down for the count! the evaluation of syncope

Down for the Count!Down for the Count!The Evaluation of SyncopeThe Evaluation of Syncope

Wyatt W. Decker, M.D.

Department of Emergency Medicine

Mayo Clinic and Mayo Medical School

OUTLINE

• Case

• Epidemiology

• Signs and symptoms

• What data help to risk-stratify patients with syncope?

• Who should be admitted after a syncopal event?

Case Presentation

• 82-year-old male was found by son, unresponsive

• When ambulance arrived, his pulse was 70 and BP was 160/98

Case Presentation82-Year-Old Male

• History: HTN on HCTZ

• Exam: Facial contusion, unable to move (L) wrist

• ECG: SR, LBBB, PVCs

• X-ray: (L) wrist fracture


• What to do?

1) Holter as outpatient

2) Echo

3 ) Admit for EP studies

4) Admit for 23° monitoring


• Risk Stratification

1) High risk for an adverse event

2) Moderate risk

3) Low risk


• Question orthostatic blood pressure

1) Always check - very useful

2) Sometimes check - can be useful

3) Never check - is useless

SYNCOPE: Definition

• A transient loss of consciousness

• Spontaneous and full recovery

• Loss of postural tone

• No prolonged confusion

“Syncope and sudden death are the

same, except that in one you wake up”

- Anonymous

SYNCOPE: Epidemiology

• 6% hospital admits

• Up to 3% ED visits

• 12-40% of young adults

• 6% incidence in > 75 y/o

SYNCOPE: Natural History

Kapoor: Medicine, 1990Kapoor: Medicine, 1990

102030405060

0 1 2 3 4 5 0 1 2 3 4 5

Y ear of follow-up

%

CardiogenicUndeterminedNoncardiac

Mortality Sudden Death

SYNCOPE: Etiology - Noncardiac

• Vasodepressor (1-29%)• Situational (1-8%)• Seizure• Psychogenic• Orthostatic (4-12%)• Drug-induced (2-9%)• Carotid sinus• Neuralgia• Neurologic (TIA, stroke, migraine)

SYNCOPE: Drug Induced

• B-blocker• Nitrates• CCB• Ace I• Phenothiazines;

antidepressants• Antiarrhythmics

• Diuretics• Digoxin• Insulin• Drugs of abuse• EtoH

• N = 70; Syncope Clinic • 13% probable drug related

SYNCOPE: Etiology Cardiac

• Obstruction to flow (3-11%)

– HOCM, AS, MS, myxoma

– PS, PE, Pulm HTN– MI, tamponade, AD

• Arrhythmias (5-30%)

–Sick sinus, AV block, pacer

–VT, SVT

Age-Dependent Causes of Syncope

Mayo Clinic: 1996-1998 (n=1,291)<65 years<65 years

n=607n=60765 years65 years

n=684n=684

13%

43%

3%

17%

24%

30%23%

10%18%

19%

CardiogenicCardiogenic VasovagalVasovagal CHSCHS UndeterminedUndetermined OtherOther

SYNCOPE: Signs/Symptoms

• Age

–Those less than 45 tend to do well

–Those over 65 are higher risk

–Ages in between are incremental

–There is no age cutoffKapoor, et al: NEJM 309;1983


• SZ vs. syncope– N = 94– SZ = 41; No SZ = 53

• Logistic Regression Analysis– SZ Diagnosis

• Frothing• Tongue biting• Disoriented• < 45 y/o• LOC > 50 min

– Not a SZ• Sweating,

nausea prior and oriented after event• > 45 y/oHoefnagels, et al: J Neurology 238; 1991


• Tongue-biting–106 SZ patients vs. 45 syncope

patients

–Sensitivity 24%; specificity 99%•Based on 8 patients with

tongue-biting

Benbadis, et al: Arch Int Med 155;1995


Feature Diagnosis- Postexertional - Structural heart disease

- 2 minutes of standing

- Orthostatic

- No prodrome- Cardiac

- Stress-related - Vasovagal

- Situational - Micturition syncope


• CHF = poor outcome–N = 491; 12% with syncope–Cardiac syncope; 49% dead 1 year–Noncardiac syncope: 39% dead 1 year–No syncope; 12% dead 1 year

–Risk factor for poor outcome in multiple studies

Middlekauff, et al: JACC 21:1; 1993


• Generally defined as drop in systolic BP> 20 mmHg on standing

• Present in 40% patients > 70 years

• Present in up to 23% patients < 60

• Reproduction of symptoms may be useful

Proceed with

Caution!

Orthostatic hypotension

SYNCOPE: Diagnostic Testing

• ECG - diagnostic 2-12%

• Blood work - low yield, not helpful

• Only lab abnormalities found are those expected based on history/PE

• Holter monitoring

• Tilt table

• Electrophysiology studiesDay, et al: Am J Med 73;1982.

SYNCOPE: Evaluation - ECG

• What to look for:– VT (3 or more beats)

– Sinus pause (> 2 seconds)

– Bradycardia with symptoms

– SVT with symptoms or hypotension

– AF slow vent response

– 2° + 3° AV block

– Pacemaker malfunctionMartin, et al: Ann Emerg Med 29:4; 1997

Diagnostic Efficacy of 24 Hour Holter Monitoring for Syncope

1,512 patients1,512 patients

Syncope/presyncopeSyncope/presyncopeduring monitoringduring monitoring

(17%)(17%)

Arrhythmia withoutArrhythmia withoutsymptomssymptoms

(15%)(15%)

DocumentedDocumentedarrhythmia (2.1%)arrhythmia (2.1%) Gibson: AJC 53, 1984

Tilt Table Testing

Positive yield(pseudo Specificity Repro-

sensitivity (%) controls (%) duciblity (%)

Passive tilt 20-75 80-90 60-70

Isoproterenol 40-85 55-80 65-90

Results of Electrophysiologic Testing in Patients with Syncope

of Unknown CausePatient Abnormal

Reference (no.) EP (%)

Sra et al 86 34DiMarco et al 25 68Gulamhusein et al 34 18Hess et al 32 56Akhtar et al 30 53Olshansky et al 105 37

SYNCOPE: The Dilemma

• Diagnostic challenge– Initial H&P, ECG non-diagnostic

30-60% ED patientsDiagnostic Studies That Demonstrated the Cause of Syncope

n=204 Study % of Patients

History and physical 25.4Electrocardiography 5.8Electrocardiographic monitoring 14.2Electrophysiologic studies 1.4Cardiac catheterization 3.4Cerebral angiography 0.9Electroencephalopgraphy 0.1Unknown 48.1 Kapoor, et al: NEJM 1983;309:4

Discord in theEvaluation of Syncope

NeurologistNeurologist CardiologistCardiologist

SYNCOPE: The Dilemma

• Disposition Challenge

– Patients often asymptomatic in

ED

– Majority of causes benign

– Concern of sudden death

SYNCOPE: Risk Stratification

• 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 towards care is indicated

SYNCOPE: Risk Stratification

• Syncope patients in ED

– Derivation N = 252

– Validation N = 374

– Data: History, PE, ECG

– Outcome: Arrhythmias and mortality at 1 year

Martin, et al: Ann Emerg Med 29;1997

SYNCOPERisk Stratification Mortality at 1 Year

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 1 2 3 to 4

Derivationcohort

Validationcohort

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 1 2 3 to 4

Died within one year of syncopal episode Strictly defined arrhythmias or diedof a cardiac cause in the 1st year

SYNCOPE: Management

• Risk factors: > 45 years, ventricular arrhythmia, abnormal ECG, CHF

• Martin, et al

–72° cardiac mortality;0% with no risk factors

–1 year mortality 57% with 3

–1 year mortality 80% with 4

ACEP Clinical Policy: Syncope

1. What data help risk stratify?Level B:• Over 60 years = high risk• CHF = high risk• Under 45 years = low risk

Level C:• PE, c/w cardiac outflow obstruction =

high risk• Hx c/w vasodepressor etiology = low

risk

ACEP Clinical Policy: Syncope

Diagnostic testingLevel B: Obtain 12-lead ECG when

history, PE indeterminate

ACEP Clinical Policy:Who Should be Admitted

Level B: Admit patients with syncope and any of the following:

A history of CHF or ventricular arrhythmias

Associated chest pain or other symptoms compatible with acute coronary syndrome

Evidence of significant CHF or valvular heat disease on PE

ECG findings of ischemia, arrhythmia, prolonged QT interval, or bundle branch block

ACEP Clinical Policy:Admission

Level C: Consider admission for patients with syncope and any of the following:

Age older than 60 years

History of coronary artery disease or congenital heart disease

Family history of unexpected sudden death

Exertional syncope in younger patinets without an obvious benign etiology for the syncope

Syncope: Summary

• Etiology is often unclear

• Risk stratification is key

• Admit high risk patients

–Intermediate risk?

• Low risk: Send out

down for the count! the evaluation of syncope

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