S-28 Long term follow-up and management of children who have received cardiotoxic treatment With the increasing success in treating childhood cancers, late onset cardiomyopathies secondary to chemotherapy and radiotherapy related cardiotoxicity is becoming a more relevant issue throughout the world. Cancer therapy in childhood raises a quality of life issue with the attendant risk of heart failure and sudden death in young adulthood. In the very young patients, there is not only the risk of diminishing contractile function of the myocardial cells, but also the likelihood of impairment of cardiac growth potential with an inadequate hypertrophic response. Progressive enlargement with thinning of the ventricular walls leads to dilated cardiomyopathy and congestive heart failure; however exposure in the infancy and childhood may lead to a restrictive cardiomyopathy pattern. Some forms of late cardiotoxicity may be related to sequential stress. The child should also be evaluated for anemia, electrolyte disturbances, kidney dysfunction, hypoproteinemia, hyperlipidemia, diabetes, obstructive sleep apnea and thyroid dysfunction. Serial measurements of troponin levels during anthracycline therapy and later plasma atrial and brain natriuretic peptide levels may have some value in monitoring late deterioration in function. ECG should be performed on routine basis. Fibrosis of myocardial cells, including the cells of conduction system can leads to ventricular arrhythmias and bundle branch blocks causing syncope or sudden cardiac arrest. Risk of cardiac arrest increases with prior history of syncope, decreased left ventricular function, ventricular dysrrhythmias, prolonged QT interval and increased QT dispersion. Children less than 2 years of age show delayed and fragmented activation potentials due to damaged myocardium on signal averaged ECG at lower doses compared to older children suggesting especial vulnerability of the myocardium in very young children. The incidence of abnormalities detected by echocardiogram progressively increase with the duration of follow-up with significantly larger left ventricular volume at end-systole, lower left ventricular mass, higher end-systolic left ventricular wall stress, reduced shortening fraction, valve thickening and calcification. Exercise testing, radiolabelled stress scintigraphy and stress echocardiography can be performed to expose latent cardiotoxicity.With stress, the inability in children to increase their systolic function in a manner similar to controls is seen to correlate strongly with the amount of cumulative anthracycline dose. Pericardial thickening and focal areas of adhesion in the pericardium are readily demonstrated by cardiac MRI. Sudden onset of congestive heart failure may be precipitated by factors that can increase the afterload such as puberty, isometric exercise, systemic hypertension or factors that can increase preload such as pregnancy, sodium and water retention, renal failure. Risk factors for atherosclerosis should be monitored as these children may be at higher risk of premature atherosclerosis. A diet low in cholesterol and salt, heart healthy lifestyle with regular exercise, weight management and abstinence from smoking, alcohol and recreational drugs are encouraged. Isometric exercise such as weighttraining is discouraged and aerobic exercise is recommended instead. Patients with valvular insufficiency should be placed on infective endocarditis prophylaxis. Beta blockers have been shown to be helpful in improving cardiac function in anthracycline induced heart failure in children. Angiotensinogen converting enzyme inhibitors have not been proven to be beneficial in younger age possibly due to regression of cardiac hypertrophy but may be useful for older children prior to symptomatic heart failure. Rhythm disturbances once detected should be treated with antiarrhythmics such as amiodarone or beta blockers. A pacemaker may be needed for significant bradycardia and cardioverter-defibrillator for those at risk of sudden death. Radiation-induced chronic pericardial effusions or constrictive pericarditis may be treated by pericardiectomy. Orthotropic heart transplantation has been successfully performed in anthracycline induced end-stage heart failure in children with little risk of recurrence of tumor or new-onset malignancy due to chronic immunosupression after the transplantation. M. Gupta Children’s Memorial Hermann Hospital, The University of Texas Medical School, Houston, Texas, USA, 2007 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.