Relation between sympathetic overactivity and left atrial spontaneous echo contrast in patients with mitral stenosis and sinus rhythm.
BACKGROUND
Spontaneous echo contrast (SEC) is common in patients with mitral stenosis (MS) and presence of SEC in left atrium (LA) is associated with a higher risk of thromboembolism. Recently, an increase in activation of platelets was demonstrated in patients with SEC raising the hypothesis that platelets are involved in the pathogenesis of SEC. In this study, we evaluated effects of autonomic nervous system activity on SEC formation in patients with rheumatic MS and sinus rhythm by heart rate variability analysis.


RESULTS
Twenty-six patients with LASEC were compared with 28 patients without LASEC. Mean heart rate, low frequency (LF) and low frequency/high frequency (LF/HF) ratio were significantly higher, standard deviation of all NN (SDNN), root mean square of successive differences (RMSSD), number of NN intervals that differed by more than 50 ms from adjacent interval divided by the total number of all NN intervals (PNN50) and high frequency (HF) values were lower in the patients with LASEC. A standard deviation of all NN intervals <90ms separated the patients with LASEC from control subjects with a sensitivity of 77% and specificity of 90%; a low frequency >79.5 with a sensitivity of 92% and specificity of 90; a low frequency/high frequency ratio >3.7 with a sensitivity of 96% and specificity of 90%. A left atrial diameter >4.3 cm increased the LASEC formation by 3.0 folds, HR >78 beats/min by 6.4 folds, standard deviation of all NN intervals <90 ms by 9.2 folds, a low frequency/high frequency ratio >3.7 by 6.4 folds, sP-selectin>142 by 5.8 folds. Variables affecting sP-selectin levels were LA diameter, mitral valve area, transmitral mean gradient, left ventricular ejection fraction, the presence of mitral regurgitation, HR, standard deviation of all NN intervals, low frequency, high frequency and low frequency/high frequency ratio.


CONCLUSIONS
Sympathetic overactivity and reduced heart rate variability are important determinants for LASEC formation and increased s-P selectin levels. Therefore, platelet activation via increased sympathetic activity may play an important role in pathogenesis of LASEC.
Ozdemir
Ozcan
O
Türkiye Yüksek Ihtisas Hospital, Cardiology Clinics, Ankara, Turkey. drozdemir75@yahoo.com
Alyan
Omer
O
Soylu
Mustafa
M
Topaloglu
Serkan
S
Aras
Dursun
D
Metin
Fatma
F
Geyik
Bilal
B
Ozbakir
Cemal
C
Demir
Ahmet Duran
AD
D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology; D016022:Case-Control Studies; D004452:Echocardiography; D005260:Female; D005786:Gene Expression Regulation; D006325:Heart Atria / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008946:Mitral Valve Stenosis / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism; D010507:Periodicity; D015539:Platelet Activation / Q000235:genetics / Q000502:physiology; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012849:Sinoatrial Node / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D019007:P-Selectin