Cardiorenal syndrome is an emerging clinical entity which includes vast array of interrelated derangements between heart and kidneys. Several studies of adult patients have reported that worsening of renal function in patients with heart failure is common and is recognized as an independent risk factor for morbidity and mortality. The relationship between heart and kidney is more complex, importantly renal function may serve as one of the most important determinint of prognosis in patients with acute heart failure.Few pediatric studies have reported development of renal insufficiency in children with heart failure, this book therefore provide awareness of this co-dependency, which inturn will help us to identify the frequency of this syndrome in our population, so that early intervention can be done to decrease the morbidity and mortality in this increasingly common condition in children. This book would be especially useful to professionals in cardiology, nephrology and pediatrics.