[Echo-Doppler study of myxomatous mitral valve insufficiency and the results of reparative surgery]. / Studio eco-Doppler dell'insufficienza mitralica mixomatosa e dei risultati della chirugia riparativa.

The aim of conservative management of mitral regurgitation caused by floppy mitral valve is to restore a valvular function which closely resembles that of normal physiology. Fifty-eight patients affected by floppy mitral valve underwent surgical procedures for severe mitral regurgitation due to chordal elongation and/or rupture. Of these, 28 presented posterior mitral prolapse corrected by quadrangular excision of the prolapsed part and posterior anuloplasty achieved by apposition of a polytetrafluoroethylene conduit. The remaining 30 patients presented anterior or bilateral prolapse corrected by transposition of chordae from the posterior leaflet to the anterior cusp together together with anuloplasty. A complete echo-Doppler study was performed preoperatively, 10 days after the operation and every 6 months thereafter. Mean follow-up was 16.1 +/- 6.3 months. Preoperatively, 44 patients presented severe mitral regurgitation and 14 had moderate regurgitation (quantified by means of pulsed Doppler). All patients showed severe enlargement of the left cavities (LVDD 67.1 +/- 8.6 mm, left atrium 53.4 +/- 10.9 mm) with normal mitral area (6.08 +/- 2.14 sqcm, Doppler measurement). Following surgery we found a significant reduction in: 1) the degree of mitral regurgitation (29 patients had no regurgitation; 20 had mild protosystolic mitral regurgitation (29 patients had no regurgitation; 20 had mild protosystolic mitral regurgition, confirmed by color-M-mode; moderate or severe regurgitation was found in 6 cases); 2) the left ventricle and left atrium dimensions (LVDD 53.4 +/- 5.2 mm, p less than 0.01; left atrium 43.8 +/- 11.1 mm, p less than 0.01). Color flow imaging provided information about the recovery of a normal valvular function.(ABSTRACT TRUNCATED AT 250 WORDS)

Heart rate variability as an index of sympathovagal interaction after acute myocardial infarction.

By analysis of spectral components of heart rate variability, sympathovagal interaction was assessed in patients after acute myocardial infarction (AMI). At 2 weeks after AMI (n = 70), the low-frequency component was significantly greater (69 +/- 2 vs 53 +/- 3 normalized units [NU], p less than 0.05) and the high-frequency component was significantly smaller (17 +/- 1 vs 35 +/- 3 NU) than in 26 age-matched control subjects. This difference was likely to reflect an alteration of sympathovagal regulatory outflows with a predominance of sympathetic activity. At 6 (n = 33) and 12 (n = 29) months after AMI, a progressive decrease in the low- (62 +/- 2 and 54 +/- 3 NU) and an increase in the high-frequency (23 +/- 2 and 30 +/- 2 NU) spectral components was observed, which suggested a normalization of sympathovagal interaction. An increase in sympathetic efferent activity induced by tilt did not further modify the low-frequency spectral component (78 +/- 3 vs 74 +/- 3 NU) in a subgroup of 24 patients at 2 weeks after AMI. Instead, 1 year after AMI, this maneuver was accompanied by an increase in the low-frequency component (77 +/- 3 vs 53 +/- 3 NU, p less than 0.05) of a magnitude similar to the one observed in control subjects (78 +/- 3 vs 53 +/- 3 NU). These data indicate that the sympathetic predominance that is detectable 2 weeks after AMI is followed by recovery of vagal tone and a normalization of sympathovagal interaction, not only during resting conditions, but also in response to a sympathetic stimulus.