الفهرس 
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Abstract
The importance of CR has gradually been recognized as part of secondary prevention after acute MI. The overall goal of CR is to improve the quality of life and reduce cardiovascular risk factors. It involves interventions that are aimed at controlling risk factors, improve blood pressure, lipid profile and diabetes mellitus control, tobacco cessation, behavioral counselling, and step-by-step physical activity. Additional components of CR include supervised sessions of aerobic exercise, nutrition counselling, screening for and managing depression, and assuring the latest immunizations. ExCR is now regarded as a class I recommendation in all stable coronary artery disease (CAD) patients in the most recent European society of cardiology (ESC) guidelines. It is also a class I recommendation in heart failure with reduced or mid-range ejection fraction. ExCR decreases cardiac mortality, hospital readmission, and anxiety. Moreover, it improves exercise capacity and quality of life. Patients who developed ACS, or underwent cardiac surgery or percutaneous intervention should be referred to an early exCR program soon after the discharge.
The right ventricle (RV) is a thin-walled chamber that functions at low oxygen demands and pressure. It is perfused throughout the cardiac cycle in both systole and diastole, and its ability to extract oxygen is increased during hemodynamic stress. All of these factors make the right ventricle less susceptible to infarction than the left ventricle. Isolated infarction of the right ventricle is extremely rare; right ventricular infarction usually is noted in association with inferior wall myocardial infarction.
The acute phase of ischemic RV dysfunction generally has no long-term consequences, and complete recovery over a period of a few weeks to months is the rule in the majority of the patients suggesting the occurrence of RV stunning rather than irreversible necrosis. Successful primary PCI in patients with Right ventricular myocardial infarction (RVMI) has been shown to normalize the RV systolic fraction and is associated with improved in-hospital mortality compared with patients in whom the intervention is unsuccessful. Reperfusion within 1 h of thrombus occlusion leads to immediate recovery of RV-free wall function and consequent improved LV filling and performance. Delayed reperfusion after 48 h is associated with a higher degree of RV dysfunction and complications, but still results in significant, yet slower, recovery of RV function.
Systolic RV function can be assessed by several methods. Cardiac magnetic resonance is considered the gold standard; however, it is limited by the cost and availability. There are many echocardiographic conventional parameters to investigate RV function. The RV fractional area change (RVFAC) is one of the conventional echocardiography parameters to assess RV function. The superiority of RVFAC over most other classical echocardiographic parameters could be due to its ability to consider both longitudinal and radial shortening. Other Local longitudinal parameters assessing the RV function are tricuspid annular plane systolic excursion (TAPSE) and Systolic TV Annular Velocity (S’ velocity). Tissue doppler imaging (TDI) has been introduced as a method to quantitatively assess regional myocardial function by providing a map of color-encoded tissue velocities.
A potentially more specific measure of regional function would be the quantification of regional deformation or strain. The concept of myocardial strain was defined by Mirsky and Parmley as fractional tissue deformation in response to the applied force (stress). Speckle tracking echocardiography (STE) is an echocardiographic imaging technique that analyzes the motion of tissues in the heart by using ultrasonic sound waves to generate interference patterns and natural acoustic reflections. Speckle tracking is based on tracking of characteristic speckle patterns created by interference of ultrasound beams in the myocardium.
STE has been utilized to quantitatively assess the LV global and segmental myocardial function. Previous studies have revealed the value of longitudinal, circumferential, and radial strains derived from 2D-STE for the identification of reversible myocardial function. Several studies showed that STE is more sensitive than conventional measures in detecting changes in myocardial function in multiple disease processes. Moreover, all studies reported low inter-and intra-observer variability and good feasibility, making longitudinal strain an effective and reproducible tool for the assessment of RV function.
To assess the role of cardiac rehabilitation on right ventricular (RV) functional recovery by 2D speckle-tracking echocardiography (STE) in a cohort of patients with successful reperfusion after the first episode of acute inferior myocardial infarction (MI) associated with RV infarction.
Fifty patients who underwent successful percutaneous coronary intervention (PCI) after inferior MI mainly associated with ECG criteria of RV infarction were prospectively included (56.08 ± 10.79 years, 40 Men). Cardiac rehabilitation program offered for the whole population. Twenty-five patients started an exercise-based cardiac rehabilitation (exCR) program after 2-4 weeks of discharge; another twenty-five patients, who refused to attend cardiac rehabilitation, received the usual care and were taken as the control group. Both groups received guideline-directed medical therapy (GDMT). Echocardiography (including 2D STE and conventional parameters for assessment of RV systolic function) was performed at baseline, and after a 3-month follow-up for all patients. High levels of strain impairment were observed in both groups at baseline. All parameters improved at 3-month follow-up compared to baseline. Nevertheless, RV global longitudinal strain (GLS) and free wall strain (FWS) improved significantly for patients who completed the cardiac rehabilitation program compared to the control group.
We concluded that cardiac rehabilitation is effective in improving RV strain parameters in patients who developed acute inferior MI associated with RV infarction. Future studies should directly assess the prognostic significance of STE measures of RV function in this population.