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Chapter 29 • Sore Throat 361
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Auscultate the Lungs
Mycoplasma pneumoniae is frequently associated with
sore throat in adolescents and young adults. If pneumonia is present, palpation, percussion, and auscultation of
the lungs reveal an area of consolidation and adventitious breath sounds (see Chapter 13 for further discussion of the lung examination).
Palpate the Abdomen
Splenomegaly is found in about half the cases of
mononucleosis, although hepatomegaly is rare. GERD
may be associated with palpable upper epigastric
tenderness.
LABORATORY AND DIAGNOSTIC STUDIES
The laboratory evaluation of sore throat is generally limited to the identication of GABHS. Other infectious
causes, such as gonorrhea or diphtheria, are rare, and
testing is conducted only if the history indicates exposure. It is important to diagnose streptococcal pharyngitis
so it can be treated promptly with antibiotics, avoiding
serious sequelae, such as peritonsillar abscesses or rheumatic fever.
Rapid Screening Tests
A throat swab is a rapid screen for streptococcal antigens and should be done if GABHS is suspected. If it
is positive, the patient is treated without follow-up
cultures. If the swab is negative, a throat culture is
obtained. The test has a sensitivity of 75% to 85% and
a specicity of 95% to 98%.
The Monospot is a rapid slide test that detects heterophil antibody agglutination; it is not specic for
EBV. It is most sensitive 1 to 2 weeks after symptoms
appear and remains positive for up to 1 year. If chronic
fatigue syndrome is being considered as a differential
diagnosis, specic EBV antibody tests should be
considered.
Antistreptolysin O Titer
GABHS produces enzymes that include streptolysin.
An ASO titer is a serological test that detects the
presence of a previous streptococcal infection. This
titer does not increase until 1 to 6 months postinfection, so it is of no diagnostic value. It is used to
aid in the diagnosis of streptococci-associated infections, such as rheumatic fever, glomerulonephritis,
and pericarditis. A caution, however, is that in as
many as 50% of positive streptococcal cultures,
an elevated ASO titer postinfection will not be
found.
Potassium Hydroxide Smear for Wet Mount
Obtain a sample of pharyngeal discharge using a
cotton-tipped applicator. Look under the microscope
at the KOH slide for the presence of branching and
budding hyphae that are characteristic of yeast infection (see Chapter 34).
Complete Blood Count with Differential
Test results that show 50% lymphocytes and at least
10% atypical lymphocytes conrm the diagnosis of
mononucleosis.
Computed Tomography Scan
Suspicion of an obstruction or swelling of the throat
should be referred for further radiographic evaluation
with a computed tomography scan.
Nasal Smear
Nasal cytology can be performed on nasal secretions
obtained by having the patient blow the nose into a
paper or by using a cotton-tipped swab to obtain secretions from the nose. The presence of eosinophils on a
nasal smear stained with Wright’s stain viewed under a
high-power microscope suggests an allergic, inammatory process.
Culture
A throat culture to detect GABHS is the gold standard
of diagnosis, with a 10% or lower false-negative rate.
When obtaining a culture, rst remove crusts from
lesions, taking care to touch only the throat or tonsils
with the sterile swab. Avoid touching the tongue. Roll
the throat swab over one tonsil, proceed across the
posterior pharynx, and then swab the other tonsil. A
culture for gonorrhea can conrm a diagnosis of gonococcal pharyngitis.
DIFFERENTIAL DIAGNOSIS
Pharyngitis Without Ulcers
Epiglottitis
Epiglottitis is caused by infection with H. inuenzae
type b that produces inammation and edema of the
epiglottis and the surrounding areas, obstructing the
ow of air. The edematous epiglottis may be pulled
into the larynx during inspiration and can completely
occlude the airway. Symptoms are respiratory distress,
sore throat, difculty with secretions, drooling, pain
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on swallowing, and a toxic appearance. The infection
occurs in both children and adults.
Peritonsillar/Retropharyngeal Abscess
A peritonsillar abscess, also called quinsy, is a collection of pus between the tonsil and the capsule of the
tonsillar pillar. This condition occurs in children but
is more common in adults, especially in persons with
a history of recurrent tonsillitis. The patient’s presenting symptoms usually include a history of respiratory
symptoms, difculty swallowing, otalgia, malaise,
fever, and cervical lymphadenopathy. On examination, there may be trismus; asymmetrical swelling of
the uvula, tonsils, or posterior pharynx; or a visible
abscess. Children’s presenting symptoms typically
include fever, toxic appearance, refusal to swallow,
drooling, and stridor. Children with retropharyngeal
abscess are usually under the age of 4 and need
immediate referral.
Viral Pharyngitis
Most sore throats are caused by viral infections.
Patients usually have symptoms of malaise, fever,
headache, cough, and fatigue. The pharynx is usually
erythematous, or it may be pale, boggy, and swollen.
There usually is no tonsillar or pharyngeal exudate or
tonsillar enlargement present, although infection with
an adenovirus may produce pharyngeal exudate. The
presence of concomitant upper respiratory tract symptoms such as cough and congestion makes the diagnosis of viral pharyngitis more likely than that of streptococcal pharyngitis. Common cold viruses cause
sore throats most frequently during the colder months
of the year.
Streptococcal Pharyngitis
The major differential diagnoses for sore throat will be
viral or bacterial infection. Fewer than 10% of adults
and 30% of children who seek care for sore throat
symptoms have streptococcal tonsillopharyngitis.
However, reliance on clinical impression to arrive at a
specic diagnosis is problematic. The symptoms most
likely to occur with streptococcal pharyngitis include a
fever with a temperature of 38.5° C (101.5° F) or
higher, tonsillar exudate, anterior cervical adenopathy,
and a history of recent exposure. The incidence of
streptococcal pharyngitis increases from 10% in the
summer and fall to 40% during the winter and early
spring. GABHS cannot be reliably diagnosed on the
basis of signs and symptoms, and even when cultures
are obtained, a causative agent may not be identied in
50% of patients. Table 29-2 shows the groups at risk
for GABHS.
Mononucleosis
Mononucleosis causes about 5% of sore throats. It is
most often a disease of young adults, and the causative
agent is EBV in more than 90% of cases. History
reveals a gradual onset, low-grade fever; mild sore
throat; posterior cervical lymphadenopathy; and pronounced malaise and fatigue. Diagnosis can be conrmed with a positive Monospot test and a complete
Table 29-2
Groups at Risk for Group A
ß-Hemolytic Streptococcus
(GABHS) Pharyngitis
RISK FACTORS DIAGNOSTIC TESTS
High Risk
Tonsillar exudate
Temperature .38.5º C
(101.5º F)
Cervical
lymphadenopathy
Existing valvular rheu-
matic heart disease
Presumed Strep
Scarlet fever None; treat
Strep epidemic
Antibiotics already
started
Medium Risk
Exudate, nodes, or fever
present
Prior rheumatic fever
“Low risk” by PE but
,25 years old and no
URI
Person with diabetes
Recent “strep” exposure
Low Risk
No exudate, nodes,
or fever
PE, physical examination; URI, upper respiratory tract infection.
None; treat on basis of risk
factors
Rapid strep screen; if
positive, treat; if negative,
do culture; treat if culture
positive; do not treat if
culture negative
Rapid strep screen; if posi-
tive, treat; if negative, do
not culture; do not treat if
culture negative
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blood count that shows greater than 50% lymphocytosis. Splenomegaly occurs in about 50% of cases, and
palatine petechiae are a less common symptom.
GABHS occurs concomitantly in 10% to 20% of cases.
Gonococcal Pharyngitis
This form of pharyngitis can occur in patients with a
history of orogenital sexual activity. The patient may
have no symptoms. Examination shows an exudative
pharyngitis with bilateral cervical lymphadenopathy.
Diagnosis is conrmed through Gram staining or
culture.
Inflammation
Inammatory sore throat occurs in the presence of
sinusitis or exposure to local irritants. The patient often
reports a postnasal drip and allergic symptoms (itchy,
watery eyes; runny nose) that may follow seasonal patterns. On examination, the patient may have sinus
tenderness. The pharynx may be swollen or pale with
posterior drainage present. The patient has no fever or
lymphadenopathy.
Pharyngitis with Ulcers
Herpangina
Herpangina is an infection caused by the coxsackievirus. The patient reports a painful sore throat, fever, and
malaise. Headache; anorexia; and neck, abdomen, and
extremity pain may occur. Within 2 days of onset,
small, grayish, papulovesicular lesions appear on the
soft palate and pharynx. These progress to shallow
ulcers, usually less than 5 mm in diameter. Outbreaks
occur during the summer months. Coxsackievirus
peaks in August, September, and October, although
some cases occur during the winter months. It is
more common in children and in immunosuppressed
patients. Diagnosis is based on symptoms and characteristic oral lesions. An antibody titer can conrm
diagnosis.
Vincent Angina
Vincent angina is caused by a fusospirochetal infec-
tion that results in necrotizing ulcerative gingivosto-
matitis. The patient’s symptoms include painful
ulcers, foul breath, and bleeding gums. Without sec-
ondary infection, there usually is no fever. On exami-
nation, gray, necrotic ulcers without vesicles are
apparent on the gingivae and interdental papillae.
Gram staining shows spirochetes and conrms the
diagnosis.
Aphthous Stomatitis
Aphthous stomatitis, or “canker sores,” appears as dis-
crete ulcers without preceding vesicles. The ulcers are
located on the inner lip, tongue, and buccal mucosa.
Lesions last about 1 to 2 weeks. The cause of the
lesions is unknown, but immunological mechanisms
play a major role.
Herpes Simplex Virus Type 1
An infection from herpes simplex virus type 1 (HSV-1)
is associated with fever, headache, sore throat, and
lymphadenitis. Characteristic clusters of yellow vesi-
cles appear on the palate, pharynx, and gingiva. Lesions
last 2 to 3 weeks. Recurrent lesions are characterized by
prodromal symptoms of burning, tingling, or itching.
Active lesions are usually painful. Recent studies indi-
cate that infections afict about 30% to 90% of the
U.S. population.
Candidiasis
Candidiasis is a yeast infection that produces white
plaques over the tongue and oral mucosa with ery-
thema; the plaques bleed when scraped. Candida
infection occurs commonly in otherwise normal
infants in the rst weeks of life; in immunocom-
promised persons, including those with diabetes;
and in persons taking antibiotics or using inhaled
steroids.
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DIFFERENTIAL DIAGNOSIS OF Common Causes of Sore Throat
CONDITION HISTORY PHYSICAL FINDINGS DIAGNOSTIC STUDIES
Pharyngitis Without Ulcers
Epiglottitis Sore throat, difficulty with
secretions, odynophagia
(seen in pediatric patients
,2 years), unable to lie flat,
unable to talk
Peritonsillar/
retropharyngeal
abscess
Viral pharyngitis Scratchy, sore throat, malaise,
Group A
ß-hemolytic
streptococcal
pharyngitis
Mononucleosis
(Epstein-Barr
virus)
Gonococcal
pharyngitis
Inflammation Exposure to irritants; postnasal
Pharyngitis with Ulcers
Herpangina
(coxsackievirus)
Fusospirochetal
infection
(Vincent angina)
Aphthous stomatitis Oral trauma, ill-fitting dentures;
History of recurrent
tonsillitis; sore throat,
difficulty swallowing,
respiratory tract symptoms,
fever, malaise
myalgias, headache, chills,
cough, rhinitis
Most common in persons
5-15 years; known exposure;
fall/winter season; sudden
onset of fever, severe sore
throat, and malaise; absence
of cough and upper
respiratory tract symptoms
Young adults; slow onset of
malaise, low-grade fever, mild
sore throat
History of orogenital sexual
activity; may be
asymptomatic
drip; allergic symptoms
More common in children;
immunosuppressed; painful
throat; fever, malaise
Poor oral hygiene; painful
ulcers, foul breath, bleeding
gums
painful ulcers vary in size;
absence of other symptoms
Respiratory distress, drooling,
toxic appearance; DO NOT
EXAMINE PHARYNX
Orthopnea, dyspnea, sym-
metrical swelling, abscess,
trismus
Erythema, edema of throat,
tender posterior cervical
nodes
Temperature .38.5º C
(101.5º F); exudate; anterior
cervical lymphadenopathy
Presence/absence of
pharyngeal exudate,
palatine petechiae, posterior
cervical lymphadenopathy,
splenomegaly
Pharyngeal exudate; bilateral
cervical lymphadenopathy
Sinus tenderness, pale or
swollen pharynx, postnasal
drainage visible, no fever or
lymphadenopathy
Lymphadenopathy; small
grayish papulovesicular
lesions on soft palate and
pharynx, progressing to
shallow ulcers, usually
,5 mm in diameter
Gray necrotic ulcers without
vesicles on gingival margins
and interdental papillae
Shallow ulcers, no vesicles;
indurated papules that
progress to 1-cm ulcers;
ulcer has yellow membrane
and red halo; no fever or
nodes
Refer immediately
Refer immediately: CT
scan; head and neck
radiographs;
laryngoscopy
None
Positive rapid strep
antibody screen; strep
culture
Positive Monospot;
CBC with differential;
.50% leukocytes
Gram stain; gonorrhea
culture
Eosinophils in nasal se-
cretions with allergies
Serology
Gram stain reveals
spirochetes
None
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DIFFERENTIAL DIAGNOSIS OF Common Causes of Sore Throat—cont’d
CONDITION HISTORY PHYSICAL FINDINGS DIAGNOSTIC STUDIES
Herpes simplex
infection
Candidiasis Immunosuppressed; persons
CBC, complete blood count; CT, computed tomography; KOH, potassium hydroxide.
History of trauma to mucosa;
pain, fever, headache
taking antibiotics or with
diabetes; sore mouth/throat
Perioral lesions;
lymphadenitis; vesicles on
palate, pharynx, gingiva
Curdlike white plaques that
bleed when scraped off
Viral culture
KOH smear shows
hyphae; culture
REFERENCES AND READINGS
Coby BA: Diagnosis and treatment of streptococcal pharyngitis,
Am Fam Physician 79:383, 2009.
Darrow DH, Siemens C: Indications for tonsillectomy and adenoid-
ectomy, Laryngoscope 112:8, 2002.
Ebell MH, Smith MA, Barry HC, Ives K, Carey M: The rational
clinical examination: does this patient have strep throat? JAMA
284:2912, 2000.
Gerber M: Diagnosis and treatment of pharyngitis in children, Pediatr
Clin North Am 52:729, 2005.
Linder JA: Evaluation and management of adult pharyngitis, Compr
Ther 34:196, 2008.
McPhee SJ, Papadakis MA: Current medical diagnosis and treatment,
ed 49, New York, 2010, McGraw-Hill.
Richardson MA: Sore throat, tonsillitis, and adenoiditis, Med Clin
North Am 83:75, 1999.
Stevens D: A sore throat or something else? Pract Nurs 19:83, 2008.
Vincent MT, Celstin N, Hussain AN: Pharyngitis, Am Fam Physician
69:1465, 2004.
C H A P T E R
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30
Syncope
yncope is the transient loss of consciousness and
postural tone that results from a sudden decrease
S
in cerebral perfusion. It is distinct from a coma,
seizures, shock, vertigo, and other states of altered consciousness. It is a symptom that about 10% of adults of
any age will experience at least some time during their
lives and the incidence exponentially increases in
people over 70 years old. It is less common in children,
except when there is a seizure disorder, primary cardiac
arrhythmia, or a breath-holding incident.
The causes of syncope can be difcult to determine
because patients generally are seen after the event has
occurred. Syncope can be quite benign, such as a vasovagal response, or it can indicate serious disease.
However, even benign syncope can place the patient at
risk for falls or injury. Cardiogenic syncope has high
associated morbidity and mortality, and the emphasis
in diagnosis is to rule out the most serious causes
through a careful history and physical examination,
with a few laboratory and diagnostic tests to establish
a possible diagnosis. The Evidence-Based Practice
box describes an evidence-based approach to the diagnosis of syncope.
EVIDENCE-BASED PRACTICE
Diagnosing Syncope
DIAGNOSTIC REASONING:
FOCUSED HISTORY
Is this really syncope?
Key Questions
n Did you lose consciousness?
n Did you have any prodromal symptoms?
n What were you doing when the event occurred?
n If you lost consciousness, how long did it last?
n Did your limbs jerk during the event?
n Did anyone see you faint?
Loss of Consciousness
Distinguish syncope from other symptoms. Dizziness,
vertigo, and presyncope do not cause loss of consciousness or postural tone.
Prodromal Symptoms
Sweating, vertigo, nausea, and/or yawning are prodromal
symptoms that are associated with syncope; seizures may
be associated with an aura or tongue biting. Aura also
suggests migraine etiology.
Syncope is a common symptom with no diagnostic gold standard and a range of prognoses. The authors of this guideline
undertook an extensive review of the literature to help clinicians maximize the diagnostic yield in the workup of syncope
and here report the following key points that assist in the
evaluation of syncope:
1. History, physical examination, and electrocardiography
(ECG) are the core of syncope workup (combined diagnostic yield, 50%).
2. Neurological testing is rarely helpful unless additional neu-
rological signs or symptoms are present (diagnostic yield
of EEG, CT, and Doppler ultrasound, 2% to 6%).
3. Patients in whom heart disease is known or suspected
and those with exertional syncope who are at higher risk
Data from Linzer M, Yang EH, Estes NA III, Wang P, Vorperian VR, Kapoor WN: Diagnosing syncope. Part 1: Value of history, physical examination,
and electrocardiography. Clinical Efficacy Assessment Project of the American College of Physicians, Ann Intern Med 126:989-996, 1997.
366
for adverse outcomes should have cardiac testing,
including echocardiography, stress testing, Holter monitoring, or EPS, alone or in combination (diagnostic yield,
5% to 35%).
4. Syncope in the elderly often results from polypharmacy
and abnormal physiological responses to daily events.
5. Long-term loop electrocardiography (diagnostic yield,
25% to 35%) and tilt-table testing (diagnostic yield,
#60%) are most useful in patients with recurrent syncope
in whom heart disease is not suspected.
6. Psychiatric evaluation can detect mental disorders associated with syncope in up to 25% of cases.
7. Hospitalization may be indicated for patients at high risk
for cardiac syncope or with acute neurological signs.
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Pre-event Characteristics
Characterize what precipitated the episodes. Loss of
consciousness precipitated by pain, exercise, urination,
defecation, or stressful events is probably not a seizure.
Breath-holding spells are common in children, causing
syncope. They are usually precipitated by pain, anger,
a sudden startle, or frustration. Syncope occurs with
rest or when supine during a seizure or arrhythmia.
Syncope that occurs without warning is considered
cardiovascular in origin.
Event and Postevent Characteristics
Rhythmic movements of extremities during the event
usually indicate a seizure, although they can occur
with syncope. Disorientation after the event, slowness in returning to consciousness, and unconsciousness lasting longer than 5 minutes indicate seizure.
Often children with breath-holding spells have associated cyanosis, clonic jerks, opisthotonos, and
bradycardia.
Witness
The patient is unconscious when the syncopal event
takes place and therefore is a poor historian. A careful
history is needed from both the patient and a witness to
help in the diagnosis. Adolescents who have hysterical
syncope episodes generally have an audience when the
event occurs and are able to describe details of the
event that would not be known to an unconscious
patient.
Does this require immediate referral?
Key Questions
n Do you have a history of heart disease? What is it?
n Do you have a congenital heart problem?
n Are you having chest pain and/or shortness of
breath?
n Did this occur after exercise?
History of Heart Disease/Congenital
Heart Problem
The presence of structural heart disease increases the
risk of sudden death. Patients with a history of coronary artery disease, congestive heart failure, or ventricular arrhythmia should be hospitalized. Cardiac
syncope may be either arrhythmic or mechanical in
origin. Cardiac outow obstruction from aortic or
mitral stenosis or a prosthetic valve may cause
syncope. Complete heart block is a leading cause of
syncope, the result of interruption of atrioventricular
conduction. Children who have had cardiac surgery
to correct severe congenital heart disease are at risk
for arrhythmias.
Chest Pain or Shortness of Breath
Obstructive mechanical blockage may be caused by
pulmonary embolism, cardiac ischemia, or myocardial
infarction with pump failure.
After Exercise
Syncope that accompanies exercise should be considered of cardiac origin unless proved otherwise. Syncope after exertion in a well-trained athlete who has no
heart disease is likely vasovagal in origin.
What do associated symptoms tell me?
Key Questions
n What other symptoms did you have?
n Do you have palpitations?
n Do you have headaches?
n Have you experienced vertigo, dizziness, or visual
changes?
Palpitations
Supraventricular or ventricular tachycardias are associated with syncope and sudden death. Ventricular tachycardia with a heart rate of 200 beats per minute may be
asymptomatic or cause syncope. Chaotic ventricular
activity of ventricular brillation is always fatal unless it
is reversed with electrical debrillation. (See Chapter 23
for more on palpitations.)
Headaches
The pain of migraine headaches and the effect of the
migraine on the brainstem can cause syncope. Generally the patient has associated symptoms, such as
vomiting, photophobia, severe headache (often on
one side), and a strong family history of migraines.
The headache continues after consciousness is
regained.
Vertigo, Dizziness, and Visual Symptoms
The presence of vertigo, dizziness, diplopia, or other
visual changes may accompany migraine headache.
Interruption in cerebral perfusion, such as with a transient ischemic attack, also must be considered.
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Is this neurocardiogenic in origin?
Key Questions
n Did this occur in response to a specic situation
(e.g., stressful event, urination, defecation)?
n Were you sitting, standing, or lying at when you
fainted?
n Do you have a history of any heart problems?
medications, and recreational drugs (e.g., alcohol, cocaine) that produce orthostasis, bradycardia, or prolonged QT interval. Adolescents may use drugs, such
as amyl nitrite and butyl nitrite, as aphrodisiacs and
euphoriants. These drugs lead to vasodilation, and syncope may occur.
Children may ingest medications that belong to
family members, and a history of such activity must be
investigated as a cause of the syncope.
Situational Fainting
Vasovagal syncope is the most common type seen in
adults and healthy children. It is neurocardiogenic and
tends to occur in families. It is often precipitated by
emotional stress, fear, extreme fatigue, or injury. It can
occur without any obvious antecedent cause. Warm
temperature, anxiety, blood drawing, and crowded
rooms may cause peripheral vasodilation. Lack of
large muscle activity prevents the venous return that is
needed for cardiac lling with consequent bradycardia
and fainting. When supine, venous return to the heart
occurs, awakening the patient. Rapid standing will
cause recurrence of the episode. Mental alertness is
present.
Situational syncope can occur in response to urination, defecation, cough, or emotional stress. Posttussive
syncope follows paroxysmal coughing caused by increased intrathoracic pressure, which is then transmitted
to the intracranial circulation, increasing intracranial
pressure and decreasing cerebral blood ow. Postmicturition syncope, occurring during or after urination, is
caused by the release of intravascular pressure on urination, which triggers vasodilation and vagally mediated
bradycardia.
Is this orthostasis?
Other Health Problems or Conditions
Diabetes may induce hypoglycemia, causing a gradual syncope. Anemias and chronic gastrointestinal
bleeding from an ulcer or another source may cause
syncope.
Patients who are pregnant or dehydrated or who
have been on prolonged bed rest are at risk for orthostatic hypotension and syncope.
Is this explained by other factors?
Key Questions
n Have you had this before? How often?
n Did it occur with sudden head turning?
n If a child: Has the child had Kawasaki disease?
n Do you have Lyme disease?
Frequent Syncope with No Heart Disease
Psychogenic syncope is often associated with repeated
episodes in which unpredictable motor reexes appear,
with a lack of pathological reexes. Also, blood pressure and pulse rate measurements are normal, and skin
and mucous membranes do not change color. Panic attacks, or hyperventilation, are often interpreted as feeling faint, but the patient does not usually appear pale,
nor are the symptoms relieved when recumbent.
Key Questions
n What medications are you taking?
n Have you recently started blood pressure medicine
or has the dose changed?
n What other health problems/conditions do you
have?
Medications
About 10% of syncopal episodes are caused by
prescribed medications (e.g., antidepressants, antidysrhythmics, b-blockers, diuretics), over-the-counter
After Sudden Head Rotation
Carotid sinus hypersensitivity produces a cardioinhibitory response that results in a profound drop in heart
rate or may induce an abrupt vasopressor response
with a drop in blood pressure.
History of Kawasaki Disease
Syncope can occur in children who have had Kawasaki
disease. These children are at risk for coronary heart
disease, which may present as chest pain associated
with exercise.
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Lyme Disease
Lyme disease can cause arrhythmia in the form of heart
block, which can result in syncope.
What other things do I need to consider?
Key Questions
n Do you have a family history of sudden death?
n Do you have a family history of fainting?
n If a child: Did the mother have systemic lupus ery-
thematosus (SLE) while pregnant?
Family History of Sudden Death
A family history of idiopathic hypertrophic subaortic
stenosis is a risk factor for sudden death, and referral is
necessary to rule out this condition. A history of a family member who had a myocardial infarction before
age 30 is a signicant risk factor for sudden death.
Family History of Fainting
Neurocardiogenic syncope is common in families.
Prenatal Systemic Lupus Erythematosus
SLE in a pregnant woman may cause autoimmune injury, resulting in congenital complete atrioventicular
block.
DIAGNOSTIC REASONING:
FOCUSED PHYSICAL EXAMINATION
Measure Blood Pressure and Pulse Rate
Obtain blood pressure readings in standing, sitting, and
supine positions. Orthostatic hypotension is either a
decrease in systolic blood pressure of at least 20 mm
Hg or symptoms that prevent further standing, such as
fainting, weakness, or lightheadedness.
Compare blood pressure readings in the two arms.
Unequal measurements may indicate a cardiac cause of
the syncope.
Bradycardia of 35 to 40 beats per minute usually
does not compromise cerebral blood ow. Rates below
this, however, will impair cerebral circulation and
function. Tachycardia up to 180 beats per minute also
does not usually compromise cerebral circulation.
Perform Heart and Lung Examination
Observe for jugular venous distention. Palpate the precordium to assess the point of maximal impulse to estimate the size of the left ventricle. Feel for lifts. Listen
for heart rate and murmurs and for radiation of murmurs. Listen for an abnormally loud S2 or the presence
of an S3. Auscultate for carotid bruits and pericardial
rub. Listen to the lungs to assess for rales associated
with congestive heart failure.
Perform a Neurological Examination
Begin with a brief mental status examination. Assess
cranial nerves, deep tendon reexes, and motor function. Perform a Romberg test, as well as gait and proprioception evaluation. Assess pupillary asymmetry
and look for nystagmus (see Chapter 12).
Perform an Abdominal Examination
Auscultate and observe for signs of aortic aneurysm.
Examine Extremities
Observe lower extremities for signs of thrombophlebitis, a source of pulmonary embolism.
LABORATORY AND DIAGNOSTIC
STUDIES
Suspected or Known Cardiac Cause
Electrocardiogram
The usefulness of the electrocardiogram usually lies in
identifying abnormalities that provide clues to underlying cardiac causes of syncope. These ndings include
evidence of conduction disorder or signs of coronary
artery disease or left ventricular hypertrophy. A 12-lead
ECG is used for the basic evaluation. This should be
rst evaluated for rhythm and rate. Hand-measured
interval measurement should be made. A Q wave found
in the anterolateral lead may indicate abnormal placement of the left coronary artery. A patient with a prolonged QT interval or the presence of Q waves must be
referred.
Complete heart block requires immediate referral
for pacemaker insertion.
Observe Hydration Status
Poor hydration status secondary to diuretic use, poor
nutrition, or loss of uids from vomiting and diarrhea
may be associated with syncope.
Carotid Sinus Massage
Carotid sinus massage (CSM) is done to evaluate patients with suspected carotid sinus hypersensitivity.
This can be performed at the bedside with the patient
370 Chapter 30 • Syncope
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in a supine or upright position while under continuous
ECG and blood pressure monitoring. Apply rm pressure and massage for 5 to 10 seconds one side at a time
at the site of the strongest carotid pulsation. Carotid
sinus hypersensitivity is diagnosed when CSM causes
a $3 second pause, a $50 mm Hg fall in systolic
blood pressure, or both, and associated syncope.
Event Monitoring or Continuous-Loop
Monitoring
These measures are used in patients with suspected
cardiac arrhythmias as the cause of the syncope.
Holter (24 hours) or long-term (weeks, months) event
monitoring is used to document electrocardiographic
recordings. Holter monitoring is a continuous, 24-hour
electrocardiographic recording to evaluate the type
and amount of irregular heartbeats during regular
activities, exercise, and sleep. The patient keeps a
24-hour diary to record daily activities and any symptoms experienced.
Cardiac event monitoring is a continuous-loop, digi-
tal memory recorder worn for extended periods of time
(up to 30 days or longer) that saves and records transient events felt by the patient. Patients activate these
monitors as symptoms occur. Loop monitors save information for a predetermined period prior to the patient
trigger, and therefore can help identify the initiation
sequence for arrhythmias. These stored events can be
transmitted through a telephone for review.
Doppler Studies
Transcranial Doppler and carotid ultrasonography are
used to detect hemodynamically signicant stenoses in
the major intracranial or extracranial arteries.
Exercise Stress Test
Cardiac stress testing is used to evaluate exerciseassociated arrhythmias and syncope. It can conrm
the presence of coronary artery disease.
Echocardiography
This is used in patients with exercise-induced symptoms
to exclude left ventricular outow tract obstruction.
Electrophysiological Studies
Electrophysiological studies (EPSs) are invasive
tests that use electrical stimulation and monitoring to
diagnose conduction disorders or the propensity for
the development of tachyarrhythmias. Electrodes are
threaded through arm or leg veins and placed at strategic positions in the ventricles, atria, or both. The
electrodes record electrical signals and allow mapping of electrical impulses. The electrodes also can
electrically stimulate the heart at programmed rates
to trigger latent ventricular tachycardias.
Suspected Neurological Cause
Baseline Blood Testing
Routine blood tests (electrolyte levels, renal function,
blood glucose level, complete blood count) rarely yield
useful diagnostic information. Most patients with abnormalities in these areas have seizures rather than syncope.
Electroencephalography
Electroencephalography (EEG) may be useful in
patients whose history suggests seizure.
Computed Tomography Scanning
Computed tomography (CT) may be useful if the
patient has focal neurological ndings.
Unexplained Syncope
Toxicology Screen
Toxicology screening may be indicated on the basis of
the history.
Tilt-Table Testing
Tilt-table testing is used to provoke vasovagal syncope in susceptible persons. Provocative agents
such as isoproterenol or nitroglycerin may be used.
Using the table, the patient is tilted upright while
continuous minute-to-minute blood pressure, heart
rate, and oxygen saturation measurements are recorded. Patient symptoms are recorded in each position. Patients with neurocardiogenic syncope develop a sudden drop in heart rate and/or blood
pressure after their body has been tilted up for several minutes. If symptoms of lightheadedness or
fainting occur during this test, the test is considered
positive for neurocardiogenic syncope.
DIFFERENTIAL DIAGNOSIS
Cardiac Causes
Cardiac causes have a higher rate of mortality than do
other causes of syncope. Cardiac causes include coronary artery disease, congenital and valvular disease,
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