syncope david robertson february 9, 2007. objectives recognize and treat: –severe orthostatic...
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Syncope
David RobertsonFebruary 9, 2007
Objectives
• Recognize and treat:– Severe orthostatic hypotension (AF)– Postural tachycardia syndrome (POTS)– Neurally mediated syncope (NMS)
AF POTS NormotensionLabileHBP
HBP
Cardiovascular Continuum
Orthostatic tachycardia
Orthostatic hypotension
~500,000 Americans
~100,000 Americans
NMS
Bradycardia/hypotension~500,000 Americans
AF POTS NormotensionLabileHBP
HBP
Cardiovascular Continuum
Orthostatic tachycardia
Orthostatic hypotension
~500,000 Americans
~100,000 Americans
NMS
Bradycardia/hypotension~500,000 Americans
symptomatic
asymptomatic
AF POTS NormotensionLabileHBP
HBP
Cardiovascular Continuum
Orthostatic tachycardia
Orthostatic hypotension
~500,000 Americans
~100,000 Americans
NMS
Bradycardia/hypotension~500,000 Americans
Severe Dysautonomias
Severe Dysautonomia: Therapy
FIRST LINE:1. Water (+40 mmHg!)2. Food (-30mmHg!)
SECOND LINE:1. Physical Maneuvers2. Exercise (in water)
THIRD LINE:1. Fludrocortisone + Salt2. Pressor Drugs (midodrine)
AF POTS NormotensionLabileHBP
HBP
Cardiovascular Continuum
Orthostatic tachycardia
Orthostatic hypotension
~500,000 Americans
~100,000 Americans
NMS
Bradycardia/hypotension~500,000 Americans Mild Dysautonomias
Postural Tachycardia SyndromePOTS
• Upright symptoms without hypotension• Upright tachycardia (>30 bpm rise)• 500,000 Americans: usually young
women• Antecedent infection; surgery;
pregnancy• Many causes• Tx: low dose (10 mg tid) propranolol
NormalNeuropathic
POTSHyperadrenergic POTS
200
50
200
0
0
60
HR (bpm)
BP(mmHg)
Tilt Angle
AF POTS NormotensionLabileHBP
HBP
Cardiovascular Continuum
Orthostatic tachycardia
Orthostatic hypotension
~500,000 Americans
~100,000 Americans
NMS
Bradycardia/hypotension~500,000 Americans Mild Dysautonomias
Neurally Mediated SyncopeNMS
Transient loss of consciousness
with loss of postural tone
followed by recovery
Syncope
EmotionalDysautonomiaViralSwallowingStandingArrhythmia
0 5 10 15 20 25 30 35 40 45 50
20
40
60
80
100BP
(mm Hg)
ECG
Time (sec)
Hypotension and Sinus Arrest During Venipuncture
Tilt-Induced Bradycardia
EKG
BP
HR
Tilt
Syncope: The Problem
• Loss of consciousness is common
• Long differential diagnosis
• Most benign; some fatal
• Treatment requires diagnosis
Syncope and its Risk
A cardiac etiology conveys risk
Wishwa Kapoor et al. NEJM 1983; 309: 197
CV DISEASES
OTHER CAUSES
Why Do We Faint ?
Blood/Injury/FearPain, blood, medical procedures, fright
After minutes or hours of upright postureGenerally standing or quiet sittingWorse in heat or warm stuffy roomsProbably related to tilt test syncope
Within 30 seconds of arising from sitting or lyingProbably increased conductance in muscle bedCan occur with starting to walk after quiet standing
At or immediately after peak heavy exercise
Syncope: Common Symptoms
Frequent symptoms or signsNausea
Diaphoresis
Pallor
Fatigue
Myoclonic twitches
Frequent presyncopal spells
Improvement on lying down
Syncope Rate in Young Adults
12-48 %
(usually no medical attention)
Syncope
• 3-5% of all ER visits (35% admitted)
• Syncope 1o diagnosis: 1-6% of admits
• 1,000,000 new patients evaluated yearly
• Prevalence: 0.7% in young; 6.0% in old
• Tends to be young women and old men
Syncope Impact
• Recurrent syncope ~ Rheumatoid arthritis
• Maybe home schooling
• Maybe lose your job
• Maybe injury: Falls 4th cause of death
• Pacemaker may make you uninsurable
Neurally Mediated Syncope
• Recurrent (>3) syncope
• No cardiac lesion
• Especially in young
• Rarely life-threatening
• Most gradually improve
Case 1
• 21 year old woman
• Syncope during choir practice
No W/U Required
• If syncope has an obvious cause
• If there is no cause for concern
• But if in clinic: H&P plus ECG
The History
• Complete Description• Other illnesses (virus?)• Type of Onset• Duration of Attacks• Posture• Associated Symptoms• Sequelae
– Prolonged fatigue is almost universal
Case 2
• 21 year old woman
• Syncope during basketball competition
Evaluation of Syncope I
• Is there structural heart disease ?– Hx– PE– ECG– Echo– Monitoring (loop recorder)
Case 3
• 21 year old woman
• Syncope during class
• Father died suddenly at 34
Evaluation Of Syncope II
• Tilt-Table Test
• EP (Electrophysiological) Study
• But……only BP, HR during spontaneous syncope is definitive.
Tilt Table Test• Widely used but rarely
helpful to patients
• Demonstrates what fainting feels like
• 20% of normal subjects test positive
• Positive test doesn’t mean the patient has NMS
• Negative test doesn’t mean patient does not have NMS
Positive Tilt Test
• Hemodynamics– Hypotension– Bradycardia
• Reproduction of Symptoms– Syncope– Pre-syncope
Tilt-Table Test: Positivity
• Normal Subjects• Syncope Patients
13 %*
24-75 %
MEV Petersen Heart 2000; 84: 509
*but ~30% of normals positive at Vanderbilt
Therapy of Syncope
• No drug or device proven helpful• Rate-drop pacemaker• Drugs sometimes employed:
– Propranolol– Fludrocortisone– SSRIs– Midodrine– Water?
No Water Water
0
15
30
45
Ort
ho
stat
ic T
ole
ran
ce (
min
)16 oz Water: Effect on Tilt Tolerance
Vanderbilt University Autonomic Dysfunction Center