Respiratory variation of mitral and pulmonary venous Doppler flow velocities in constrictive pericarditis before and after pericardiectomy.

The objective of this study was to determine whether Doppler echocardiography is useful in assessing the effects of pericardiectomy in patients with constrictive pericarditis by studying the postoperative change in the respiratory variation of mitral inflow and pulmonary venous Doppler flows. The study population consisted of 35 cases with surgically proven constrictive pericarditis. Thirty-five patients had preoperative Doppler echocardiography, whereas 4 patients died of non-cardiac causes and 1 patient had a heart transplant before follow-up. Postoperative studies were performed at a mean of 1081 +/- 84 days (range 120-2700 days) after pericardiectomy. The mean (+/- SD) respiratory variation changed after surgery from a baseline value of 17% +/- 14% to 8% +/- 8% for peak mitral E velocity (P <.01); from 25% +/- 18% to 7% +/- 13% (P <.001) for pulmonary venous (PV) peak diastolic flow velocity, and from 21% +/- 13% to 11% +/- 13% (P =.009) for PV peak systolic flow velocity. The 23 patients who became asymptomatic after surgery had a significantly lower mean mitral and PV respiratory variation than the 7 patients who were NYHA class II (4% +/- 4% and 6% +/- 4% vs 21% +/- 6% and 19% +/- 10%, respectively, P <.0001 for both). Pulsed Doppler echocardiographic assessment of respiratory variation is useful for evaluating the outcome of pericardiectomy.     

健康成年新西兰兔肺动脉、肺静脉血流频谱分析及右心系统压力检测

目的 利用超声心动图及右心导管测量新西兰兔肺动脉、肺静脉频谱指标及右心系统压力指标,了解其频谱特点及右心系统压力的正常值范围。 方法 选择健康成年新西兰兔24只,用彩色多普勒超声诊断系统测量其肺动脉、肺静脉频谱,并同步记录心电图及呼吸曲线。通过右心导管记录并测量其右心房、右心室、肺动脉的收缩压及舒张压。 结果 频谱多普勒结果显示新西兰兔肺静脉频谱的峰值血流速度吸气相与呼气相的差异均无统计学意义(P均>0.05),肺动脉频谱峰值血流速度吸气相高于呼气相,差异有统计学意义(P<0.001)。右心导管压力测值结果显示新西兰兔肺动脉收缩压范围为16.07~23.99 mmHg、肺动脉舒张压为11.18~19.22 mmHg。 结论 超声心动图可清晰显示新西兰兔肺动脉、肺静脉血流;其肺动脉血流频谱随呼吸周期呈规律性变化。     

Diagnostic value of mitral annular velocity for constrictive pericarditis in the absence of respiratory variation in mitral inflow velocity

Respiratory variation of 25% or more in transmitral early diastolic filling (E) velocity is a well-recognized diagnostic feature of constrictive pericarditis (CP) that is useful for distinguishing it from restrictive cardiomyopathy. However, a subset of patients with CP do not exhibit the typical respiratory change. Recent data showed that mitral annular (E') velocity measured by Doppler tissue echocardiography (DTE) is markedly reduced in patients with restrictive cardiomyopathy whereas E' velocity is well-preserved in CP. This study evaluated the role of DTE for the diagnosis of CP when there is no characteristic respiratory variation of E velocity. From September 1999 to March 2001, 19 patients (17 men, 2 women; mean age, 57 +/- 13 years) with surgically confirmed CP underwent comprehensive echocardiography preoperatively, including pulsed wave and DTE examination with simultaneous recording of respiration. Nine (47%) of the 19 patients had less than 25% respiratory variation in E velocity. There was no significant difference in mitral inflow peak velocity, deceleration time, early-to-late ventricular filling ratio, and E' velocity between patients with and patients without respiratory variation of E velocity of 25% or more. Regardless of the presence or absence of a significant respiratory variation of E velocity, E' velocity was relatively normal (mean, 12 +/- 4 cm/s) in all patients with CP. In conclusion, E' velocity is well preserved in patients with isolated CP even when there is no characteristic respiratory variation of E velocity. Thus, when the respiratory variation in Doppler E velocity is blunted or absent during the evaluation of suspected CP in patients with restrictive mitral inflow velocity, preserved E' velocity shown by DTE should support the diagnosis of CP over a primary myocardial disease.     

呼吸对慢性阻塞性肺病左心室充盈的影响及其机制的超声心动图研究

目的探讨超声心动图检测慢性阻塞性肺病（COPD）患者左心室功能和COPD病程的可行性。方法采用Sequoia512彩色超声诊断仪,记录21例COPD患者及50名健康人自然呼吸时二尖瓣口E峰、A峰血流速度,同步记录心电图和呼吸曲线,计算二尖瓣舒张早期E峰血流速度呼吸性波动指数（RVI）及E峰与A峰血流速度比值（E/A）呼吸变化率。结果两组均表现为E峰血流速度、E/A吸气相低于呼气相（P〈0.001）;COPD组A峰血流速度吸气相与呼气相差异无统计学意义（P=0.076）,而健康对照组A峰血流速度吸气相低于呼气相（P〈0.001）。COPD组二尖瓣E峰血流速度RVI及E/A呼吸变化率均较对照组增大（P=0.002）。结论自然呼吸对COPD患者二尖瓣血流影响具有规律性,进一步验证了呼吸影响心功能机制新假说,同时也为利用多普勒技术评价COPD患者左室功能损害程度和肺实质病变严重程度的进一步研究提供更多信息。     

Influence of Doppler sample volume location on the assessment of changes in mitral inflow velocity profiles

Previous studies that have validated Doppler indexes of mitral inflow have used pulsed wave sample volume locations either at the level of the mitral valve anulus or at the tips of the mitral valve leaflets. Although significant differences between absolute values for peak velocities and velocity time integrals at these sample volume locations have previously been reported, no information exists that has compared changes in inflow profiles after an intervention to improve left ventricular filling. To address this question, 13 patients with severe pulmonary hypertension (mean pulmonary artery pressure, 50 +/- 13 mm Hg) caused by chronic thromboembolic disease were studied with use of Doppler echocardiography immediately before and after surgical reduction of pulmonary hypertension (pulmonary vascular resistance decreased from 916 +/- 413 to 233 +/- 89 dynes.sec.cm5). This clinical model has been shown to have abnormal mitral inflow velocity profiles that improve markedly after surgery. Doppler measures of early and late peak velocities were significantly lower both before and after surgery when sampling at the mitral anulus compared with the leaflet tips, although late filling parameters and the deceleration of early flow velocity tended to differ little. With surgery, the significant increase in peak early velocity and the ratio of early to late velocity was present regardless of the sample volume location (peak E at leaflet tips, 47.1 +/- 16.0 to 68.9 +/- 15.4 [p less than 0.001], and at anulus, 40.7 +/- 11.3 to 56.2 +/- 14.6 cm/sec [p less than 0.001]; peak E/A at leaflet tips, 0.95 +/- 0.4 to 1.55 +/- 0.9, and at anulus, 0.78 +/- 0.3 to 1.32 +/- 0.7 [both p less than 0.02]).(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of left atrial appendage wall velocities by transesophageal tissue Doppler echocardiography: a clinical study in patients with sinus rhythm.

To assess left atrial appendage (LAA) wall velocities, 42 patients in sinus rhythm underwent tissue Doppler interrogation during a clinically indicated transesophageal echocardiography. Color Doppler (B-mode and M-mode) and pulsed Doppler of LAA walls were obtained and analyzed in all patients. Color-coded tissue Doppler rendered a qualitative assessment of LAA wall, depicting both the timing and the sequence of LAA contraction. With pulsed Doppler interrogation, a triphasic signal was recorded in all patients, consisting of a positive wave (D1), followed by a biphasic wave (positive D2 and negative D3). Peak velocities of D1, D2, and D3 were 6.1 +/- 2, 20.1 +/- 7, and 16.1 +/- 5 cm/s, respectively. Mean coefficient of variation of LAA wall velocities was 6%, significantly lower than that of LAA percentage area change (29%). Compared with patients with abnormal relaxation, patients with normal mitral inflow had higher D1 peak velocities (7.3 +/- 1.2 vs 4.3 +/- 1 cm/s, respectively; P <.0001). Time sequence of ECG, LAA flow, and mitral inflow indicates that D1 component of LAA wall occurs in early diastole and is likely due to the upward movement of the mitral ring toward the base of the LAA wall. In conclusion, evaluation of LAA wall using tissue Doppler is feasible and reproducible. Although color tissue Doppler analysis allows a qualitative assessment, pulsed Doppler gives new quantitative insights for the comprehensive assessment of LAA wall dynamics, which complements the information obtained with flow interrogation.     

Abnormal cardiac function in fetuses with increased nuchal translucency.

OBJECTIVE: To evaluate cardiac function in structurally and chromosomally normal fetuses with increased nuchal translucency (NT). METHODS: Forty-two structurally and chromosomally normal fetuses with increased NT at 11-14 weeks of gestation underwent fetal echocardiographic examination at 20-23 weeks. Fifty fetuses with normal NT values were considered as controls. Pulmonary and aortic peak velocity and time to peak velocities were measured as indices of ventricular systolic function. The ratios between the E-wave and A-wave (E/A) and the ratios between the E-wave and time velocity integral (E/TVI) at the level of both atrioventricular valves were evaluated as indices of ventricular diastolic function. RESULTS: In fetuses with increased NT the E/A ratios were significantly decreased when compared to control fetuses at the level of both the mitral (0.52 +/- 0.09 vs. 0.60 +/- 0.10, P = 0.0002) and tricuspid (0.51 +/- 0.09 vs. 0.61 +/- 0.09, P < 0.0001) valves. Similar results were found for the E/TVI ratios (mitral valve 4.79 +/- 1.03 vs. 5.63 +/- 1.23, P = 0.0007 and tricuspid valve 4.40 +/- 0.88 vs. 5.19 +/- 0.82, P < 0.0001). No significant relationship was found between the degree of NT and the abnormalities in Doppler indices. There were no significant differences in Doppler systolic indices. CONCLUSION: Structurally and chromosomally normal fetuses with increased NT have low E/A and E/TVI ratios at 20-23 weeks of gestation. These findings might indicate cardiac diastolic dysfunction.     

正常成人上腔静脉多普勒血流频谱分析

目的利用多普勒超声对正常成人上腔静脉（SVC）频谱进行分析,探讨其血流频谱变化与呼吸、心动周期的关系。方法对随机选取的56名成年健康志愿者经右锁骨上窝切面,在彩色多普勒引导下获取SVC血流频谱,测定不同心动周期及呼吸周期的SVC血流动力学指标。结果经右锁骨上窝SVC长轴切面获取SVC多普勒图像,成功率为100%,声束与血流方向夹角<10°。在平静呼吸状态下,吸气相S波、D波速度较呼气相加快（P<0.001）,VR、AR则减慢（P<0.05）。呼气相时各波速度则相反。结论经右锁骨上窝SVC长轴切面能获得较满意的SVC彩色及脉冲多普勒图像;SVC血流频谱随心动周期、呼吸周期呈规律性变化。     

Effect of fetal breathing movements on fetal cardiac hemodynamics.

Maximum flow velocity waveforms were studied at atrioventricular and outflow tract level in 12 cases during fetal breathing activity and in 12 cases during fetal apnea matched for maternal and gestational age and maternal parity. Gestational age ranged between 27 and 40 weeks (median 30 weeks). All flow velocity waveforms were obtained using a mechanical sector scanner with a pulsed Doppler system (carrier frequency 3.5 MHz). Time-averaged flow velocities were clearly different between inspiration and expiration at all four recording levels, reflecting changes in venous return as a result of fluctuations in intrathoracic pressure during fetal breathing activity. Percentage change between inspiration and expiration at outflow tract level was positively correlated with gestational age. Time-averaged flow velocity at mitral level and ascending aorta level was significantly higher during fetal breathing activity than during apnea, suggesting increased shunting of blood flow through the foramen ovale. Acceleration time at outflow tract level demonstrated very little change relative to inspiration and expiration.     

Phasic flow in the left ventricular inflow tract: the importance of Doppler sample volume position

Variability of Doppler transmitral flow was studied in 42 normal patients (aged 19-68 years). Starting at the mitral annulus level (ANL) in an apical four-chamber view, the sample volume was moved downstream at 1-cm intervals. At all positions, peak early (E) and later atrial mediated (A) diastolic velocity were measured, and the distance from the transducer to the level with the highest E wave (HEL) and highest A wave (HAL) determined. The A/E ratio and time velocity integral (TVI) at ANL, HAL, and HEL were also calculated. Peak E velocity at HEL was 33% higher than at ANL (p less than 0.01) and peak A velocity was 15% higher at HAL than at ANL (p less than 0.01). The A/E ratio was minimal at HEL and maximal at ANL (0.68 +/- 0.28 vs 0.85 +/- 0.32, p less than 0.01), whereas TVI was highest at HEL and lowest at ANL. Thus, inflow parameters vary along the inflow axis. This is of importance for cardiac output measurement. The A/E ratio was more dependent on age than on sample volume position.     

Pulse and Systolic Pressure Variation Assessment in Partially Assisted Ventilatory Support

OBJECTIVE: The use of pulse pressure variation (PPV) and systolic pressure variation (SPV) is possible during controlled ventilation (MV). Even in acute respiratory failure, controlled MV tends to be replaced by assisted ventilatory support. We tested if PPV and SPV during flow triggered synchronized intermittent mechanical ventilation (SIMV) could be as accurate as in controlled MV. METHODS: Prospective case-controlled study. Thirty patients who met criteria of weaning from controlled MV. Twenty minutes pressure support ventilation with 3 min(-1) flow triggered SIMV breathes (10 ml kg(-1)) T1, then three consecutive breaths in controlled MV (respiratory rate 12 min(-1),10 ml kg(-1)) T2. PPV and SPV were measured in T1 and T2. Correlation and Bland-Altman analysis were used to compare respective values of PPV and SPV in the two modes of ventilation. RESULTS: Significant correlations were found between dynamic indices in SIMV during pressure support ventilation and those in controlled MV mode. The mean differences between two measurements were: PPV 0.6+/-2.8% (limit of agreement: -5.0 and 6.2), SPV 0.5+/-2.3 mmHg (limit of agreement: -4.0 and 5.1). CONCLUSIONS: PPV and SPV measured during SIMV fitted with the findings in controlled MV. Dynamic indexes could be accurately monitored in patients breathing with assisted respiratory assistance adding an imposed large enough SIMV breath.     

Assessment of left ventricular systolic and diastolic function by Doppler tissue imaging in patients with preinfarction angina.

BACKGROUND: The aim of this study was assessment of left ventricular (LV) systolic and diastolic function by pulsed wave Doppler tissue imaging (DTI) in patients with or without preinfarction angina in acute myocardial infarction. METHODS: We prospectively evaluated 31 consecutive patients (4 women, 27 men; age 58 +/- 10 years) with a first acute myocardial infarction. LV systolic and diastolic function was assessed by classic methods and DTI on the third day during acute myocardial infarction. Patients were divided into 2 groups according to the presence (group 1; n = 10) or absence (group 2; n = 21) of preinfarction angina. Mitral inflow velocities and early diastolic mitral annular velocity (Em), late diastolic mitral annular velocity (Am), peak systolic mitral annular velocity, Em/Am, the ratio of early diastolic mitral inflow velocity (E) to Em, and myocardial performance index were calculated by DTI. RESULTS: Group 1 had significantly higher Em and Em/Am than group 2 (11.3 +/- 3.34 cm/s vs 7.4 +/- 2.07 cm/s, P <.0001; 1.01 +/- 0.38 cm/s vs 0.6 +/- 0.2 cm/s, P =.001, respectively). The E/Em ratio and myocardial performance index were significantly lower in group 1 than in group 2 (5.1 +/- 2.92 vs 8.10 +/- 3.15, P=.018; 0.49 +/- 0.15 vs 0.65 +/- 0.24, P =.042, respectively). Wall-motion score index was lower in those with preinfarction angina than in those without (1.6 +/- 0.36 vs 1.9 +/- 0.39; P =.04, respectively). Peak systolic mitral annular velocity and Am were not statistically different between groups (9.4 +/- 1.84 vs 8.3 +/- 2.03, P =.172; 11.7 +/- 3.07 vs 12.1 +/- 3.34, P =.72, respectively). There were no significant differences between the 2 groups regarding transmitral E velocity, atrial contraction mitral inflow velocity (A), E/A ratio, isovolumetric relaxation time, and deceleration time of the mitral E wave (P =.91, P =.08, P =.58, P =.81, and P =.71, respectively). CONCLUSION: LV diastolic function was better in patients with preinfarction angina than in patients without. This condition could not be detected by conventional mitral inflow Doppler velocities, but could be detected by DTI. This preliminary evidence shows that DTI is better than conventional mitral Doppler indices in the assessment of a favorable LV diastolic function in patients with preinfarction angina.     

Normal and respiratory variations of the hepatic and portal venous duplex Doppler waveforms with simultaneous electrocardiographic correlation.

To understand hepatic vein (HV) and portal vein (PV) duplex waveforms and their normal and respiratory variations, HV and PV duplex sonography with simultaneous electrocardiography was performed on 11 volunteers. Absolute velocities of the waveforms' components and their ratios were determined at mid-inspiration, full inspiration, full expiration, and Valsalva maneuver. The normal HV waveform was variable in shape and component velocities and ratios but essentially consisted sequentially of (1) an antegrade systolic wave resulting from movement of the tricuspid annulus toward the cardiac apex and occurring shortly after QRS; (2) a retrograde v-wave resulting from atrial overfilling and occurring immediately after the T-wave; (3) an antegrade diastolic wave resulting from opening of the tricuspid valve and occurring shortly after the T-wave; and (4) a retrograde a-wave resulting from atrial contraction and occurring immediately after the P-wave. The ratio of the maximum systolic velocity to maximum diastolic velocity varied from 1.0 to 2.8 (mean 1.4). Systolic-to-diastolic ratio decreased during inspiration but was always greater than 0.6 and increased during expiration. The Valsalva maneuver diminished waveform pulsatility. PV waveforms were more triphasic than biphasic but less pulsatile, flow was totally antegrade, and respiratory changes were less remarkable than HV waveforms. All normal HV and most normal PV waveforms showed multiphasicity that corresponded to cyclic cardiac changes. The shapes of these waveforms were variable and were modified by respiratory movements.     

Comparison of myocardial tissue Doppler with transmitral flow Doppler in left ventricular hypertrophy

We sought to determine the most useful echocardiographic measurements for assessment of diastolic function in patients with left ventricular hypertrophy (LVH) and normal systolic function. We compared myocardial Doppler velocities of the basal inferoposterior wall with mitral inflow pulsed wave Doppler velocities in 11 healthy volunteers (age, 36 +/- 6 years), 25 patients (age, 64 +/- 14 years) without LVH, and 37 patients (age, 67 +/- 14 years) with LVH and otherwise normal echocardiograms. The discriminatory measurements were myocardial A-wave duration (120 +/- 18 versus 98 +/- 20 and 92 +/- 12 ms, P <.0001), myocardial isovolumetric relaxation time (124 +/- 45 versus 95 +/- 48 and 78 +/- 25 ms, P =.0035), mitral A-wave velocity (0.98 +/- 0.37 versus 0.73 +/- 0.28 m/s and 0.61 +/- 0.22 m/s, P =.009), and mitral E-wave deceleration time (257 +/- 93 versus 201 +/- 85 ms and 184 +/- 83 ms, P =.015), which were significantly increased, and myocardial E-wave velocity (0.84 +/- 0.04 m/s versus 0.13 +/- 0.03 m/s and 0.14 +/- 0.03 m/s, P <.0001), which was significantly decreased, in patients with LVH compared with patients without LVH and normal volunteers, respectively. Left ventricular posterior wall thickness correlated with myocardial isovolumetric relaxation time (r = 0.52, P <.0001) and myocardial A-wave duration (r = 0.59, P <.0001), negatively with myocardial E wave (r = -0.43, P <.0001), and showed no correlation with mitral inflow parameters except mitral inflow A wave (r = 0.43, P =.002). On multivariate analysis using these variables, myocardial isovolumetric relaxation time (P =.0014) and A-wave duration (P =.001) were the only 2 variables that correlated with posterior wall thickness (multiple R = 0.71). In the presence of LVH and preserved left ventricular systolic function, myocardial relaxation time and velocities are more sensitive than mitral Doppler inflow parameters in detecting abnormal left ventricular relaxation.     

Left ventricular long-axis diastolic function is augmented in the hearts of endurance-trained compared with strength-trained athletes

In order to determine left ventricular global and regional myocardial functional reserve in endurance-trained and strength-trained athletes, and to identify predictors of exercise capacity, we studied 18 endurance-trained and 11 strength-trained athletes with left ventricular hypertrophy (172+/-27 and 188+/-39 g/m(2) respectively), and compared them with 14 sedentary controls. Global systolic (ejection fraction) and diastolic (transmitral flow) function, and regional longitudinal and transverse myocardial velocities [tissue Doppler echocardiography (TDE)], were measured at rest and immediately after exercise. In endurance-trained compared with strength-trained athletes, resting heart rate was lower (59+/-11 and 76+/-9 beats/min respectively; P<0.001), and the increase at peak exercise was greater (+211% and +139% respectively; P<0.001). In addition, exercise duration, workload, maximal oxygen consumption and global systolic functional reserve (but not peak ejection fraction) were higher in the endurance-trained athletes, and resting global diastolic function (E/A ratio 1.62+/-0.40 compared with 1.18+/-0.23; P<0.01) (where E-wave is peak velocity of early-diastolic mitral inflow and A-wave is peak velocity of mitral inflow during atrial contraction) and long-axis diastolic velocities (E(TDE)/A(TDE) ratio 2.2+/-1.2 compared with 1.1+/-0.3; P<0.01) (where E(TDE) and A(TDE) represent peak early- and late-diastolic myocardial or tissue velocity respectively) were augmented. Systolic velocities were similar. Exercise capacity was best predicted from end-diastolic diameter index and E/A ratio at rest, and end-diastolic volume index and diastolic longitudinal velocity during exercise (r=0.74, n=43, P<0.001). In conclusion, endurance-trained athletes had higher left ventricular long-axis diastolic velocities, augmented global early diastolic filling, and greater chronotropic and global systolic functional reserve. Maximal oxygen consumption was determined by diastolic loading and early relaxation rather than by systolic function, suggesting that dynamic exercise training improves cardiac performance by an effect on diastolic filling.     

超声心动图观察室间隔运动新方法研究

目的 利用室间隔运动时曲率半径的变化,观察正常人呼吸性胸压变化对室间隔摆动和形变的影响,评价新方法 观察室间隔运动的敏感性.方法 应用Acuson Sequoia 512型超声仪对21例健康志愿者进行检查.分别获取呼气相和吸气相左室腱索短轴观图像;同步记录各瓣口血流速率、心电图和呼吸曲线.两名医师在双盲条件下采用自制的测量软件.分别测量吸气相与呼气相室间隔曲率半径.结果 二尖瓣E峰血流速率和主动脉血流速率在呼气相均高于吸气相;三尖瓣E峰血流速率和肺动脉瓣血流速率则相反.吸气相室间隔曲率半径为(25.14±6.082)mm.呼气相室间隔曲率半径为(22.296±4.398)mm,二者差异有统计学意义(P<0.0001).结论 曲率半径可以评估室壁摆动和形变,具有良好的重复性,为临床评价呼吸性胸压变化提供一种敏感而可靠的新方法 .     

Impact of mitral E/A ratio on the accuracy of different echocardiographic indices to estimate left ventricular end-diastolic pressure

The objective was to determine the influence of left ventricular (LV) inflow pattern on the accuracy of different echocardiographic indices for estimation of LV end-diastolic pressure (LVEDP). Echocardiography with color tissue Doppler imaging (TDI) and LVEDP measurements using fluid-filled catheters were performed in 176 consecutive patients on the same day. Mitral peak diastolic velocities (E, A) and the difference in duration between pulmonary venous retrograde velocity and mitral A-velocity (PV(R)-A) were recorded by pulsed Doppler. Propagation velocity of the early mitral inflow (V(P)) was assessed using color M-mode. Early diastolic longitudinal (E'(lat)) and radial (E'(radial)) velocities of mitral annulus were measured by TDI. Area under ROC curve (AUC) for prediction of elevated LVEDP (> or =15 mm Hg) was computed for each parameter. For E/A > or =1 (98 patients, 46 with elevated LVEDP), the AUC values were: PV(R)-A: 0.914; E/E'(lat): 0.780; E/E'(radial): 0.729; E/V(P): 0.712 (p < 0.001). When E/A <1 (78 patients, 26 with elevated LVEDP), only PV(R)-A reached statistical significance (AUC = 0.893, p < 0.001). The conclusions were: PV(R)-A enabled the most accurate noninvasive estimation of LVEDP irrespective of LV filling profile and combined indices E/V(P), E/E'(lat) and E/E'(radial) represent more feasible alternatives for patients with mitral E/A-1.     

Diastolic flow pattern in the normal left ventricle.

OBJECTIVES: This study sought to clarify the diastolic flow pattern in the normal left ventricle. BACKGROUND: During left ventricular filling, basally directed (retrograde) velocities are seen in the outflow compartment. These velocities may represent blood returned from the apical region or a shortcut at a more basal level. METHODS: Left ventricular flow patterns were identified in 18 healthy individuals (age 47 +/- 12 years) with the use of high frame-rate two-dimensional color Doppler and color M-mode Doppler echocardiography techniques. Intraventricular velocities were measured with single pulsed Doppler at 3 levels in both inflow and outflow compartments (posterolateral and anteroseptal parts of the left ventricle). RESULTS: During early transmitral flow acceleration, all intraventricular velocities were directed towards the apex. However, after peak early and late inflow velocities and during diastasis, retrograde velocities were identified in the outflow compartment. These retrograde velocities occurred earlier, and were higher, at the level of the deflected anterior mitral leaflet tip compared with more apical levels (P <.001). A velocity pattern was established, consistent with early intraventricular vortex formation behind both mitral leaflets. The vortex adjacent to the anterior leaflet subsequently enlarged to include a major part of the left ventricle. CONCLUSION: Uniform diastolic flow patterns were identified in the normal left ventricles. The findings suggest that both early and late diastolic filling start with an initial motion of a fluid column, succeeded by vortex formation, which explains retrograde flow in the outflow compartment.     

Effects of percutaneous mitral commissurotomy on longitudinal left ventricular dynamics in mitral stenosis: quantitative assessment by tissue velocity imaging.

OBJECTIVE: We hypothesized that mitral annular velocities would improve immediately after relief of mitral stenosis and that serial assessment could be used as an index for quantifying functional changes after percutaneous mitral commissurotomy (PMC). METHODS: Longitudinal left ventricular annular velocities were quantified by spectral pulsed wave Doppler tissue velocity imaging in 25 patients (16 women; mean age [+/-SD], 29.2 +/- 8.6 years) who had isolated mitral stenosis and were in sinus rhythm, and were compared with 30 age- and sex-matched control subjects. Echocardiography was performed 1 to 24 hours before PMC and 48 to 72 hours after, and changes in velocities from the lateral and septal corners of the mitral annulus in early diastole, late diastole, isovolumic contraction, and ejection were recorded. RESULTS: Systolic and diastolic mitral annular velocities were significantly less in patients with mitral stenosis than in control subjects. After PMC, peak annular velocity of systolic excursion in ejection and peak annular velocity in early diastole showed significant improvement. The change in peak annular velocity in early diastole in the lateral wall correlated well with improvement in the mitral valve orifice area by planimetry (ratio of mitral valve orifice area, 1.92 +/- 0.42; ratio of peak annular velocity in early diastole, 1.36 +/- 0.22; r = 0.65; P <.001). CONCLUSION: Serial evaluation of changes in mitral annular velocities by Doppler tissue imaging aids clinical assessment of immediate improvement in left ventricular function after PMC.     

超声心动图研究正压通气对犬心功能的影响及其机制

目的观察正压通气时心内瓣口血流速度和左、右心功能的变化,研究正压通气影响血流动力学机制的新理论。方法11条杂种犬,用超声心动图测定正压通气时心内各瓣口的血流速度,右室、左室每搏量,左室容积和射血分数的变化。结果三尖瓣和肺动脉瓣口血流速度正压吸气相减低,呼气相增加;二尖瓣和主动脉瓣口血流速度变化与之相反(P<0.05)。与自主呼吸相比,正压吸气时,右室每搏量减少,左室舒张末和收缩末容积减小,射血分数降低(P<0.05)。结论正压通气使室间隔趋于右移,同时,肺血管床回心血量增加,但与自主呼吸时相比,腔静脉回心血量相对减少,故心功能降低。