EFFECTS OF INTRAVENOUS DIGOXIN ON PULMONARY VENOUS AND TRANSMITRAL FLOWS IN PATIENTS WITH CHRONIC HEART-FAILURE OF DIFFERENT DEGREES

Acute effects of digoxin on diastole were evaluated noninvasively by c ombining data simultaneously obtained by Doppler echocardiograms (echo -Doppler) of transmitral and pulmonary venous flow curves in 38 patien ts with dilated and failing hearts, who had been stable for at least 7 days before the study. According to the resting ejection fraction (EF ), patients were subdivided into Group 1 (EF < 30%: n = 20, mean EF va lues 23 +/- 8%) and Group 2 (EF greater-than-or-equal-to 30%: n = 18, mean EF values 40 +/- 3%). Significant differences were observed at re st between the two groups in both transmitral (shorter deceleration ti me and isovolumic relaxation time and increased peak E and E/A ratio i n Group 1 vs. Group 2) and transpulmonary (reduced systolic forward co mponent and systolic fraction of the flow curves in Group 1 compared w ith Group 2 and control subjects) parameters. Digoxin (1 mg subdivided into two doses, each infused over a 15-min period with 2 h between th e doses) significantly modified the diastolic profile in Group 1 patie nts in the absence of statistically relevant changes in EF: a signific ant decrease of transmitral peak E (from 76 +/- 17 to 60 +/- 15 cm/s, p < 0.05) and E/A ratio (from 2.5 +/- 1 to 1.6 +/- 0.6; p < 0.05) and a significant lengthening of deceleration time (from 115 +/- 20 to 160 +/- 18 ms; p < 0.05) were detected. A simultaneous consistent decreas e of the diastolic forward velocity (from 51 +/- 14 to 40 +/- 13 cm/s, p < 0.05) and an increase of the percent systolic fraction (from 31 /- 5% to 41 +/- 8%; p < 0.05) of the pulmonary venous flow curves, com pared with the control state (p<0.05), were also observed. No differen ce was detected in any of the echo-Doppler transmitral and transpulmon ary vein flow parameters after digoxin in Group 2 of patients. Among p atients with dilated and failing hearts, those with more advanced left ventricular systolic dysfunction (EF < 30%) exhibited a diastolic pro file characterized by a restrictive transmitral filling pattern combin ed with a clear reduction of systolic fraction and with an increase in the diastolic forward component of the pulmonary venous flow curves. These patients show significant changes in diastolic parameters after digoxin injection, expressed by a trend toward a normalized transmitra l filling flow pattern (significant decrease of peak E, E/A ratio, and significant lengthening of deceleration time) and toward a restoratio n of the amount of systolic left atrial filling at the pulmonary venou s flow curves (significant increase in systolic fraction and significa nt decrease in the diastolic forward component). These changes are con sistent with a reduction of left ventricular driving pressures. Conver sely, patients with a lesser degree of systolic dysfunction exhibited a normal pulmonary venous flow profile together with a transmitral fil ling pattern of abnormal relaxation type: in these patients no changes were observed in any of the echo-Doppler transmitral and transpulmona ry vein flow parameters after acutely injected digoxin.