Indian Society of Electrocardiology

Long-term monitoring:

Unraveling mechanism of Syncope

Amit Vora

Syncope: Etiology

Orthostatic Cardiac

Arrhythmia

Structural

Cardio-

Pulmonary

*

1

• Vasovagal

• Carotid

Sinus

• Situational Cough

Post-

micturition

2

• Drug

Induced

• ANS

Failure Primary

Secondary

3

• Brady Sick sinus

AV block

• Tachy VT

SVT

• Long QT

Syndrome

4

• Aortic

Stenosis

• HOCM

• Pulmonary

Hypertension

5

• Psychogenic

• Metabolic

e.g. hyper-

ventilation

• Neurological

Non-

Cardio-

vascular

Neurally-

Mediated

Unknown Cause = 34%

24% 11% 14% 4% 12%

DG Benditt, UM Cardiac Arrhythmia Center

History, examination, ECG

Neurally mediated syncope

Orthostatic hypotension

Unexplained syncope

Echo, Exercise test

Abnormal Normal

EP study

Episodes: Single Infrequent Frequent

Evaluation complete Implantable loop Holter, event recorder

recorder ILR

History

Inflow /outflow obstruction Examination

SN dysfunction / AV block

MI, LVH, long QT etc. ECG

Implantable ECG Monitoring Systems

Activator

Base Station

Monitoring Center

Implanted Device

Physician

13 yrs-old-boy,

3 episodes of unconsciousness over 1 year,

urinary incontinence.

Examination: Normal

Investigation of choice:

A. EEG /CT / MRI brain

B. ECG

C. Holter / Event recorder

D. All of the above

E. None of the above

Event recorder:

Your diagnosis:

1.SN dysfunction

2.AV block

3.Vaso-vagal

Tilt Table Test

29 yrs-old Nurse

5 episodes of syncope over 3 years

Seen by physician, intensivist, neurologist

Clinical examination – normal

EEG – normal

MRI brain ‘thrice’ – normal

ECG in pt with syncope:

1. LVH

2. WPW

3. Long QT

4. ARVC / Brugada

5. Chamber enlargement

6. Pulmonary embolism

7. Coronary ischemia

CV cause of syncope

& normal ECG:

1. Vagally mediated

2. Long QT

3. LVH

4. Pre-excitation

5. Rapid SVT

6. Paroxysmal AV block

7. LA myxoma

8. VBI – steal syndrome

9. Pulmonary embolism

10.Idiopathic VF

Management plan:

A. Anxiolytics / anti-depressants

B. Anti-epileptics

C. Echo

D. Holter / Long-term ECG monitoring

E. EP study

72 hr Holter

Is this artifact

a. Yes

b. No

4 yr-old girl, presented with seizures

Twice in the morning while getting

ready to go to school

Clinical examination - normal

How do we proceed?

A. EEG/CT/MRI

B. HUTT

C. ECG/Echo/Holter-Event recorder

D. All of the above

Holter…

Best treatment option for LQTS pts:

A. Beta-blockers

B. Beta-blockers & pacemaker

C. Left cervical sympathectomy

D. AICD

Exertional Syncope

1. Coronary insufficiency

2. Outflow obstruction

3. Fixed output states – PH

4. WPW / Long QT syndrome

5. RVOT - VT

6. Infra-Hisian AV blocks

82 yrs-old lady

HT on amlodepin

Recent episode of unsteady gait,

Loss of consciousness – few minutes,

Disorientation for a while & then ok

Neurologic Examination / ECG: normal

MRI brain: Thallimic infarct

How to manage?

A. Anti-platelets & Statins

B. Anti-coagulation

C. CAG

D. Further evaluation

Event

Monitor..

Any change of Rx plan?

A. Anti-platelets & Statins

B. Anti-coagulation

C. Β blockers

D. Amiodarone

One un-fine day.....

• 65 yr-old-lawyer, father of medicine resident

• Pituitary adenoma – 15 yrs

• Anterior wall MI – 12 yrs

• Repeated fainting spells for the past 3 years

(multiple hospitalizations)

• ECG – sinus rhythm, old AWMI with RBBB

• Echo – LVEF 0.35 (steady for the past 10 yrs)

• Holter – no bradycardia, AV blocks, PVCs, NSVT

• CT/MR/EEG – all normal

• CAG – no evidence of reversible ischemia

• Consulted physician, cardiologist, neurologist…

ECG

Fainting spells are due to:

A. Pituitary adenoma

B. Epilepsy

C. Bradyarrhythmia

D. Tachyarrhythmia

E. Vagally mediated

2:1 AV block

EP study…

A H

43 yr old lady, sudden

unconsciousness with fall and

convulsions early morning

• CT (brain): small intracranial bleed

• Examination: normal

Next step? A. Anti-convulsants

B. 4 vessel MR Angio

C. Further cardiac evaluation

Event monitor..

Diagnosis: “Paroxysmal” AV block

Paroxysmal atrio-ventricular block

Mechanism

Local phase-4 depolarization in the

sub AV nodal conduction system

94001/1

Mechanisms initiating paroxysmal AV block

Critical P-P lengthening following:

1. Atrial premature beat conducted/non-conducted

2. Ventricular premature beat with VA conduction

3. HIS bundle extrasystole

4. Critical P-P lengthening after carotid sinus massage

5. After valsalva maneuver

84338

96616

96616

96619/2

• 64 yrs-old-gentleman

• S/P CABG

• Transient uneasy/dizzy feeling

• NYHA I-II

• LVEF 0.25

ECG:

64 yrs, CABG, transient uneasy/dizzy feeling, NYHA I-II, LVEF 0.25

What do you suspect?

A. AV block

B. Postural hypotension

C.TIA

D.Coronary ischemia

E. Ventricular tachycardia

Investigation of choice:

A. Electrophysiology study

B. Coronary angiography

C. Holter / Event monitor

D. CT scan / MRI brain

EP study:

AH: 140 ms HV: 60 ms

1:1 AV @ 450 ms

In patients with wide QRS & LV dysfunction,

there is a 50% or more chance of syncope

due to ventricular tachyarrhythmia.

67 yrs-old, HT/DM

Intermittent pre-syncope

(once in 2-3 months; off late increased)

ECG: SR & RBBB

Echo: LVEF 0.60

Investigation of choice:

A. Holter / Event recorder

B. EP study

C. Carotid Doppler / MRI brain

Diagnosis:

A. AV nodal block

B. Infra-Hisian Block

C. Atrial tachycardia

Pacemaker indicated

a. Yes

b. No

c. Don’t know

d. Needs CAG

Elderly man, repeated syncope,

normal Echo

What do you suspect?

A. AV block

B. Postural hypotension

C. Coronary ischemia

D. Ventricular tachycardia

EPS

65 yr-old-lady, VVI pacemaker 3 yrs ago for CHB, now c/o syncope

Likely cause of syncope:

1.Pacemaker malfunction

2.Postural hypotension

3.TIA

4.Ventricular tachycardia

GP started sparfloxacin for respiratory tract infection!

Conventional Diagnostic Methods/Yield Test/Procedure Yield

(based on mean time to diagnosis of 5.1 months7

History and Physical

(including carotid sinus massage)

49-85% 1, 2

ECG 2-11% 2

Electrophysiology Study without SHD* 11% 3

Electrophysiology Study with SHD 49% 3

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

Ambulatory ECG Monitors:

• Holter 2% 7

• External Loop Recorder

(2-3 weeks duration)

20% 7

• Insertable Loop Recorder

(up to 14 months duration)

65-88% 6, 7

Neurological †

(Head CT Scan, Carotid Doppler)

0-4% 4,5,8,9,10

* Structural Heart Disease † MRI not studied

1 Kapoor, et al N Eng J Med, 1983.

2 Kapoor, Am J Med, 1991.

3 Linzer, et al. Ann Int. Med, 1997.

4 Kapoor, Medicine, 1990.

5 Kapoor, JAMA, 1992

6 Krahn, Circulation, 1995

7 Krahn, Cardiology Clinics, 1997.

8 Eagle K,, et al. The Yale J Biol and Medicine. 1983; 56: 1-8.

9 Day S, et al. Am J Med. 1982; 73: 15-23.

10 Stetson P, et al. PACE. 1999; 22 (part II): 782.

Warning Signs for Malignant Syncope

• Structural heart disease

• During exercise

• Unusual circumstances:

– loud noise, swimming, sleep

• Family history of Sudden Cardiac Death