Echocardiography in infective endocarditis.

BACKGROUND: Echocardiographic demonstration of valvular infection now ranks with positive blood cultures as one of the two major clinical criteria for diagnosis of infective endocarditis (IE), according to new, more accurate guidelines for diagnosis. Because early detection of IE and its complications is essential for determining whether to pursue medical therapy or to intervene surgically, transthoracic echocardiography (TTE) is an essential part of the initial examination of patients with suspected IE. METHODS: Using MEDLINE, we searched and reviewed all articles with the key words infective endocarditis and transesophageal echocardiography. RESULTS: With its superior imaging, transesophageal echocardiography (TEE) has proven to be more sensitive than TTE for the diagnosis of IE as well as in the detection of IE-associated complications. CONCLUSIONS: While superior in predicting which patients with IE have perivalvular abscess or prosthetic valve dysfunction and which are most susceptible to systemic embolism, TEE is more invasive and must be used selectively.

Functional mitral stenosis resulting from a large mitral valve prosthesis vegetation.

Obstruction of a prosthetic valve by an infective vegetation is a rare and life-threatening complication of endocarditis that demands emergent surgical intervention. In our patient's case, transthoracic echocardiography showed the large vegetation, transthoracic Doppler imaging showed severe obstruction of diastolic flow through the bioprosthetic valve, and transesophageal echocardiography showed that no perivalvular abscess was present. Rapid diagnosis of prosthetic valve infection and obstruction demanded application of all three major echocardiographic modalities and proved critical to the patient's recovery.

Pulmonary vein Doppler flow patterns specific for elevated left ventricular filling pressures in older cardiac patients are common in healthy adults < 40 years old.

In older cardiac patients, elevated left-sided heart filling pressures are predicted by both a systolic PV flow fraction < 40% and a greater duration during atrial systole of reversal flow into the PVs than forward flow through the mitral valve. However, this study shows that these Doppler findings are not uncommon in younger subjects without cardiac disease. Use of these PV Doppler flow parameters to assess LV filling pressures should be limited to older patients.

Association of acidic fibroblast growth factor and untreated low grade rejection with cardiac allograft vasculopathy.

Acidic fibroblast growth factor (aFGF) is a potent growth factor for vascular smooth muscle cells and may mediate vasculopathy in cardiac allografts subjected to chronic immunological injury. Therefore, we examined cardiac expression of aFGF, the number of rejection episodes, and other potential risk factors in 32 heart transplant patients who underwent intravascular ultrasound (IVUS) for detection of cardiac allograft vasculopathy (CAV). As defined by IVUS, CAV was present in 21 patients and absent in 11 patients (follow-up time: 52 +/- 21 vs. 51 +/- 12 months, respectively, P = NS). The level of aFGF in myocardial biopsies obtained at the time of IVUS was measured by semiquantitative reverse transcriptase polymerase chain reaction and expressed as the aFGF:GAPDH ratio. Higher level of aFGF were associated with CAV (mean aFGF:GAPDH ratio was 1.45 +/- 0.99 in patients with vs. 0.18 +/- 0.12 in patients without CAV [P < 0.001]). A strong association was found between high levels of cardiac aFGF and CAV, as 18 of 19 patients (95%) with high levels of aFGF (aFGF:GAPDH > 1) but only 3 of 13 patients with low levels of aFGF had CAV (P < 0.001). The relative risk of high level of aFGF for CAV was 4.1. Untreated low grade rejection (ISHLT I), but not treated high grade rejection (ISHLT > 2), was also associated with CAV (average number of untreated low grade rejection episodes was 3.5 +/- 1.8 in patients with vs. 2.1 +/- 1.0 in patients without CAV [P = 0.04]). Among other risk factors examined (age, sex, serum cholesterol, blood pressure, CMV infection, dose of immunosuppressants, and ischemic time), only triglycerides were higher in patients with than those without CAV (P = 0.003). We conclude that increased cardiac production of aFGF is significantly associated with CAV, which suggests that aFGF may serve as an important mediator in CAV. Untreated low grade rejection also poses an increased risk for CAV.