The recent onset of new or increased left-sided valve regurgitation, detected by the presence of a new or louder murmur followed by TTE confir- mation, may be attributable to endocarditis, so it is prudent to obtain blood culture samples to exclude this diagnosis. 3. The Modified Duke Criteria (Tables 24 and 25) have been well validated by comparison with surgical or autopsy findings and in the clinical outcomes of numerous studies involving a wide spectrum of patients, including children, the elderly, prosthetic valve recipients, injection drug users, and non drug users, as well as patients in both primary- and tertiary-care settings. About three-fourths of patients with IE are diagnosed within 30 days of the onset of infection, so clas- sic clinical features of IE, such as embolic or vasculitic skin lesions, renal disease caused by immune complex deposition, and immunologic abnormalities, are often absent. In these cases, maintaining a high level of clinical suspicion with regard to the possibility of IE in patients who are susceptible is paramount.4,6 10 4. The diagnosis of IE can still be difficult and is fre- quently delayed, which may cause progressive and potentially irreparable structural damage to the heart and other organ systems second- ary to vascular embolic and immunologically mediated events. Additionally, stroke (16.9%), embolization other than stroke (22.6%), HF (32.3%), intracardiac abscess (14.4%), and the need for surgical therapy (48.2%) remain common. Patients with suspected IE are most optimally managed in an environment that coordinates the management of specialists who are well attuned to the various organ systems, pathological processes, and potential treatment Table 24. 