Toshihiko Koeda

Relationship between plasma atrial and brain natriuretic peptide concentration and hemodynamic parameters during percutaneous transvenous mitral valvulotomy in patients with mitral stenosis

Brain natriuretic peptide (BNP), a family of peptides with structural and biologic homologies to previously identified atrial natriuretic peptide (ANP), has been found in human cardiac tissue and plasma. To examine the secretion mechanism of these peptides, we have studied the relationship between their plasma concentrations and hemodynamic parameters before and at 0.5 and 24 hours after percutaneous transvenous mitral commissurotomy (PTMC) in 14 patients with mitral stenosis. We have also investigated the validity of measuring plasma natriuretic peptides as a means for estimating changes in hemodynamic parameters after PTMC. The procedure decreased left atrial pressure (p < 0.01) with an elevation in left ventricular end-diastolic pressure (p < 0.05). Plasma ANP levels decreased significantly after PTMC (before, 64.1 +/- 33.7 fmol/ml; at 0.5 hour, 58.9 +/- 27.7 fmol/ml; at 24 hours, 45.7 +/- 18.3 fmol/ml; p < 0.01), whereas plasma BNP levels remained unchanged after the procedure (before, 5.3 +/- 1.5 fmol/ml; at 0.5 hour, 5.6 +/- 1.9 fmol/ml; at 24 hours, 5.0 +/- 1.9 fmol/ml; p = NS). There was a significant relationship between basal plasma ANP and left atrial pressure (r = 0.88; p < 0.001), and changes in plasma ANP were correlated with those in left atrial pressure (r = 0.69; p < 0.01). Basal plasma BNP was significantly correlated with basal left ventricular end-diastolic pressure (r = 0.65; p < 0.05) but not with the other measured hemodynamic parameters or with plasma volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in hemodynamics due to the contrast medium during left ventriculography.

Seventeen patients with heart diseases examined by left ventricular angiography were divided into two groups consisting of those with a clinical history of heart failure (CHF+) and those without (CHF-). Changes in hemodynamics, circulating blood volume, and plasma volume due to injection of the contrast medium were studied, and the following results were obtained. Both the CHF - and CHF + groups showed an increase in heart rate after injection of the contrast medium, but a statistically significant difference (p < 0.05) was noted only at one and two minutes after angiography in both groups. Left ventricular systolic pressure decreased after injection of the contrast medium in both groups, but the CHF+ group required a longer time for recovery. In the CHF - group, the left ventricular end-diastolic pressure increased slightly after injection of the contrast medium, but in the CHF+ group it increased markedly with a statistically significant difference (p < 0.01). Stroke volume, measured by a noninvasive, continuous cardiac output monitor according to the impedance method, increased upon injection of the contrast medium in the CHF— group. However, in the CHF+ group it decreased, although no statistically significant difference was noted in either group. Cardiac index increased markedly upon injection of the contrast medium in the CHF— group with a statistically significant difference (p < 0.01), but hardly any change was observed in the CHF+ group. Circulating blood volume increased in both groups ten minutes after injection of the contrast medium, but whereas the CHF - group showed no statistically significant increase and had a gradual reduction to the original state an hour afterward, a statistically significant increase over original values in the CHF+ group was observed at ten minutes and one hour after injection. The mean value of the CHF+ group was statistically significantly higher than that of the CHF- group at one hour after injection. Circulating plasma volume showed statistically significant mean increases over original values in both groups at ten minutes and at one hour after injection of the contrast medium. The mean value of the CHF+ group was statistically significantly higher than that of the CHF- group at one hour after injection. In conclusion, patients with heart failure, in comparison with those without, showed different changes in hemodynamics, circulating blood, and plasma volumes caused by the contrast medium, and thus it was necessary to be cautious when the contrast medium was injected into patients with a history of heart failure.

Venous Pressure and Compliance of the Peripheral Capacitance Vessels

Compliances of the peripheral capacitance vessels decreased gradually in accordance with the increase in pressure of the brachial vein. The relationship between them formed a number of hyperbolic-like curves, the same results as those found in many cases of both normal subjects and patients with congestive heart failure. The decrease of compliance of the peripheral capacitance vessels was not the result of an organic change, but of a functional change of the vessels caused by distention.