Download Influence of right branch bundle block at cardiac MRI on heart

Influence of right branch bundle block at cardiac MRI on
heart volumetry and performance parameters
Poster No.:
C-0723
Congress:
ECR 2010
Type:
Scientific Exhibit
Topic:
Cardiac
Authors:
R. Marterer, E. Sorantin, K. Murg, B. Nagel, T. Robl; Graz/AT
Keywords:
cardiovascular magnetic resonance imaging, congenital heart
defects, right bundle branch block
DOI:
10.1594/ecr2010/C-0723
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Purpose
Magnetic resonance tomography (MRT) has become an important tool in the assessment
of cardiac diseases. Cardiac magnetic resonance imaging (cMRI) with magnetic
resonance (MR) morphology, MR volume measurement, MR flow measurement and MR
angiography represents the gold standard in the follow-up of congenital heart defects
(CHD). For example, transposition of the great arteries (Fig. 1 on page 2), Tetralogy
of Fallot (Fig. 2 on page 3), double outlet right ventricle, pulmonary atresia...
In up to 50 cases of 1000 live births, a congenital heart defect (CHD) occurs. The
prevalence of patients with CHD can only be estimated, but due to the introduction of
surgical repair there is now a large population of patients with CHD.
There are standard protocols for follow-up examinations. In the German guidelines for
heart diagnostic with cMRI three critical visual elements are added: the trabeculae/
papillary muscle, the myocardium of the septum and the basal 1-2 layers. But there is
another important factor in the evaluation of cardiac function in patients with CHD: the
right bundle branch block (RBBB).
The RBBB exists in up to 80% in patients with CHD. Therefore the right ventricle (RV)
contracts after the left one, so there is a difference between the end-systolic phase of RV
and left ventricle (LV) and no difference between the end-diastolic phases. Less is known
about the effects of not paying attention to the later RV contraction at ventricular volume
measurement. Therefore this paper was targeted to assess the influence of RBBB on RV
stroke volume (SV) and ejection fraction (EF).
Images for this section:
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Fig. 1: 4 chamber view of a heart with transposition of the great arteries after Senning
operation
Page 3 of 13
Page 4 of 13
Fig. 2: Short axies view - corrected Tetralogy of Fallot
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Methods and Materials
18 patients (11 male, 7 female; age 22.7 ± 8.0 years) with CHD and RBBB were studied.
All patients underwent cMRI for clinical follow-up examinations. The criterion was an
excellent correlation between ventricular SV and velocity encoding (VENC) imaging
based flow measurements of the great arteries. The selection was made retrospectively
and automated with following formula: (RVSV/pulmonary gross forward volume + LVSV/
aorta net forward volume + pulmonary net forward volume/LVSV)/3. The result should
be 1 ± 0.05.
cMRI was performed at all subjects by using a 1.5 Siemens Symphony unit. MR volume
measurement was performed by manual tracing of endocardial borders of contiguous
short-axis slices at end-diastole (image phase with largest cavity area) and end-systole
(image phase with smallest cavity area) and therefore RV end-diastolic volume (EDV)
and RV end-systolic volume (ESV) could be calculated and subsequently RV SV and RV
EF conducted.
The original analysis, taking in account the later RV contraction due to RBBB (Fig. 1 on
page 6), the corresponding SV (absolute and normalized to body surface area) and
EF served as reference values. Second analysis was performed assuming that the right
ventricle contracts at the same time as the left one and SV and EF were calculated again.
Because the diastolic phase did not change, EDV did not change.
Images for this section:
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Fig. 1: Extract from a MR volume measurement
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Results
RV results of the original analysis including the RBBB: EDV 198.78 ± 55.64 ml, EDV/
2
2
BSA 120.67 ± 29.34 ml/m , ESV 106.23 ± 40.81 ml, ESV/BSA 64.05 ± 21.28 ml/m , SV
2
92.48 ± 21.11 ml, SV/BSA 56.62 ± 12.96 ml/m , EF 47.98 ± 9.59 %.
RV results of the second analysis excluding the RBBB: EDV 198.78 ± 55.64 ml, EDV/
2
2
BSA 120.67 ± 29.34 ml/m , ESV 116.71 ± 44.90 ml, ESV/BSA 70.31 ± 23.44 ml/m , SV
2
82.07 ± 19.48 ml, SV/BSA 50.36 ± 12.07 ml/m , EF 42.85 ± 9.95 %.
2
ESV increased by 10.41 ± 6.27 ml and ESV/BSA by 6.26 ± 3.57 ml/m (p < 0.001) (Fig.
1 on page 8). The difference of 10.4 ± 5.87 % is statistically significant (p < 0.001).
2
Consequently, SV decreased by 10.40 ± 5.87 ml and SV/BSA by 6.26 ± 3.57 ml/m , in
percentage by 11.12 ± 6.18 % (p < 0.001) (Fig. 2 on page 9). There was also a
significant decrease (p < 0.001) of the EF (Fig. 3 on page 10). Because the diastolic
phase did not change, EDV did not change.
Images for this section:
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Fig. 1: Difference of the RV ESV/BSA including and excluding the RBBB (p < 0.001)
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Fig. 2: Difference of the RV SV/BSA including and excluding the RBBB (p < 0.001)
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Fig. 3: Difference of the RV EF including and excluding the RBBB (p < 0.001)
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Conclusion
In many cardiovascular diseases - especially CHD - the RV is an important parameter for
assessment of the cardiac function. Additionallly, cMRI represents the standard reference
for RV measurements including volumetry.
Currently the RV EF is the most accurate and reproducible parameter for the assessment
of the RV function. If the ejection fraction is reduced, thereby a worsening outcome is
related and an early detection in connexion with an intervention can improve the outcome.
Results confirm that biventricular asynchronous contraction due to RBBB should be
obeyed at cMRI based volume measurement, otherwise significant underscoring of RV
performance will be the consequence.
References
[1] Didier, D., Ratib, O., Lerch, R. & Friedli, B. 2000, 'Detection and quantification of
valvular heart disease with dynamic cardiac MR imaging', Radiographics, vol. 20, no. 5,
pp. 1279-99; discussion 1299-301.
[2] van den Berg, J., Wielopolski, P.A., Meijboom, F.J., Witsenburg, M., Bogers, A.J.J.C.,
Pattynama, P.M.T. & Helbing, W.A. 2007, 'Diastolic function in repaired tetralogy of Fallot
at rest and during stress: assessment with MR imaging', Radiology, vol. 243, no. 1, pp.
212-9.
[3] Roest, A.A.W., Helbing, W.A., Kunz, P., van den Aardweg, J.G., Lamb, H.J., Vliegen,
H.W., van der Wall, E.E. & de Roos, A. 2002, 'Exercise MR imaging in the assessment
of pulmonary regurgitation and biventricular function in patients after tetralogy of fallot
repair', Radiology, vol. 223, no. 1, pp. 204-11.
[4] Maceira, A.M., Prasad, S.K., Khan, M. & Pennell, D.J. 2006, 'Reference right
ventricular systolic and diastolic function normalized to age, gender and body surface
area from steady-state free precession cardiovascular magnetic resonance', Eur Heart
J, vol. 27, no. 23, pp. 2879-88.
[5] Niezen, R.A., Helbing, W.A., van der Wall, E.E., van der Geest, R.J., Rebergen, S.A.
& de Roos, A. 1996, 'Biventricular systolic function and mass studied with MR imaging in
Page 12 of 13
children with pulmonary regurgitation after repair for tetralogy of Fallot', Radiology, vol.
201, no. 1, pp. 135-40.
[6] Roest, A.A.W., Lamb, H.J., van der Wall, E.E., Vliegen, H.W., van den Aardweg,
J.G., Kunz, P., de Roos, A. & Helbing, W.A. 2004, 'Cardiovascular response to physical
exercise in adult patients after atrial correction for transposition of the great arteries
assessed with magnetic resonance imaging', Heart, vol. 90, no. 6, pp. 678-84.
[7] Helbing, W.A., Niezen, R.A., Le Cessie, S., van der Geest, R.J., Ottenkamp, J. & de
Roos, A. 1996, 'Right ventricular diastolic function in children with pulmonary regurgitation
after repair of tetralogy of Fallot: volumetric evaluation by magnetic resonance velocity
mapping', J Am Coll Cardiol, vol. 28, no. 7, pp. 1827-35.
[8] Bouzas, B., Kilner, P.J. & Gatzoulis, M.A. 2005, 'Pulmonary regurgitation: not a benign
lesion', Eur Heart J, vol. 26, no. 5, pp. 433-9.
[9] Carvalho, J.S., Shinebourne, E.A., Busst, C., Rigby, M.L. & Redington, A.N. 1992,
'Exercise capacity after complete repair of tetralogy of Fallot: deleterious effects of
residual pulmonary regurgitation', Br Heart J, vol. 67, no. 6, pp. 470-3.
[10] Davlouros, P.A., Kilner, P.J., Hornung, T.S., Li, W., Francis, J.M., Moon, J.C.C.,
Smith, G.C., Tat, T., Pennell, D.J. & Gatzoulis, M.A. 2002, 'Right ventricular function in
adults with repaired tetralogy of Fallot assessed with cardiovascular magnetic resonance
imaging: detrimental role of right ventricular outflow aneurysms or akinesia and adverse
right-to-left ventricular interaction', J Am Coll Cardiol, vol. 40, no. 11, pp. 2044-52.
Personal Information
Robert Marterer
Department of Radiology, Medical University of Graz, Austria
E-mail: [email protected]
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