Both tissue and the lead tip should be cultured for fungi and mycobacteria if the initial Gram stain is negative; mycobac- teria and fungal stains also should be obtained on resected pocket tissue. Percutaneous aspiration of the device pocket should not be done, in general, because of the lack of adequate diagnostic yield and the theoretical risk of introduc- ing microorganisms into the pocket site and causing device infection. Because leads are extracted through an open generator pocket in most cases, lead contamination can occur if a pocket is infected. This likely explains the lack of systemic manifestations and negative blood cultures in many cases in which a positive lead-tip culture is demonstrated. Recommendations for Diagnosis of CIED Infection and Associated Complications Class I 1. All patients should have at least 2 sets of blood cultures drawn at the initial evaluation before prompt initiation of antimicrobial therapy for CIED infection. (Level of Evidence: C) 2. Generator-pocket tissue Gram s stain and culture and lead-tip culture should be obtained when the CIED is explanted. (Level of Evidence: C) 3. Patients with suspected CIED infection who either have positive blood cultures or who have negative blood cultures but have had recent antimicrobial therapy before blood cultures were obtained should undergo TEE for CIED infection or valvular endocarditis. (Level of Evidence: C) 4. All adults suspected of having CIED-related endocar- ditis should undergo TEE to evaluate the left-sided heart valves, even if transthoracic views have demonstrated lead-adherent masses. In pediatric patients with good views, transthoracic echocardiography may be suffi- cient. (Level of Evidence: B) Class IIa 1. Patients should seek evaluation for CIED infection by cardiologists or infectious disease specialists if they develop fever or bloodstream infection for which there is no initial explanation. (Level of Evidence: C) Class III 1. 