A 51-year-old female had episodes of syncope and headache a few months back for which the patient had consulted a neurologist. MR imaging of the brain was done to look for organic causes, which revealed no significant abnormality. The patient also had complaints of blurring of vision and was diagnosed with papillitis and was advised to screen for sexually transmitted diseases which revealed a positive Treponema pallidum hemagglutination (TPHA) test and a non-reactive Venereal Disease Research Laboratory (VDRL) test. She was referred to a sexually transmitted diseases clinic in our tertiary care centre and incidentally detected to have ulcers in bilateral groin regions. Serial investigations revealed Venereal Disease Research Laboratory (VDRL)-NR, VCTC (Voluntary Counselling and Testing Center) − ve, Treponema pallidum hemagglutination (TPHA).
+ ve, HSV (Herpes simplex virus) 1, 2 IgM − ve. The culture for Trichomonas vaginitis and candida was negative. Hence, based on laboratory and clinical findings, the patient was diagnosed with late latent syphilis. Currently, she had presented with multiple episodes of syncopal attacks and was rushed to an outside hospital where ECG (electrocardiogram) revealed a complete heart block. She was again referred to our tertiary care centre. The patient was received in the cardiac care unit, following which she was stabilized.
IM Penicillin injection was continued for late latent syphilis.
The patient was then referred for cardiac MRI to identify a potential cause for the complete heart block. The magnetic resonance imaging was performed in 3T magnetic resonance scanner (Siemens Healthineers, Erlangen, Germany). Standard institute cardiac MR protocol with TRUFISP (True Fast Imaging with steady-state free precision) (white blood) images and HASTE (half Fourier single-shot turbo spin echo) (dark blood) axial and coronal sections were done for morphologic imaging. Two-chamber, four-chamber, and short-axis cine images were obtained to evaluate wall motion abnormalities and cardiac function. Parametric mapping with Native T1 and T2 mapping was done, and ECV (extracellular volume) was calculated as per SCMR (Society for Cardiovascular magnetic resonance) guidelines. Pre-contrast T1 maps were obtained from three short-axis images (basal, mid cavity, and apical) of the left ventricle using a single short true FISP based on the modified look-locker inversion recovery (MOLLI) sequence.
The standard T1 and T2 mapping values in our institute were as follows: normative T2 values: 38.25 ± 1.2 ms, normative T1 values: 1186.47 ± 45 ms. Normative ECV values were 25.2 ± 3.55%.
Gadolinium contrast was administered at 0.1 mmol/kg. Late gadolinium images were obtained at 10, 12, and 15 min. The findings noted in cardiac MRI were significant hypertrophy (18 mm) of the lateral wall of base of left ventricle (Fig. 1A–G). Delayed phase-sensitive inversion recovery (PSIR) imaging revealed significant subepicardial delayed hyperenhancement involving the lateral wall of base of left ventricle and septal wall (Figs. 2A, B and 3), reflecting fibrosis. There was corresponding increased native T1 (Fig. 4A, B), T2 (Fig. 5) and ECV values. The native T1 values in the septum and lateral wall were 1351 and 1331, respectively. The T2 values were 50.03 and 39.45, respectively. The ECV values were 68.46 and 39.2, respectively.
No significant wall motion abnormality was noted, and a normal ejection fraction was observed.
A temporary pacemaker was inserted to maintain cardiac rhythm. Hence in a patient with late latent syphilis (clinical and laboratory results positive), the above features in parametric mapping and late gadolinium enhancement reflect myocardial infiltration/myocarditis.
To rule out other causes of myocarditis, an infectious panel was done and Treponema pallidum hemagglutination (TPHA) was found to be positive. Investigations for Candida, HSV, Trichomonas, Rubella, Adenovirus, parvovirus, enterovirus, EBV, CMV, and mumps were found to be negative. KOH smear was negative. Venereal Disease Research Laboratory (VDRL) was non-reactive, and VCTC (Voluntary Counselling and Testing Center) was negative. A neurologist's opinion was sought and lumbar puncture was attempted to obtain a diagnostic CSF (cerebrospinal fluid) tap, which was found to be acellular with no growth on CSF culture. Blood cultures were found to be negative.
The patient was later referred to PET (positron emission tomography) scan, which revealed status post-temporary cardiac pacing with few nonspecific subcentimetric nodules in both lungs with low-grade FDG avidity.
A few prominent mediastinal lymph nodes were seen with a few of them showing mild increased FDG (fluorodeoxyglucose) avidity, the largest subcarinal node measuring ~ 19 × 12 mm (SUV max = 3.4).
The likelihood of infective aetiology was suggested, and a differential of sarcoidosis was suspected; however, no other characteristic features like interlobular septal thickening and perilymphatic nodules were detected. ACE (angiotensin-converting enzyme) levels were done to rule out sarcoidosis and were found to be within normal limits. TB quantiferon samples were also sent, which were found to be negative.
Dilated left ventricle with patchy increased metabolic activity was seen in the wall of the left ventricle (SUV max = 8) (Fig. 6). Increased metabolic activity was also seen along the right lateral wall of the superior vena cava.
Repeated attempts to withdraw the patient from a temporary pacemaker resulted in the patient developing RBBB (right bundle branch block) or CHB (Complete heart block) 2–3 days post-temporary pacemaker removal.
Hence, a permanent pacemaker was inserted, following which the patient maintained a normal sinus rhythm. Based on the above findings, a clinical diagnosis of late latent syphilis, with a rare manifestation presenting as a complete heart block, was made, following which the patient was discharged and advised follow-up. Cardiac MRI with parametric mapping and delayed contrast imaging was helpful not only in picking up the correct diagnosis of myocarditis in this patient with a background of syphilis, but also demonstrated fibrosis of the septal wall, involving the conduction pathway and possible cause of the heart block.