The association of left atrial volume with exercise capacity in patients with chronic severe mitral regurgitation.

BACKGROUND: Left atrial volume and exercise capacity are strong predictors of cardiovascular risk. Decreased exercise capacity is expected when LAV is increased due to its association with abnormal left ventricular filling pressure. However, LAV enlargement is expected in chronic mitral regurgitation as well. OBJECTIVES: To examine the link between LAV and exercise capacity in chronic MR and to determine whether larger LAV has indeed better exercise capacity in patients with chronic severe degenerative MR and good LV systolic function. METHODS: The study included asymptomatic patients with severe chronic degenerative MR and normal LV systolic function that underwent stress echocardiography. LAV was measured at rest using the biplane Simpson's method and indexed to body surface area. The cutoff of good exercise capacity was determined at 7 METS. RESULTS: The patient group comprised 52 consecutive patients (age 60 +/- 14 years, 36 males). Two subgroups (19 vs. 33 patients), age- and gender-matched, were formed according to LAVi cutoff of 42 ml/m2. Those with higher LAVi had lower exercise capacity (P = 0.004) albeit similar MR grade, baseline blood pressure, LV function and size. Receiver-operator curve analysis revealed indexed LAV value of < or = 42 as 51% sensitive and 88% specific for predicting exercise capacity > 7 METS (AUC = 0.7, P = 0.03). In multivariate analysis, age, gender and LAVi were identified as independent predictors of exercise capacity. CONCLUSIONS: In asymptomatic patients with severe chronic degenerative MR and normal LV systolic function, mild enlargement of the left atrium (< or = 42 ml/m2) is associated with good exercise capacity.

The impact of intraoperative transesophageal echocardiography in infective endocarditis.

BACKGROUND: [corrected] The use of intraoperative transesophageal echocardiogram in patients with infective endocarditis is usually reserved for cases of inadequate preoperative testing or suspected extension to perivalvular tissue. OBJECTIVES: To explore the impact of routine intraoperative TEE in patients with infective endocarditis. METHODS: The impact of intraoperative TEE on the operative plan, anatomic-physiologic results, and hemodynamic assessment or de-airing was analyzed in 59 patients (38 males, 21 females, mean age 57.7 +/- 16.8 years, range 20-82) operated for active infective endocarditis over 56 months. RESULTS: Immediate pre-pump echocardiography was available in 52 operations (86.7%), and changed the operative plan in 6 of them (11.5%). Immediate post-pump study was available in 59 patients (98.3%) and accounted for second pump-run in 6 (10.2%): perivalvular leak (3 cases), and immobilized leaflet, significant mitral regurgitation following vegetectomy, and failing right ventricle requiring addition of vein graft (1 case each). Prolonged de-airing was necessary in 6 patients (10.2%). In 5 patients (8.5%) the postoperative study aided in the evaluation and treatment of difficult weaning from the cardiopulmonary bypass pump. In 21 patients (35.6%) the application of intraoperative TEE affected at least one of the four pre-specified parameters. CONCLUSIONS: Intraoperative TEE has an important role in surgery for infective endocarditis and should be routinely implemented.

Relation of tricuspid inflow E-wave peak velocity to severity of tricuspid regurgitation.

E-wave velocity in mitral flow has previously been shown to discriminate between severe and nonsevere mitral regurgitation. In this study, we sought to explore this association in the tricuspid position. The peak velocity of the tricuspid inflow E wave was measured in 118 patients (mean age 62 +/- 16.6 years; 48% women). Patients with tricuspid stenosis, transvenous pacemakers, and tricuspid prostheses were excluded. E-wave measurements were taken during shallow breathing. Tricuspid regurgitation (TR) was quantified as none or mild (group 1), moderate (group 2), or severe (group 3), according to American Society of Echocardiography guidelines. Forty-three patients had mild TR, 43 had moderate TR, and 33 had severe TR. Peak E-wave velocity was 48.6 +/- 13.8, 48.6 +/- 11.7, and 78.3 +/- 26.1 cm/s in groups 1, 2, and 3, respectively (p > 0.0001). Mean E-wave velocity was similar in groups 1 and 2 but greater in group 3 (p < 0.0001). A peak E-wave velocity of > or = 65 cm/s had a sensitivity of 73% and specificity of 88% for the detection of severe TR. In conclusion, increased peak tricuspid E-wave velocity is associated with severe TR and thus can be used as a simple measure of TR grade.

Impact of intraoperative transesophageal echocardiography in patients undergoing valve replacement.

BACKGROUND: The role of intraoperative transesophageal echocardiography (IOTEE) in valve replacement surgery is not well established. The aim of this study was to explore the impact of immediate postpump IOTEE in valve replacement surgery at a single tertiary medical center. METHODS: The departmental database was screened for valve replacement operations (mechanical or bioprosthetic valves) performed during a 55-month period that were succeeded by immediate postpump IOTEE. Data was gathered regarding the impact of IOTEE on the immediate postoperative course. RESULTS: The study group included 417 patients (44.8% male, 55.2% female, age 65.2 +/- 13.9 years). Prepump IOTEE was performed in 352 patients (84.4%). A single valve was replaced in 336 patients (80.6%) and two or more valves were replaced in 81 patients (19.4%). Overall 501 valves were inserted: mitral, 237 (131 mechanical, 106 biological); aortic, 221 (89 mechanical, 132 biological); tricuspid, 43 (2 mechanical, 41 biological). Unexpected pathologic echocardiographic findings on postpump IOTEE necessitated immediate surgical correction in 15 patients (3.6%): perivalvular leak in 8 patients (4 mitral, 4 aortic), immobilized leaflet in 4 patients (3 mitral, 1 tricuspid), coronary obstruction by an aortic bioprosthesis in 2 patients, and incompetent xenograft in 1 patient. Prolonged removal of air was necessary in 45 patients (10.8%). In 47 patients (11.3%) the postpump IOTEE contributed to the evaluation of difficult weaning from the bypass pump and to its appropriate therapeutic management (volume expansion, inotropic agents, vasodilators, or mechanical assistance). CONCLUSIONS: Immediate postpump IOTEE is an important diagnostic and therapeutic role in valve replacement surgery and should be widely implemented.