Left atrial appendage function in patients with mitral stenosis in sinus rhythm

AIMS

Left atrial appendage thrombi are believed to be the source of embolism in patients with rheumatic mitral stenosis in atrial fibrillation. There are a few studies which search the effects of left atrial appendage dysfunction in patients with mitral stenosis in sinus rhythm.

METHODS AND RESULTS

Left atrial appendage function and flow patterns in 41 patients with rheumatic mitral stenosis in sinus rhythm and 11 healthy subjects were studied by transoesophageal echocardiography. Left atrial appendage flow profiles were recorded within the proximal third of the appendage. The left atrial appendage ejection fraction was expressed as (maximal area of appendage minimal area of appendage)/maximal area of appendage. In addition, two-dimensional imaging was used to determine the presence of spontaneous echocardiographic contrast and thrombus formation. Patients with mitral stenosis in sinus rhythm had significantly decreased left atrial appendage emptying and filling velocities compared to controls (0.40+/-0.15m/s vs 0.82+/-0.19 m/s and 0.42+/-0.21 m/s vs 0.68+/-0.28, respectively, P<0.001 and P<0.05). Compared with the control subjects, patients with mitral stenosis had significantly greater maximal area of the appendage and had reduced left atrial appendage ejection fraction (5.3+/-2.2 cm(2) vs 2.4+/-0.5 cm(2) and 50+/-16% vs 70+/-7%, respectively, P<0.001 and P<0.05). Of the patients with mitral stenosis in sinus rhythm, seven patients had spontaneous echocardiographic contrast and one of these had left atrial appendage thrombus. Compared with patients without spontaneous echocardiographic contrast, patients with spontaneous echocardiographic contrast had decreased left atrial appendage ejection fraction (33+/-21% vs 54+/-13%,P <0.01). One of the patients with mitral stenosis had central retinal artery occlusion, but thrombus was not observed in left atrial appendage.

CONCLUSION

The study found that left atrial appendage dysfunction may occur in patients with mitral stenosis in sinus rhythm.

Increased nitric oxide in exhaled air in patients with rheumatic heart disease

BACKGROUND

Endogenous production of nitric oxide and its presence in exhaled air was observed in humans. Prior studies have yielded contrasting information about the production of nitric oxide in patients with heart failure.

AIMS

The aim of this study was to measure nitric oxide in the exhaled air of patients with chronic rheumatic heart disease with and without pulmonary hypertension.

METHODS

Seventy-four patients (6 patients had isolated mitral stenosis; 13 patients had combined mitral stenosis and mitral regurgitation; 1 patient had isolated mitral regurgitation; 54 patients had combined mitral and aortic valve disease) and 27 healthy subjects were entered in the study. The nitric oxide concentration in exhaled air was determined with a chemiluminescence analyser. Echocardiography was performed in all patients to assess the severity of the valve disease and for the measurement of pulmonary artery pressure.

RESULTS

The level of exhaled nitric oxide was significantly greater in patients with rheumatic heart disease than in controls. The value of nitric oxide concentration in exhaled air was significantly increased in patients with pulmonary hypertension, as compared with patients who had normal pulmonary artery systolic pressure.

CONCLUSION

We found increased nitric oxide in the exhaled air in patients with rheumatic heart disease, especially in those with pulmonary hypertension, compared with healthy patients.