4
0.3
0.3
0.2
0.2
0.1
0.1
0.0
0.0
0
1
2
3 to 4
Died within one year of syncopal episode
0
1
3 to 4
Strictly defined arrhythmias or died
of a cardiac cause in the 1st year
At 72º, zero patients with no risk factors had events.
At one year:
3 risk factors 57% mortality
4 risk factors 80% mortality
Management
ACEP Syncope Clinical Policy14
When to admit:
1)
History CHF, ventricular arrhythmias
2)
Scenario consistent with ACS
3)
Evidence of CHF or valvular heart disease
4)
Abnormal ECG
Consider admission if:
1)
Age > 60
2)
Hx CAD, congenital heart disease
3)
Family history of sudden death
4)
Exertional syncope
2
Syncope Update: Evaluation And Treatment
Wyatt Decker, MD, FACEP
Page 9 of 9
Reference List
1) Kapoor WN: Evaluation and outcome of patients with syncope. Medicine 1990;69:160-174.
2) Kapoor WN, Karpf M, Wieand S, et al: A prospective evaluation and follow-up of patients
with syncope. NEJM, July 1983;309(4):197-204.
3) Kapoor WN: Evaluation and management of the patient with syncope. JAMA
1992;268(18):2553-2560.
4) Jahangir A, Smars PA, Decker WW, et al: Differential clinical predictors of
bradyarrhythmia vs tachyarrhythmia in patients with cardiogenic syncope. [Abstract]
Circulation 100(18) Nov 2, 1999; I721-I722.
5) Driscoll DJ, Jacobsen SJ, Porter CJ, Wollan PC: Syncope in Children and Adolescents. J
Am Coll Cardiol 1997;29:1039-1045.
6) Hanlon JT, Linzer M, MacMillian JP, et al: Syncope and presyncope associated with
probable adverse drug reactions. Arch Int Med 150:2309-2312.
7) Eagle KA, Black HR: The impact of diagnostic tests in evaluating patients with syncope.
Yale J Biol Med 1983;56:1-8.
8) Hoefnagels WAJ, Padberg GW, Overweg J, et al: Transient loss of consciousness: the value
of the history for distinguishing seizure from syncope. J Neurol 1991;238:39-43.
9) Benbadis SR, Wolgamuth BR, Goren H, et al: Value of tongue biting in the diagnosis of
seizures. Arch Int Med 1995;155:2346-2349.
10) Middlekauff HR, Stevenson WG, Stevenson LW, Saxon LA: Syncope in advanced heart
failure: High risk of sudden death regardless of origin of syncope. J Am Coll Cadiol
1993;21:110-116.
11) Atkins D, Hanusa B, Sefcik T, Kapoor W: Syncope and orthostatic hypertension. Am J Med
1990;91:179-185.
12) Martin TP, Hanusa BH, Kapoor WN: Risk stratification of patients with syncope. Ann
Emerg Med 1997;29(4):459-466.
13) Gibson TC, Heitzman MR: Diagnostic efficacy of 24-hour electrocardiographic monitoring
for syncope. Am J Card, April 1984;53(8):1013-1017.
14) American College of Emergency Physicians. Clinical policy: critical issues in the
evaluation and management of patients presenting with syncope. Ann Emerg Med June
2001;37:771-76.