Syncope Victoria E Judd Disclosure Slide - PowerPoint Presentation

Slide1

Syncope

Victoria E Judd

Slide2

Disclosure Slide

Nothing to disclose

Slide3

Slide4

Slide5

Syncope Is

t

he abrupt and transient loss of consciousness

associated with absence of postural tone

followed by complete and usually rapid spontaneous recovery

Slide6

Syncope

alarming for the individual, witnesses, family, and providers

most often benign and self-limited

a harbinger of a multitude of disease processes

i

njuries resulting from

syncopal

attacks occur in about one-third of patients

recurrent episodes can be psychologically devastating

can be a premonitory sign of cardiac arrest, especially in patients with organic heart disease

Slide7

Syncope

The most frequent age for first syncope is 15 years.The lifetime incidence of 1 fainting episodes is ∼40%.

 

Slide8

Vasovagal Syncope

Mediated by emotional distress: fear, pain, instrumentation, blood phobia

Mediated by orthostatic stress

Slide9

Situational Syncope

Cough, sneeze

Gastrointestinal stimulation (swallow, defecation, visceral pain)

Micturition (

postmicturation

)

Post-exercise

Postprandial

Others (e.g., laughter, brass instrument playing, weightlifting)

Carotid sinus syncope

Slide10

Syncope Due to Orthostatic Hypotension

Primary autonomic failure:

Pure autonomic failure, multiple system atrophy, Parkinson's disease with autonomic failure,

Lewy

body dementia

Secondary autonomic failure:

Diabetes, amyloidosis, uremia, spinal cord injuries

Drug-induced orthostatic hypotension:

Alcohol, vasodilators, diuretics, phenothiazine's, antidepressants

Volume depletion:

Hemorrhage, diarrhea, vomiting, etc.

Slide11

Cardiac Syncope

Arrhythmia as primary cause:

Bradycardia:

Sinus node dysfunction (including bradycardia/tachycardia syndrome)

Atrioventricular

conduction system disease

Implanted device malfunction

Tachycardia:

Supraventricular

Ventricular (idiopathic, secondary to structural heart disease or to

channelopathies

)

Drug-induced bradycardia and

tachyarrhythmias

Slide12

Cardiac Syncope

Structural disease:

Cardiac: cardiac

valvular

disease, acute myocardial infarction/ischemia, hypertrophic cardiomyopathy, cardiac masses (atrial

myxoma

, tumors, etc.), pericardial disease/

tamponade

, congenital anomalies of coronary arteries, prosthetic valves dysfunction

Others: pulmonary embolus, acute aortic dissection, pulmonary hypertension

Slide13

Causes of Syncope

■Reflex (

neurally

-mediated; this includes vasovagal, POTS) — 58 percent

■Cardiac disease, most often a

bradyarrhythmia

or tachyarrhythmia — 23 percent

■Neurologic or psychiatric disease — 1 percent

■Unexplained syncope — 18 percent; a higher value (41 percent) was noted in another large series

Slide14

Slide15

Slide16

Slide17

Slide18

Slide19

Slide20

Slide21

The initial evaluation should answer three key questions

■Is it a

syncopal

episode or other type of event?

■Has the etiology been determined?

■Is there evidence suggestive of a high risk of cardiovascular events or death?

Slide22

Slide23

Slide24

If Yes, Then Syncope

■Was loss of consciousness complete?

■Was loss of consciousness transient with rapid onset and short duration?

■Did the patient recover spontaneously, completely and without

sequela

?

■Did the patient lose postural tone?

Slide25

Recurrent Syncope

The number of

syncopal

episodes can predict the risk of recurrence.

Slide26

Slide27

Clinical features that suggest a diagnosis on initial evaluation

Neurally

mediated syncope:

Absence of heart disease

Long history of recurrent syncope

After sudden unexpected unpleasant sight, sound, smell or pain

Prolonged standing or crowded, hot places

Nausea, vomiting associated with syncope

During a meal or post-prandial

With head rotation or pressure on carotid sinus (as in tumors, shaving, tight collars)

After exertion

Slide28

Clinical features that suggest a diagnosis on initial evaluation

Syncope due to Orthostatic Hypotension(OH):

After standing up

Temporal relationship with start or changes of dosage of

vasodepressive

drugs leading to hypotension

Prolonged standing especially in crowded, hot places

Presence of autonomic neuropathy or Parkinsonism

Standing after exertion

Slide29

Clinical features that suggest a diagnosis on initial evaluation

Cardiovascular syncope:

Presence of definite structural heart disease

Family history of unexplained sudden death or

channelopathy

During exertion, or supine

Abnormal ECG

Sudden onset palpitation immediately followed by syncope

Slide30

Cardiovascular syncope:

ECG findings suggesting arrhythmic syncope:

-

Bifascicular

block (defined as either LBBB or RBBB combined with left anterior or left posterior fascicular block)

- Other

intraventriclar

conduction abnormalities (QRS duration ≥0.12 s)

-

Mobitz

I second degree AV block

- Asymptomatic inappropriate sinus bradycardia (<50 bpm), sinoatrial block or sinus pause ≥3 s in the absence of negatively

chronotropic

medications

Slide31

Cardiovascular syncope:

- Non-sustained VT

- Pre-excited QRS complexes

- Long or short QT intervals

- Early repolarization

- RBBB pattern with ST-elevation in leads V1-V3 (

Brugada

syndrome)

- Negative T waves in right precordial leads, epsilon waves and ventricular late potentials suggestive of ARVC

- Q waves suggesting myocardial infarction

Slide32

Slide33

Slide34

Figure 2. Different patterns of QT prolongation in LQTS. Morphology of the QT segment and T wave may be different in different genetic subsets of the LQTS, although there is significant individual variation.

Strickberger S et al. Circulation 2006;113:316-327

Copyright © American Heart Association, Inc. All rights reserved.

Slide35

Figure 3. ECG changes in the Brugada syndrome.

Strickberger S et al. Circulation 2006;113:316-327

Copyright © American Heart Association, Inc. All rights reserved.

Slide36

Slide37

Slide38

History

"Auras" are associated with seizures. In comparison, vasovagal (

neurocardiogenic

/reflex) syncope is usually, but not always, associated with a

prodrome

of nausea, warmth, pallor, lightheadedness, and/or diaphoresis.

Sudden onset of syncope without a

prodrome

is more common among patients with cardiac syncope (arrhythmic or mechanical cardiac etiology).

Slide39

History

Neurocardiogenic

syncope commonly occurs when the patient is erect, not usually when supine.

Syncope resulting from orthostatic hypotension is frequently associated with the change from a supine to erect posture.

In comparison, syncope that occurs when the patient is supine suggests an arrhythmia.

Slide40

History

An evaluation to rule out potentially life-threatening causes for syncope is required if syncope occurs during exertion

Slide41

History

A prolonged loss of consciousness may indicate a seizure. By comparison, arrhythmias and

neurocardiogenic

syncope are often associated with a brief period of syncope, since the supine position reestablishes some blood flow to the brain and can therefore result in the restoration of consciousness. Recovery of consciousness may occur even if the arrhythmia is maintained.

Slide42

History

Persistence of nausea, pallor, and diaphoresis in addition to a prolonged recovery from the episode suggest a vagal event. These findings are helpful in distinguishing

neurocardiogenic

syncope from syncope due to an arrhythmia. Significant neurologic changes or confusion during the recovery period may be due to a stroke or seizure.

Slide43

History

A witness to the

syncopal

event may verify the loss of consciousness, any associated limb movements, and the presence or absence of pallor, diaphoresis, or a pulse.

Neurocardiogenic

syncope is more likely to occur among young, otherwise healthy patients.

Slide44

History

Important elements of the family history include history of sudden death, pacemakers in young people, syncope, seizures, single car accidents, drowning, cardiomyopathy.

Slide45

History

Seizures are the probable cause of 5 to 15 percent of apparent

syncopal

episodes. They can mimic syncope when the seizure is atypical and not associated with tonic-

clonic

movements, the seizure is not observed, or a complete history cannot be obtained. In addition, some patients with syncope present with myoclonic or other involuntary movements that are suggestive of a seizure but are actually due to cerebral hypoxia.

Slide46

History

One distinguishing feature is that patients with seizures rarely have a rapid and complete recovery. Instead, the postictal state is characterized by a slow and complete recovery.

Another feature is usually those with syncope are pale and those with seizures are usually flushed.

Slide47

Physical Exam

Blood pressure obtained in the supine, sitting, and erect position may detect orthostatic hypotension.

Slide48

Orthostatic Measurement

Orthostatic blood pressure measurement is performed with the patient standing after at least three minutes of lying supine. Blood pressure should be measured each minute (or more often) in the standing position for three minutes or more (or as long as the patient tolerates) until the blood pressure nadir is reached. A sphygmomanometer (manual blood pressure cuff) may allow greater flexibility than an automatic arm-cuff device in measuring blood pressure prior to and during active standing

Slide49

Orthostatic syndromes

■Classic orthostatic hypotension (OH) is defined as a decrease in systolic blood pressure (BP) of ≥20 mmHg and in diastolic BP ≥10 mmHg within three minutes of standing. This syndrome is diagnosed by active standing or tilt testing.

■Initial OH is defined by a BP decrease immediately on standing of >40 mmHg with BP spontaneously and rapidly returning to normal, so the period of hypotension and symptoms is <30 s. This is diagnosed by active standing.

Slide50

Orthostatic syndromes

■Reflex syncope (vasovagal syncope) triggered by standing is characterized by an initial normal adaption reflex followed by rapid fall in venous return and vasovagal reaction (reflex bradycardia and vasodilatation). This is diagnosed by tilt table.

■Delayed (progressive) OH is defined by a slow progressive decrease in systolic BP on standing with no

bradycardic

reflex (in contrast to reflex syncope). This is diagnosed by tilt table.

Slide51

Orthostatic syndromes

■Delayed (progressive) OH plus reflex syncope occurs when a vasovagal reaction (reflex bradycardia and vasodilation) follows delayed OH. This is diagnosed by tilt table.

Slide52

Orthostatic syndromes

■Postural orthostatic tachycardia syndrome (POTS) presents with severe orthostatic intolerance (not syncope) with marked increase in heart rate (by >30 beats per minute or to >120 beats per minute)within ten minutes of standing. This is diagnosed by tilt table or passive standing. POTS can be diagnosed with bedside measurements of heart rate and blood pressure taken in the supine (laying down) and standing up position at 2, 5 and 10 minute intervals.

In

children and adolescents, a revised standard of a 40 bpm or more increase has recently been

adopted.

Slide53

Slide54

Physical Exam

The heart rate may be rapid or slow due to a number of possible rhythm disturbances, or irregular due to atrial fibrillation.

The pulse and blood pressure should be obtained with the patient supine, seated, and erect.

Hyperventilation can be seen with pulmonary embolism or psychiatric causes of syncope.

Slide55

Physical Exam

The cardiac examination may reveal the murmur of aortic stenosis, pulmonic stenosis, or atrial

myxoma

(mitral stenosis).

Pulmonary hypertension may be suggested by a loud, palpable P2.

Increase in an outflow murmur with the Valsalva maneuver may help diagnose hypertrophic cardiomyopathy.

Slide56

Physical Exam

Unilateral abnormalities found upon neurologic examination may reflect a cerebral vascular accident.

Slide57

ECG

An electrocardiogram (ECG) should be obtained in all patients with syncope. The ECG is suggestive of an arrhythmic cause of syncope if any of the following abnormalities is present:

■

Bifascicular

block (defined as left bundle branch block or right bundle branch block combined with left anterior or left posterior fascicular block)

■Other

intraventricular

conduction abnormalities (QRS duration ≥0.12 sec)

■

Mobitz

II second degree

atrioventricular

block

Slide58

ECG

■Asymptomatic sinus bradycardia (<50 beats/min), sinoatrial block or sinus pause ≥3 seconds in the absence of negatively

chronotropic

medications

■

Preexcited

QRS complexes, suggesting Wolff-Parkinson-White syndrome

■Long or short QT intervals

■Right bundle branch block pattern with ST-elevation in leads V1-V3 (

Brugada

syndrome)

■Negative T waves in right precordial leads, epsilon waves and ventricular late potentials suggestive of

arrhythmogenic

right ventricular cardiomyopathy

■Q waves suggesting myocardial infarction

Slide59

Testing

Additional testing is based on the results of the initial evaluation. A variety of tests, mostly cardiologic, can be used in the evaluation of the patient with syncope. Neurologic testing is generally of low yield and overused, unless specifically suggested by history or physical examination.

■Carotid sinus massage in patients >40 years old.

■Echocardiogram when there is previous known heart disease or data suggestive of structural heart disease or syncope secondary to cardiovascular cause.

Slide60

Testing

Immediate ECG monitoring when there is a suspicion of arrhythmic syncope.

■Orthostatic challenge (lying to standing orthostatic test or head-up tilt testing) when syncope is related to the standing position or there is suspicion of a reflex mechanism

■Other less specific tests such as neurological evaluation or blood tests are indicated only when there is suspicion of non-

syncopal

transient loss of consciousness.

Slide61

Slide62

Slide63

Slide64

Testing

E

chocardiography is recommended in patients with syncope when structural cardiac disease is suspected.

Electrocardiographic (ECG) monitoring is indicated if there is a high probability of identifying an arrhythmia associated with syncope.

Electrophysiology study (EPS) is indicated in selected patients with unexplained syncope.

Slide65

Implantable Loop Recorders (ILR)

ILR

Patient

Assist Device

Automatically detects

bradycardia

tachycardia

asystole

Records rhythm at

time of trigger

Slide66

ILRs

Slide67

Example tracing from ILR

Slide68

ILR in unexplained syncope with normal conventional work-up

Tachycardia

56%

11%

33%

Asystole /

bradycardia

No arrhythmia

Diagnostic yield: 35%

(175/506 patients)

Brignole et al. Europace 2009;11,671-687

Slide69

Testing

Neurologic tests, including electroencephalogram (EEG), brain CT scan, brain magnetic resonance imaging, and carotid Doppler ultrasound, are frequently obtained in patients with syncope. In one review of 649 patients, 53 percent had at least one neurologic test. However, such testing was rarely useful.

Slide70

Slide71

Postural Orthostatic Tachycardia Syndrome (POTS)

A form of orthostatic intolerance occurs in patients, particularly younger adults and children, who consistently or frequently experience symptoms of orthostatic intolerance in response to postural stressors.

Autonomic reflexes are relatively preserved in these patients, and orthostatic hypotension and syncope rarely occur.

Some patients may have slightly elevated blood pressure.

The hallmark of this disorder is an exaggerated heart rate increase in response to postural change.

Slide72

Names of POTS

■Chronic orthostatic intolerance

■Mild orthostatic intolerance

■Orthostatic tachycardia

■

Sympathotonic

orthostatic hypotension

■

Hyperdynamic

beta adrenergic state

■Idiopathic hypovolemia

■Mitral valve prolapse syndrome

■

Neurocirculatory

asthenia

■Irritable heart

■Soldier's heart

■Effort syndrome

Slide73

Facts POTS

It is the most prevalent form of orthostatic intolerance. It is estimated that 500,000 Americans suffer from this disorder.

It is the most common syndrome of young people seen in autonomic dysfunction clinics.

Patients present at a relatively young age (14 to 45 years).

Slide74

Facts POTS

Women predominate among patients with POTS with a female to male ratio of 4-5:1.

The reason for this is not known, however, observed gender differences in muscle sympathetic nerve discharge characteristics in healthy patients may explain why women are more likely to develop POTS.

Slide75

Etiology POTS

The etiology of postural tachycardia syndrome (POTS) is heterogeneous. Investigators have reported a number of different abnormalities in patients with POTS.

It remains uncertain as to which of these abnormalities are primary and causative and which are secondary.

Slide76

Etiology POTS

Distal denervation — Several clinical and empiric observations suggest the presence of distal, predominantly lower extremity, denervation with preserved cardiac innervation in this disorder.

Slide77

Etiology POTS

Hypovolemia — Patients with POTS frequently experience symptomatic improvement with saline infusion.

Additional evidence of a decrease and/or redistribution of blood volume is observed in several studies of patients with POTS, which have noted:

■Hypovolemia

■Trend toward hypovolemia

■Reduced erythrocyte volume

■Excessive venous pooling with redistributive

hypovolemia

Slide78

Etiology POTS

Changes in venous function — Abnormal venous function with decreased venous return on assumption of the upright posture could stimulate a compensatory tachycardia in order to maintain cardiac output.

Baroreflex

abnormalities — The increase in heart rate without blood pressure change upon standing in POTS suggests a primary abnormality in

baroreflex

control.

Slide79

Etiology POTS

Increased sympathetic activity — Increased sympathetic activity is the final common pathway of most proposed mechanisms in POTS.

Genetic abnormalities — In one large series, 12.5 percent of 152 patients with POTS reported a family history of orthostatic intolerance

Slide80

Clinical POTS

Patients with postural tachycardia syndrome (POTS) report dizziness, lightheadedness, weakness, blurred vision, and fatigue upon standing.

Other predominantly orthostatic symptoms include palpitations, tremulousness, and anxiety.

Slide81

Clinical POTS

Gastrointestinal symptoms such as nausea, abdominal cramps, early satiety, bloating, constipation, and diarrhea may be particularly problematic in some.

There may also be evidence of venous pooling, as manifested by

acrocyanosis

and edema when upright.

Syncope is relatively unusual, but does occur in about 40 percent of patients.

Slide82

Slide83

Clinical POTS

The

onset often follows a

flulike illness

.

I

llness

may occasionally

represent a

self-limited

autoimmune disease.

The

role of immune

and epigenetic

factors remains

ill defined.

Some

patients have an

insidious onset

over years, sometimes

with a

past history of

VVS.

Slide84

Clinical POTS

? Some

patients have joint hypermobility syndromes.

Causality is unclear.

While supine or seated, some patients appear well, others pasty pale.

Slide85

Clinical POTS

Patients are unable to remain

upright for

long periods of

time.

Symptoms

are similar to

the

prodrome

of

VVS

.

BP

is typically well maintained

and may

increase when upright

in

hyperadrenergic

individuals.

Prolonged laboratory

tilt may

provoke VVS.

Slide86

Clinical POTS

Cognitive deficits and exercise intolerance are prominent complaints.

Gastrointestinal symptoms include

dysmotility

issues.

Young women may be underweight, and POTS must be differentiated from eating disorders, which can produce POTS-like

Orthostatic Intolerance

in early stages.

Slide87

Clinical POTS

Environmental

heat reroutes

blood to

the skin and makes

patients worse

.

Air-conditioning

may be

required and

standing hot

showers untenable.

Schoolwork

may be impaired.

Home schooling

is

common in adolescents.

Colleges are often

accommodating because

of adaptive

scheduling and

improved logistics.

Slide88

Clinical POTS

The symptoms may appear abruptly, often after a viral illness; others experience a more insidious onset.

The severity of symptoms is also quite variable.

Some patients experience only mild symptoms and often only in the setting of additional orthostatic stress (e.g., menstrual cycle, relative dehydration).

Others are profoundly incapacitated.

The course of the disorder may be self limited or may follow a relapsing remitting course over several years.

Slide89

Diagnosis POTS

The characteristic autonomic abnormality in patients with postural tachycardia syndrome (POTS) is an exaggerated increase in heart rate on tilt table testing or standing.

Diagnostic criteria from several laboratories have in common a sustained heart rate increase of greater than 30 beats per minute or an increase to 120 beats per minute or greater within the first 10 minutes of tilt.

There is usually no orthostatic hypotension.

Slide90

Diagnosis POTS

Autonomic neuropathies, central

dysautonomias

,

bedrest

deconditioning, side effects of medications, and dehydration can produce similar symptoms to POTS.

Ruling out these conditions is essential to making a diagnosis of POTS.

In most cases, historical information and a neurologic examination specifically looking for other evidence of autonomic failure, neuropathy, and extrapyramidal signs, will provide evidence of the underlying disorder.

Slide91

Diagnosis POTS

Patients with POTS may be thought to have panic, anxiety, somatization disorder, or chronic fatigue syndrome in part because of the vague nature of the symptoms.

In fact, patients with POTS report subjective cognitive dysfunction and have objectively increased scores on inattention scales, but do not have an increased prevalence of depression or anxiety.

The prominent postural nature of the symptoms should prompt the clinician to look for the diagnostic heart rate response.

Slide92

Diagnosis POTS

The syndrome of inappropriate sinus tachycardia is characterized by an elevated heart rate that is not influenced by postural changes.

Slide93

Treatment POTS

The optimal therapy of postural tachycardia syndrome (POTS) is uncertain.

No intervention has been systematically studied.

The placebo effect may be substantial in POTS, highlighting the need for controlled studies.

Exacerbating factors, medications, dehydration, and inactivity should be avoided.

Slide94

Treatment POTS

Because many patients with POTS have a low plasma volume, correction with oral volume expansion, a high salt

diet (3,000 mg to 10,000 mg per

day), and fludrocortisone, a mineralocorticoid agonist may improve symptoms.

This regimen is similar to that used in orthostatic hypotension in general.

Slide95

Treatment POTS

Some patients report symptomatic benefit with acute ingestion of 16

oz

of water and from a saline infusion of 500 to 2000 cc, corresponding to objective improvement in tilt testing response.

However, it is not clear that this translates to a therapeutic response to chronic treatment.

Fludrocortisone (0.1 to 0.4 mg per day) is most effective when combined with increased salt and water intake.

Treatment may be complicated by supine hypertension, fluid retention, and hypokalemia and should be monitored closely.

Slide96

Treatment POTS

Adrenoreceptor

agonists may be helpful in some patients (e.g.,

midodrine

2.5 to 10 mg three times daily).

Both intravenous phenylephrine and oral

midodrine

have been associated with improved symptoms and heart rate response in some patients during tilt testing.

However, benefit from chronic therapy is not established.

Slide97

Treatment POTS

Preliminary evidence suggests that the

acetylcholinesterase

inhibitor

pyridostigmine

(30 mg daily) may attenuate the tachycardia and improve symptoms.

Further confirmation from larger trials is needed to establish the benefit of

acetylcholinesterase

inhibition for POTS.

Slide98

Treatment POTS

Some patients, particularly those troubled by prominent adrenergic symptoms, may benefit from beta blocking agents.

These should be started in low doses and increased gradually (e.g., propranolol 10 to 20 mg three or four times daily).

In one placebo-controlled, randomized crossover study, a single low-dose of oral propranolol (20 mg) was associated with improved tachycardia and reduced symptoms, while higher dose propranolol (80 mg) was associated with unchanged or worsened symptoms.

Slide99

POTS Treatment

Water ingestion is a useful,

short lived palliation.

Effects

are

through TRPV4

receptors in the

splanchnic vasculature.

Sixteen

ounces

of water

and waiting 20 to 30

minutes yields

benefit for

hours.

Salt

and water loading can

help but

often require Spartan

efforts.

Slide100

POTS Treatment

Even when the cause is known

pharmacologic

treatment is rarely curative.

Most young people improve over time. In some, POTS persists.

Slide101

Volume Expansion

Fludrocortisone

0.05-0.2 mg daily – Many patients with POTS

are hypovolemic

4, so fludrocortisone (an aldosterone analogue) is often used.

Through enhanced

renal sodium retention, it should expand the plasma volume (although

the data

are poor). Potassium wasting can result in hypokalemia, so serum K+

should be

monitored periodically.

Slide102

Sympatholysis

Propranolol 10-20 mg PO QID – Many patients report intolerance to

beta blockers when

first seen at the Vanderbilt Autonomic Dysfunction Center. The

vast majority

of POTS patients, however, respond well hemodynamically

and symptomatically

to low doses of

propranolol.

Of note, more complete

beta blockade with

higher doses of propranolol cause symptoms to worsen. Long

acting propranolol

was not found to be

helpful.

Slide103

Sympatholysis

Methyldopa 125mg QHS-BID – Methyldopa is a false neurotransmitter that

can lower

central sympathetic tone. It is particularly useful in

hyperadrenergic

patients.

Clonidine

0.05-0.2 mg PO BID (or a long acting patch) - Alpha 2

adrenergic agonist

that acts centrally to decrease sympathetic nervous system tone. It

can stabilize

HR and BP, but it can also cause drowsiness, fatigue and worsen

the mental

clouding of some patients.

Slide104

Vasoconstrictor Therapy

Midodrine

5-10mg PO q4H x3/day - Since a failure of vascular resistance may

be an

integral part of neuropathic POTS, vasoconstrictors such as

midodrine

(

alpha-1 agonist

) can be

employed.

Slide105

Increasing Vagal Tone

Pyridostigmine

30-60 mg PO TID –

Pyridostigmine

is a

peripheral

acetylcholinesterase

inhibitor. By increasing synaptic acetylcholine at both

the autonomic

ganglia and the peripheral muscarinic parasympathetic

receptors,

pyridostigmine

significantly restrains the heart rate in response to standing

in patients

with

POTS.

Pyridostigmine

is most effective in combination

with low

dose propranolol. Since

pyridostigmine

enhances bowel motility, it is often

not well

tolerated in patients with diarrhea-predominant irritable bowel

syndrome symptoms.

Slide106

? Treatment of POTS

Cardiovasc

Ther

. 2014 Feb 4.

doi

: 10.1111/1755-5922.12067. [

Epub

ahead of print]

Melatonin reduces tachycardia in Postural Tachycardia Syndrome (POTS): A Randomized, Crossover Trial.

Green EA1, Black BK,

Biaggioni

I,

Paranjape

SY,

Bagai

K,

Shibao

C,

Okoye

MC,

Dupont

WD, Robertson D, Raj SR.

Autonomic Dysfunction Center, Division of Clinical Pharmacology, Departments of Medicine, Vanderbilt University, Nashville, Tennessee, USA.

Slide107

Figure. Treatment strategies for POTS.

Grubb B P , and Karabin B

Circulation

. 2008;118:e61-e62

Copyright © American Heart Association, Inc. All rights reserved.

Slide108

POTS Treatment

One confounding and alarming

issue is

the tendency for POTS patients

to bed rest

.

Prolonged bed rest emulates microgravity

and has deleterious

effects including Orthostatic Instability (OI)

profound reductions

in blood

volume and cardiac size,

redistribution of

blood, osteoporosis,

skeletal muscle

pump atrophy, and

more.

Vasoconstriction is impaired.

Bed rest causes

a self-perpetuating state of

OI, which

can emulate or intensify POTS.

Slide109

POTS Treatment

It is paramount for POTS patient to leave bed and recondition.

Well-structured exercise protocols are essential and must accommodate patients who start off bed rested.

Reconditioning invariably improves patient well-being. Recent work supports the idea that POTS patients are also exercise deconditioned compared with matched volunteers.

Although

exercise deconditioning may or may not be causal in POTS, it is clear that exercise reconditioning is beneficial and should be advocated for all POTS patients.

Slide110

Diagnostic Criteria for Postural Tachycardia Syndrome

HR increase ≥30 bpm from lying to standing

Absence

of significant drop in BP with standing

Positional

symptoms

○ Many symptoms are worse with upright posture and improve on lying down

○ Some symptoms can be non-positional (e.g. fatigue, headache)

Chronic

symptoms

○ Duration ≥6 months

Absence

of other overt cause for tachycardia

○

E.g.,

acute blood loss, prolonged

bedrest

, hyperthyroidism, tachycardia promoting medications

Slide111

Slide112

Reflex (Neurally Mediated) Syncope

Reflex (

neurally

mediated) syncope is a transient loss of consciousness due to a reflex response that encompasses vasodilatation and/or bradycardia (rarely tachycardia), leading to systemic hypotension and cerebral

hypoperfusion

.

Types of reflex syncope include vasovagal syncope, situational syncope, carotid sinus syncope, and atypical forms (without apparent triggers and/or atypical presentation).

Slide113

Reflex Syncope

Vasovagal:

Mediated by emotional distress: fear, pain, instrumentation, blood phobia

Mediated by orthostatic stress

Slide114

Reflex Syncope

Situational:

Cough, sneeze

Gastrointestinal stimulation (swallow, defecation, visceral pain)

Micturition (

postmicturition

)

Post-exercise

Postprandial

Others (e.g., laughter, brass instrument playing, weightlifting)

Hair grooming

Stretching

Slide115

Reflex Syncope

Carotid sinus syncope

Atypical forms (without apparent triggers and/or atypical presentation)

Slide116

Reflex Syncope

Vasovagal syncope (also known as

neurocardiogenic

syncope) is the most common cause of syncope.

The diagnosis may be suggested or diagnosed by a specific history with well-known triggers, but a classic history is not required.

The diagnosis can also be made by exclusion of other causes of syncope and by a characteristic response to upright tilt table testing during which the patient may pass out from bradycardia and/or hypotension.

Slide117

Slide118

Reflex Mechanism - Bezold Jarisch

Chang-Sing P.

Cardiol

Clinics. 1991;9(4):641-651

Inotropy

Contractility

Venous return

Trigger

BP

Sympathetic

tone

Arterial

tone

BP

HR

Vasodilation

BP

Syncope

Vagal

efferent

Small ventricle

Vagal

afferent

Sympathetic

withdrawal

Wall stretch

Reflex

C-fibers

Slide119

Reflex Syncope

Upright posture causes pooling of blood in lower extremities

Decrease in venous return causes transient

hyperdynamic

ventricle

Cardiac C fibers (mechanoreceptors) activate causing parasympathetic response resulting in bradycardia, peripheral vasodilation and hypotension

Abrupt decrease in BP and HR ±

asystole

Slide120

Reflex Syncope

Alterations in autonomic activation are responsible for reflex syncope. Three types of responses are seen: a

cardioinhibitory

response, a vasodepressor response, and a mixed response with features of both.

Slide121

Reflex Syncope

An individual patient may have separate

syncopal

events characterized by a primary vasodepressor,

cardioinhibitory

or mixed responses, but the episodes can vary in their presentation for any individual such that

asystole

may occur at one time and hypotension at another.

Furthermore, the response observed during tilt table testing is not necessarily the same as that recorded during clinical episodes.

Asystolic

pauses are more common during spontaneous episodes, but hypotension is more common during tilt table testing.

Slide122

Reflex Syncope

Vasovagal (

neurocardiogenic

) syncope (also known as the “common faint”) refers to a variety of clinical scenarios in which a neural reflex results in usually self-limited systemic hypotension characterized by bradycardia and/or peripheral vasodilation.

It is the most common cause of syncope (approximately 20 to 35 percent of cases), particularly in patients without apparent cardiac or neurologic disease.

However, reflex syncope is the most common cause of syncope even among patients with heart disease and should be considered as a potential cause in such patients.

Slide123

Reflex Syncope

Vasovagal syncope is a common cause of syncope in athletes.

However, other potential causes of syncope should be considered and evaluated before identifying the etiology of syncope, particularly if the syncope occurs during exertion.

Athletes with syncope during physical activity should be evaluated for potential risk of sudden death.

Slide124

History Reflex Syncope

Clinical presentation — Patients with vasovagal syncope are most commonly young and otherwise healthy.

Typical triggers and premonitory symptoms are strongly suggestive of vasovagal syncope, although these may be absent or difficult to correlate to the

syncopal

episode.

Women and patients younger than 40 are more likely to have typical symptoms.

However, older patients are also frequently diagnosed with vasovagal syncope.

Older individuals have specific triggers that may be absent in younger individuals (i.e., micturition, cough, defecation, deglutition).

Slide125

History Reflex Syncope

Vasovagal syncope (“classical”) refers to syncope triggered by emotional or orthostatic stress such as venipuncture (experienced or witnessed), painful or noxious stimuli, fear of bodily injury, prolonged standing, heat exposure, or exertion (post exertion).

Slide126

History Reflex Syncope

Vasovagal syncope is often associated with a

prodrome

and persistence of nausea, pallor, and diaphoresis, consistent with increased vagal tone.

Syncope is typically of short duration and occurs in the sitting or standing position.

The supine position restores adequate blood flow to the brain.

Slide127

History Reflex Syncope

However, full recovery may be delayed as the patient may feel depressed or fatigued.

This course may help distinguish vasovagal syncope from syncope associated with arrhythmia, which is typically of abrupt onset and of short duration.

Loss of consciousness may be prolonged with some other causes of syncope, such as seizures and aortic stenosis, but rarely with vasovagal syncope

Slide128

Tilt Table Testing

T

he tilt table test has limited specificity, sensitivity, and reproducibility.

Slide129

Slide130

Treatment Reflex Syncope

No therapy has been proven effective for recurrent vasovagal syncope.

Some intuitively appealing therapies have not proven effective.

Therapy is particularly important in patients who have recurrent syncope in high-risk settings (e.g., commercial vehicle driver, pilot) and who wish to continue these activities.

Patients with recurrent episodes may require restriction of activities until therapy is shown to be effective.

Slide131

Treatment Reflex Syncope

Explanation — Patients with vasovagal syncope should be provided with reassurance and education regarding the nature, risks, and prognosis of the condition.

The patient should be advised to assume the supine position with legs raised at the onset of symptoms.

The patient should be advised to avoid trigger events when feasible, and medications that may induce hypotension should be modified or discontinued.

A study of self-reported symptom burden in 418 patients diagnosed with vasovagal syncope indicated that 35 percent were symptom free at median five-year follow-up, regardless of presenting symptom or treatment received.

Slide132

Treatment Reflex Syncope

Physical

counterpressure

— Studies have found that isometric activity, such as crossing the legs and the arms, may be helpful to offset a

syncopal

response, but release of this position may be associated with precipitous decline in heart rate and blood pressure.

Counter-pressure maneuvers, such as tensing the arms with clenched fists, leg pumping, and leg-crossing may abort a

syncopal

episode or at least delay it long enough that patients can assume the supine position.

Physical

counterpressure

maneuvers are intended to reduce lower-extremity venous pooling and therefore improve cardiac output and prevent vasovagal syncope.

Slide133

Treatment Reflex Syncope

Maneuvers include:

■Leg-crossing with simultaneous tensing of leg, abdominal, and buttock muscles.

■Handgrip, which consists of maximum grip on a rubber ball or similar object.

■Arm tensing, which involves gripping one hand with the other while simultaneously abducting both arms

Slide134

Treatment Reflex Syncope

Evidence from clinical trials suggests a limited role for pacemaker therapy in patients with vasovagal syncope.

Slide135

Treatment Reflex Syncope

Some have recommended support stockings (in some cases,

Jobst

stockings), volume expansion by liberalizing salt intake, and occasionally administration of the mineralocorticoid fludrocortisone (similar to the regimen used in the treatment of orthostatic hypotension).

Data are lacking to support this approach in treating reflex syncope.

Slide136

Treatment of Reflex Syncope

Beta blockers

Although beta blockers have been the most commonly used drug therapy for vasovagal syncope, available evidence does not support their efficacy.

They have been postulated to act upon the ill-defined afferent limb of the reflex arc involved in the

Bezold-Jarisch

reflex and to potentially also inhibit the discharge frequency of the C fibers originating from the cardiac mechanoreceptors and chemoreceptors.

Slide137

Treatment Reflex Syncope

■

Midodrine

, an alpha-1-adrenergic agonist, had a beneficial effect in a small randomized trial and a number of observational studies.

The benefits have ranged from prevention of

syncopal

episodes in 95 percent of previously untreated patients to efficacy for up to 22 months in as many as 78 percent of patients who failed to respond to a beta blocker or other conventional therapy.

However, the efficacy of

midodrine

is uncertain, and another alpha agonist,

etilefrine

, was ineffective in a placebo-controlled study of 126 patients

Slide138

Treatment Reflex Syncope

Some patients with vasovagal syncope respond poorly to general measures. Orthostatic or tilt training may be an effective approach, although study results have been mixed.

Slide139

Treatment Reflex Syncope

The efficacy of orthostatic training started in hospital and continued at home was suggested by a controlled but non-randomized study. Forty-seven patients with recurrent syncope and a positive upright tilt table test who were refractory to traditional therapies were assigned to a tilt-training program or to continued medical therapy, depending upon their consent. The training program included five daily in-hospital upright tilt table studies increasing in duration from 10 to 50 minutes. The training program was continued at home with the patient instructed to stand against a wall for up to 40 minutes twice a day, under supervision of a family member.

Slide140

Treatment Reflex Syncope

Wall stands with progressive

increase in

time over 6 to 8 weeks can improve symptoms, possibly by retraining

baroreceptor reflexes. While

the individual is standing, the upper back is positioned against

a wall

without arm and leg movement, beginning with 5-minute intervals twice

daily and

increasing gradually to 30-minute to 40-minute intervals over 6 to 8 weeks.

Slide141

Treatment Reflex Syncope

Moderate exercise training — Limited uncontrolled data suggest that moderate exercise training may increase orthostatic tolerance in patients with syncope.

Slide142

Driving Restrictions

The 2009 ESC guidelines recommend no restriction with a single mild episode of vasovagal syncope in a private driver.

If there are recurrent and severe episodes, private drivers are allowed to return to driving after symptoms are controlled.

For a professional driver, no restriction is recommended for a single mild episode, unless it occurs during high-risk activity.

For recurrent and severe episodes, permanent restriction is recommended unless effective treatment has been established.

Slide143

References

Vanderbilt

Autonomic Dysfunction

site (

www.mc.vanderbilt.edu/gcec/adc

)

http://

www.dysautonomiainternational.org

DOI:

10.1542/peds.2012-2610 Pediatrics

2013;131;968; originally published online April 8,

2013; Julian

M. Stewart Common Syndromes of Orthostatic

Intolerance

Postural Tachycardia

Syndrome: A

Heterogeneous and Multifactorial

Disorder Eduardo

E.

Benarroch

, MD,

DSc

Mayo

Clin

Proc

. 2012;87(12):1214-1225

Slide144