Actinobadllus actinomycetemcomitans is an uncommon cause of endocarditis. This organism is a slow-growing, fastidious Cram-negative bacillus normally found in the oral cavity. Approximately 50 cases of endocarditis due to A actinomycetemcomitans have been reported since the first case report in 1964, all involving the native left-sided cardiac valves or prosthetic cardiac valves. The purpose of this report is to document a case of right-sided endocarditis occurring on a native valve due to A actinomycetemcomitans and to stress the value of two-dimensional echocardiographic studies over standard M-mode techniques in the routine assessment of patients with suspected endocarditis.
In August 1981, a 48-year-old male dress manufacturer came to the Dallas Veterans Administration Medical Center with three weeks of recurrent fevers, chills, and nausea. He had had a nonproductive cough for two days. His temperature was 38.1°C (100.5°F), with otherwise normal findings on physical examination. The hematocrit reading was 40.9 percent, the hemoglobin level was 14.1 g/100 ml, and the white blood cell (WBC) count was 11,400/cu mm (segmented cells, 59 percent; and band cells, 14 percent). The bilirubin level was 0.9 mg/100 ml, and the serum glutamic-oxaloacetic transaminase (SCOT) level was 28 mU/ml. The chest x-ray film was within normal limits. Three weeks later, the patient was admitted to the hospital because of continuing similar complaints, with worsening anorexia and malaise. He admitted to excessive intake of alcohol during the past 15 years and to several gingival surgical procedures from January to May 1981, and denied previous rheumatic fever, cardiac murmur, intravenous drug abuse, or recent antibiotic therapy. The patients temperature was 40.4°C (104.7°F), the blood pressure was 135/70 mm Hg, the pulse rate was 120 beats per minute and regular, and the respiration rate was 16/min. Physical examination revealed poor dentition, no retinopathy, normal cardiac findings without murmurs, clear pulmonary fields, no abdominal organomegaly, a mildly enlarged and tender prostate gland (read more about causes of enlarged prostate gland here – http://healthcaremall4you.com/canadian-healthcare-mall-exposes-the-risks-of-male-sex-enhancement-supplements.html), and no rash or cutaneous lesions. Laboratory values were as follows: hematocrit reading, 27.5 percent; hemoglobin level, 9.1 g/100 ml; reticulocyte count, 0.8 percent; WBC count, 9,900/cu mm (segmented cells, 67 percent; and band cells, 17 percent); bilirubin level, 2.4 mg/100 ml; SGOT level, 19 mU/ml; total protein level, 7.1 g/100 ml; albumin level, 3.1 g/100 ml; and hepatitis В surface antigen, negative. Electrophoresis of the hemoglobin revealed an AA pattern; G6PD was normal. Findings from urinalysis were unremarkable. The chest x-ray film was within normal limits. The electrocardiogram showed only sinus tachycardia.
A gallium citrate scan demonstrated slightly increased uptake at 48 to 72 hours in the area of the left kidney. An intravenous pyelogram showed a small collection of contrast material adjacent to two calices of the left kidney, compatible with papillary necrosis. Six cultures of blood obtained during the first 24 hours alter admission all grew A actinomycetemcomitans sensitive to all antimicrobial agents tested except for penicillinase-resistant penicillins. Cultures of the urine, prostatic secretions, and sputum were negative.
An M-mode echocardiogram revealed normal mitral, aortic, and pulmonary valves. The tricuspid valve was not well visualized. The left atrium and left ventricle were of normal dimensions, and the right ventricle appeared minimally dilated. There was no pericardial effusion. A two-dimensional echocardiogram was obtained, and a large tricuspid valvular vegetation was visualized (Fig 1). Findings from the examination were otherwise normal. The patient was treated with ampicillin (12 g/day intravenously) for six weeks, with rapid and complete resolution of symptoms. Serial two-dimensional echocardiograms demonstrated no significant change in the size of the tricuspid valvular vegetation during a six-month follow-up.
Figure 1. Apical four-chamber two-dimensional echocardiogram showing vegetation (V) on tricuspid valve (TV). Schematic representation at left shows left ventricle (LV), right ventricle (RV), right atrium (RA), and mitral valve (MV).