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Objective-To identify variables that could be applied at rest to diagnose subclinical ventricular dysfunction in asymptomatic patients with severe aortic regurgitation. Design-Cross sectional study. Patients-Left ventricular long axis contraction was studied using tissue Doppler and M mode echocardiography in 21 patients with no symptoms (New York Heart Association (NYHA) functional class < 2a) but severe aortic regurgitation (jet area/left ventricular outflow tract area > 40%). Main outcome measures-Left ventricular ejection fraction (LVEF) at baseline and peak exercise (Weber protocol), cardiopulmonary function, and left ventricular long axis function at rest (peak systolic velocity and excursion of the mitral annulus). Results-In 11 patients, ejection fraction increased or did not change (from mean (SD) 55 (5)% to 58 (4)%, p < 0.05) (group I); in 10 patients it decreased by > 5% (from 54 (4)% to 42 (5)%, p < 0.001) (group II). Exercise ejection fraction was < 50% in all patients in group II. At rest, there were no diVerences between the groups in ejection fraction, left ventricular diameter indices, wall stress, and short axis contraction. However, patients in group II had reduced long axis contraction compared with group I: peak systolic velocity 8.6 (0.6) v 11.9 (2.2) cm/s (p < 0.001); excursion 11 (2) v 14 (2) mm (p < 0.01). A resting velocity of < 9.5 cm/s was the best indicator of poor exercise tolerance (sensitivity 90%, specificity 100%). Conclusions-Markers of reduced long axis contraction may provide simple and reliable indices of subclinical left ventricular dysfunction in asymptomatic patients with severe aortic regurgitation. (Heart 2001;85:30-36) Keywords: aortic regurgitation; long axis function; tissue Doppler echocardiography; exercise echocardiography Asymptomatic patients with chronic aortic regurgitation have an excellent prognosis if their resting ejection fraction is greater than 45%.1-3 The annual mortality rate is less than 0.5%, but such patients are not a homogeneous group. Thus many remain clinically stable, while 4-6%/year develop left ventricular dysfunction and require surgery.2-4 If operation is deferred in all patients until they become symptomatic, a subset may already have irreversible left ventricular dysfunction. 2-5It is a challenge to recognise patients with subclinical myocardial dysfunction in order to operate early enough to prevent postoperative heart failure, but not so early as to subject them to unnecessary operative risks and morbidity related to prosthetic valves. The reported best predictors of subnormal left ventricular performance in asymptomatic patients with severe aortic regurgitation are a decrease in ejection fraction on exercise (by more than 5%) and a low ejection fraction on exercise (less than 50%) coupled with inappropriately high wall stress, assessed by echocardiography or radionuclide ventriculography.3 5-7 Dynamic stress echocardiography with quantification of left ventricular function is diYcult and time consuming, however, and so it i...

Patients with severe cystic fibrosis can develop cor pulmonale, but little is known about the function of the right ventricle (RV) early in the disease. We hypothesized that such patients might have subclinical RV dysfunction, detectable by tissue Doppler echocardiography, and related to the severity of lung disease. We studied 21 clinically stable patients (Group 1), five patients with severe lung disease (Group 2), and 23 age-matched healthy subjects. Patients had impaired RV systolic function. The mean (SD) systolic velocities of the RV free wall were 8.9 (1.7) cm/s in Group 1, 7.7 (1.0) in Group 2, and 10.8 (1.9) in healthy subjects (p < 0.001). The velocities of the tricuspid annulus were less in patients (p < 0.0001). Patients had a greater isovolumic relaxation time (p < 0.001), indicating RV diastolic dysfunction. RV wall thickness was greater in patients (0.4 [0.1] versus 0.3 [0.1] cm/m(2), p < 0.01). RV systolic function was related to C-reactive protein (r = - 0.66, p < 0.001) and FEV(1) (r = 0.62, p = 0.003) and diastolic function to interleukin-6 (r = 0.64, p < 0.005). Patients with cystic fibrosis have subclinical RV dysfunction, which correlates with the severity of lung disease. Tissue Doppler echocardiography provides a quantifiable indicator useful for detection and monitoring of disease progression.

The transcripts of three putative ammonia (NH 3 /NH 4 + ) transporters, Rhesus-like glycoproteins AeRh50-1, AeRh50-2 and Amt/Mep-like AeAmt1 were detected in the anal papillae of larval Aedes aegypti. Quantitative PCR studies revealed 12-fold higher transcript levels of AeAmt1 in anal papillae relative to AeRh50-1, and levels of AeRh50-2 were even lower. Immunoblotting revealed AeAmt1 in anal papillae as a pre-protein with putative monomeric and trimeric forms. AeAmt1 was immunolocalized to the basal side of the anal papillae epithelium where it co-localized with Na +

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