1. Syncope is often related to cardiac causes in adults. Common cardiac causes include structural heart disease, arrhythmias, and obstructive lesions.
2. Long QT syndrome is an inherited condition that can cause syncope, seizures, or sudden cardiac death, especially with exercise or emotions. It is diagnosed by an elongated QT interval on ECG.
3. Congenital heart defects can cause left-to-right shunts, obstructive lesions, or valvular issues, each with their own pathophysiology that can potentially lead to syncope.
2. Essentials in looking at an ECG
Rhythm (sinus….nonsinus)
Rate, Atrial and ventricular rates.
QRS axis, T axis, QRS-T angle
Intervals: PR. QRS, and QT
P wave amplitude and duration
QRS amplitude and R/S ratio
Q wave
St- Segment and T wave abnormalities
3. ECG tips
How do you determine Sinus rhythm?
What is T axis?
What is QRS/T angle?
4. Rhythm
P before every QRS
P axis (0-90). P inverted in aVR
5. P wave axis
The location of the P-wave axis determines the origin of
an atrial-derived rhythm:
• 0 to 90 degrees = a high right (normal sinus rhythm)
• 90 to 180 degrees = a high left
• 180 to 270 degrees = a low left
• 270 to 0 degrees = a low right
6. T wave
In most leads, the T wave is positive.
A negative T wave is normal in lead aVR.
Lead V1 may have a positive, negative, or biphasic T
wave. In addition
It is not uncommon to have an isolated negative T wave
in lead III, aVL, or aVF.
7. Inverted (or negative) T waves can be a sign of
Coronary ischemia
Left ventricular hypertrophy
8. T axis
Determined by the same methods as QRS
0 to + 90 is normal
T Axis out side the normal quadrant could suggest
conditions with Myocardial dysfunction.
9. QRS-T Angle
Formed by the QRS axis and the T axis
QRS-T angle >60 degrees is unusual but if > 90
degrees, it is abnormal.
Abnormally wide angle, with T axis outside the normal
quadrant is seen in
- severe ventricular hypertrophy with starin
- Ventricular conduction disturbances
- Myocardial dysfunction of a metabolic or ischemic nature.
12. Do not forget, nothing replaces good traditional
clinical examination and detailed history
teaching 1.asx
13. Syncope
How often related to the heart?
What are the related cardiac conditions?
How do we approach it?
14. Definition
Syncope is a transient loss of consciousness and muscle
tone.
Near syncope:
premonitory signs and symptoms of imminent syncope
occur; dizziness with or without blackout, pallor,
diaphoresis, thready pulse and low BP
15. Cause
Brain function depends on Oxygen and glucose.
Circulatory, metabolic, or neuropsychiatric causes.
Adults syncope mostly cardiac.
Children’s mostly benign.
16. Causes of Syncope in Children
Extra cardiac causes
Vasovagal
Orthostatic
Failure of systemic venous return
Cerebrovascular occlusive disease
Hyperventilation
Breath holding
17. 1- Vasovagal Syncope
Neurocardiogenic
Common Syncope
Predrome for few seconds; dizziness, light-headedness,
pallor, palpitation, nausea, hyperventilation then Loss of
consciousness and muscle tone
Falls without injury
Lasts about a minute, awake gradually
19. Vasovagal Syncope
Pathophysiology
Standing posture without movement shifts blood to the
lower extremities
Decrease venous return, stroke volume, BP
Less stretching of vent muscle and mechanoreceptors
(mrcpts), decline in neural traffic form mrcpts, decreased
arterial pressure, increase sympathetic output with
Higher HR, vasoconstriction (higher diastolic pressure)
20. Vasovagal Syncope Patients
Decreased venous return produces large increase in
ventricular contraction force
Activation of LV mechanoreceptors (normally only
responds to stretch)
Increase neural traffic mimicking high BP condition
21. Paradoxical withdrawal of sympathetic activity,
vasodilatation, hypotension and bradycardia
Reduction of brain perfusion
22. Diagnoses
ECG, Holter, EEG, glucose tolerance test all are
normally negative in V V E
Tilt test
24. 2- Orthostatic Hypotension
What happen when we stand up?
HR, vasoconstriction
Absent or inadequate upright position response,
Hypotension without increased HR
25. Diagnoses
BP and HR supine and standing up.
BP drop after 5-10 minutes up still by 10-15 mmHG
Positive tilt test without autonomic signs
26. Management
Elastic stockings
High salt diet
Corticosteroids
Slow upright position
27. Micturition Syncope
Rare form of orthostatic
Rapid bladder decompression associated with
degreased total peripheral vascular resistance.
35. Arrhythmia
Arrhythmia
Lack of output
(Fast or slow heart)
SVT, VT, SSS, CHB,
Abnormal Heart
Structure
Normal Ebstein's, MS, MR,
heart structure CCTGA
Long QT, WPW Post op, TOF, TGA
MVP VT
Cmpthy SVT, VT,
s brady
36. Long QT
Syncope, seizures, palpitation during exercise or with
emotion
ECG
Ventricular arrhythmias (Tachy) with risk of sudden
death
37. Long QT
Defective ion
channels
Congenital
Over 50 mutations in
Acquired
4 sites
Drugs, illnesses,
Jarvell-lange-nielson
Autoimmune
Deafness AR
Neurological
Romano-ward
Nutritional
no deafness AD
Electrolytes
Sporadic no FH
no Deafness
38. clinically
FH 60%
Deafness 5%
Presentation with Syncope 26%, seizure 10%, cardiac arrest 9%,
presyncope palpitation 6%
Symptoms during exercise or emotion
Normally symptoms related to ventricular arrhythmias, mostly end of
second decade of life.
39. Syncope in adrenergic arousal, exercise (swimming is a
particular trigger)
Abrupt noises (Alarm, doorbell, phone..)
40. Tests
ECG with QTc >0.46 seconds
Frequently finding abnormal T wave
Bradycardia (20%)
Exercise test, maximum prolongation after 2 minutes of
recovery, ventricular arrhythmia in 30% during exercise
Holter monitoring may show longer QTc
41. Diagnoses Criteria
Electrophysiological society
- QTc >0.44 with no other causes (0.46 sec)
- Positive family history plus unexplained syncope,
seizure or cardiac arrest proceeded by trigger such as
exercise, emotion
42. Treatment
Discuss with cardiologist
Avoid drugs associated with long QT
Avoid swimming, competitive sports
Beta blockers
Demand cardiac pacing (Pacemaker and defib)
Left cardiac sympathetic denervation
43. Prognoses
Untreated 75-80% mortality
Beta blockers reduce mortality to some extent
The adjusted annual mortality rate on treatment is 4.5%
(10 year mortality of 50%)
44. Advise related to CHD
If one child has CHD, what are the chances of the
second?
One parent has CHD, can offspring be affected? What
are the chances?
See Handouts, statistical list of potential risks