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Preserved left ventricular twist and circumferential deformation, but depressed longitudinal
and radial deformation in patients with diastolic
heart failure
Wang J, Khoury DS, Yue Y, Torre-Amione G, Nagueh SF.
Eur Heart J 2008; 29: 1283-1289
Reviewers: Robina Matyal, MD
Beth Israel Deaconess Medical Center
Harvard Medical School,
Boston, MA
Sachchidanand Tewari
Medical Student
GSVM Medical College
Kanpur, India
Objectives
The aim of the study was to use the newer two-dimensional
(2D) speckle tracking technology to assess the differences present
in myocardial function between systolic (SHF) and diastolic heart
failure (DHF).
Methods
A total of fifty consecutive patients with heart failure (age: 58+/16 years) were enrolled. Seventeen normal subjects were enrolled
as control. All patients were imaged in supine position with GE (CT
USA) Vivid-7 ultrasound system. Parasternal 2D short-axis views of
left ventricle (LV) were acquired at basal, mid-papillary and apical
levels. Transmitral flow propagation velocity (Vp) and pulse wave
Doppler derived mitral inflow waves (E and A waves and deceleration time) were measured. The analysis was performed offline using
Echo-PAC workstation (GE Medical Systems CT USA) without
knowledge of the hemodynamic data. Myocardial deformation was
measured using tissue speckle tracking. The average value of peak
systolic longitudinal strain from three apical views was calculated
as global LV longitudinal strain (GSll). Global LV circumferential
strain (GSlc) in three short-axis views and radial strain (GSlr) was
measured in all 16 segments and calculated average was taken as
the final value. Cardiac rotation was measured as a positive value
for counterclockwise rotation and negative value for clockwise
rotation. The difference between apical and basal rotations at each
corresponding time point was calculated as LV twist. One-way
ANOVA test for continuous data and stepwise multivariable analysis
for prediction of LV twist was performed. ROC analysis was used to
select cutoff values to distinguish SHF, DHF and normal controls.
Results
There were 20 patients in DHF group, they were significantly
older, and had higher systolic blood pressure at baseline. LV enddiastolic volume (EDV), LV end-systolic volume (ESV) and LV
mass were significantly lower in DHF and control groups. Using
a cut-off value of GSll at -16%, DHF patients were distinguished
from normal controls at a sensitivity and specificity of 95%. GSll
and GSlr were significantly lower in patients with SHF as compared
to DHF patients. LV twist was significantly related to LVEDP, ESV,
mass, EF, LA volume, GSll and GSlc, meridonial end systolic wall
stress (ESSm) and circumferential end-systolic wall stress (ESSc).
Only LV twist and GSlc were independent predictors of LVEF on
multiple regression analysis.
Discussion
The authors concluded that the patients with DHF have reduced
longitudinal and radial strains, but have preserved circumferential
strain and LV twist, while patients with SHF had impaired longitudinal, radial and circumferential strains and the LV twist. All patients
in the study with DHF were older, had diabetes and/ or coronary
artery disease i.e. LV micro or macrovascular disease resulting in
endocardial fibrosis. All these patients had intact circumferential
strain, as the disease did not affect the mid-myocardial fiber layers.
These patients had intact twist as the subepicardial counterclockwise
rotation overcomes the subendocardial clockwise rotation.
The limitations of the study as pointed out by the authors are the
small sample size and the fact that patients with DHF were older,
and control subjects had significantly lower heart rates. Also, these
observations need to be done in larger population models so that
patients with all stages of diastolic dysfunction can be included
and studied. Based on these findings, it may be possible to linearly
classify diastolic dysfunction based on the speckle tracking of
strain pattern.
The existing parameters for the diagnosis of diastolic function
i.e. transmitral flow velocities and pulmonary venous flow patterns
are dependent on the preload and rate and rhythm of the myocardium. Even the more recent parameters e.g. Vp and Doppler tissue
velocities are also partly load dependant and extrapolate regional
myocardial motion to the global myocardial motion. It is possible
that we may be able to stratify patients with different stages of
diastolic dysfunction by using speckle straining in a larger population study. Since 2D speckle tracking has the spatial and temporal
orientation and, unlike tissue Doppler, is not angle dependant, it
may be an ideal modality to diagnose diastolic filling abnormalities.
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