ABSTRACT
Background: Complete embolization of a prosthetic heart valve is extremely rare and dangerous. This case reports a total embolization of a mechanical aortic valve and contributes to the literature regarding the diagnostic challenges related to infective endocarditis and follow-up after valvular surgery. Case summary: A 28-year-old male 11.5 years status-post a mechanical aortic valve replacement presented with acute onset of chest pain and dyspnoea while jogging. The patient lost consciousness and went into cardiopulmonary arrest with acute pulmonary oedema and circulatory shock. An echocardiogram revealed an empty aortic annulus, and a chest radiograph showed an embolized valve in the aortic arch. The patient underwent emergent removal of the embolized valve and replacement with a new mechanical aortic valve. The patient survived with minimal sequelae. At a 3-month follow-up, he had resumed work, and the only sequelae were mild left ventricular dysfunction and minor vision loss. Although he experienced no warning signs or symptoms, the most likely aetiology for embolization of the valvular prosthesis was infective endocarditis, which was revealed by re-evaluation of an echocardiogram recorded 1 month before the presentation which demonstrated a subtle motion abnormality of the valve. Conclusions: We present a case of a late complete embolization of a mechanical aortic valve most likely caused by asymptomatic infective endocarditis. The case illustrates the challenges in follow-up after valvular surgery and highlights the ultimate benefit of a well-functioning pre-hospital to hospital chain.
ABSTRACT
This study assesses positional changes in cardiac power output and stroke work compared with classic hemodynamic variables, measured before and after elective coronary artery bypass graft surgery. The hypothesis was that cardiac power output was altered in relation to cardiac stunning. The study is a retrospective analysis of data from two previous studies performed in a tertiary care university hospital. Thirty-six patients scheduled for elective coronary artery bypass graft surgery, with relatively preserved left ventricular function, were included. A pulmonary artery catheter and a radial artery catheter were placed preoperatively. Cardiac power output and stroke work were calculated through thermodilution both supine and standing prior to induction of anesthesia and again day one postoperatively. Virtually all systemic hemodynamic parameters changed significantly from pre- to postoperatively, and from supine to standing. Cardiac power output was maintained at 0.9-1.0 (±0.3) W both pre- and postoperatively and from supine to standing on both days. Stroke work fell from pre- to postoperatively from 1.1 to 0.8 J (P < 0.001), there was a significant fall in stroke work with positional change preoperatively from 1.1 to 0.9 J (P < 0.001). Postoperatively the stroke work remained at 0.8 J despite positional change. Cardiac power output was the only systemic hemodynamic variable which remained unaltered during all changes. Stroke work appears to be a more sensitive marker for temporary cardiovascular dysfunction than cardiac power output. Further studies should explore the relationship between stroke work and cardiac performance and whether cardiac power output is an autoregulated intrinsic physiological parameter.
