12 Lead ECG of single ventricle

1. ECG in single
ventricle
SIMPLICITY IS THE FINEST ART

2. SV of LV morphology with NRGA

3. Van Praagh et al.1964
1. Type A, DILV ; absence of right ventricular sinus.
2. Type B, DIRV; absence of left ventricular sinus.
3. Type C, Double-inlet ventricle of mixed morphology (absence of the
ventricular septum); and
4. Type D, Double-inlet ventricle of indeterminate or undifferentiated
morphology.

4. Single ventricle
 Apply to a double-inlet/single inlet
or common-inlet ventricle
opening into one ventricular
chamber

5. 1858, Thomas Peacock
“The auricular sinuses are separated
by a more or less complete septum,
and there are generally two auriculo-
ventricular apertures, while the
ventricle is either wholly undivided or
presents only a very rudimentary
septum. The arteries which are given
off are usually two in number—an
aorta and a pulmonary artery”

6. ANATOMY
 A=NON INVERTED AND NO PS
 B=INVERTED +NO PS
 C=NON INVERVETED +PS
 D=INVERTED+PS

8. VENTRICULAR TOPOLOGY

9. Refresh yours as the conductions bundles just rounds around the pulmonary artery
Sometimes anterior, sometimes posterior, then right side and then left side

11. Normal development
 Ventricular components of the conduction axis are carried on the
crest of the muscular ventricular septum, and the atrioventricular
node, or in some instances nodes, is formed at the point, or points,
of union of the septum with the atrioventricular junctions

12. Abnormalities continued….
 Ring of specialized tissue with AV ring-forms special node
anterolateral.
 AV connection affects location of AV node
 Location of rudimentary ventricle-decides location of contact B/W
septum and conduction tissue.
 Atrial Situs –sidedness of SA node and AV node.

13. Morphologic left ventricle
Non inverted outlet Inverted outlet
 A long non branching
penetrating bundle runs
down the right parietal wall
of the single ventricle
toward the outlet foramen
before bifurcating into right
and left bundle branches
 Inlet portion of the ventricular mass absent
 The QRS axis is directed inferior and to the right, away from the
inverted outlet chamber and toward the main ventricular mass
 The posterior AV node is hypoplastic and does not form a His
bundle or establish a ventricular connection
 A well-developed anterior accessory AV node gives rise to the
His bundle and establishes atrioventricular connections
 Penetrating bundle encircles the outflow tract of the single
ventricle before branching at the outlet foramen
 The left bundle branch is concordant with left ventricular
morphology of the single left ventricle and Right bundle
branch is concordant with the outlet chamber

14. SV-LV-INVERTED OUTLET-ANGIOGRAM

15. Morphologic Right Ventricle
 An inlet septum is also lacking in univentricular hearts with a
morphologic right ventricle
 Outflow tract is rudimentary posterior trabecular pouch
 However, the ventricular segment between the morphologic right
ventricle and the trabecular pouch extends to the crux where a
regular posterior AV node and His bundle are formed
 Distribution of the bundle branches apparently depends on the
right/left orientation of the trabecular pouch

16. morphologically indeterminate
 No outlet chamber, no trabecular pouch
 No the inlet septum nor trabecular septal tissue reaches the crux
 AV node is anterior or anterolateral
 Penetrating bundles descend as single fascicles among free-running
trabeculae.

17. ECG
 Features depends upon
 Anatomic variations
 Ventricular morphology
 Physiologic derangements
 When pulmonary blood flow is increased ,P waves show left atrial or biatrial
abnormalities
 When pulmonary blood flow is reduced P waves show right atrial
abnormalities
 The PR interval tends to be normal with normal atrioventricular conduction
despite an elongated nonbranching penetrating bundle

18. Non inverted outlet +morphologic LV
 QRS axis tends to be directed leftward and superior—left axis
deviation axis deviation
 Initial depolarization is anterior and leftward, so small Q waves
occasionally appear in left precordial leads
 Left ventricular hypertrophy
 Pulmonary blood flow is increased and the single ventricle is volume
overloaded
 Precordial QRS complexes then exhibit voltages of remarkably
great amplitude and patterns that are stereotyped
 precordial leads may show a dominant R wave in leadV1 and
large equidisphasic RS complexes in midprecordial leads

19. LV morphology and inverted outlet
 the QRS axis is inferior and to the right, directed away from the
inverted outlet chamber toward the main ventricular mass

20. Conduction problem
 PR interval prolongation
 Complete heart block is occasional and progressive
 The P wave axis shifts to the left, so tall peaked right atrial P waves
appear in mid and left precordial leads . This pattern also occurs
with noninversion of the outlet chamber ventricular depolarization is
clockwise, so Q waves appear in leads 2, 3, and aVF
 Because initial forces of ventricular depolarization are posterior and
leftward, Q waves may be present in right precordial leads but not
in left precordial leads

21.  Even though the univentricular heart is morphologically a left
ventricle, In univentricular hearts with a morphologic right ventricle
and a trabecular pouch,.

22. Morphologic right ventricle
 Atrioventricular conduction is normal because a regular posterior
AV node and His bundle are formed at the crux
 Right axis deviation and tall stereotyped precordial R waves
 The QRS axis is usually rightward but occasionally is leftward and
superior

23.  AV conduction
abnormal
 PR prolongred—CHB
 P wave
◦ left axis
◦ Tall peaked RT atrial P
waves in mid to left
precordial leads
 QRS axis inferior and
right
 Clockwise loop-Q in
2,3,aVF
 Q in RT precordial leads
 Dominant R in V1 and
RS in mid precordial
leads
DILV-inverted outlet chamber
ECG

24.  DILV-noninverted outlet
chamber
◦ PR normal
◦ P wave-
 LAE in increased PBF
 RAE in decreased PBF
◦ QRS axis away from inverted
outlet chamber
◦ LAD- Counterclockwise loop
◦ Small Q in left leads
◦ Stereotyped complexes
ECG

25.  Dominant RV
 Normal posterior AV
node and HIS bundle
 RAD
 Tall stereotyped R in
precordial leads.

28. Summary
DOMINANT VENTRICLE
LEFT (A)
RIGHT(B)
COMMON AND
INDETERMINATE(C&D)
ABNORMAL ANTERIOR ACCESSORY NODE
INVERTED
NON INVERTED
ANTERIOR TO PA LATERAL TO PA
No septum
Normal
TOPOLOGY
RT(NON INV) LT (INV)
SLING OF CONDUCTION TISSUE BETWEEN ANT AND REG NODE

29. Very difficult ! I can not hear that