ECG Quiz Answer: Palpitations and Fatigue in a Football Player
Cortland P. Bassett, PA-C, MAE, ATC; Raymond J. Barile, MS, ATC; Michael A. Goodfriend, MDTHE PHYSICIAN AND SPORTSMEDICINE - VOL 24 - NO. 3 - MARCH 96
The ECG (figure 2) shows a third-degree atrioventricular (AV) block, with atrial and ventricular rhythms independent of each other. A presumptive diagnosis of Lyme carditis was made, and the patient was admitted to coronary care. He was placed on ECG monitoring with an external pacemaker on standby. An echocardiogram showed no pericarditis. Intravenous ceftriaxone sodium was given at 2 g daily for 14 days; the patient became afebrile after the first dose and later experienced rapid improvement in AV block. He was hospitalized for 4 days and was disqualified for the rest of the football season.
Lyme titers done locally and at Yale University demonstrated marginally significant enzyme-linked immunosorbent assay (ELISA) titers for immunoglobulin M (IgM) of 100 units and immunoglobulin G (IgG) of 400 units on admission. Repeat tests 16 days later showed a significant and diagnostic increase in IgM of 800 units, with IgG remaining at 400 units.
Lyme disease is transmitted by the deer tick, Ixodes dammin (1). Borellia burgdorferi, the responsible spirochete, is found in the tick's saliva (2). AV block is the primary manifestation of Lyme carditis and most often appears within a few weeks of erythema marginatum (EM), the characteristic skin lesion. Carditis occurs in 4% to 10% of untreated patients with EM (3). It is caused by the spirochete's invasion of the conduction system, usually above the level of the AV node (1).
Not all patients with Lyme carditis, however, recall a tick bite or develop EM (4). Most have mild, nonspecific systemic symptoms, and almost all have antibodies for B burgdorferi and, typically, IgM antibodies (1). As in this case, patients at times have seroconversion only with repeat sampling.
Carditis can manifest as varying degrees of block, but half of patients have third-degree, or complete, block. A study (5) of patients with EM given early antibiotics suggests that treatment may prevent AV block and carditis. Although carditis usually resolves completely regardless of treatment, ceftriaxone therapy should be given in all cases because it cures the primary and secondary stages, such as cranial neuritis. Oral doxycycline, ampicillin, or erythromycin remain standard treatment for uncomplicated Lyme disease. Round-the-clock ECG monitoring continues until the patient has major improvement of AV block-in this case, to a first-degree block.
Cardiac involvement usually lasts 3 days to 6 weeks (6). A permanent pacemaker is rarely needed; however, isolated cases of persistent abnormalities and deaths have been reported (7). No systematic studies of functional cardiac capacity with exercise have been done. This may be especially important to young athletes, who should be screened periodically with exercise stress testing before they return to activity. Stress testing can help check for relapse with exertion and generate an exercise prescription. Return to sports should probably take at least 6 weeks.
Mr Bassett is a physician's assistant at Cornell University in Ithaca, New York, and a fellow of the American Academy of Physician Assistants. Mr Barile is head athletic trainer for the St Louis Blues of the National Hockey League and a member of the National Athletic Trainers' Association. Dr Goodfriend is a cardiologist in private practice in Ithaca. Address letters to Cortland P. Bassett, PA-C, MAE, ATC, Gannett Health Center, Cornell University, 10 Central Ave, Ithaca, NY 14853-3101; e-mail to [email protected]