Low incidence of cardiac abnormalities in treated trichinosis: a prospective study of 62 patients from a single-source outbreak.

PURPOSE: The reported incidence of cardiac involvement in trichinosis is highly variable, ranging from 21% to 75%. This study sought to determine the incidence and type of cardiac lesions in trichinosis using serial echocardiographic examinations.

SUBJECTS AND METHODS: Sixty-two consecutive patients admitted to the Banja Luka Medical Center during an outbreak of trichinosis (November to December 1996) were included in the study. Diagnosis was made by typical clinical presentation, positive epidemiologic history, serologic testing, and the detection of Trichinella larvae in contaminated meat. All patients underwent serial electrocardiograms and two-dimensional and Doppler echocardiographic examinations within 20 days after the onset of symptoms. Repeated echocardiographic examinations were performed weekly during the hospital stay in all patients with electrocardiographic abnormalities or an abnormal initial echocardiogram.

RESULTS: Cardiac involvement (electrocardiographic and/or echocardiographic changes) was detected in 8 (13%) of the 62 patients. Nonspecific transient electrocardiographic ST-T changes were found in 6 patients (10%); 1 patient had frequent premature ventricular complexes. Echocardiographic examinations revealed pericardial effusions in 6 patients (10%), 5 of whom had minimal effusions without impairment of global and regional left ventricular systolic function. One patient had hypokinesis of the interventricular septum with a small pericardial effusion, both of which resolved within 2 weeks. Only 2 of the patients with electrocardiographic abnormalities lacked echocardiographic evidence of cardiac involvement. At 6-month follow-up, none of the patients had electrocardiographic or echocardiographic abnormalities.

CONCLUSIONS: The incidence of cardiac involvement in trichinosis appears to be lower than previously reported. Pericardial effusion is the most common manifestation of cardiac involvement, and nonspecific transient electrocardiographic changes, traditionally ascribed to myocarditis, more frequently reflect pericarditis.