Masato Tanimoto

Left atrial systolic performance in the presence of elevated left ventricular end-diastolic pressure: evaluation by transesophageal pulsed Doppler echocardiography of left ventricular inflow and pulmonary venous flow velocities

We recorded left ventricular inflow (LVIF) and pulmonary venous flow (PVF) velocities by trans‐esophageal pulsed Doppler echocardiography in 25 patients with a ratio of peak atrial systolic to early diastolic LVIF velocity of < 1 and a left ventricular end‐diastolic pressure (LVEDP) of 15 mmHg or greater, as well as in 30 normal subjects. The group consisted of 14 patients with prior myocardial infarction, 7 with dilated cardiomyopathy, and 4 with cardiac amyloidosis, and were divided into: (1) group A (n = 7): peak atrial systolic LVIF velocity of 40 cm/sec or greater; (2) group B (n = 7): peak atrial systolic LVIF velocity of < 40 cm/sec and peak atrial systolic PVF velocity of 30 cm/sec or greater; and (3) group C (n = 11): peak atrial systolic LVIF velocity of < 40 cm/sec and peak atrial systolic PVF velocity of < 30 cm/sec. Although LVEDPs in groups B and C were significantly greater than in group A, there was no difference between groups B and C. The mean pulmonary capillary wedge pressure (mPCWP) in group C was significantly greater than in groups A and B, but there was no difference between groups A and B. The difference between LVEDP and mPCWP (LVEDP — mPCWP) in group B was significantly higher than in groups A and C. Dilatation of the left atrium (LA) was seen in all three groups, particularly in groups B and C. There were no differences in peak atrial systolic LVIF velocity and LA volume change during atrial contraction between group A and the control group, and there were no differences in LA volume change and peak second systolic PVF velocity between groups A and B. LA volume change and peak second systolic PVF velocity were significantly less in group C than in groups A and B. Among the four patients whose courses could be observed after medical treatment with diuretic and vasodilator, one changed from group B to A, one from group B to C, one from group C to A, and one remained in group C. Thus, recording of peak atrial systolic LVIF and PVF by transesophageal pulsed Doppler echocardiography permits detailed evaluation of LA systolic performance in the presence of elevated LVEDP. These two variables provide important information for less invasive differentiation of LA afterload mismatch from LA myocardial failure.

Transesophageal Pulsed Doppler Echocardiographic Study of Pulmonary Venous Flow in Mitral Stenosis

For evaluation of pulmonary venous flow (PVF) in mitral stenosis, transthoracic and transesophageal echocardiography were performed in 33 patients with mitral stenosis and 20 normal controls. The peak systolic flow velocity of the PVF was significantly lower in patients with mitral stenosis and atrial fibrillation. The peak diastolic flow velocity of the PVF was significantly lower in the patients with mitral stenosis than in normal controls. The diastolic wave recorded as laminar flow in the mitral stenosis group showed a peak in the rapid filling phase with a gradually descending slope of velocity during mid to late diastole. There was a significant negative correlation between the peak diastolic flow velocity of the PVF and the pressure half time from transmitral flow obtained by continuous wave Doppler in the mitral stenosis group. These results demonstrate that evaluation of the PVF is helpful in understanding hemodynamic events between the left atrium and left ventricle in patients with mitral stenosis.

Three-Dimensional Echocardiographic Reconstruction of the Left Ventricle by a Transesophageal Tomographic Technique: In Vitro and In Vivo Validation of its Volume Measurement.

Accurate determination of left ventricular (LV) volume has important therapeutic and prognostic implications in patients with cardiac disease. Volume estimations by two‐dimensional techniques are not very accurate due to geometric assumptions. Objectives: To validate LV volume determinations by a new transesophageal three‐dimensional echocardiographic technique. We performed three‐dimensional reconstruction of the LV using an echo‐computed tomographic (CT) technique based on serial pullback parallel slice imaging technique in both in vitro and in vivo settings. Fourteen latex‐balloons with various sizes (30–235 mL) and shapes (conical, pear shaped, round, elliptical, and aneurysms in various locations) filled with known volumes of water were imaged in a water bath. From the static three‐dimensional image, the LV long axis was defined and the LV was sectioned perpendicular to this axis into 2‐mm slices. The volume of each slice was calculated with the observer blinded to the actual volume as the product of the slice thickness and the manually traced perimeter of the slice and the LV volume as the sum of the volumes of the slices (Simpsons method). The calculated LV volume closely correlated with the actual volume (r = 0.99, P < 0.0001, calculated volume = 1.06x – 11.3, Δvolume =‐5.7 ± 10.0 cc). Using the same system, transesophageal echocardiographic (TEE) images of the LV were obtained in 15 patients gated to respiration and ECG. Satisfactory dynamic three‐dimensional reconstruction of the LV was possible in ten patients. The three‐dimensional LV volumes (systolic and diastolic) using Simpsons method correlated well with those obtained from biplane or multiplane TEE images using the area length method (r = 0.89, P < 0.0001, y = 12.7 + 0.84x, Δvolume = 1.3 ± 18.1 cc). The LV major‐axis diameters by the two methods showed very close correlations as well (r = 0.86, P < 0.0001, y = 19 + 0.74x, Δdiameter = 1.0 ± 7.2 mm). We conclude that three‐dimensional LV volume calculation by the echo‐CT technique is intrinsically sound, is independent of LV geometry, and with some limitations, is applicable in vivo.

Assessment of Right-to-Left Shunt Flow in Atrial Septal Defect by Transesophageal Color and Pulsed Doppler Echocardiography

To investigate the clinical significance and problems of right-to-left (R-L) shunt flow dynamics in atrial septal defects, we performed transesophageal color and pulsed Doppler echocardiography in 30 patients with atrial septal defects of the ostium secundum type. The 30 patients consisted of 20 with a pulmonary artery systolic pressure of less than 40 mm Hg, four with a pressure of 40 to 60 mm Hg, three with a pressure of 90 mm Hg or more, two patients with pulmonic stenosis, and one patient with Ebsteins anomaly. R-L shunting was determined by the presence of a shunt flow signal across the defect during each cardiac cycle. The time of R-L shunt flow was compared with the various parameters obtained by echocardiography and cardiac catheterization. R-L shunt flow signals were detected at the following times: (1) at the onset of ventricular contraction or the closing phase of the tricuspid valve in five patients with isolated atrial septal defect. These patients showed an increase of mean right atrial pressure but had no severe pulmonary hypertension; (2) during ventricular systole in five of 26 patients with tricuspid regurgitation and one patient with Ebsteins anomaly. The tricuspid regurgitant signal was directed toward the ostium of the defect in three patients and was massive in the other patients; (3) during middiastole in three patients without pulmonary hypertension. These patients showed massive left-to-right shunt flow from end systole to early diastole; and (4) during atrial systole in three patients with severe pulmonary hypertension and two patients with pulmonic stenosis. The former, in particular, showed the aliasing signal as a high-speed shunt flow. In two of the three patients with severe pulmonary hypertension, R-L shunting continued from atrial systole to early ventricular systole and was also observed in early diastole. R-L shunt flow was detected in patients with atrial septal defects not only with pulmonary hypertension but also without pulmonary hypertension and was influenced by the right atrial pressure in the phase of tricuspid valve closing, the volume or direction of tricuspid regurgitation, rebound flow caused by massive left-to-right shunt flow, the grade of right ventricular distensibility or the complication of pulmonary hypertension, and complications with other cardiac anomalies. Thus R-L shunt flow in patients with atrial septal defects was detected easily by transesophageal color and pulsed Doppler echocardiography because of the high efficiency of this method for its detection.

Transesophageal echocardiographic evaluation of mitral regurgitation in hypertrophic cardiomyopathy: Contributions of eccentric left ventricular hypertrophy and related abnormalities of the mitral complex

This study was designed to evaluate the contribution of eccentric left ventricular hypertrophy and its related organic and spatial abnormalities of the mitral complex to the occurrence of mitral regurgitation in patients with hypertrophic cardiomyopathy We selected 45 consecutive patients with systolic mitral regurgitation by color Doppler echocardiography and performed transesophageal echocardiography in all patients. Eighteen patients were in the obstructive group and 27 patients were in the nonobstructive group of hypertrophic cardiomyopathy with asymmetric septal hypertrophy. Twenty subjects without any cardiac disorders served as the control group. The maximum area of mitral regurgitation was significantly greater in the obstructive group than in the nonobstructive group. Mitral regurgitation appeared more frequently during pansystole in the two groups with hypertrophic cardiomyopathy, particularly in the obstructive group. Mitral valve prolapse was observed in 20 (44%) of the 45 patients with hypertrophic cardiomyopathy. Distances between the posterior papillary muscle and anterior or posterior mitral anulus were significantly smaller in the two groups with hypertrophic cardiomyopathy than in the normal control group. In the obstructive group, the length of the anterior mitral leaflet and the thickness of the rough zone of the anterior mitral leaflet at mid-diastole were significantly greater than in the other groups. Systolic anterior motion was observed in all patients with obstructive cardiomyopathy and contact between the interventricular septum and the anterior mitral leaflet during early diastole was observed in 17 of the 18 patients in the obstructive group.(ABSTRACT TRUNCATED AT 250 WORDS)

Transesophageal Echocardiographic Analysis of the Systolic Pattern of the Anterior Mitral Leaflet in Patients with Flat Chest

Transesophageal echocardiography was conducted to determine the systolic pattern of the anterior mitral leaflet in patients with flat chest, and to differentiate it from that associated with mitral valve prolapse. The fronto‐sagittal index (an index of chest flattening) was determined in 50 subjects using chest radiographs, and was used to classify them into a flat chest group (index < 0.38, n= 28) and a normal chest group (index ≥ 0.38, n= 22). We then used transesophageal echocardiography to examine the anterior leaflet in these subjects. A significant positive correlation was observed between the fronto‐sagittal index and the short‐to long‐axis diameter ratio of the left ventricle in all patients. These parameters, and the left atrial dimension were lower in the flat than the normal chest group. The clear zone area of the anterior leaflet during mid‐to late‐systole was significantly larger in the flat chest group. However, no intergroup differences existed in the rough zone area of the anterior leaflet or in the middle scallop area of the posterior leaflet. Mitral regurgitation was observed in 20 and 12 subjects in the flat and normal chest groups, respectively. The maximum mitral regurgitant area did not differ between the two groups. The clear zone area of the anterior leaflet increased significantly following inhalation of amyl nitrite in 22 subjects of both groups, but the other areas did not increase. The mitral regurgitant area decreased or disappeared after amyl nitrite at a similar rate in each group. Thus, the decrease in the antero‐posterior dimension of the thorax in subjects with flat chest affects the systolic pattern of the clear zone of the anterior leaflet more than that of the rough zone of the anterior leaflet or the posterior leaflet. This systolic pattern in such patients differs from that associated with mitral valve prolapse.