Description

A 24-year-old man with a bioprosthetic tricuspid valve related to a history of infective endocarditis secondary to intravenous drug use was admitted to the hospital with fever and dyspnoea over the course of 2–3 weeks in the context of recidivism. On examination, the temperature was 38.0°C and the respiratory rate 24 breaths per minute. Qualitative analysis of the jugular venous waveform revealed the usual components, including two peaks, the a and v waves, and two troughs, the x and y descents. However, the first peak was more pronounced than usual, an abnormality known as a giant a wave. These waves coincided with a late diastolic murmur heard over the left lower sternal border that augmented with inspiration (see video 1). Blood cultures grew methicillin-sensitive Staphylococcus aureus. Transthoracic echocardiography demonstrated a large vegetation on the bioprosthetic tricuspid valve with an associated mean transtricuspid valve gradient of 17 mm Hg, consistent with severe tricuspid stenosis. The a wave is a normal feature of the jugular venous waveform and results from atrial contraction during late diastole. When there is resistance to atrial emptying, such as in tricuspid stenosis, atrial contraction causes increased back pressure in the venous fluid column, which manifests as a giant a wave in the jugular vein. This patient was treated with intravenous antibiotics but blood cultures remained positive and clinical deterioration ensued. Valve replacement was not offered because of unfavourable psychosocial factors and he was discharged home with hospice support.