Case report of young woman presents involvement of dilated cardiomyopathy and rhythm disturbances in 18 months after infection of tick, with direct assessment of spirochetes in myocardial tissue. Cardial decompensation occured after asthma exacerbation, complicated by bronchopneumonia. Rhythm disturbances and heart failure gradually subside after parenteral antibiotic treatment and peroral treatment of heart failure. Nevertheless there is a long-lasting persistence of dilated cardiomyopathy with significant systolic dysfunction, which is supposedly last consequence of Borrelia infection. Resynchronic therapy combinated with cardioverter-defibrilator primary considering was postponed for improvement clinical condition and myocardial electric stability. There is demonstrating complicated serologic diagnostics of Lyme disease in discussion. Lyme carditis would be part of differential diagnosis in rhythm disturbances and cardiomyopathy of unknown etiology, including serious or fatal events.