Post on 03-May-2020
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