Culture-negative endocarditis is an infection and inflammation of the lining of one or more heart valves, but no endocarditis-causing germs can be found on a blood culture. This is because certain germs do not grow well in a laboratory setting, or some people have received antibiotics in the past that keep such germs from growing.
Endocarditis is usually a result of a blood infection. Bacteria can enter the bloodstream during certain medical procedures, including dental procedures. Then bacteria can travel to the heart, where they can settle on damaged heart valves.
Baddour LM, Freeman WK, Suri RM, Wilson WR. Cardiovascular infections. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 10th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 64.
Update Date 11/24/2014
Updated by: Daniel Levy, MD, Infectious Diseases, Lutherville Personal Physicians, Lutherville, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.