A Patient with Sjögren’s Syndrome, Fever and Palpitations

Case Description

A 37-year-old woman with a history of Sjögren’s syndrome was admitted with fever, diffuse arthralgia and palpitations since a week.

The ECG at admission is shown in Figure 1.

(1.)

What is the baseline rhythm?

(2.)

What etiological differential diagnosisshould be considered in this patient?

Discussion

The ECG shows sinus tachycardia at 120 bpm with first-degree AV block (PR interval of 460ms) with occasional second-degree AV block (second to last P-wave). A junctional reentrant tachycardia is unlikely due to the variable RP intervals, the presence of a blocked Pwave (not occurring in the middle of two QRS complexes), and the morphology of the Pwaves (which would be negative in the inferior leads and narrow in case of AV nodal re-entrant tachycardia).

The etiological differential diagnosis of the AV conduction disease is active Sjögren’s syndrome versus infectious endocarditis with a paravalvular abcess. The latter diagnosis was ruled out by sterile haemocultures and a normal transoesophageal echocardiogram. The patient was administered intravenous corticosteroids with a rapid improvement of her clinical status and the disappearance of the AV block (ECG at day 5 is shown in Figure 2).

There have been rare reports of AV block in adult patients with Sjögren’s syndrome [1,2]. The development of AV block seems to be related to disease activity [2], as well as to the presence of anti-SS-A[1] and anti-SS-B [2] antibodies, both of which were present in our patient.