Syncope David Robertson February 9, 2007

Objectives Recognize and treat: –Severe orthostatic hypotension (AF) –Postural tachycardia syndrome (POTS) –Neurally mediated syncope (NMS)

AFPOTSNormotension Labile HBP Cardiovascular Continuum Orthostatic tachycardia Orthostatic hypotension ~500,000 Americans ~100,000 Americans NMS Bradycardia/hypotension ~500,000 Americans

AFPOTSNormotension Labile HBP Cardiovascular Continuum Orthostatic tachycardia Orthostatic hypotension ~500,000 Americans ~100,000 Americans NMS Bradycardia/hypotension ~500,000 Americans symptomatic asymptomatic

AFPOTSNormotension Labile 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 Maneuvers 2.Exercise (in water) THIRD LINE: 1.Fludrocortisone + Salt 2.Pressor Drugs (midodrine)

AFPOTSNormotension Labile HBP Cardiovascular Continuum Orthostatic tachycardia Orthostatic hypotension ~500,000 Americans ~100,000 Americans NMS Bradycardia/hypotension ~500,000 Americans Mild Dysautonomias

Postural Tachycardia Syndrome POTS 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

Normal Neuropathic POTS Hyperadrenergic POTS  60  HR (bpm) BP(mmHg) Tilt Angle

AFPOTSNormotension Labile HBP Cardiovascular Continuum Orthostatic tachycardia Orthostatic hypotension ~500,000 Americans ~100,000 Americans NMS Bradycardia/hypotension ~500,000 Americans Mild Dysautonomias

Neurally Mediated Syncope NMS Transient loss of consciousness with loss of postural tone followed by recovery

Syncope Emotional Dysautonomia Viral Swallowing Standing Arrhythmia

BP (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/Fear Pain, blood, medical procedures, fright After minutes or hours of upright posture Generally standing or quiet sitting Worse in heat or warm stuffy rooms Probably related to tilt test syncope Within 30 seconds of arising from sitting or lying Probably increased conductance in muscle bed Can occur with starting to walk after quiet standing At or immediately after peak heavy exercise

Syncope: Common Symptoms Frequent symptoms or signs Nausea Diaphoresis Pallor Fatigue Myoclonic twitches Frequent presyncopal spells Improvement on lying down

Syncope Rate in Young Adults % (usually no medical attention)

Syncope 3-5% of all ER visits (35% admitted) Syncope 1 o 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 4 th 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 %* % 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 Orthostatic Tolerance (min) 16 oz Water: Effect on Tilt Tolerance

Vanderbilt University Autonomic Dysfunction Center