Indexed Left Atrial Volume is a More Sensitive Indicator of Filling Pressures and Left Heart Function Than Is Anteroposterior Left Atrial Diameter

Introduction: Left atrial (LA) size is an indicator of the pressure to which it is chronically subjected. Although guidelines recommend measuring it using volume indexed to body surface, the anteroposterior diameter is still normally used. Aim: To evaluate which of these measurements correlates better with atrial pressure‐related echocardiographic parameters. Methods: Atrial diameter and volume, together with parameters of systolic function, diastolic function, pressure, and degree of mitral regurgitation, were measured in 121 consecutive outpatients. Results: Atrial diameter correlated with its indexed volume (r: 0.69) with a low degree of agreement for detecting dilation (Kappa: 0.51). Atrial diameter was related to the parameters associated with atrial pressure: E/E′ (r: 0.44), pulmonary vein systolic/diastolic rates quotient (r: 0.25) and degree of mitral regurgitation (r: 0.19). The correlations improved when volume indexed to body surface was measured (r: 0.52; 0.38 and 0.44, respectively). In a multiple regression analysis that included E/E′, pulmonary vein flow and degree of mitral regurgitation, LA diameter depended entirely on E/E′ (r: 0.44; B: 0.04; P: 0.000). The relationship improved when the diameter was corrected for body surface or the volume was measured (r: 0.54 and 0.54, respectively), and in particular when volume indexed to body surface was measured (r: 0.66). In this case, pulmonary vein flow (B: 6.8; P: 0.03), degree of mitral regurgitation (B: 5.2; P: 0.000) and E/E′ ratio (B: 0.8; P : 0.000) were included in the equation. Conclusions: Indexed atrial volume correlates better with LA pressure surrogates than the anteroposterior diameter, even when this is corrected for body surface. (Echocardiography 2010;27:1049‐1055)     

Predicting pH at birth in pregnancies with abnormal pulsatility index and positive end-diastolic velocity in the umbilical artery

Objectives: To identify potential associations between fetal surveillance tests and acidosis at birth in pregnancies with abnormal but positive end-diastolic velocity in the umbilical artery. Methods: A prospective case–control study [group 1: pH < 7.2; group 2: pH ≥ 7.2] including 46 fetuses with abnormal but positive end-diastolic velocity in the umbilical artery was conducted between February 2007 and March 2009. Outcome variables were evaluated by univariate analysis and compared between the two groups. Clinically relevant and statistically significant variables were analyzed by logistic regression. Results: Abnormal nonstress test, presence of deceleration, and absent fetal breathing movements were statistically significant. Logistic regression analysis revealed that fetal heart rate (FHR) deceleration in the nonstress test is the only predictor of fetal acidosis at birth (p = 0.024; OR = 8.2; 95%CI: 1.2–52). Conclusions: In fetuses with positive end-diastolic flow velocity, acute variables of the antenatal surveillance tests are correlated with acidosis at birth and FHR deceleration in the nonstress test is the only predictor of fetal acidosis.     

支气管舒张试验在不明原因咳嗽患者中的应用价值

目的：分析支气管舒张试验在不明原因咳嗽患者中的应用价值。方法：43例受试者先测定基础FEV1,然后雾化吸入定量β2受体激动剂,吸入后15 min重复测定FEV1。结果：该方法诊断不典型哮喘23例,接受以糖皮质激素为主的抗炎解痉平喘治疗后,咳嗽得到较好控制。结论：支气管舒张试验是不明原因咳嗽患者方便实用的检查方法,在不典...     

运动前后心电时限指标比值的比较

目的 鉴于基于心电R波峰点(Rp)与T波终点(Tn)的心室收缩期与舒张期比率(RSDI)易受Tn定位精度的影响,揭示基于Rp与T波峰点(Tp)的心电时限指标比值(RSD2)能否反映RSDI的趋势.方法 计算Rp至Tp的时限(RpTp)与心室收缩期(RpTn)的相关系数,计算Tp至其后Rp的时限(TpRp)与心室舒张期(...     

Aortic wall elasticity and left ventricular function in hypertensive patients with nonsignificant coronary artery disease

PurposeHypertension is an important cause of nonischemic heart failure. It is important to identify subclinical left ventricular dysfunction in patients with hypertension in an early stage to lower the risk of progression to more severe illness. The aim of our study was to assess the correlation between indices of left ventricular function and aortic stiffness in patients with hypertension.MethodsOur study was a case control study of 42 hypertensive and 40 normotensive patients with nonsignificant coronary artery disease. All the patients underwent echocardiography and left ventricular ejection fraction, global longitudinal strain, post systolic index, pulsed Doppler early transmitral peak flow velocity, early diastolic mitral annular velocity (e′), and aortic elasticity measurements were calculated.ResultsThe hypertensive patients were older (58.47 ± 9.57 vs. 52.94 ± 10.38 years, p = 0.018) and had a higher body mass index (30.09 ± 5.08 vs. 27.48 ± 4.17 kg/m², p = 0.013) and E/e′ ratio (8.16 ± 1.81 vs. 6.56 ± 1.71, p < 0.001) and a lower e′ velocity (8.25 ± 2.28 vs. 9.52 ± 2.34 cm/s, p = 0.015) than normotensives. They also had a lower aortic distensibility (p = 0.008) and a higher aortic stiffness index (p = 0.039) compared with the normotensive group. The hypertensive patients did not show any association between aortic elasticity and stiffness with age or e′ velocity despite significant association in normotensives.ConclusionHypertension is associated with a high prevalence of diastolic dysfunction, elevated left ventricular filling pressure, and increased arterial stiffness, all of which have significant association with adverse outcomes. The measurements found in the hypertensive patients compared with the normotensive group may be due to several age-independent mechanisms.     

高血压患者右室舒张功能72例分析

目的：运用超声心动图，分析高血压患者左室收缩功能衰竭前，右室舒张功能的变化。方法：用多普勒超声心动图测量正常组、高血压组（左室肥厚组、非左室肥厚组）左右室舒张功能参数。统计采用Ｆ检验和ｑ检验。结果：肺动脉流速在高血压左室肥厚组比对照组及非肥厚组块（Ｐ〈０．０１）；高血压非肥厚组与对照组比较，右室舒张早期Ｅ峰较低，Ｄｅｃ１／２Ｔ延长，舒张晚期Ａ峰较高，Ｅ／Ａ比值较小，Ａ波充盈分数增大（Ｐ〈０．０１）     

Atrioventricular Filling Dynamics, Diastolic Function and Dysfunction

Left ventricular diastolic dysfunction is associated with slowing of LV relaxation and a decrease in LV chamber compliance. This impairment of function leads to changes in filling velocities as measured by pulsed wave Doppler echocardiography in the pulmonary veins and across the mitral valve, and in intraventricular flow propagation velocity as measured by color M-mode Doppler. This paper explores some of the physiology of LV filling in a clinical context.     

Effects of chronic β-blockade on rest and exercise hemodynamics in mitral stenosi

β-blocker therapy for mitral stenosis is controversial. This study compares right and left heart hemodynamics at rest and supine submaximal exercise in patients (n = 7) receiving chronic β-antagonists with untreated patients (n = 17) matched for age (mean ± SD = 51 ± 12 years) and valve area (0.7 ± 0.2 cm²/m²). Little benefit was observed with treatment at rest. Although pulmonary capillary wedge pressures (PCWP) were lower during exercise in the β-blocker group (22±4 vs. 31 ± 9 mmHg; P>0.05), exercise performance was not enhanced and cardiac output response during exercise was reduced (control = 41% increase vs. 12% for β-blockade). PCWP rose rapidly when diastolic filling periods were >300 msec in both groups. Pulmonary capillary wedge pressure was found to be a nonlinear functions (P<0.001) of diastolic filling period (PCWP = 15.9 + 5.84 × 10⁵/dfp²). These data suggest that there is a critical heart rate in patients with mitral stenosis above which hemodynamic compromise rapidly occurs. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Is 'diastolic heart failure' a diagnosis of exclusion? Echocardiographic parameters of diastolic dysfunction in patients with heart failure and normal systolic function

Background: Diastolic heart failure (DHF) is reported to account for 30–50% of heart failure presentations, but its prevalence in the absence of overt coronary disease is unclear. Diastolic heart failure is usually defined by exclusion (heart failure with normal left ventricular (LV) systolic function), and few studies have sought a specific diagnosis of diastolic dysfunction. The objective of the present study was to determine the prevalence of isolated DHF and characterise LV diastolic function in patients without clinical evidence of coronary disease, who were referred for LV function assessment.

Methods: Among 938 consecutive patients referred for assessment of LV function, diastolic dysfunction was sought in patients with clinical heart failure, normal systolic function, and no valvular or coronary disease. The evaluation was based on measurement of early (E) and late (A) transmitral velocities and E wave deceleration time (DT). Pulmonary vein systolic, diastolic and atrial reversal velocities were used to differentiate pseudonormal filling in patients with normal E/A and DT.

Results: Normal LV systolic function was present in 331 patients (35%), of whom 53 (6%) met criteria for a clinical diagnosis of DHF. Diastolic dysfunction was confirmed by echocardiography in 38 patients (72% of clinical DHF patients), of whom 27 had impaired LV relaxation, 10 had pseudonormal filling, and one had restrictive filling. Diastolic function was normal in 13 and indeterminate in two patients. Pseudonormal or restrictive LV filling were more prevalent in patients with acute heart failure (7/20, P < 0.05).

Conclusions: Carefully defined, isolated DHF is uncommon, but most of these patients demonstrate echocardiographic evidence of diastolic dysfunction.