Indeed, association of obesity with cardiac toxicity can be spotted throughout the literature. As a practical approach, reduction of HD cyclophosphamide dosage in patients whose actual BW exceeds by >20% of the IBW is a safety measure that doesn’t affect the efficacy of chemotherapy and minimizes the risk of toxicity.In the current study, the ejection fraction decline was highly pronounced in older age groups compared to younger group with highly statistically significant difference (P-value 0.001). The ejection fraction decline was seen more in male cases compared to females (P-value 0.009).The comparison between autologus and allogeneic recipients is especially important. More pronounced cardiotoxic effects could be expected in allogeneic recipients as a result of a different spectrum of conditioning regimens, infectious complications and also an effect of GVHD.In our study, no difference was found between the incidence of EF decline and the type of transplant. However, the number of allo HSCT in this study is much fewer than the auto patients.Hernstein et al found that despite the speculation of higher incidence of cardiotoxic complications in patients undergoing allo-HSCT, a higher incidence heart failure was found in autologus recipients in their study. However, the number of autologus patients in their study was small.There is a statistical significance between the decline in ejection fraction and the conditioning regimen used for the transplant with patients in the TBI-based regimens are more affected followed by patients who received high dose cyclophosphamide.Comparing TBI-based regimens to non-TBI regimens there is highly statistically significant difference between the decline in ejection fraction and the use of TBI (P-value 0.012).The epidemiology of RICVD is complicated by the continual improvements in radiation dosimetry and shielding that tend to reduce cardiovascular exposure and the latent effects of radiation, which takes years or decades to manifest.Several large studies have been published over the last few years that analyzed the outcome of RT administered between one and four decades ago.Radiation-induced pericarditis is the earliest form of RICVD to occur following mediastinal irradiation. It may occur in either of two forms, early and acute or delayed and chronic, which should be regarded from a histopathological standpoint as two distinct disease entities.The risk of radiation-induced cardiomyopathy increases after 5 years, but it can evolve decades after initial RT. Pathologically, RICM is characterized by inflammation followed by the development of a diffuse, patchy interstitial fibrosis of the myocardium and effacement of perimyocyte and endothelium.More recently, researchers at the Netherlands Cancer Institute found a stepwise decrease in 30-year cumulative incidence of valvular heart disease (VHD) corresponding to diminishing doses of RT, from 12.4% at doses greater than 40 Gy to 3.0% at doses less than 30 Gy.A large case control study of breast cancer survivors in Denmark and Sweden undertaken in 2013 found that the risk of a major CHD event begins to increase within the first 5 years post-treatment and continues to significantly exceed that of the general population through at least 20 years of follow-up. These patients experienced increased risk of angina pectoris, MI, and sudden cardiac death despite having been treated with a modest mean heart dose of 3.6 Gy RT between 1958 and 2001.Another large study of women in Denmark and Sweden (n =35000) comparing incidences of MI in breast cancer survivors observed an incidence ratio of 1.22 in patients undergoing left-sided vs right-sided RT.