بررسي اثرات تغيير وضعيت بدن روي اندازه و شدت سوفل نارسايي دريچه ميترال در كودكان 15-10 ساله به پرولاپس دريچه ميترال با استفاده از كوكار ديوگرافي دوبعدي

Effects of postural changes on duration and intensity of mitral regurgitation in mitral valve prolapse with 2-dimensional echocardiography in 10-15 years children

Introduction: MVP (Mitral valve prolapse) is one of the most common psychosomatic syndromes. It is a long time that the effect of body position on cardiac murmurs is recognized. Although authorities imagined that auscultatory findings during postural changes in the patients with mitral valve prolapse (MVP) and mitral regurgitation (MR) and late systolic murmur (LSM) are associated with more prolapsing of mitral valve due to decrease in LV volume in the standing position, but this issue is not analytically estimated. Material and Methods: We studied 12 patients with mean age of 12±2 year (yr) (±2SD), mean weight was 50±6 kg (±2SD) with match controled population. Echocardiographic parameters were extracted separately in supine and standing positions: left ventricular end diastolic volume (LVEDV), left ventriclular end systolic volume (LVESV), Q-W interval, velocity time intergeration (VTI), heart rate (HR), focal dyskinesia of posterior ventricular wall motion and color flow-jet of MR. LVESV and LVEDV used for estimation of volumetric changes, like Q-W interval (from Q wave to the beginning of MR signal pulsation) for duration of LSM. VTI (velocity-time integration) used for assessment of intensification of the murmur. Abnormal motion of ventricular wall at the level of apposition of mitral leaflets just above papillary muscles for evaluation of focal ventricular wall dyskinesia. Results: Patients were divided into two groups according to the response of postural changes on duration and intensification of the murmur at various states: group A (responder); 8 patients had prolonged duration and intensification of murmur: group B (non-responder); 4 patients who showed none of these changes (nearly similar findings were obtained in control population): HR were significantly increased in responder patients like decrease in their LV volume, whereas no considerable changes in non-responder group which might be due to no effect on LV volume. One of responder group also showed abnormal posterior ventricular wall motion (ventricular dyskinesia) but occurred only in one non-responder group (65% against 25%), that changes on LV volumes were not considerable. The postural changes in color Doppler signal also corresponded well with those in murmurs with regard to the duration and intensification of responder group. We proposed that establishment of focal dyskinesia in responder group could be related to the more complex interactions for initiation of dyskinesia rather than simple variation of ventricular volume (although all of them were mild or non-significant). Conclusion: The postural changes in MR of MVP patients from supine to standing position were greatly determined by decrease in LV volume which are corresponding well with the development of abnormal LV posterior wall motion (focal ventricular dyskinesia), whereas in non-responder group did not occurred because of no affection on LV volumes.