CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013
132
AFRICA
CARDIOLOGY AND THE IMAGING REVOLUTION
ing aorta: 3.9
±
0.9 vs 3.2
±
0.4 m/s,
p
<
0.01). Systolic biventricular
function was preserved (LV ejection fraction 57
±
8 vs 56
±
6%,
p
=
0.74; RV ejection fraction 56
±
8 vs 52
±
6%,
p
<
0.01), whereas
biventricular mass was increased (LV 52.1
±
8.4 vs 36.0
±
9.9 g/m
2
,
p
<
0.01; RV 26.8
±
6.5 vs 10.4
±
5.0 g/m
2
,
p
<
0.01). Also, delayed
biventricular relaxation was found after MSS: E-wave deceleration
time was significantly prolonged across the mitral valve (MV) (184
±
61 vs 116
±
28 ms,
p
<
0.01) and tricuspid valve (TV) (192
±
67 vs
126
±
40 ms,
p
<
0.01) with loss of diastasis time (MV: 22
±
35 vs
159
±
92 ms,
p
<
0.01; TV: 13
±
24 vs 113
±
70 ms,
p
<
0.01). Also,
peak filling rates corrected for end-diastolic volume (PFR
EDV
) across
the MV and TV were significantly reduced (MV: PFR
EDV
of E wave
2.54
±
0.56 vs 3.08
±
0.63,
p
=
0.01; PFR
EDV
of A wave 1.10
±
0.26
vs 1.31
±
0.30,
p
=
0.03; TV: PFR
EDV
of E wave 1.81
±
0.44 vs 2.09
±
0.29,
p
=
0.04; PFR
EDV
of A wave 1.11
±
0.22 vs 1.42
±
0.39,
p
<
0.01). Increased PWV in the aortic arch and descending aorta were
associated with increased LV mass (
r
=
0.62,
p
<
0.01, and
r
=
0.51,
p
<
0.01, respectively) and delayed LV relaxation parameters (MV
diastasis:
r
=
0.50,
p
<
0.01, and MV E deceleration time:
r
=
0.38,
p
=
0.03, MV diastasis:
r
=
0.34,
p
=
0.04, respectively).
Conclusions:
Despite adequately preserved systolic biventricular
function, reduced aortic elasticity in paediatric patients after MSS
may indicate aortic wall pathology, being associated with ventricu-
lar hypertrophy and concomitant delayed ventricular relaxation.
Long-term prognosis in MSS survivors may therefore be negatively
affected considering the cumulative effects of cardiovascular disease
and aging during a lifetime.
6: PREDICTING SUBENDOCARDIAL ISCHAEMIA IN
HUMANS
Julien Hoffman
1
, Gerald Buckberg
2
1
Department of Paediatrics, University of California, San Francisco,
California, USA
2
Department of Cardiothoracic Surgery, University of California, Los
Angeles, California, USA
In 1972 we demonstrated that a ratio DPTI/SPTI
<
0.8 predicted rela-
tive subendocardial ischaemia in normal dogs. (DPTI – area between
aortic and left atrial diastolic pressures; SPTI – area below systolic
LV pressure curve.) To correct for anaemia, multiply DPTI by arte-
rial oxygen content (ml/100 ml blood); the critical ratio is –10. This
ratio probably applies to normal human hearts, but not to hearts with
hypertrophy or dilatation in which SPTI underestimates myocardial
oxygen demand (MVO
2
) in proportion to excess wall tension or wall
thickness. In most abnormal hearts, wall tension remains normal, so
that MVO
2
∝
mass or wall thickness, and the critical ratio must be
multiplied by relative wall thickness. If wall tension rises because of
ventricular dilatation, then the ratio must be multiplied also by the
relative wall tension. These variables can be quantitated easily by
echocardiography and applied to patients.
7: ABNORMAL VENTRICULAR TORSION: KEY TO DIAS-
TOLIC DYSFUNCTION
Julien Hoffman
1
, Gerald Buckberg
2
1
Department of Paediatrics, University of California, San Francisco,
California, USA
2
Department of Cardiothoracic Surgery, University of California, Los
Angeles, California, USA
Helical muscles in the LV wall are essential for effective systolic
emptying and subsequent refilling. During systole, the base of the
heart rotates clockwise and the apex counterclockwise; the angular
difference in these rotations (torsion) is measured by magnetic reso-
nance imaging or speckle tracking echocardiography.
After systole, rapid untwisting is needed for ventricular suction
and optimal LV filling. Torsion loses efficiency if the LV dilates and
1: REAL-TIME THREE-DIMENSIONAL ECHOCARDIO-
GRAPHIC CHARACTERISTICS OF LEFTVENTRICLEAND
LEFT ATRIUM IN NORMAL CHILDREN
Bao Phung Tran Cong, Nii Masaki, Miyakoshi Chihiro, Yoshimoto
Jun, Kato Atsuko, Ibuki Keichiro, Kim Sunghae, Mitsushita Norie,
Tanaka Yasuhiko, Ono Yasuo
Cardiac Department, Shizuoka Children Hospital, Japan
Background:
The accurate assessment of left atrial (LA) and/or left
ventricular (LV) volume and contractility is crucial for the manage-
ment of patients with congenital heart disease. The real-time three-
dimensional echocardiography (RT3DE) is reported to show better
correlation with magnetic resonance imaging (MRI) in estimating
LV and LA volume than conventional two-dimensional echocardiog-
raphy (2DE). On the other hand, the volume measurement in RT3DE
is also reported to be significantly smaller than those in MRI, neces-
sitating the establishment of normal values of RT3DE itself. The aim
of this study was to identify the normal values of LV and LA volume
measured by RT3DE in Japanese children.
Methods:
Sixty-four normal school children [age: median 9.6 years;
range (5.5–14.5); male 26, female 38] were enrolled in this study.
End-diastolic and end-systolic LV and LA volumes were analysed
using M-mode in short-axis view, 2D biplane method, and RT3DE.
We used IE-33 (PHILIPS) with matrix probe X7 and X4 off-line
assessment to calculate LA, and LV volume was done using QLAB
8.1 (Philips).
Results:
Forty-nine children [age: median 9.1 years, range (6–14);
male 21, female 28] had adequate RT3DE data sets and were
analysed.
• RT3DE: LV end-diastolic volume index (LVEDVI)
=
51.4
±
5.7
ml/m
2
, LV end-systolic volume index (LVESVI)
=
21.0
±
4.2
ml/m
2
, max LA volume index (LAVI)
=
21.4
±
5.0 ml/m
2
, min
LAVI
=
7.7
±
2.7 ml/m
2
, LV ejection fraction (LVEF)
=
59.1
±
6.9%, and LA volume change [(max LAV–min LAV)/max LAV
×
100%]
=
63.7
±
9.3%.
• M-mode: LVEDVI
=
70.9
±
10.8 ml/m
2
, LVESVI
=
23.5
±
5.5 ml/
m
2
, LVEF
=
66.8
±
6.1%.
• 2DE biplane: max LAVI
=
22.8
±
5.6ml/m
2
.
LV end-diastolic volume on RT3DE showed good linear correlation
with body surface area (BSA): LVEDV
=
–4.52 + 55.75
×
BSA,
R
2
=
0.746.
Conclusion:
Approximately 77% of normal children had adequate
RT3DE images. The discrepancy of LVEDV between RT3DE and
M-mode was significant and the measurements of RT3DE were
constantly smaller than those of M-mode.
4: REDUCED AORTIC ELASTICITY AND VENTRICULAR
DYSFUNCTION LATE AFTER PAEDIATRIC MENINGO-
COCCAL SEPTIC SHOCK: A PRECURSOR OF ATHERO-
SCLEROSIS?
Heynric Grotenhuis
1
, Hennie Knoester
1
, Jeanine Sol
1
, Albert de Roos
2
1
Emma Children’s Hospital, Academic Medical Centre, Amsterdam
2
Leiden University Medical Centre, Netherlands
Background:
Given the strong similarities in inflammatory path-
ways between septic shock and atherosclerosis, aortic wall abnormal-
ities and associated ventricular sequelae may be expected after MSS.
Objectives:
To prospectively assess aortic elasticity and biventricular
systolic and diastolic function in paediatric patients after meningo-
coccal septic shock (MSS) using magnetic resonance imaging (MRI).
Methods:
Eighteen paediatric MSS survivors (eight male; age 14.5
±
.9 years; MRI 8.2
±
2.4 years after MSS) treated with at least two
inotropic and vasoconstrictive agents for
>
48 hours, and 18 matched
controls were studied. Routine MRI was used to assess aortic pulse-
wave velocity (PWV) and systolic and diastolic biventricular function.
Results:
MSS patients showed reduced aortic elasticity vs controls
(PWV aortic arch: 4.1
±
0.3 vs 3.3
±
0.5 m/s,
p
<
0.01; PWV descend-
