الفهرس 
ISCHEMIC CARDIOMYOPATHYOnly 14 pages are availabe for public view
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Abstract
Differentiating between ischemic and non-ischemic etiology of left ventricular dysfunction has important clinical and therapeutic implications in patients with chronic heart failure. Several non-invasive techniques (i.e. echocardiography, dobutamine echocardiography, thallium-scintigraphy, positron emission tomography, magnetic resonance) have been proposed to establish the etiology of left ventricular dysfunction, but the results are controversial and the optimal strategy remains unsettled (Michal Pewkal et al., 2005).
The aim of this work is to study the potential role of tissue Doppler echocardiography in identifying the ischemic etiology in patients with dilated cardiomyopathy. The patients were selected from the outpatient clinic at coronary care unit and department of cardiology Ain Shams University Hospital and National Heart Institute (NHI), during the period from February 2007 to March 2008.
The current study included (40) Patients with chronic heart failure (ischemic and non-ischemic) all with globally reduced contractility (EF<40%), and excluded Patients with left bundle branch block, atrial fibrillation, and patients with valvular heart disease.
All patients included in the study were subjected to: Full history taking, general clinical examination, local cardiac examination, resting twelve-lead surface ECG, Chest X-ray, routine lab,echo Doppler study to determine EF% using modified Simpson’s rule, tissue Doppler echocardiography and coronary angiography.
Tissue Doppler echocardiography:
In this study pulsed - wave TDE parameters were recorded in standard apical four-chamber, two-chamber and three-chamber views in the middle of basal segments of the lateral wall, posterior interventricular septum, anterior wall, inferior wall, anterior interventricular septum and posterior wall. For each basal segment, we measured peak TDE myocardial velocities: Systolic velocity (Sm), early diastolic velocity (Em), and late diastolic velocity (Am). The following time intervals of cardiac cycle were measured: Pre-ejection period (PEPm), ejection time (ETm), isovolumic relaxation time (IVRTm), rapid filling time (RFTm), diastasis time (DTm) and atrial contraction time (ACTm).
After statistical analysis of our results we found that:
Comparison between the two groups regarding ECG and regional wall motion abnormalities by echocardiography showed that, 3patients (15%) with idiopathic cardiomyopathy, ECG showed signs suggestive of ischemic etiology inspite of normal coronary angiography. In 7 patients (35%) with idiopathic cardiomyopathy regional wall motion abnormalities were present, suggesting ischemic heart disease inspite of normal coronary angiography.
However, 5 patients (25%) with ischemic cardiomyopathy revealed no ischemic changes in resting ECG, inspite of coronary angiography revealed 2-vessel disease. Also, 6 patients (30%) with ischemic cardiomyopathy showed no regional wall motion abnormalities.
As regard, routine transthoracic echocardiographic measurements showed that: patients with idiopathic cardiomyopathy had significantly greater diameter of the left ventricle, left atrium and right ventricle dilatation (P < 0.05). The prevalence of mitral and tricuspid regurgitation were significantly higher in patients with idiopathic cardiomyopathy than patients with ischemic cardiomyopathy (P < 0.01). The mean pulmonary artery pressure was significantly higher in patients with idiopathic cardiomyopathy than patients with ischemic cardiomyopathy (P < 0.001)
There was no significant differences between patients with ischemic and non-ischmic causes of cardiomyopathy regarding the drug therapy except for nitrates as 19 patients (95%) with ischemic cardiomyopathy were on nitrates, however, 11 patients (55%) with non-ischemic cardiomyopathy.
Among the TDE parameters, mean early diastolic velocity (Em) was significantly lower in patients with ischemic cardiomyopathy than in idiopathic cardiomyopathy (P < 0.05), whereas there were no significant differences between patients with ischemic and non-ischemic cardiomyopathy in mean systolic (Sm) and late diastolic velocities (Am) (p > 0.05). In patients with ischemic cardiomyopathy, pre-ejection period (PEPm) was significantly shorter with prolongation of isovolumic relaxation time (IVRTm) and diastasis time (DTm) than in patients with idiopathic cardiomyopathy (P < 0.05).
The present study concluded that: Tissue Doppler echocardiography parameters; early diastolic velocity, pre-ejection period, isovolumic relaxation time and diastasis time can reliably differentiate ischemic and non-ischemic cardiomyopathy.