A simultaneous study of doppler-echo and catheterization in noninvasive assessment of the left ventricular dp/dt

To confirm the feasibility and accuracy of the method for the noninvasive measurement of the left ventricular dp/dt, 53 patients with mitral regurgitation underwent simultaneous determination of left ventricular dp/dt by continuous-wave Doppler echocardiography and cardiac catheterization. Doppler-determined left ventricular dp/dt is derived from the Doppler mitral regurgitant spectrum by dividing the magnitude of the left ventricular-atrial pressure gradient rise between 1 and 3 m/s of the mitral regurgitant velocity signal by the time taken for this change. Left ventricular dp/dt by Doppler ranged from 629 to 3494 mmHg/s (x? ± SD, 1971 ± 785 mmHg/s), and that by catheterization varied between 716 and 3650 mmHg/s (x? ± SD, 1974 ± 727 mmHg/s). There was a high correlation (r = 0.93, y = 0.862 × + 274.77, SEE = 271 mmHg/s, p < 0.001) of left ventricular dp/dt between the two techniques. It is concluded that left ventricular dp/dt is one of the most commonly used parameters for the evaluation of left ventricular systolic function and that Doppler echocardiography provides a new, accurate and noninvasive method of evaluation.     

A Novel Noninvasive Method to Assess Left Ventricular −dP/dt Using Diastolic Blood Pressure and Isovolumic Relaxation Time

Background: Left ventricular Doppler‐derived ?dP/dt determined from the continuous‐wave Doppler spectrum of the mitral regurgitation (MR) jet has been shown to be a valuable marker of diastolic function, but requires the presence of MR for its assessment. We sought to determine if a novel method of determining ?dP/dt using the diastolic blood pressure and isovolumic relaxation time (DBP‐IVRT method) correlates with Doppler‐derived ?dP/dt using the MR method (Doppler‐MR method). Methods: Thirty‐three patients with less than severe MR were enrolled. ?dP/dt was determined using the Doppler‐MR method from the continuous‐wave Doppler spectrum of the MR jet (32 mmHg/time from 3 to 1 m/sec). ?dP/dt was also determined using the DBP‐IVRT method using the following equation: ?dP/dt = (DBP ? LVEDP)/IVRT, where left ventricular end‐diastolic pressure (LVEDP) was estimated based on tissue Doppler and mitral inflow patterns. Results: Twenty‐five patients had adequate Doppler waveforms for analysis. The average amount of MR was mild‐to‐moderate severity. The mean ?dP/dt was 680 ± 201 mmHg by the Doppler‐MR method and 681 ± 237 mmHg by the DBP‐IVRT method. There was a significant correlation between the 2 methods of determining ?dP/dt (Pearson r = 0.574, P = 0.003). The Bland–Altman plot revealed almost no bias between the 2 methods; the difference in ?dP/dt between the 2 techniques was noted to be greater for patients with higher ?dP/dt, however. Conclusion: Diastolic blood pressure and isovolumic relaxation time may be used to noninvasively assess diastolic function in patients who do not have MR, especially in those with reduced diastolic function.     

Hemodynamic abnormalities during coronary angiography: comparison of Hypaque-76, Hexabrix, and Omnipaque-350

The hemodynamic effects induced by coronary angiography in dogs with low osmolar ionic dimer Hexabrix (HB) and nonionic Omnipaque-350 (OM) were compared to the standard ionic contrast medium, Hypaque-76 (H76), both in the normal heart and in one with simulated severe cardiac disease. Left coronary angiography was performed in 12 "normal" closed-chest dogs with 10-cc injections of H76, HB, and OM in a randomized, blinded fashion. The maximal change in the left ventricular (LV) systolic pressure (SP), mean aortic pressure (MAP), left ventricular end diastolic pressure (LVEDP), and LV dp/dt were recorded. The LVSP and MAP fell 30 +/- 3 mm Hg and 26 +/- 4 mm Hg with H76, 22 +/- 2 mm Hg and 19 +/- 2 mm Hg with HB, and 7 +/- 1.5 mm Hg and 5 +/- 1 mm Hg with OM (P less than .001). The LVEDP increased 4.8 +/- 0.5 mm Hg with H76, 3 +/- 0.5 mm Hg with HB, but only 0.2 mm Hg with OM (P less than .001). The LV dp/dt decreased 392 +/- 63 mm Hg/sec with H76 and 235 +/- 21 mm Hg/sec with HB, but increased 411 +/- 50 mm Hg with OM (P less than .001). In eight additional open-chest dogs, left coronary angiography was performed 1 hr after occlusion of the proximal LAD coronary artery and in the presence of a critical circumflex coronary artery (CX) stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Study of left ventricular function and myocardial viability in patients with left ventricular aneurysm developed after myocardial infarction. A comparative study of medical and surgical therapy

We evaluated the treatment of left ventricular aneurysm (LVA) caused by myocardial infarction in 44 patients showing cineangiographical features of left ventricular aneurysm. Of the 44 patients, 28 were treated non-surgically (N-S) and 16 were treated surgically (S). Combined aortocoronary bypass graft (ACBG) with aneurysmectomy was performed on 10 patients. Clinical symptoms in LVA patients were angina (34%), congestive heart failure (31.8%), arrhythmia (29.5%), mitral regurgitation (9%), embolism (4%) and septal perforation (2.3%). Distribution of coronary arterial lesions were single vessel (isolated LAD) 29.5% and multiple vessel 59%. Parameters of LV performance measured at baseline in all LVA patients were: CI 3.05 +/- 0.64 L/min/m2, LVEDP 19.0 +/- 3.5 mmHg, LVEDV 200.6 +/- 25.9 ml, diast. wall stress 50.7 +/- 16.8 g/cm2, EF 0.46 +/- 0.15, LV dp/dt/p 17.8 +/- 2.1 S-1, SWI 61 +/- 24 gm/m2. LV performance after surgery showed clear decreases in LVEDP, LVEDV and wall stress (p less than 0.05, p less than 0.02 and p less than 0.02, respectively). In contrast, EF, LV dp/dt/p and SWI increased significantly (p less than 0.02, p less than 0.1 and p less than 0.01, respectively). Comparison of the results of restudy with first catheterization data in the N-S group showed decreases of EF, contractility index and LV dp/dt/p, each reaching p less than 0.1. Residual myocardial motion 1 year after the first cineangiographic study showed a significant decrease (-12.8 +/- 26.7%) in the N-S group, whereas in the S group it significantly increased to (+60.4 +/- 52.7%). A significant difference in coefficient of variation between N-S and S groups was found. Thus, it can be concluded that aneurysmectomy or concomitant myocardial revascularization with aneurysmectomy improves left ventricular diastolic performance and increases residual myocardial viability.     

Differential hemodynamic effects of Hypaque-76 and Renografin-76 during coronary angiography: the role of calcium-binding additives

Hypaque-76 (H76) and Renografin-76 (R76) are nearly identical ionic contrast media, except that R76 binds more calcium than H76 because of the presence of sodium citrate and EDTA in R76. To determine whether the calcium-binding additives in ionic contrast media contribute to the hemodynamic effects of contrast media during coronary angiography, left coronary angiography was performed in anesthetized dogs. In nine closed-chest dogs, 10 cc of H76 and R76 were injected in each dog in a blinded, randomized fashion. The effect of H76 and R76 on left ventricular systolic pressure (LVSP) and left ventricular diastolic pressure (LVDP), on mean aortic pressure (MAP), and on left ventricular (LV) dp/dt was recorded. Compared with H76, R76 produced a greater decrease in the LVSP (77 +/- 25 mmHg vs 48 +/- 17 mmHg P less than .05), MAP (72 +/- 24 mmHg vs 38 +/- 18 mmHg P less than .01), and LV dp/dt (747 +/- 87 mmHg/sec vs 460 +/- 81 mmHg/sec P less than .01). In nine additional open-chest dogs, left coronary angiography was performed 1 hour after occlusion of the proximal LAD coronary artery. Seven cc R76 produced a 35 +/- 15 mmHg decrease in LVSP, compared with 20 +/- 9 mmHg with H76 (P less than .01). The LV dp/dt decreased 720 +/- 387 mmHg/sec with R76, compared with 462 +/- 222 mmHg/sec with H76 (P less than 0.05). Thus, R76 produces significantly greater hemodynamic abnormalities than H76. Contrast media lacking calcium-binding agents may be preferable for coronary angiography.     

A new method for estimating left ventricular dP/dt by continuous wave Doppler-echocardiography. Validation studies at cardiac catheterization

In this study, we explored the use of continuous wave Doppler-echocardiography guided by color Doppler flow-mapping as a method for noninvasively calculating the rate of pressure rise (RPR) in the left ventricle. Continuous wave Doppler determination of the velocities in mitral regurgitant jets allows calculation of instantaneous pressure gradients between the left ventricle and the left atrium. Left atrial pressure variations in early systole can be considered negligible; therefore, the rising segment of the mitral regurgitation velocity curve should reflect left ventricular pressure increase. We studied 50 patients (mean age, 51 years; range, 25-66 years) in normal sinus rhythm with color Doppler-proven mitral regurgitation and compared the Doppler-derived left ventricular RPR with peak dP/dt obtained at cardiac catheterization. Doppler studies were performed simultaneously with cardiac catheterization in 11 patients and immediately before in the remaining cases. Two points were arbitrarily selected on the steepest rising segment of the continuous wave mitral regurgitation velocity curve (point A, 1 m/sec, point B, 3 m/sec), and the time interval (t) between them was measured. Following the Bernoulli relation, the pressure rise between points A and B is 32 mm Hg (4vB2-4vA2) and the RPR is 32 mm Hg/t. Results showed a linear correlation between the Doppler RPR and peak dP/dt (r = 0.87, SEE = 316 mm Hg/sec). The RPR in the left ventricle can be derived from the continuous wave Doppler mitral regurgitation velocity curve.     

Noninvasive estimation of the instantaneous first derivative of left ventricular pressure using continuous-wave Doppler echocardiography

BACKGROUND. The complete continuous-wave Doppler mitral regurgitant velocity curve should allow reconstruction of the ventriculoatrial (VA) pressure gradient from mitral valve closure to opening, including left ventricular (LV) isovolumic contraction, ejection, and isovolumic relaxation. Assuming that the left atrial pressure fluctuation is relatively minor in comparison with the corresponding LV pressure changes during systole, the first derivative of the Doppler-derived VA pressure gradient curve (Doppler dP/dt) might be used to estimate the LV dP/dt curve, previously measurable only at catheterization (catheter dP/dt). METHODS AND RESULTS. This hypothesis was examined in an in vivo mitral regurgitant model during 30 hemodynamic stages in eight dogs. Contractility and relaxation were altered by inotropic stimulation and hypothermia. The Doppler mitral regurgitant velocity spectrum was recorded along with simultaneously acquired micromanometer LV and left atrial pressures. The regurgitant velocity profiles were digitized and converted to VA pressure gradient curves using the simplified Bernoulli equation. The instantaneous dP/dt of the VA pressure gradient curve was then derived. The instantaneous Doppler-derived VA pressure gradients, instantaneous Doppler dP/dt, dP/dtmax, and -dP/dtmax were compared with corresponding catheter measurements. This method of estimating dP/dtmax from the instantaneous dP/dt curve was also compared with a previously proposed Doppler method of estimating dP/dtmax using the Doppler-derived mean rate of LV pressure rise over the time period between velocities of 1 and 3 m/sec on the ascending slope of the Doppler velocity spectrum. Both instantaneous Doppler-derived VA pressure gradients (r = 0.95, p less than 0.0001) and Doppler dP/dt (r = 0.92, p less than 0.0001) correlated well with corresponding measurements by catheter during systolic contraction and isovolumic relaxation (pooled data). The Doppler dP/dtmax (1,266 +/- 701 mm Hg/sec) also correlated well (r = 0.94) with the catheter dP/dtmax (1,200 +/- 573 mm Hg/sec). There was no difference between the two methods for measurement of dP/dtmax (p = NS). Although Doppler -dP/dtmax was slightly lower than the catheter measurement (961 +/- 511 versus 1,057 +/- 540 mm Hg/sec, p less than 0.01), the correlation between measurements by Doppler and catheter was excellent (r = 0.93, p less than 0.0001). The alternative method of mean isovolumic pressure rise (896 +/- 465 mm Hg/sec) underestimated the catheter dP/dtmax (1,200 +/- 573 mm Hg/sec) significantly (on average, 25%; p less than 0.001). CONCLUSIONS. The present study demonstrated an accurate and reliable noninvasive Doppler method for estimating instantaneous LV dP/dt, dP/dtmax, and -dP/dtmax.     

Hemodynamic difference accounted for the orientation of a Bj?rk-Shiley mitral prosthesis: a color Doppler echocardiographic study]

To determine whether the orientation of the major orifice of a mitral tilting disc prosthesis affects hemodynamics, intracavitary blood flow patterns were studied in 45 patients with well-functioning Bj?rk-Shiley mitral prosthesis using color Doppler flow imaging. The major orifice was oriented towards the septum in 23 patients (12 men, 11 women, age 58 +/- 11 years; group S), and towards the posterior wall in 22 patients (8 men, 14 women, age 55 +/- 9 years; group P). 1) The left ventricular end-diastolic dimensions (S: 4.8 +/- 0.9 cm, P: 5.2 +/- 1.0 cm), end-systolic dimensions (S: 3.6 +/- 0.9 cm, P: 3.8 +/- 1.2 cm), and left atrial dimensions (S: 5.0 +/- 1.0 cm, P: 4.7 +/- 0.9 cm) did not differ significantly between the 2 groups. 2) The peak mitral flow velocities (S: 1.43 +/- 0.38 m/sec, P: 1.43 +/- 0.27 m/sec), pressure gradients (S: 8.5 +/- 4.0 mmHg, P: 8.4 +/- 3.1 mmHg), and pressure half-times (S: 94.0 +/- 19.0 msec, P: 86.5 +/- 21.7 msec) did not differ significantly between the 2 groups. 3) Although mitral regurgitation was detected in 8 patients (35%) in the S group and in 2 patients (9%) in the P group, hemodynamically significant regurgitation was detected in only 4 patients in the S group (3 mild, one moderate). 4) The patients in the S group had reversed intracavitary blood flow; mitral flow was first directed towards the left ventricular outflow tract during diastole, while the outflow pattern was displaced into the left ventricular inflow tract.(ABSTRACT TRUNCATED AT 250 WORDS)     

Accuracy of Doppler ultrasound in evaluating changes of left ventricular diastolic properties

In order to evaluate the effect of an increase in preload caused by contrast medium (Renografin-75) on Doppler echocardiographic indices of left ventricular diastolic properties, left ventricular pressure using a catheter tip micromanometer and pulsed-Doppler measurement of transmitral flow signals were measured simultaneously in 15 patients with coronary artery disease pre- and post-left ventricular angiography. After left ventricular angiography, changes in indices determined from left ventricular pressure were significant: left ventricular end-diastolic pressure increased from 17 +/- 2 mmHg to 24 +/- 2 mmHg (mean +/- SE) (P less than 0.001), maximum -dP/dt increased from 1,129 +/- 63 to 1,307 +/- 90 mmHg/sec (P less than 0.005), and time constant decreased from 73 +/- 2 to 67 +/- 1 msec (P less than 0.01). Changes in Doppler-derived indices were also significant: A/E ratio decreased from 0.99 +/- 0.08 to 0.81 +/- 0.07 (P less than 0.01), peak velocity of early diastolic filling increased from 0.61 +/- 0.03 to 0.79 +/- 0.03 M/sec (P less than 0.01), and deceleration rate increased from 3.1 +/- 0.2 to 4.6 +/- 0.2 M/sec 2 (P less than 0.01). Changes in Doppler echocardiographic indices (DR, acceleration half time, deceleration half time, and A/E ratio) were accompanied by changes in time constant and maximum -dP/dt after left ventricular angiography. However, the correlations between changes in hemodynamic indices and changes in Doppler echocardiographic indices were poor (r = 0.06 to 0.67).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of Dobutamine Infusion on Mitral Regurgitation

Both intensity of mitral regurgitant murmur and color-coded Doppler regurgitant signal area have been reported to correlate with the degree of regurgitation. To evaluate the relationship between the intensity of regurgitant murmur and severity of mitral regurgitation, phonocardiography, echocardiography, and Doppler ultrasound were performed in 18 patients with mitral regurgitation before and during dobutamine infusion. Mitral regurgitation was due to mitral valve prolapse with ruptured chordae tendineae in 8 patients, rheumatic change in 5 patients, and dilated cardiomyopathy in 5 patients. With intravenous dobutamine infusion, heart rate (77–103 beats/min), systolic blood pressure (119–144 mmHg), peak mitral regurgitant jet velocity (4.5–5.4 m/sec), intensity of mitral regurgitant murmur (to 201% of that before infusion in early systole) increased, while left ventricular end-diastolic volume (124–102 mm), left ventricular end-systolic volume (57–42 mm), mitral anular diameter (33–28mm), and color Doppler mitral regurgitant signal area (704–416 mm²) decreased (P < 0.05). Total (forward + backward) left ventricular stroke volume (66–61 mL/beat) showed no change. Dobutamine decreased mitral regurgitant flow/beat, regardless of etiology of mitral regurgitation, which was probably due to the decrease of left ventricular size and mitral annular diameter. Although total (forward + backward) left ventricular stroke volume was unchanged, dobutamine effectively increased forward left ventricular stroke volume by decreasing backward regurgitation. Mitral regurgitant murmur became louder despite the decrease of mitral regurgation, indicating the uselessness of auscultation in the grading of the severity of mitral regurgitation.     

Correlation between Doppler derived dP/dt and left ventricular asynchrony in patients with dilated cardiomyopathy: A combined study using strain rate imaging and conventional Doppler echocardiography

AIM: To evaluate the relationship between Doppler-derived left ventricular (LV) dP/dt and the degree of LV mechanical asynchrony measured by strain rate imaging. METHODS AND RESULTS: The study group consisted of 69 patients with variable degree of LV dysfunction and mitral regurgitation (MR). Conventional echo variables and LV dP/dt were calculated from the MR Doppler spectrum by rate-pressure-rise method. Strain rate traces were obtained by 12-segment model and LV long axis images were analyzed off-line. The longest time intervals between the peak negative strain rate waves at isovolumic contraction period and peak systole from reciprocal segments were defined as asynchrony index AIc or AIs, respectively. The maximum differences in time-to-peak systolic velocities between opposing walls were also measured as asynchrony index by tissue Doppler (AItd). The dP/dt, mean QRS duration, AIc, AIs, and AItd were 836 +/- 266 mmHg/sec, 125 +/- 31, 38 +/- 28, 64 +/- 44, and 52 +/- 32 m, respectively. No significant correlation between the dP/dt and the LV dimension, ejection fraction or QRS duration was observed. However, dP/dt correlated negatively with AIc, or AIs (r:-0.78, -0.72, P < or = 0.0001) and AItd (r:-0.65, P < or = 0.001). A cutoff dP/dt value of under 700 mmHg/sec can discriminate patients over median AIs (55 ms) or patients with AIc over 30 ms with high sensitivity and specificity. CONCLUSIONS: Doppler-derived LV dP/dt is related to the degree of LV dyssynchrony rather than the conventional systolic function indices such as EF% in patients with severe heart failure. Noninvasive dP/dt assessment in addition to advanced imaging techniques can be used to define patients for cardiac resynchronization therapy (CRT).     

Changes in hemodynamics and bradykinin concentration in coronary sinus blood in experimental coronary artery occlusion.

The following parameters were studied before and after acute occlusion of the anterior descending branch of the left coronary artery in 17 dogs: bradykinin (BK) in the coronary sinus blood, heart rate (HR), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), left ventricular max dp/dt (LV max dp/dt), and an index of myocardial contractility (LV max dp/dt/IP). BK levels increased, reaching a maximum of 30 +/- 13 ng/ml 2 min after coronary ligation, accompanied by a significant elevation of LVEDP, and lowering of the myocardial contractility index. HR and LV max dp/dt showed no significant changes. A positive correlation obtained between the level of BK and LVEDP, as well as a negative correlation between the level of BK and of both LVSP and myocardial contractility index. Pretreatment with aprotinine (Trasylol), an inhibitor of kinin forming enzyme, prevented the increase in both BK and LVEDP after coronary artery ligation and caused an elevation of myocardial contractility index. These results suggest that BK formed within ischemic myocardium exerts a negative inotropic action on the heart.     

Hemodynamic effects of contrast media during coronary angiography: a comparison of three nonionic agents to Hypaque-76

Coronary angiography with standard ionic contrast media is associated with marked alterations in cardiac hemodynamics because of the depressant effects of the contrast media on cardiac contractility. Nonionic contrast media have been reported to produce less hemodynamic alteration than standard ionic contrast media. However, there is no information on how one nonionic media compares to another. Thus we compared the hemodynamic effects of three nonionic contrast media, Iopamidol (IOP), Iohexol (IOH), and Ioversol (IOV) to each other as well as to the standard ionic contrast media Hypaque-76 (H76). In 20 closed-chest anesthetized dogs, we recorded the maximal change in left ventricular systolic pressure (LVSP), mean aortic pressure, left ventricular diastolic pressure (LVDP), and left ventricular dp/dt during 10-cc left main coronary artery injections of H76, IOP, IOH, and IOV. The mean aortic pressure and LVSP decreased 36 +/- 17 mm Hg and 46 +/- 21 mm Hg with H76 but only 5 +/- 5 mm Hg and 6 +/- 5 mm Hg with IOP, 5 +/- 4 mm Hg and 6 +/- 6 mm Hg with IOH, and 5 +/- 4 mm Hg and 7 +/- 6 mm Hg with IOV (P less than 0.001). The LVDP increased 6 +/- 5.0 mm Hg with H76 but only 0.2 +/- 0.5 mm Hg with IOP, 0.2 +/- 0.3 mm Hg with IOH, and 0.5 +/- 1.0 mm Hg with IOV (P less than 0.001). The LV dp/dt decreased 545 +/- 261 mm Hg/sec with H76 but increased 886 +/- 477 mm Hg/sec with IOP, 910 +/- 96 mm Hg/sec with IOH, and 473 +/- 335 mm Hg/sec with IOV (P less than 0.001). Whereas each nonionic agent produced significantly less hemodynamic abnormalities than H76, there was no significant difference between any of the nonionic agents on any hemodynamic parameter. Thus, as compared to H76, these nonionic contrast media produced only trivial alterations in hemodynamics and LV dp/dt. These agents may be preferable in patients with LV dysfunction.     

Acute effects of cardiac resynchronization therapy on functional mitral regurgitation in advanced systolic heart failure

OBJECTIVES: We studied the acute effects of cardiac resynchronization therapy (CRT) on functional mitral regurgitation in heart failure (HF) patients with left bundle branch block (LBBB). BACKGROUND: Both an decrease [corrected] in left ventricular (LV) closing force and mitral valve tethering have been implicated as mechanisms for functional mitral regurgitation (FMR) in dilated hearts. We hypothesized that an increase in LV closing force achieved by CRT could act to reduce FMR. METHODS: Twenty-four HF patients with LBBB and FMR were studied after implantation of a biventricular CRT system. Acute changes in FMR severity between intrinsic conduction (OFF) and CRT were quantified according to the proximal isovelocity surface area method by measuring the effective regurgitant orifice area (EROA). Results were compared with the changes in estimated maximal rate of left ventricular systolic pressure rise (LV+dP/dt(max)) and transmitral pressure gradients (TMP), both measured by Doppler echocardiography. RESULTS: Cardiac resynchronization therapy was associated with a significant reduction in FMR severity. Effective regurgitant orifice area decreased from 25 +/- 19 mm(2) (OFF) to 13 +/- 8 mm(2) (CRT). The change in EROA was directly related to the increase in LV+dP/dt(max) (r = -0.83, p < 0.0001). Compared with OFF, TMP increased more rapidly during CRT, and a higher maximal TMP was observed (OFF 73 +/- 24 mm Hg vs. CRT 85 +/- 26 mm Hg, p < 0.01). CONCLUSIONS: Functional mitral regurgitation is reduced by CRT in patients with HF and LBBB. This effect is directly related to the increased closing force (LV+dP/dt(max)). The results support the hypothesis that an increase in TMP, mediated by a rise in LV+dP/dt(max) due to more coordinated LV contraction, may facilitate effective mitral valve closure.     

Conventional and color Doppler echocardiography in mitral balloon valvotomy]

With the aim of assessing the value of conventional echocardiography and Doppler and colour Doppler during and in the follow-up of percutaneous mitral valvotomy we have studied prospectively 100 consecutive patients with 1 (90%), 6 (69%) and 12 (53%) months follow-up. Age was 50 years and 80% were women. The single balloon technique was used in 68%, mitral valve area increased from 0.9 +/- 0.2 to 1.8 +/- 0.3 cm2 and decrease in pulmonary artery pressure was 10 +/- 0.05 mmHg. We found that: 1) percutaneous mitral valvotomy produced and acute and transient decrease in left ventricular ejection fraction (pre 69 +/- 9%, post 61 +/- 10% p less than 0.001; 1 month 70 +/- 10; 2) a severe mitral regurgitation appeared in 4% of patients and 17% of patients had a moderate degree of regurgitation after valvotomy; 3) after valvular dilation an increase in the width of the aliasing greater than 29% predicted a successful procedure (final area greater than 1.5 cm2) with a sensibility 80% and specificity 94%, and 4) colour Doppler detected an atrial septal defect immediately after valvular dilation in 77% of patients, and permitted non invasive follow-up of the left to right shunt. At one year a left to right shunt at the atrial level persisted roughly in 1/3 of patients. We conclude that colour Doppler Echocardiography during percutaneous mitral valvotomy is useful for a rapid assessment of the increase in valve area, the detection and quantification of mitral regurgitation induced by valvular dilation and the follow-up in these patients.     

福辛普利对猪急性心肌梗死再灌注后无再流的影响

目的评价福辛普利防治猪急性心肌梗死再灌注后无再流的作用。方法中华小型猪24只随机分成对照组、福辛普利组(1mg·kg-1·d-1)和假手术组,每组8只。冠状动脉结扎3h,松解1h制备急性心肌梗死再灌注模型。梗死前、后和再灌注后均行血液动力学测定和心肌声学造影检查,最终行病理学分析。结果心肌声学造影和病理染色所测的冠状动脉结扎区心肌范围(LA)差异无统计学意义。与对照组相比,福辛普利可促进急性心肌梗死后心功能的恢复,增加再灌注后1h冠状动脉血流量(对照组50·6%,福辛普利组72·1%,P<0·01),减少无再流面积(对照组心肌声学造影和病理:78·5%和82·3%LA;福辛普利组心肌声学造影和病理:24·5%和25·2%LA,P均<0·01),减少心肌坏死面积(对照组98·5%,福辛普利组88·9%LA,P<0·05)。结论福辛普利能有效地防治心肌梗死再灌注后无再流。     

Experimental coxsackie B3 virus myocarditis in golden hamsters. II. Evaluation of left ventricular function in intact in situ heart 14 months after inoculation

The hemodynamic changes of the left ventricle (LV) of golden hamsters surviving for 14 months after acute coxsackie B3 virus myocarditis were assessed with the use of a high fidelity micromanometer pressure system. Of 25 infected hamsters, 10 survived to the 14th month, and 4 of these had cardiomegaly. Body weight (BW) was 150.0 +/- 20.7 g (mean +/- SD) (controls, 164.5 +/- 20.1 g, NS); heart weight (HW), 0.499 +/- 0.084 g (controls, 0.448 +/- 0.035 g, NS); and HW/BW, 3.39 +/- 0.79 X 10(-3) (controls, 2.74 +/- 0.23 X 10(-3), p less than 0.05). The hemodynamic data under anesthesia were: HR, 378 +/- 42 (controls, 414 +/- 43, NS); LVSP, 108 +/- 16 mmHg (controls, 126 +/- 16, NS); LVDP, 4.0 +/- 4.8 mmHg (controls, 0.6 +/- 0.7, NS); LVEDP, 9.7 +/- 7.5 mmHg (controls, 3.4 +/- 1.4, NS); peak positive dp/dt, 4960 +/- 1431 mmHg/sec (controls, 6714 +/- 1326, p less than 0.05); (dp/dt)/DP40, 56.8 +/- 9.8 sec-1 (controls, 73.1 +/- 7.0, p less than 0.01); peak negative dp/dt, 3876 +/- 1072 mmHg/sec (controls, 4971 +/- 599, p less than 0.05); and time constant T of LV pressure fall, 7.7 +/- 1.3 msec (controls, 5.9 +/- 0.7, p less than 0.01). Five hamsters had congestion of the lungs and liver with or without an elevation of LVEDP. One of them had an organizing thrombus in the left atrium, and one had an aneurysm in the LV free wall. Though markedly varied in extent, residual myocardial fibrosis was always evident in the hearts in which isovolumic contractility and early diastolic relaxation of the LV were significantly impaired. In a clinical extension of these findings, it may be that some cases of dilated cardiomyopathy in man develop in a way similar to the pathological processes noted in this experiment.     

Echo-Doppler study of myxomatous mitral valve insufficiency and the results of reparative surgery

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)     

Noninvasive estimation of left ventricular Max(dP/dt) from aortic flow acceleration and pulse wave velocity

The Doppler method of obtaining left ventricular Max(dP/dt) proposed recently was based on the measurement of mitral regurgitation velocity. Since Max(dP/dt) is an isovolumic phase index, its use in cases of mitral regurgitation may be open to argument. However, we had proposed a noninvasive method of estimating left ventricular Max(dP/dt) based on different principles. In our method, Max(dP/dt) had been given by Max(dP/dt) = (rho)cMax (du/dt), where rho is the blood density, c is the pulse wave velocity, and u is the flow velocity in the aorta. We had derived the above equation theoretically, and confirmed its validity by animal experiments. In our previous study, we also applied our method in the clinical setting. The aortic flow velocity was measured by Doppler echocardiography, and the pulse wave velocity by mechanocardiography or Doppler echocardiography. (Rho)cMax(du/dt) obtained noninvasively was compared with Max(dP/dt) measured with a catheter-tip micromanometer. We found an excellent correlation between (rho)cMax(du/dt) and Max(dp/dt), and concluded that (rho)Max(du/dt) is useful in assessing noninvasively the contractile state of the left ventricle. Here, we summarize our method, review previous results, and report new results of the clinical application of our method.     

Double-transseptal, double-balloon valvuloplasty for congenital mitral stenosis.

BACKGROUND. Eight patients with severe congenital mitral stenosis underwent double transseptal, double-balloon valvuloplasty; two had isolated congenital mitral stenosis, six had additional cardiac defects, and one had previous surgical valvotomy. Ages ranged from 0.6 to 36 years (median, 9 years). METHODS AND RESULTS. All procedures were tolerated well. After valvuloplasty, the left atrial a wave minus the left ventricular end-diastolic pressure (LVEDP) gradient was reduced from 25 +/- 6 mm Hg to 9 +/- 3 mm Hg (p less than 0.001), the mitral valve mean gradient was reduced from 18 +/- 7 mm Hg to 8 +/- 3 mm Hg (p = 0.003), and the LVEDP was unchanged. All patients had marked clinical improvement. Only one patient developed significant mitral regurgitation. Two of the first four patients underwent repeat balloon valvuloplasty 7 months later. Follow-up evaluation on six patients from 4 to 54 months revealed no recurrence of symptoms or increased mitral regurgitation. CONCLUSIONS. Double transseptal, double-balloon valvuloplasty is an effective treatment for many forms of congenital mitral stenosis. Mitral regurgitation is uncommon after this procedure. The double transseptal approach results in less trauma to the atrial septum and femoral veins and allows easy assessment of any residual postvalvuloplasty gradient.