In patients with TR undergoing left- sided valve surgery, an annular diastolic diameter ) indicates an increased risk of persistent or progressive TR after isolated mitral valve surgery.13 Pulmonary artery systolic pressure is estimated from maximal TR velocity. Assessment of RV systolic function is challenged by geometric and image acquisition constraints, as well as by variability in RV loading condi- Normal RV systolic function is defined by several parameters, including tricuspid annu- lar plane systolic excursion >16 mm, tricuspid valve systolic annular velocity >10.0 cm/s, and RV end-systolic area <20.0 cm2 or fractional area change >35%. Other imaging modalities, such as 3D TEE, magnetic resonance imaging, and CT scan, may provide more accurate information on the status of the RV. 2. When physical examination and TTE data on estimated pulmonary artery systolic pressure are either discordant or inadequate, invasive mea- surement of pulmonary artery pressures and pul- monary vascular resistance can be helpful to guide Table 19. Classification of TR Primary Secondary Rheumatic Infective endocarditis Iatrogenic (device leads, endomyocardial biopsy) Congenital (eg, Ebstein s, levo- transposition of the great arteries) Other (eg, trauma, carcinoid, drugs, irradiation) Pulmonary hypertension with RV remodeling (primary or secondary to left-sided heart disease) Dilated cardiomyopathy Annular dilation (associated with AF)* RV volume overload (shunts/high output) *Isolated TR is associated with AF and has LVEF >60%, pulmonary artery systolic pressure <50 mm Hg, and no left-sided valve disease, with normal- appearing tricuspid valve leaflets. AF indicates atrial fibrillation; LVEF, left ventricular ejection fraction; RV, right ventricular; and TR, tricuspid regurgitation. CLINICAL STATEMENTS AND GUIDELINES clinical decision-making in individual patients.3 5 A weak TR signal or the presence of severe TR may result in underestimation of pulmonary systolic pressure; direct invasive measurement can resolve this uncertainty. 