Transcript Slide 1

UOG Journal Club: October 2011
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
B. Tutschek and K. G. Schmidt
Volume 38, Issue 4, Date: October 2011, pages 406–412
Journal Club slides prepared by Dr Aly Youssef
(UOG Editor for Trainees)
Background
• Fetal arrhythmias may lead to fetal cardiac failure,
hydrops and death
• Precise evaluation of the type and mechanism of a fetal
arrhythmia is mandatory in order to define prenatal
treatment options and prognosis
Background: Current assessment of fetal arrythmias
Pulsed-wave Doppler of
blood flow
M-mode
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High temporal resolution
Dependent on fetal position
May require multiple attempts
to acquire appropriate
tracings
(e.g. at the pulmonary artery/vein)
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Displays diastolic and systolic flow
events in one recording
Mostly independent of fetal position
Different pulsed-wave propagation
times may interfere with the analysis
of electromechanical coupling
Pulsed-wave tissue
Doppler echocardiography
(current study)
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Objective: To study normal and abnormal fetal cardiac rhythm using
pulsed-wave tissue Doppler echocardiography (PW-TDE)
Patients:
100 fetuses
15–40 weeks referred for cardiac evaluation
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55
45
Normal anatomy and function
Cardiac arrhythmias
All fetuses had a complete fetal echocardiographic examination before entry into the study
Axial excursions of the ventricular wall at the atrioventricular (AV) valve annulus were recorded using
PW-TDE
Both PW-TDE and pulsed-wave Doppler of the blood flow through the AV valves were recorded
simultaneously in several of the normal fetuses (in order to study the temporal correlation between
flow and tissue signals)
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Methods
Ultrasound system
Several different high resolution ultrasound systems equipped for prenatal or neonatal
studies, but without specific tissue Doppler probes or software
Ultrasound settings
↓ Pulse repetition frequency (PRF) (to about ± 15 cm/sec)
↓ Wall filter (minimum)
↓ Receive gain (to remove blood flow signals)
Technique
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The heart is imaged in an apical (or close to apical) insonation angle
Pulsed Doppler sample volume adjusted in size and placed over the area covering the
entire valve annulus excursion during systole and diastole
Data acquired during fetal and maternal apnea and absence of fetal body movements
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Results: Correlation with blood flow Doppler
mitral inflow, aortic outflow /
left ventricular TD
tricuspid inflow /
right ventricular TD
tissue Doppler (TD) signals
blood flow Doppler signals
Note that blood flow and wall
movements are
synchronous, but run in
opposite directions
The temporal relation of
PW-TDE and conventional
blood flow Doppler signals
was depicted in such tracings,
confirming the interpretation of
the PW-TDE signals
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Results: Normal pattern of PW-TDE
Early diastole
Late diastole
Isovolumetric contraction
Isovolumetric relaxation
Away from
the apex
• Best signal-to-noise ratio was usually obtained from
right ventricular wall (tricuspid valve annulus)
• Separate E’ and A’ were often seen, followed by S’
• Fusion of E’ and A’ occurred if rates are > 130bpm
Towards
the apex
Systole
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Results: PW-TDE in fetal arrhythmias
Premature ventricular contractions
(PVC)
Non-conducted premature
atrial contraction (PAC)
• Atrial activity (A’) is regular
• Atrial activity is irregular due to PAC
• Interval preceding PVC (dashed red bar)
• Absence of systolic excursion (S’)
plus post-ectopic interval (solid red bar)
equals interval between two normal sinus
beats (white bar) i.e. compensatory pause
• In post-ectopic pause (post PVC), E’ and A’
are separate
after PAC (non-conducted)
• Interval between pre- and post-ectopic
Conducted premature
atrial contraction (PAC)
• PAC is followed by systolic
excursion (&)
• Conducted PAC shows an early
atrial activation with associated
atrial activation is shorter than the
ventricular response (&), but also a
expected interval between two normal
non- compensatory pause
beats (non- compensatory pause)
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Results: PW-TDE in fetal arrhythmias
Supraventricular
tachycardia (SVT)
• E’ and A’ (below baseline) always
coincided
• There was a 1:1 association of
atrial and ventricular motion
2nd degree atrioventricular
block, type Wenckebach
• There was progressive lengthening
of conduction time in successive
cardiac cycles until ventricular
response was skipped (*)
Ventricular tachycardia
with AV dissociation
• There were regular atrial activations
(A), but much more rapid and
dissociated ventricular contractions
(S)
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Results: PW-TDE of complete fetal atrioventricular block
Ventricular contractions
Atrial contractions
Atrial activations obscured
by ventricular activation
Atrial activity immediately
after ventricular emptying
(large amplitude)
Atrial activation occurring
after S’, associated with
separation of E’ and A’
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Discussion: Comparison with pulsed-wave blood flow Doppler
Pulsed-wave Doppler of blood
flow
(e.g. in the pulmonary vessels,
Carvalho et al., Heart 2007)
Pulsed-wave tissue Doppler
echocardiography
(Tutschek and Schmidt, UOG 2011)
Movement detected
Blood flow
(in the peripheral lung vessels)
AV annulus motion
(one step closer to the actual
electromechanical basis)
Segments interrogated
Two
(simultaneous pulmonary artery and
vein)
One
(AV annulus)
Dependence on fetal
position
Mostly independent
Dependent
(apical insonation angle is
mandatory)
Visualization of intracardiac
structures
Mostly unnecessary
Necessary
(AV annulus)
Special hard- or software?
No
No
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Arrythmias with a difficult
assessment
Pulsed wave Doppler of blood
flow in the pulmonary vessels
(Carvalho et al., Heart 2007)
Pulsed wave Tissue Doppler
echocardiography
(Tutschek and Schmidt , UOG 2011)
Complete AV block
(due to difficulty in recognizing the
‘‘A’’ wave against
a background of low or absent
venous velocities in different
phases of the cardiac cycle)
Complete AV block
(A’ can be obscured by the
“stronger” S’ if they coincide)
In this case M-mode proved to offer complementary help to both techniques
Pulsed-wave tissue Doppler echocardiography for the
analysis of fetal cardiac arrhythmias
Tutschek and Schmidt, UOG 2011
Conclusion
• The study demonstrated that high-resolution ultrasound systems for fetal
imaging without specific hard- or software can be used for the recording of
tissue motion and detailed characterization of fetal arrhythmias
• The study provided detailed descriptions of normal PW-TDE recordings
and provided examples of PW-TDE recordings in common fetal
arrhythmias
• The study showed potential of PW-TDE for estimating AV conduction
time, depicting directly tissue movement
These findings may improve the ability to analyze precisely fetal
arrhythmias and to select appropriate therapeutic options