Legionellosis is a versatile disease often presenting diagnostic challenges. Rhythm and conduction abnormalities are rare complications.
A 59 year-old woman noted the acute onset of chills, nausea, chest pressure and dizziness. She was hypotensive (82/42 mmHg), tachypneic with heart rate of only 72/minute.Oxygen saturation was 92% on room air. Her chest was clear and there was no calf tenderness or swelling. The chest radiograph and CT were unremarkable.Broad-spectrum antibiotic therapy including azithromycin was initiated. Electrocardiogram showed junctional rhythm at rate of 72/min (Fig.1).White blood cell count was 7.7x109/L, hemoglobin 12.2 g/dL, serum electrolytes were normal. Serial creatine kinase and troponin levels were within normal limits. Pulmonary embolism was ruled out. An echocardiogram demonstrated normal left and right systolic ventricular function. Blood and urine cultures showed no growth. A pharmaceutical stress test showed no ischemia. The urine tested positive for Legionella pneumophila antigen serotype 1. All antibiotics but azithromycin were discontinued. The patient reverted to sinus rhythm after 48 hours (Fig. 2).She felt improved, didn’t require supplemental O2 anymore. One week after admission the patient was discharged home asymptomatic and in normal sinus rhythm.DISCUSSION: Although numerous infectious processes such as acute rheumatic fever have been associated with conduction abnormalities including prolongation of the PR interval and various degrees of atrioventricular block, only one previous case of isolated sinoatrial node dysfunction has been reported with Legionella infection. Rhythm and conduction disturbances due to Legionella appear to be more common in children and, in some cases, those are associated with clinical and biochemical evidence of myocarditis. In other cases, as in ours, the intrinsic pacing system seems to be selectively affected.CONCLUSIONS: Awareness of the potential electrophysiological complications of Legionellosis allows establishing an early diagnosis, initiating the appropriate treatment in a timely manner, preventing this way further morbidity.
B.I. Medarov, None.