Rare and life-threatening cardiovascular complication of chronic thromboembolic pulmonary hypertension diagnosed by trans-thoracic echocardiography

An 83-year-old female was admitted to the cardiac care unit of Hopital Emile Muller (Mulhouse, France) due to acute respiratory distress. She had a history of recurrent pulmonary emboli that had led to group-IV chronic thromboembolic pulmonary hypertension (CTEPH) according to the classification of pulmonary arterial hypertension (PAH) set by the World Health Organization (WHO). CTEPH was treated from 2013 with long-term oxygen therapy and oral anticoagulation. She presented with a dramatic increase in dyspnoea accompanied by acute chest pain with dorsal irradiation. She was in respiratory distress with blood saturation at 70% in ambient air. She showed signs of right-heart failure (turgid jugular veins, lowerlimb oedema). Under 5 l of O2, arterial blood gases were 81 mm Hg for paO2 and 50 mm Hg for paCO2, whereas bicarbonate was −29 mmol/l, brain natriuretic peptide was 167 ng/l, and D-dimer was 1151 ng/ml. Right-axis deviation with right ventricular hypertrophy was found upon electrocardiography. Chest radiography revealed reticular/ nodular densities in the right base with alveolar opacity in the left base, which led us to suspect pneumonia. Trans-thoracic echocardiography (TTE) demonstrated: normal left ventricular ejection fraction