Table 1.
Summary of Lyme Carditis Cases
| Case 1 | Case 2 | |
|---|---|---|
| Patient demographics | 48-year-old woman | 59-year-old man |
| Presenting symptoms | Dizziness, shortness of breath | Dizziness, 2 episodes of nonprodromal syncope |
| Lyme symptoms (including erythema migrans) | Nonspecific rash on abdomen 3 months prior, myalgia | Headache, myalgia |
| Initial ECG/telemetry | Complete heart block | Atrial fibrillation with slow ventricular response and pauses |
| SILC score | 8 | 4 |
| Lyme serology | Positive | Positive |
| Echocardiogram | Normal LV function, moderate MR, mild TR, left atrial enlargement | Normal LV function, aortic sclerosis, mild AR, mild biatrial enlargement |
| Pacemaker device | Medtronic W3DR01 Azure S DR MRI | St. Jude Medical 2272 Assurity MRI |
| Antibiotic treatment | Ceftriaxone 2 grams, IV once daily for 4 weeks | Doxycycline 100 mg orally, twice daily for 3 weeks |
| Follow-up ECG | NSR with HR 65, PR 166 ms, QRS 84 ms | NSR with HR 79, PR 178 ms, QRS 90 ms |
| Device interrogation | 14 weeks after pacemaker insertion: ventricular pacing <1% | 38 weeks after pacemaker insertion: ventricular pacing <1% |
| Time to total conduction recovery (based on pacemaker HR histograms) | 4 weeks | 7 weeks |
| Stress test results | HR response 165 beats/min with 1:1 conduction (BRUCE 10:50 min, achieving maximum work level) | HR response 150 beats/min with 1:1 conduction (BRUCE 10:02 min, achieving maximum work level) |
| Successful device explantation (number of weeks after insertion) | 19 weeks | 42 weeks |
| Lead Borrelia tissue sampling results | Negative | Negative |
AR = aortic regurgitation; ECG = electrocardiogram; HR = heart rate; IV = intravenous; LV = left ventricle; MR = mitral regurgitation; NSR = normal sinus rhythm; TR = tricuspid regurgitation.