SyncopeSyncope

Teresa Menendez Hood , M.D.Teresa Menendez Hood , M.D.

DefinitionDefinition

SyncopeSyncope is a symptom in which there is is a symptom in which there is transient (<30 secs) and self-limited loss of transient (<30 secs) and self-limited loss of consciousness usually leading to a fall. The consciousness usually leading to a fall. The onset is rapid and recovery is spontaneous, onset is rapid and recovery is spontaneous, complete and prompt. The underlying complete and prompt. The underlying mechanism is relatively abrupt cerebral mechanism is relatively abrupt cerebral hypoperfusion.The onset may or may not have hypoperfusion.The onset may or may not have warning and some older patients may have warning and some older patients may have retrograde amnesia. Fatigue is common post-retrograde amnesia. Fatigue is common post-syncope.syncope.

SYNCOPE STATSSYNCOPE STATS

25% people will have syncope at some 25% people will have syncope at some point point

6% of hospital admits are for syncope6% of hospital admits are for syncope3% of all ER visits3% of all ER visits30% have recurrences30% have recurrences40% remain undiagnosed after initial 40% remain undiagnosed after initial

evaluationevaluation

Syncope: EtiologySyncope: Etiology

OrthostaticCardiac

Arrhythmia

StructuralCardio-

Pulmonary

*

Non-Cardio-

vascularNeurally-Mediated

Unknown Cause = 34%

24%

11%

14%

4%

12%

Causes of SyncopeCauses of Syncope

Neurally-mediated reflex syncopeNeurally-mediated reflex syncope-a -a reflex that when triggered gives rise to reflex that when triggered gives rise to vasodilation and/or bradycardiavasodilation and/or bradycardiaVasovagal Vasovagal -look for precipitating events: fear, -look for precipitating events: fear,

pain, prolonged standingpain, prolonged standingCarotid sinusCarotid sinus - -turning head to one side, age turning head to one side, age

>40>40Situational Situational -cough, micturition, post-exercise, -cough, micturition, post-exercise,

post-prandial, swallow, defecation….post-prandial, swallow, defecation….

Causes of SyncopeCauses of Syncope

OrthostaticOrthostatic Autonomic FailureAutonomic Failure-- the autonomic nervous system the autonomic nervous system

does not work well and one does not get the does not work well and one does not get the vasoconstrictor mechanisms to upright posture :vasoconstrictor mechanisms to upright posture :

primary or multisystem, secondary (DM, amyloid), drug induced primary or multisystem, secondary (DM, amyloid), drug induced (the most common). Look for autonomic problems in other (the most common). Look for autonomic problems in other organs..i.e cannot sweat, impotence, disturbed micturitionorgans..i.e cannot sweat, impotence, disturbed micturition

Volume depletionVolume depletion

Cardiac ArrhythmiasCardiac Arrhythmias Sinus node dysfunction, AVN disease, SVT/VT, Sinus node dysfunction, AVN disease, SVT/VT,

inherited diseases(LQT, Brugada, WPW,ARVD,HCM)inherited diseases(LQT, Brugada, WPW,ARVD,HCM)

Causes of SyncopeCauses of Syncope

Structural Cardiac or Cardiopulmonary Structural Cardiac or Cardiopulmonary disease- disease- an obstruction of blood flowan obstruction of blood flowValvular diseaseValvular diseaseObstructive CMObstructive CMAtrial MyxomaAtrial MyxomaAortic dissectionAortic dissectionTamponadeTamponadePEPE

Causes of SyncopeCauses of Syncope

CerebrovascularCerebrovascularVascular steal syndromeVascular steal syndrome -subclavian -subclavian

steal:rare, syncope associated with arm steal:rare, syncope associated with arm exercise: the blood vessel supplies both the exercise: the blood vessel supplies both the brain and the arm. Check for BP in both arms!brain and the arm. Check for BP in both arms!

VetebrobasilarVetebrobasilar TIATIA -doubtful that can really -doubtful that can really cause syncopecause syncope

Features suggestive of Features suggestive of cardiaccardiac causes?causes?

Occur in the Occur in the supinesupine position or position or duringduring exertionexertion

Preceded by Preceded by palpitationspalpitationsPresence of Presence of severesevere heart disease heart diseaseEKGEKG abnormalities: wide QRS, AV abnormalities: wide QRS, AV

conduction disease, Q waves, LQT, delta conduction disease, Q waves, LQT, delta wave, SQT, epsilon wavewave, SQT, epsilon wave

Features suggestive of Features suggestive of Neurally-MediatedNeurally-Mediated causes? causes?

ProlongedProlonged standing in crowded, warm standing in crowded, warm placeplace

Preceding Preceding nauseanausea, feeling cold and , feeling cold and sweatysweaty

AfterAfter exertion or post-prandial exertion or post-prandialTonic-clonic movements are short in Tonic-clonic movements are short in

duration and occur duration and occur afterafter the loss of the loss of consciousnessconsciousness

Long duration of symptoms …>4yearsLong duration of symptoms …>4years

Causes of Causes of non-syncopalnon-syncopal attacksattacks

Impairment of /loss of consciousnessImpairment of /loss of consciousnessMetabolicMetabolic-hypoglycemia , hypoxia, -hypoglycemia , hypoxia,

hyperventilation syndromehyperventilation syndromeEpilepsyEpilepsy-Typical premonitory aura? Post-ictal -Typical premonitory aura? Post-ictal

state?state?Loss of muscle controlLoss of muscle control

CataplexyCataplexy-usually with narcolepsy-usually with narcolepsyPsychogenicPsychogenic

The Initial EvaluationThe Initial Evaluation

Careful HistoryCareful History - from patient and - from patient and witnesses: this is the most important tool witnesses: this is the most important tool in the diagnosis!in the diagnosis!Prior to attack, onset, eyewitnesses, end of Prior to attack, onset, eyewitnesses, end of

the attack, PMH, FH, drug history?the attack, PMH, FH, drug history?Physical examPhysical exam- include orthostatic BP- include orthostatic BPStandard EKGStandard EKG

EvaluationEvaluation

The use of EEG, CT, MRI , carotid The use of EEG, CT, MRI , carotid dopplers are dopplers are notnot usually helpful in the usually helpful in the workup of syncopeworkup of syncope

HospitalizeHospitalize patients when the features patients when the features suggest a suggest a cardiaccardiac cause, when it results cause, when it results in in severesevere injury, or when the syncope is injury, or when the syncope is frequentfrequent

EvaluationEvaluation

When the cause of the syncope is When the cause of the syncope is notnot evident evident after the initial evaluation after the initial evaluation andand there is evidence there is evidence of heart disease of heart disease thenthen the possibility of cardiac the possibility of cardiac syncope must be entertained as these patients syncope must be entertained as these patients have a have a highhigh mortality at one year( mortality at one year(18-30%18-30% mortality)mortality)

Cardiac evaluationCardiac evaluation: echo, stress test, : echo, stress test, holter/loop and EP testing.holter/loop and EP testing.

In a patient with cardiac disease In a patient with cardiac disease butbut with with negative cardiac workup, then proceed with tilt negative cardiac workup, then proceed with tilt testing and / or implantable loop recorder.testing and / or implantable loop recorder.

EvaluationEvaluation

In those In those withoutwithout heart disease, then tilt heart disease, then tilt table testing and carotid massage (more table testing and carotid massage (more important in the patients > 40) for neurally important in the patients > 40) for neurally mediated syncope is recommended for mediated syncope is recommended for those with recurrent or severe syncope.those with recurrent or severe syncope.

SAECG has fallen out of favor. If it is SAECG has fallen out of favor. If it is normal it helps.normal it helps.

Test/ProcedureTest/Procedure YieldYield(based on mean time to diagnosis of 5.1 (based on mean time to diagnosis of 5.1

monthsmonths77

History and Physical History and Physical

(including carotid sinus massage)(including carotid sinus massage)

49-85%49-85% 1, 21, 2

ECGECG 2-11%2-11% 22

Electrophysiology Study without SHD*Electrophysiology Study without SHD* 11%11% 33

Electrophysiology Study with SHDElectrophysiology Study with SHD 49%49% 33

Tilt Table Test (without SHD)Tilt Table Test (without SHD) 11-87%11-87% 4, 54, 5

Ambulatory ECG Monitors:Ambulatory ECG Monitors:

HolterHolter 2% 2% 77

External Loop RecorderExternal Loop Recorder

(2-3 weeks duration)(2-3 weeks duration)

20% 20% 77

Implantable Loop RecorderImplantable Loop Recorder

(up to 14 months duration)(up to 14 months duration)

65-88%65-88% 6, 76, 7

Neurological Neurological ††

(Head CT Scan, Carotid Doppler)(Head CT Scan, Carotid Doppler) 0-4%0-4% 4,5,8,9,104,5,8,9,10

Patient Activator Reveal® Plus ILR 9790 Programmer

Offers up to 14 months of continuous, leadless ECG Offers up to 14 months of continuous, leadless ECG monitoringmonitoring

High diagnostic yield (65-88%) High diagnostic yield (65-88%)

High patient complianceHigh patient compliance

Patient and Patient and auto triggeredauto triggered to capture ECG to capture ECG

Reveal® Plus ILR

• Implant parallel to the midline in the region

• From left parasternal area to the mid-clavicular line

• First to the fourth rib

Implant zone for optimal auto activation performanceImplant zone for optimal auto activation performance

0.4mV

0.2

0.0

-0.2

-0.4

0.4

0.2

0.0

-0.2

-0.4

0.4

0.2

0.0

-0.2

-0.4:45:44:43:42:41:40:39:38:37

:37:36:35:34:33:32:31:30:29

:29:28:27:26:25:24:23:22:21

08:23:21

8:23:29

08:23:37

Randomized Assessment of Syncope Trial (RAST)

Comparison of the Implantable Loop Recorder with Conventional Diagnostic Testing for Unexplained

Syncope1

Andrew D. Krahn, George J. Klein, Raymond Yee, Allan C. Skanes

University of Western Ontario

London Ontario Canada

1. Krahn A, et al. Circ. 2001;104(11):46-51

• Prospective randomized trial (60 patients with unexplained syncope referred for cardiac investigation)

• Inclusion:

• Recurrent unexplained syncope

• Referred to the arrhythmia service for cardiac investigation

• No clinical diagnosis after history, physical, ECG and at least 24 hours of cardiac monitoring

• Exclusion:

• LVEF < 35%

• Unable to give informed consent

• Major morbidity precluding 1 year of follow-up

Methods

• Conventional Investigations:

• ELR then HUT then EPS(see below for definitions)

ILR4

• Left sided implant with antibiotics

• Patient education

• 1 year of follow-up

• Crossover

• After primary arm was completed, patients were offered crossover to facilitate

diagnosis

Methods

1. External loop recorder(ELR)2. Head up tilt test(HUT)3. Electrophysiological

study(EPS)4. Insertable Loop Recorder(ILR)

ILR (n=30) Conventional (n=30)

Age (years) 64 +/- 14 68 +/- 14

Gender (# male) 19 (63%) 14 (47%)

Syncopal Episodes 4.1 +/- 3.3 5.8 +/- 6.6

Duration of Syncope (yrs) 6.6 +/- 12 8.7 +/- 2.7

LVEF (%) 55 +/- 8 55 +/- 6

Results

RAST Results

Randomized Assessment of Syncope Trial

3in fo llow-up

14diagnosed

13undiagnosed

30ILR

6diagnosed

24undiagnosed

30conventional

U nexpla ined Syncopen=60

RAST Crossover Results

1diagnosed

5undiagnosed

13 / 30undiagnosed after m onitoring

6 accepted crossover to conventional

8d iagnosed

5undiagnosed

8in fo llow-up

24 / 30undiagnosed after conventional

21 accepted crossover to m onitoring

U nexpla ined Syncopen=60

Diagnosis By: ILR* Conventional p value

Primary Strategy 14/27 (52%) 6/30 (20%) p=0.012

Crossover 8/13 (62%) 1/6 (17%) p=0.069

Primary and Crossover 22/40 (55%) 7/36 (19%) p=0.0014

*3 primary ILRs and 8 crossover ILRs have not completed follow up.

RAST Results

Conclusions

• This prospective randomized trial suggests that the implanted loop

recorder has a superior diagnostic yield as a primary strategy.

• The diagnostic yield of conventional testing in these patients is

disappointing (19%).

• The loop recorder retains high utility when used after conventional

testing is negative.

• Consideration should be given to use at an earlier stage in the

diagnostic cascade in this patient population.

AsystoleAsystole BradyBrady NormalNormalSRSR

TachyTachy Syncope Syncope RecurrenceRecurrence

Pilot studyPilot studyCirculation, Circulation, 9595

N/AN/A 7 7 (47%)(47%)

6 6 (40%)(40%)

2 2 (13%)(13%)

15/1615/1694%94%

Krahn et alKrahn et alCirculation, Circulation, 9999

N/AN/A 14 14 (69%)(69%)

7 7 (30%)(30%)

2 2 (9%)(9%)

23/8523/8527%27%

Nierop et alNierop et alPACE, 2000PACE, 2000

N/AN/A 4 4 (29%)(29%)

6 6 (43%)(43%)

4 4 (29%)(29%)

14/3514/3540%40%

ISSUE studyISSUE studyCirculation, Circulation, 20012001

16 16 (50%)(50%)

3 3 (9%)(9%)

12 12 (34%)(34%)

1 1 (3%)(3%)

32/11132/11129%29%

TotalTotal 444452%52%

313137%37%

9911%11%

84/24784/24734%34%

IndicationsIndications

Patients with clinical syndromes or Patients with clinical syndromes or situations at increased risk of cardiac situations at increased risk of cardiac arrhythmiasarrhythmias

Patients who experience transient Patients who experience transient symptoms that may suggest a cardiac symptoms that may suggest a cardiac arrhythmiaarrhythmia

The Reveal Plus Insertable Loop Recorder is indicated for:

Tilt Table DiagnosisTilt Table Diagnosis

Neurocardiogenic-seen in Neurocardiogenic-seen in 50%50% of patients with of patients with heart disease and heart disease and 75%75% of patients without heart of patients without heart disease who present with syncopedisease who present with syncope

Type 1 mixed: bp falls before heart rate and the heart rate Type 1 mixed: bp falls before heart rate and the heart rate does not get <40 and no pauses >3 secs and heart rate falls does not get <40 and no pauses >3 secs and heart rate falls at the time of syncopeat the time of syncope

Type 2a: cardioinhibitory without asystole-bp falls before the Type 2a: cardioinhibitory without asystole-bp falls before the heart rate and heart rate gets below 40 but no asystole > 3 heart rate and heart rate gets below 40 but no asystole > 3 secssecs

Type 2b: cardioinhibitory with asystole-heart rate falls below Type 2b: cardioinhibitory with asystole-heart rate falls below 40 for > 10secs and asystole is present >3 secs40 for > 10secs and asystole is present >3 secs

Type 3: pure vasodepressor-bp falls but heart rate does not Type 3: pure vasodepressor-bp falls but heart rate does not fall >10% from peak heart rate .fall >10% from peak heart rate .

Tilt Table DiagnosisTilt Table Diagnosis

DysautonomicDysautonomic Gradual decline in the systolic and diastolic bp with or Gradual decline in the systolic and diastolic bp with or

without a drop in the heart rate. without a drop in the heart rate. Orthostatic intolerance is the key problemOrthostatic intolerance is the key problem

POTS-Postural orthostatic tachycardia POTS-Postural orthostatic tachycardia syndromesyndrome An excessive heart rate response to maintain a low An excessive heart rate response to maintain a low

normal blood pressure. Will have an excess of >30 normal blood pressure. Will have an excess of >30 beats increase when placed uprightbeats increase when placed upright

Tilt Table DiagnosisTilt Table Diagnosis

Cerebral syncopeCerebral syncopeAssociated with cerebral vasoconstriction in Associated with cerebral vasoconstriction in

the absence of systemic hypotension and the absence of systemic hypotension and would need a transcranial Doppler for would need a transcranial Doppler for confirmationconfirmation

PsychogenicPsychogenic

ProtocolsProtocols

WestminsterWestminsterPassive tilt for 45 minutes at 60-80 degrees and Passive tilt for 45 minutes at 60-80 degrees and

has a positive rate of 75% with specificity of 95%has a positive rate of 75% with specificity of 95%

ProtocolsProtocols

ItalianItalian

Passive tilt for 20 minutes and the challenge Passive tilt for 20 minutes and the challenge with SUBLINGUAL NITROGLYCERIN while with SUBLINGUAL NITROGLYCERIN while still upright and has specificity of 94%.still upright and has specificity of 94%.

Will see a progressive drop in the BP with no Will see a progressive drop in the BP with no bradycardia if the effect is due to the drug bradycardia if the effect is due to the drug alone and this is not a positive test..seen in alone and this is not a positive test..seen in 20%!20%!

Syncope

History and Physical

ECG

KnownSHD

NoSHD

Echo

EPS

+

Treat

> 30 days; > 2 Events

Tilt ILR

Tilt Holter/ ELR

ILR

Tilt/ILR

< 30 days

-