Cardiac electrophysiology is the science concerned with the diagnosis and treatment of the electrical activities of the heart. It may involve the study of cardiac responses to programmed electrical stimulation (PES) or invasive catheter recording of spontaneous activity. Such studies are done to assess arrhythmias and the risk of developing arrhythmias, evaluate abnormal electrocardiograms, elucidate symptoms and design treatment strategies. Echocardiography is a diagnostic technique used to create images of the heart. It allows insight into the size and shape of the heart, pumping capacity and the extent and location of tissue damage, if any. Calculation of the diastolic function of the heart, the cardiac output and ejection fraction is also possible through echocardiography. Cardiac electrophysiology and echocardiography are innovative diagnostic tools of medical science that have undergone rapid development over the past few decades. Some of the diverse topics covered in this book address the applications of these diagnostic techniques for the diagnosis of cardiac conditions. Those in search of information to further their knowledge will be greatly assisted by this book.