A 43-year-old woman presented in hospital with pain and asymmetric swelling of her left leg, which had been accompanied by shortness of breath during physical activity over the previous 2 weeks. At presentation, she was a smoker, had a long history of taking contraceptive medication and she was on substitution treatment for hypothyreosis. Her history also included two spontaneous abortions. The previous year, she had been admitted to hospital for pyelonephritis complicated by septic shock; during this hospital stay the patient underwent transthoracic ECG where a Chiari network in the right atrium was found. The patient's mother had suffered from a postoperative pulmonary embolism at the age of 50 years.
On physical examination, the patient was stable with a blood pressure of 140/80 mm Hg, heart rate 80 bpm; her height was 165 cm and weight was 68 kg. Except for the left leg oedema, with positive Homan's sign, there were no other pathological findings. No signs of right heart failure were present. A laboratory blood examination found d-dimers, mild leucocytosis and above normal levels of C reactive protein. A ventilation-perfusion lung scan confirmed a bilateral pulmonary embolism. The source of the embolus was established by Doppler ultrasonography, which documented a femoral-popliteal venous thrombosis in the left leg.
The patient was haemodynamically stable, so treatment with a full-anticoagulation dose of unfractioned heparin (UFH) was started. A transthoracic ECG was performed, which showed two large stationary masses within the right atrium. Their structure and density were suggestive of emboli (, ). One mass was protruding from the right atrium through the tricuspid valve into the right ventricle, but without causing a gradient; systolic functions of both ventricles were normal and there were no signs of right heart overload. Transoesophageal ECG described the hypoechogenic masses as well-circumscribed (23 × 15 mm and 14 × 20 mm) with homogenous structure. The masses appeared to stem from the posterior wall of the right atrium and were caught in the Chiari network ().
Transthoracic ECG showing two large stationary masses. Their structure and density were suggestive of emboli.
Hypoechogenic mass protruding from the right atrium through the tricuspid valve into the right ventricle without a change in gradient. The systolic function of both ventricles was normal. There were no signs of right heart overload.
Transoesophageal ECG described the hypoechogenic masses as well-circumscribed with homogenous structure. The masses appeared to stem from the posterior wall of the right atrium and were caught in the Chiari network.
Both structures were assessed as thromboemboli lodged in the right atrium. Thrombolytic treatment with an intravenous infusion of 100 mg recombinant tissue-type plasminogen activator (rt-PA), over a period of 2 h, with continuous ECG monitoring was performed. Following rt-PA treatment, full dose UFH was restarted. In subsequent control ECGs, the two masses found to persist without any change in their shape or size. MRI further confirmed the thromboembolic aetiology of these right atrial masses (). With respect to the high risk of a fatal pulmonary embolism and the inefficacy of the most potent lytic strategy, surgical embolectomy was indicated. Preoperatively, a control Doppler ultrasonography documented the persistence of thrombotic materials in the veins of the left leg. Therefore, a temporary inferior vena cava filter was implanted prior to surgery.
MRI confirmed a thromboembolic aetiology of the right atrial masses.
The right atrial masses were completely removed under cardiopulmonary bypass (). Histological evaluation confirmed a mixed thromboemboli, with thrombus structures showing signs of organisation and surrounded by a fibrous capsule ().
The right atrial masses were completely removed under cardiopulmonary bypass.
Histological evaluation confirmed a mixed thromboemboli, with thrombus structures showing signs of organisation and surrounded by a fibrous capsule.
The patient, with a positive family history of pulmonary embolism, had further known risk factors for venous thromboembolism—that is, cigarette smoking and use of oral contraceptive. Because of the high suspicion of thrombophilia, the patient was tested for thrombophilic disorders. A heterozygous methylenetetrahydrofolate reductase gene polymorphism was found and the plasma level of the plasminogen activator inhibitor type-1 (PAI-1) was 50% higher than the normal upper limit.
The patient was discharged home in good condition. She was placed on standard warfarin anticoagulation treatment. The patient also stopped cigarette smoking and discontinued with her contraception. One month after discharge, a control angiography of the vena cava showed persistence of thrombotic masses so the preoperatively implanted temporary vena cava filter was replaced by a permanent one.