Going With the Flow: The Dilemma of a Laminar Jet

Abstract

To comment on this case and the clinical decisions made, please go to: http://JCVAblog.blogspot.com To comment on this case and the clinical decisions made, please go to: http://JCVAblog.blogspot.com COBEY AND COLLEAGUES present an interesting dilemma on how to evaluate tricuspid regurgitation (TR) in the absence of a well-defined “jet.” Conventional methods for the assessment of regurgitant jets have relied on characteristics of abnormal flow across an incompetent valve. This abnormal flow usually results in eddy currents because of high-pressure and high-velocity flow that produces a “turbulent” jet when assessed with color-flow Doppler on echocardiography. A turbulent jet then lends itself easily to the measurement of parameters that indicate severity, such as the jet area, the vena contracta, and flow convergence. However, when the regurgitant flow is laminar, severity becomes harder to define with confidence. The tricuspid valve is especially prone to laminar flow regurgitation because it separates 2 low-pressure chambers, which, in the presence of a large regurgitant orifice, will produce lower-velocity, large-volume flow. This phenomenon has long been recognized,1Minagoe S. Rahimtoola S.H. Chandraratna P.A. Significance of laminar systolic regurgitant flow in patients with tricuspid regurgitation: A combined pulsed-wave, continuous-wave Doppler and two-dimensional echocardiographic study.Am Heart J. 1990; 119: 627-635Abstract Full Text PDF PubMed Scopus (15) Google Scholar and the valve regurgitation assessment guidelines from the American Society of Echocardiography recommend an integrated approach for TR assessment that includes other parameters such as hepatic vein flow and chamber size.2Zoghbi W.A. Enriquez-Sarano M. Foster E. et al.Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography.J Am Soc Echocardiogr. 2003; 16: 777-802Abstract Full Text Full Text PDF PubMed Scopus (3323) Google Scholar The case presented poses the following intriguing questions: “Could this TR have been predicted?” and “Should the TR have been addressed in the operating room?” Although the prebypass transesophageal echocardiographic assessment did not reveal severe TR, it did show a dilated right atrium and mild prolapse of the tricuspid valve. The conventional measurement metrics revealed a mild TR jet and a normally functioning, nondilated right ventricle. Hence, worsening of TR could not have been predicted with confidence. The laminar TR flow was appreciated with tricuspid annular dilation only after completion of the mitral valve repair. At that time, the decision not to undertake an immediate repair of the tricuspid valve was based on 2 issues. First, the surgical approach was minimally invasive with limited access designed for the mitral valve and a significant modification would have to be made for performing a subsequent tricuspid valve repair. Second, the absence of a clearly defined TR jet and conventional indicators of TR severity meant that a diagnosis of severe TR could not be made with confidence. Given these related issues, the surgical team proceeded with a conservative approach. However, the TR progressed, and a valve repair was required early in the postoperative period. Given the significance of TR in patients undergoing left-sided valve surgery, the true characterization of TR is critical.3Bianchi G. Solinas M. Bevilacqua S. et al.Which patient undergoing mitral valve surgery should also have the tricuspid repair?.Interact Cardiovasc Thorac Surg. 2009; 9: 1009-1020Crossref PubMed Scopus (32) Google Scholar This case highlights the presence of and difficulties in diagnosing TR when flow is laminar. Should the echocardiographer detect associated signs, such as a dilated right atrium, systolic flow reversal in the hepatic veins, and a dilated tricuspid annulus, then severe TR must be strongly suspected, and characterization of the TR cannot be based simply on conventional parameters, such as the vena contracta or the jet area. More importantly, the assessment of TR needs to be made early so that surgical management can be designed to include the tricuspid valve. It would appear that once the diagnosis of severe TR has been made in the operating room in the setting of mitral valve surgery, there is a strong case for immediate tricuspid repair, given the subsequent risk of long-term deterioration and adverse outcomes in this patient population.4Di Mauro M. Bivona A. Iaco A.L. et al.Mitral valve surgery for functional mitral regurgitation: Prognostic role of tricuspid regurgitation.Eur J Cardiothorac Surg. 2009; 35: 635-639Crossref PubMed Scopus (60) Google Scholar, 5Shiran A. Sagie A. Tricuspid regurgitation in mitral valve disease incidence, prognostic implications, mechanism, and management.J Am Coll Cardiol. 2009; 53: 401-408Abstract Full Text Full Text PDF PubMed Scopus (238) Google Scholar Severe Tricuspid Valve Regurgitation: A Case for Laminar FlowJournal of Cardiothoracic and Vascular AnesthesiaVol. 26Issue 3PreviewA 67-YEAR-OLD WOMAN presented with progressive dyspnea limiting her ability to perform daily activities. Her past medical history was significant for hyperlipidemia and Hashimoto thyroiditis. Upon further workup, a transthoracic echocardiogram (TTE) was performed, which revealed severe mitral regurgitation (MR) with mild tricuspid regurgitation (TR). Subsequently, she was scheduled for mitral valve repair. Full-Text PDF