[Continuous wave Doppler echocardiographic evaluations of the severity of mitral regurgitation].

To ascertain the usefulness of continuous wave Doppler echocardiography in evaluating the severity of mitral regurgitation (MR), 29 patients with MR and 10 normal subjects were examined. The patients were categorized in three groups according to the angiographic evidence of severity of MR. To analyze the flow velocity patterns of MR, the time to peak velocity index (time from onset of MR signal to peak flow velocity/duration of MR signal), the A/B ratio (the ratio of the first and second half of the systolic MR signal area), systolic peak velocity, and diastolic peak velocity were measured using continuous wave Doppler echocardiograms. The velocity patterns of MR differed significantly among the three groups. With severer MR, the flow velocity pattern showed an earlier appearance of the peak in systole, a steeper decrease in systole and a greater increase in early diastole. The time to peak velocity index was 55 +/- 7% (mean +/- SD) in mild MR, 42 +/- 6% in moderate MR and 35 +/- 5% in severe MR. This index shortened significantly in accord with the severity of MR (mild vs moderate MR: p less than 0.001, moderate vs severe MR: p less than 0.05). The A/B ratio was 1.06 +/- 0.12 in mild MR, 1.23 +/- 0.10 in moderate MR and 1.41 +/- 0.07 in severe MR. This ratio increased significantly with the severity of MR (mild vs moderate MR: p less than 0.01, moderate vs severe MR: p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Incidence of tricuspid regurgitation in normal subjects according to a new Doppler echographic criterion].

To develop a Doppler echocardiographic criterion for tricuspid regurgitation (TR) and to determine the incidence of TR in normal subjects, we examined 357 apparently normal subjects ranging in age from five to 95 years using pulsed and continuous wave Doppler echocardiography. A Doppler transducer was placed over the right ventricular apex, with the Doppler beam directed parallel with TR flow. TR was judged to be present when a holosystolic abnormal flow pattern with the peak velocity greater than 1.5 m/sec was recorded at the tricuspid valve orifice. This was based on the theory that in TR systolic pressure gradient across the tricuspid valve should be 10 mmHg or greater in normal subjects. TR was detected in 87 (24%) of 357 subjects and the mean peak velocity of the TR was 2.1 +/- 0.2 m/sec (mean +/- SD). It was more frequent in women (28%) than in men (19%) and differed significantly among the young, middle and old age groups. It was 79% in the first decade, 30% in the second, 10% in the third, 21% in the fourth, 5% in the fifth, 19% in the sixth, 14% in the seventh, 23% in the eight, 37% in the ninth and 40% in the tenth. The minimum dimension of the tricuspid annulus was significantly enlarged (p less than 0.001) in subjects with TR (2.2 +/- 0.3 cm/m2) compared to that of subjects without TR (1.8 +/- 0.3 cm/m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Color Doppler echocardiographic assessment of the change in the mitral regurgitant volume.

We studied the possibility that a mitral regurgitant Doppler signal area on a two-dimensional color Doppler echocardiogram can reflect changes in mitral regurgitant volume in 24 patients with several types of mitral regurgitation. In 20 patients, mitral regurgitant Doppler signal areas were clear enough to measure. Injections of phenylephrine were given to these patients during the recording of the mitral regurgitant Doppler signal area in the same views and with the same Doppler gains. The mitral regurgitant Doppler signal area, blood pressure, and heart rate were measured before and after phenylephrine provocation. In addition, inhalation of amyl nitrite was performed during the recording of the mitral regurgitant Doppler signal area in the same way. Injection of phenylephrine resulted in an increase in the mitral regurgitant Doppler signal area accompanied by an increase in blood pressure and a decrease in heart rate. On the other hand, inhalation of amyl nitrite resulted in a decrease in the mitral regurgitant Doppler signal area, a decrease in blood pressure, and an increase in heart rate. A positive correlation between the change in blood pressure and that in the mitral regurgitant Doppler signal area was observed. In conclusion, two-dimensional color Doppler echocardiography may be useful in the assessment of the acute change in regurgitant volume in the patient with mitral regurgitation.

[Two-dimensional contrast echocardiographic assessment of the time course of regional ischemic myocardial function].

The time course of percent fractional area change (%FAC) of the ischemic left ventricular wall as identified by myocardial contrast echocardiography was assessed. Two-dimensional echocardiograms of the left ventricular short axis at the level of the chordae tendineae were recorded in 16 anesthetized open-chest dogs. Myocardial ischemia was produced by occluding the left circumflex coronary artery (LCX) for 30 min, and identified by myocardial contrast echocardiography using aortic root contrast injection. The left ventricular wall in the short-axis view was divided into eight segments. The experiments were completed in nine dogs. The %FAC of the segment which includes the center of the ischemic area was normal before LCX occlusion (35 +/- 6%: mean +/- S.D.), markedly decreased during 30 min of LCX occlusion (-3 +/- 4%) and gradually recovered after coronary reperfusion. However, it was significantly decreased 150 min after reperfusion (8 +/- 9%) (p less than 0.001) compared to that before LCX occlusion. The %FAC of the segment which includes the center of the non-ischemic area was not significantly changed throughout the experiment. In conclusion, 1) the time course of regional ischemic myocardial function could be assessed by the analysis of the %FAC of the ischemic area determined by myocardial contrast echocardiography, 2) the %FAC is significantly decreased 150 min after coronary reperfusion following 30 min occlusion compared to that before coronary occlusion.

[Diastolic pulmonary forward flow associated with pulmonary regurgitation demonstrated by Doppler echocardiography].

To demonstrate diastolic pulmonary forward flow, pulsed and continuous wave Doppler echocardiograms were recorded in four patients with postoperative residual pulmonary stenosis and regurgitation (Group I). To clarify the mechanism, we further examined 24 patients with pulmonary regurgitation without diastolic pulmonary forward flow, including three patients with surgical correction of tetralogy of Fallot (Group IIa) and 21 patients with functional pulmonary regurgitation (Group IIb), and compared the peak velocity and pressure half time of pulmonary regurgitation among the three groups. Diastolic pulmonary forward flow was characterized as a flow signal which began after the abrupt cessation of pulmonary regurgitation and continued until the beginning of ejection flow. The onset of the flow coincided with that of premature opening of the pulmonary valve, and was following atrial contraction in one, before atrial contraction in two, and mid-diastolic in one. The velocity of diastolic pulmonary forward flow was increased during inspiration and its maximum velocity was 1.3 m/sec. Simultaneous recording of pressures and continuous wave Doppler echo performed in two patients in Group I showed the equalization of right ventricular and pulmonary artery pressures during the flow. There was no significant difference in the peak velocity of pulmonary regurgitation among the three groups of patients. The mean pressure half time was significantly shortened in patients in Group I (90 +/- 11 msec) compared with those in patients in Group IIa (143 +/- 40 msec, p less than 0.05) and Group IIb (310 +/- 71 msec, p less than 0.001). In conclusion, a diastolic pulmonary forward flow seems to be produced by the rapid equalization of right ventricular and pulmonary artery pressures due to severe pulmonary regurgitation in the face of decreased right ventricular compliance.

[Continuous wave Doppler echocardiographic assessment of prosthetic aortic valves].

To assess the prosthetic aortic valve functions according to types and sizes of valves, the peak flow velocity was recorded by means of continuous wave Doppler echocardiography in 40 patients (age 45 +/- 15 years) with prosthetic aortic valves and in 25 normal subjects. Twenty-one patients had Björk-Shiley valves (1-18 months after replacement); 12 had St. Jude Medical valves (6-48 months after replacement); and seven had Carpentier-Edwards porcine xenografts (48-84 months after replacement). The peak blood flow velocity across the prosthetic valve was recorded at the left ventricular apex, the suprasternal notch, and the right parasternal border in the second intercostal space. The pressure gradient was derived from the peak flow velocity by means of the simplified Bernoulli equation (P = 4V2). The peak and mean flow velocities and the peak and mean pressure gradients were measured to evaluate the opening function of the prosthetic valves. The results were as follows; The peak flow velocities were recorded in 33 patients (83%) with aortic valve replacements. All four measurements were significantly greater in patients with prosthetic aortic valves than in normal subjects, but there was no significant difference according to the valve type. The opening function was less in patients with smaller valves than in those with larger ones. There was a clear correlation between opening function and valve size. We concluded that continuous wave Doppler echocardiography is a useful noninvasive method for evaluating the opening function of a prosthetic aortic valve.

[Mechanism of systolic anterior motion of the mitral valve in dogs].

The mechanism of systolic anterior motion (SAM) of the mitral valve remains somewhat controversial. We previously reported that SAM can be produced in dogs using dobutamine infusion. In the present study, dobutamine infusion, dextran infusion and venesection were performed in 13 anesthetized closed-chest dogs to study the mechanism of SAM. The degree of SAM was determined by M-mode echocardiography. End-systolic and end-diastolic short-axis areas of the left ventricle at the level of the chordae tendineae and the fractional area changes were measured by two-dimensional echocardiography. SAM was produced in six of the 13 dogs during dobutamine infusions (Group 1), but not in the other seven dogs (Group 2). During dobutamine infusions, % fractional area changes were greater in Group 1 (85 +/- 5; mean +/- standard deviation) than in Group 2 (65 +/- 15) (p less than 0.01), and the end-systolic short-axis area of the left ventricle was smaller in Group 1 (0.7 +/- 0.4 cm2) than in Group 2 (1.9 +/- 0.3 cm2) (p less than 0.01), although no significant change was observed between Groups 1 and 2 in the end-diastolic short-axis area of the left ventricle. Subsequent injections of dextran (mean 340 ml) in Group 1, decreased the degree of SAM and increased the end-diastolic and end-systolic short-axis areas of the left ventricle. Subsequently, venesections (mean 400 ml) in Group 1 resulted in increases in the degrees of SAM and decreases in the end-diastolic and end-systolic short-axis areas of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

[Continuous wave Doppler measurement of transmitral pressure gradients in mitral stenosis: comparisons with simultaneous catheterization measurements].

To determine the accuracy and reliability of measurements of mitral flow velocity and pressure gradients obtained from continuous wave Doppler (CWD) echocardiography, the left ventricular pressure, pulmonary capillary wedge pressure and CWD echo were simultaneously recorded simultaneously for 22 patients with mitral stenosis. An ultrasonic transducer was placed over the left ventricular apex to direct the ultrasonic beam parallel with the mitral flow. High-pitched audio signals were used to determine whether the ultrasonic beam direction was appropriate. The angle formed by the beam direction and the blood flow was assumed to be zero when a good Doppler echo was recorded. The maximum flow velocity and pressure gradients calculated from CWD echo were compared with pressure gradients obtained by catheterization. These were analyzed during the same heart beats. The results were as follows: Good recordings of pressures and CWD echograms were obtained for 17 patients, and their data were used for the analysis. The maximum flow velocity through the mitral valve obtained by CWD echography was very similar to the pressure gradients obtained by catheterization in terms of phases and patterns. The pressure gradients (x) calculated from CWD using a simplified Bernoulli's equation correlated well with those (y) measured at the same time on pressure tracings (y = 1.2x + 1.5, r = 0.92, p less than 0.001). Mean diastolic pressure gradients (X) obtained by CWD echography also correlated well with those (Y) recorded at catheterization (Y = 1.2X + 0.15, r = 0.95). Based on these results, we conclude that CWD echography is a reliable, noninvasive method to measure the pressure gradient across the mitral valve in patients with mitral stenosis.

[Continuous wave Doppler assessment of prosthetic valves in the mitral position: comparison of the St. Jude medical mechanical valve and the porcine xenograft valve].

To assess the opening function of prosthetic valves in the mitral position with special reference to the type and size of the valve and the years since replacement, we recorded maximum flow velocity through the mitral orifice using continuous wave Doppler echocardiography for 50 patients with mitral valve replacement and 15 normal subjects. There were 33 patients with St. Jude Medical valves and 17 with porcine xenograft valves. An ultrasonic transducer was placed over the left ventricular apex and the direction of the ultrasonic beam was positioned to be parallel with mitral flow using the Doppler audio signals. A pressure gradient was calculated from continuous wave Doppler flow velocity with a simplified Bernoulli's equation proposed by Hatle et al. The peak and mean maximum flow velocity, mean pressure gradient across the valve and the pressure half time were measured to evaluate the opening function of the prosthetic valve. The results were as follows: All four measurements were significantly larger in patients with valve replacements than in normal subjects, and were significantly increased in patients with porcine xenograft valves compared to those with St. Jude Medical valves. The opening function was well maintained in patients having larger valves than in those having smaller ones in the group of St. Jude Medical valve replacement. In patients who had porcine xenograft valve for four years or more, the opening function was decreased the more years they had been implanted. We conclude that continuous wave Doppler echocardiography is a useful noninvasive method for the quantitative assessment of the diastolic opening function of the prosthetic mitral valve.(ABSTRACT TRUNCATED AT 250 WORDS)

[Systolic honk in mitral stenosis: a case report].

This case report describes a mitral systolic honk originating from the mitral valve and adjacent structures in a 52 year-old woman with mitral stenosis. The patient was hospitalized because of dyspnea. Auscultation of the heart revealed a grade 3/6 apical early systolic honk accompanied by an increased first heart sound, an opening snap and a diastolic rumble. The phonocardiogram demonstrated an early systolic honk at a frequency of 115 Hz. Intensity of the honk varied on beat to beat basis, increasing in the short preceding R-R interval compared to that in the long one. The M-mode echocardiogram showed early systolic fluttering of the mitral valve and chordae tendineae at the same frequency as the honk. The two-dimensional echocardiogram showed bulging of the anterior mitral leaflet toward the left atrium in early systole. After treatment with digitalis and diuretics, the early systolic honk disappeared in beats with preceding long R-R intervals (greater than 1100 msec). In beats without the honk, systolic fluttering of the mitral valve was not observed. The genesis of the early systolic honk is analogous to that of the honk audible in mitral or tricuspid valve prolapse. The bulging of the anterior mitral leaflet into the left atrium may produce vibrations of the mitral valve leaflets and adjacent structures.

Pharmacological action of FD-008, a new dopamine-beta-hydroxylase inhibitor.

The effects of 5-(4'-chlorobutyl)-picolinic acid (FD-008), a new dopamine beta-hydroxylase inhibitor of fusaric acid derivatives, on the central nervous system in mice and rats were investigated. FD-008 and fusaric acid did not show marked effects on spontaneous movement, convulsion, sleeping time, tremor and conditioned avoidance response but lowered the body temperature of rats at 100 mg/kg p.o. FD-008 potentiated the depressive action of ethanol on conditioned avoidance response in spite of the lack of aldehyde dehydrogenase inhibition. FD-008 markedly depressed the performance on a shuttle box and lowered the body temperature in rats after reserpine treatment at a dose at which FD-008 per se had no effect.