الفهرس 
Chapter (1) AnatomyOnly 14 pages are availabe for public view
 |  | from | 80 |  |  |
| | | from | 80 | | |
Abstract
Chronic total occlusion (CTO) , is a common condition in patients< with coronary artery disease, represents one of the most challenging
targets of lesion recanalization for percutaneous coronary
interventions (PCI) (1,2). Because of its complexity, CTO PCI is
associated with lower rates of procedural success, higher complication
rates, greater radiation exposure, and longer procedure times
compared with interventions in non-CTO stenosis. (3, 4, 5, 6).
The rationale for the recanalization of a chronic total coronary
occlusion is the possible improvement of left ventricular (LV)
function through the recovery of hibernating myocardium. (7, 8, 9, 10, 11)
The assessment of global and regional LV function is of
great importance in the diagnosis and assessment of myocardial
ischemia ,the presence of ischemia results in changes in both
systolic and diastolic function.(12)
Two dimensional echocardiography has been described as the
ideal imaging modality for assessment of global and regional
ventricular function. (12) However, conventional assessment of wall
motion, based on visual interpretation of endocardial excursion and
myocardial thickening, suffers from the limitations of a qualitative
method and is subjective and experience dependent. (14)
Tissue Doppler imaging is an extension of conventional
Doppler echocardiography, conventional Doppler echocardiography
was originally developed to measure velocity and directions of
blood and modification in image acquisition process now enables
direct measurement of tissue velocities. The initial application of
DTI in quantifying myocardial mechanical activity was to measure the peak systolic and diastolic tissue velocities of the given
segment and the results so far were promising. (13)
The aim of our study was to assess the LV function (global and
regional) by using the conventional and PW-TDI echocardiographic
modality that was done 24h before and after PCI and also after 3
months of CTO artery lesions.
Forty patients were involved in the study but only thirty seven of
them were successfully managed to complete the full follow up
regimen, we divided them into two main groups, non infarction group
(22), and infarction group (15), all patients were subjected to full
history taking, physical examination, 12 lead ECG, echocardiographic
examination involving 2D, and TDI to assess LV territories according
to the target CTO vessel, Conventional echo. parameters were,
LAD,AOD,LVEDv,LVESv,FS% ,EF%,E,A and E/A ratio. TDI
parameters were IVCPv, Sv, E’, A’, E’/A’, IVC acceleration, Tp, IVCt,
Ct, IVRtand TEI. Our patients were subdivided into 3 subgroups
according to the CTO vessel and non infarction and infarction type.
[LAD (10+7), RCA (6+6), and LCX (6+2)].
Our study showed that there was significant improvement of most
of the systolic and diastolic indices by TDI in non infarction group
regardless the CTO vessel and only S wave velocity was improved in
LAD subgroup as it is represented by more segments, while the other
infarction group showed no improvement at that time of follow up (3
months). Acceleration of IVC TDI parameter was the only early
predictor of improvement and it was positively correlated with the
Werner class of coronary collateral development.