الفهرس 
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Abstract
Acute myocardial infarction is characterized by loss of contractile tissue and changes of the ventricular geometry. The right ventricle plays an important role in the morbidity and mortality of patients presenting with signs and symptoms of cardiopulmonary disease (Haddad et al., 2008).
Echocardiography is the most commonly used imaging modality for routine clinical evaluation of the RV since it is widely available, extremely safe and relatively inexpensive (Gali et al., 2005). However, standard techniques are limited due to the complex RV geometry, retrosternal position, and the marked load dependence of RV function indices, so quantification is often only an estimation (Sanz et al., 2010).
Tissue Doppler imaging is a technique that offers information on myocardial velocities, allowing a quantitative assessment of myocardial function during the entire cardiac cycle (Jurcut et al., 2010).
This study aimed to investigate the peak myocardial systolic velocity (Sm) and myocardial performance index (MPI) of the right ventricle measured by pulsed wave tissue Doppler imaging (TDI) in patients with first acute myocardial infarction.
The current study included 30 Patients with first attack of acute ST elevation myocardial infarction admitted to CCU unit of beni suef university hospital during the period from April 2011 to October 2011 and diagnosed by at least two of the following: typical ischemic chest pain > 20 minutes in duration, electrocardiographic evidence of ST elevation ≥ 1 mm in two or more consecutive leads and elevation of serum cardiac enzymes especially CK-MB.
Patients who had left bundle branch block, atrial fibrillation, valvular heart disease or other left sided heart disease, previous history of ischemic heart disease, previous coronary artery by pass graft surgery (CABG), percutaneous coronary artery intervention (PCI) and with pre-existing pulmonary disease were excluded from the study.
In this study, the patients were divided into two main groups regarding the site of myocardial infarction, group A included 15 patients with first attack of acute anterior ST elevation myocardial infarction and group B included 15 patients with first attack of acute inferior ST elevation myocardial infarction which divided into 2 subgroups: those with RV infarction ”Ba” were 6 patients and those without RV infarction”Bb” were 9 patients.
All patients were subjected to detailed history taking, clinical examination, electrocardiogram, necessary laboratory tests, conventional M-mode, 2-D transthoracic echocardiographic examination, Doppler study, TDI and coronary angiography.
from the apical four-chamber view, at the level of the tricuspid annulus of the right ventricular free wall, a major positive Sm was recorded the systolic wave. The right ventricular MPI was calculated as (IVRT + IVCT)/ET, by using the values obtained from the right ventricular free wall.
Regarding the demographic data and the risk factors, they are of no statistically significance between the two groups.
Concerning transthoracic echocardiographic measurements, there was statistically significant difference between the two studied groups regarding the left ventricle EF where the patients with first attack of acute anterior myocardial infarction had significant lower LV EF than the patients with first attack of acute inferior MI.
Regarding the Tissue Doppler findings
It had been noticed that group A (patients with anterior MI) had highly statistically significant lower RVSm (P-value = 0.003) as compared to group B (patients with inferior MI) and had also statistically significant higher MPI (P-value = 0.047) as compared to group B (patients with inferior MI), denoting that the right ventricular systolic dysfunction is more in patients with anterior myocardial infarction than with inferior myocardial infarction. Regarding the 2 subgroups Sm reduced significantly in patients with RV MI (group Ba) as compared with those without RV MI (group Bb). P-value = 0.028.
Therefore it was concluded that:
Contrary to the expectation, anterior MI results in RV dysfunction when compared with inferior MI. This relationship is explained by the effect of LV dysfunction on RV function.
RV MI can be predicted correctly by the use of these parameters, which are easily obtained by TDI.