ECG is generally not helpful in the diagnosis of IE, except for IE with periannular extension, in which prolongation of the PR interval or frank heart block can occur.

Valvular vegetations may be detected on gated cardiac CT. CT is not recommended in the evaluation of endocarditis.

Cardiac perfusion with delayed imaging is helpful to visualize inflammation of the endocardium and possible myocarditis (Fig. 8.2). Triple inversion recovery (TIR) images may also detect edema and inflammation in the endocardium and myocardium. Functional MRI may be used to evaluate for decreased left ventricular function, and valvular vegetations may be detected on cine gradient recalled echo (GRE) imaging (Fig. 8.3). Cardiac perfusion imaging may be helpful to look for delayed enhancement within the endocardium and to look for myocardititis.

Transthoracic echocardiogram (TTE ) can detect the size and location of a vegetation (a Duke major criterion ), so it should be performed on all patients in whom there is a reasonable suspicion of endocarditis. Other echocardiogram findings that make up the Duke major criteria include new valvular regurgitation, paravalvular abscess, or valve dehiscence. TTE may show the extent of valve damage, the presence and degree of valvular stenosis, the presence of paravalvular extension, conduit or shunt obstruction, ventricular function, or the presence of pericardial effusion. Because of suboptimal echocardiographic windows, it may be inadequate for certain children, including those who are overweight or have significant respiratory disease or congenital heart disease (CHD) postoperative complex. In these cases, we recommend using transesophageal echo (TEE), which is also better at detecting periannular extension.

TTE is not 100 % sensitive or specific, and a negative echocardiogram does not rule out endocarditis [5]. False negative results are possible if the vegetations are small or if embolization of the vegetation has occurred.

In most pediatric cases of suspected IE, especially in infants and younger children, TTE is adequate to detect the presence of a vegetation and to monitor hemodynamic and valvular function. It is a much more sensitive diagnostic tool in children than in adults.

IE has two major identifiable risk factors : congenital heart disease (CHD) or chronic indwelling catheters. The rate of IE has risen since the 1960s because of the increased survival of children with CHD and the increased use of indwelling central venous catheters [3,4].

Ninety percent of IE cases occur in patients who have heart disease, usually congenital [5]; only 20 % of pediatric patients with IE have normal cardiac anatomy [6]. The risk of IE is increased in patients with complex cyanotic heart disease, especially those who have had surgical intervention [3].

Other pediatric populations at risk include critically ill and premature infants and children with cancer or connective tissue disease. The increased use of invasive procedures in neonatal and pediatric intensive care units also increases the risk of IE in children with structurally normal hearts.