Download Complete atrioventricular block associated with toxoplasma

Europace (2006) 8, 221–223
doi:10.1093/europace/euj046
CASE REPORT
Complete atrioventricular block associated with
toxoplasma myocarditis
Matteo Mariani, Massimo Pagani, Corinna Inserra, and Stefano De Servi*
Department of Cardiovascular Disease, Unit of Cardiology, Ospedale Civile di Legnano, Via Candiani, 2Legnano, Milan, Italy
Received 16 April 2005; accepted after revision 21 November 2005; online publish-ahead-of-print 13 February 2006
KEYWORDS
Toxoplasma;
Myocarditis
Myocarditis has been described during and after a wide variety of infectious agents: viral,
rickettsial, bacterial, protozoal, and metazoal diseases may cause cardiac inflammation. We report a
case of toxoplasma myocarditis in a young healthy man.
A 19-year-old man, with a medical history of paracetamolinduced coma, developed symptoms of fever, nausea, and
vomiting. He was taking no medication at the time of admission to the hospital. Physical examination revealed hepatomegalia as the only abnormal finding. After a few days of
hospitalization, he was discharged with a diagnosis of
acute viral hepatitis associated with junctional bradycardia
with a period of sinus bradycardia (Figure 1) raising a suspicion of viral myocarditis.
One week later, he complained of dyspnoea during light
physical activity. Physical examination revealed only bradycardia. ECG showed complete atrioventricular (AV) block,
with a narrow QRS at a rate of 32 bpm and an atrial
rate of 66 bpm (Figure 2); cardiac enzymes and echocardiography were normal. An ergometric test showed no
increase of heart rate on physical activity.
All serological tests were normal or negative (including
HIV) except the IgM and IgG titres to Toxoplasma gondii,
respectively, 1.94 IU/mL (International Unit) (negative ,1,
positive 1.75) and IgG 56 IU/mL (negative ,10, positive
15). No myocardial biopsy was performed.
Further, patient history indicated that he had worked as a
gardener 1 month before the symptoms started.
Thoracic and abdominal computed tomography was
performed without evidence of abnormal findings. Cranial
magnetic resonance showed small areas (in the occipitoparietal brain cortex bilaterally and in the right hemisphere
of cerebellum) of low density probably related to toxoplasma infection (Figure 3).
Therapy with antibiotics (co-trimixazole) was started.
* Corresponding author. Tel: þ39 0331 449513; fax: þ39 0331 449810.
E-mail address: [email protected]
Several electrocardiograms and 24 h recordings showed
constant complete AV block with a junctional rate of
32 bpm.
After 3 weeks of antibiotic therapy, electrocardiogram
showed no change. Considering the complete AV block and
echocardiographic findings (early right atrial and right
ventricular enlargement), we decided to implant a dualchamber pacemaker.
Two months later, the patient had resumed a normal
life with unrestricted physical activity without
symptoms. A new echocardiogram showed normal diameters
of right atrium and ventricle, a normal left ventricular
ejection fraction. During pacemaker interrogation, AV
block was still present (the patient was pacemakerdependent).
T. gondii is a zoonotic infection; in areas of Europe
(France, Germany, Switzerland, and Spain), the prevalence
of latent T. gondii infection is high with reports of 50–70%
of population testing seropositive for anti-toxoplasma antibodies (10–40% in the USA).1 The parasite infects all
orders of mammals, but cats are the most common hosts.
Cats excrete T. gondii oocysts in their faeces and ingestion
of faecally contaminated material by humans leads to
primary T. gondii infection (undercooked meat is a second
route of infection).2,3
Our patient, working as a gardener, had probably been
infected by the first way of contamination (he denied
having eaten undercooked meat).
Toxoplasmosis manifests as encephalitis, pneumonitis
(usually in immunosuppressed patients), chorioretinitis,
and myocarditis. However, myocardial involvement is
uncommon; manifestations of toxoplasma myocarditis may
include arrhythmias (atrial and ventricular), sudden death,
AV block, pericarditis, and heart failure. Antibiotic
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222
M. Mariani et al.
treatment of toxoplasma myocarditis has a variable
response and has no effect on the cystic form.
Our patient had two toxoplasmosis manifestations: cerebral lesions, documented by cranial magnetic resonance,
Figure 1 Rhythm strip showing period of normal sinus rhythm 1 week before
AV block.
Figure 2 Rhythm strip showing atrioventricular block, with junctional rate
of 32 bpm and an atrial rate of 66 bpm.
Figure 3
and myocardial involvement with complete AV block (no
lesions were found in the lungs and retina).
The elevation of IgM titre of toxoplasma indicated a
recent infection and combined with the clinical history, we
believe that this patient probably had toxoplasma myocarditis involving the conduction system with persistent complete AV block.
To our knowledge, this patient is the second AV block case
related to toxoplasma infection described in the literature.
Duffield et al. 4 described a case of T. gondii myocarditis that
resulted in recurrent, symptomatic AV block in a 25-year-old
woman. On the contrary, our patient developed constant AV
block. Dual-chamber pacemakers were implanted in both
the patients.
Protozoal myocarditis includes trypanosomiasis, prevalent
in Central and South America,5 and toxoplasmosis that
occurs most commonly in immunosuppressed patients with
malignant diseases and also occasionally in patients with the
acquired immunodeficiency syndrome and after cardiac or
bone marrow transplantation.6
We believe that the importance of this case is related
to the high probability of implanting pacemaker
when T. gondii myocarditis involves the conduction
tissue of the heart, even if appropriate antibiotic
therapy is used.
Cranial magnetic resonance showing small areas of low density in the left occipito-parietal brain cortex probably related to toxoplasma infection.
AV block with toxoplasma myocarditis
References
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3. Bearman M, McCabe R, Wong S, Remington J. Toxoplasma gondii. In:
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