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Links to relevant publications by
members of the Irish Cardiac Echo Group.
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Echo articles
published with Irish authors:
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Article title:
Published Online
First: 12 May 2008.
doi:10.1136/hrt.2008.142083.
Gerard J King, Ross
T Murphy, Ibraham
Almuntaser, Kathleen
Bennett, Emily Ho,
and Angie Brown
[Abstract]
[Accepted
Manuscript]
Abstract:
Background.
In elite
athletes left
ventricular
morphologic
changes are
predicted to
alter passive
pressure/volume
characteristics
by reducing
myocardial
stiffness and
increasing
compliance.
Aim We
investigated the
utility of a new
Doppler tissue
index based on
the pressure
volume relation
((E/Ea)/LVEDD),
which provides a
measure of
myocardial
stiffness, and
assessed its
usefulness in
detecting
cardiac
adaptation in
elite rowers.
Methods
Thirty-six
international
rowers (mean age
27±7 years,) who
had trained
intensively for
15-20 hours per
week for more
than 5 years and
a control group
of 30 sedentary
but otherwise
normal subjects
(mean age 26±8
years,) were
consented and
enrolled into
the study. The
groups were
similar in age
and gender. Left
ventricular (LV)
septal and
posterior wall
thickness, mass,
chamber size,
transmitral
Doppler peak
early (E) and
late (A)
diastolic
filling
velocities and
isovolumic
relaxation times
were measured.
Early diastolic
myocardial
velocities (Ea)
were averaged
from 4 sites at
the mitral
annulus;
Diastolic
stiffness was
assessed with
the use of three
indices E, Ea,
and the left
ventricular end
diastolic
diameter in
diastole (LVEDD).
The ratio,
[(E/Ea)/LVEDD],
represents a
pressure/volume
relationship and
provides a novel
index of
diastolic
stiffness.
Rowers were
further divided
into 2 groups
based on the
presence or
absence of left
ventricular
hypertrophy (LVH),
12mm and > 12mm.
Results There
was no
significant
difference in Ea
(4 site average)
between the two
groups, but
there was a
difference in
the stiffness
index, with
rowers having
significantly
more compliant
ventricles
(p=0.0003). When
compared with
controls and
adjusted for
body surface
area (BSA) and
heart rate this
difference
remained
statistically
significant (p=
0.016). When the
rowers were
divided into 2
groups based on
the presence or
absence of LVH
there was no
difference in
the stiffness
index (p = 0.68)
Conclusions The
key
distinguishing
feature of
intense training
is a reduction
of myocardial
stiffness
despite the
development of
left ventricular
hypertrophy.
St James
Hospital,
Dublin, Eire.
* To
whom
correspondence
should be
addressed.
E-mail:
.
Accepted 15
April 2008
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Article title:
King G, Foley JB, Royse CF,
Yastrebov K, Hussey M, Boyle G,
Bennet K, Cosgrave J, Crean P,
Walsh M
pages
423-429
Abstract |
Full Text |
PDF (529 KB)
Corresponding author: Dr. G.
King.
First author: Dr. G. King
Cardiology Department, St James
Hospital, Dublin 8, Ireland.
Reference: YEUJE906
Journal title: European Journal
of Echocardiography
volume 7, issue 6, on pages
423-429, cover date December
2006.
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Department of Cardiology, St. James Hospital, Dublin, Ireland.
Contraction of the left atrium in diastole generates a pressure wave that moves along the postero-lateral wall of the left ventricle (LV), rebounds off the LV apex, and is then directed toward the outflow tract. The movement of this atrial pressure wave may be detected with pulsed Doppler echocardiography by placing a sample volume in the LV outflow tract. The resulting spectral profile shows the initial. A velocity wave and also the Ar velocity wave, which is caused by the atrial pressure wave rebounding off the LV apex. The transit time from the inflow tract to the outflow tract of the atrial pressure wave (A-Ar interval) may be determined from the time axis of the spectral profile by measuring the peak-to-peak separation of the A and Ar, velocity waves. It occurs in the range 25 to 80 milliseconds. The primary determinant of the A-Ar interval is the elasticity of the LV myocardium. We correlated ventricular elasticity with the A-Ar interval in 47 patients and found a significant negative linear correlation (r = -0.782, p < 0.001). Because the pressure in a viscoelastic conduit such as the LV is determined by the elasticity of the ventricular wall, we correlated end-diastolic pressure with the A-Ar interval and again showed a significant negative linear correlation (r = -0.701, p < 0.001). The A-Ar interval is an easily measured noninvasive index of the diastolic function of the LV that reflects its intrinsic elasticity and end-diastolic pressure. It is therefore a quantitative measurement of LV wall stiffness and end-diastolic pressure.
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Keane D, Hynes B, King G, Shiels P, Brown A. |
Related Articles
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Cardiac Arrhythmia Department, St. Vincent's University Hospital, Dublin, Ireland. bghynes@hotmail.com.
BACKGROUND: Left ventricular outflow tract (LVOT) obstruction in the setting of hypertrophic cardiomyopathy (HCM) confers negative adverse outcomes. Current nonpharmacologic treatment options include surgical myectomy and percutaneous transcoronary ablation of septal hypertrophy (TASH). While TASH negates a more invasive procedure, concern remains with particular regard to the arrhythmogenic potential of the resultant myocardial scar. Percutaneous transvalvular endomyocardial septal cryoablation (PTESC) may circumvent some of these potential limitations and offer a novel treatment strategy. OBJECTIVES: The purpose of this study was to report our early experience and outcomes with percutaneous endomyocardial cryoablation of the interventricular septum in obstructive HCM. METHODS AND RESULTS: Between March 2005 and May 2006, 3 patients (2 male, 1 female) with symptomatic obstructive HCM underwent PTESC. Basal LVOT gradients measured during left heart catheterization were 70, 126 and 100 mmHg for Patients 1, 2 and 3, respectively. Using 7 Fr and 9 Fr 8 mm tip CryoCath Freezor catheters (CryoCath Technologies, Inc., Montreal, Quebec, Canada), cryothermal energy was applied to the interventricular septum under fluoroscopic guidance. A total of 20 to 32 applications of cryothermal energy were delivered, with the mean nadir temperature sustained during cryoablation being -88 degrees Celcius. Two of the 3 patients had an immediate reduction in the LVOT gradient. However, at 6 months, only 1 patient had a significant sustained reduction in LVOT gradient. No adverse events relating to the procedure were experienced. CONCLUSION: PTESC is feasible, but did not result in a significant, sustained reduction in LVOT gradient in 2 of the 3 patients in this small series of obstructive HCM patients. The technique warrants further study to improve the consistency and duration of reduction in outflow gradient.
PMID: 17541123 [PubMed - in process]J Invasive Cardiol. 2007 Jun;19(6):247-51.
PMID: 17541123 [PubMed - in process] |
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