Left ventricular diastolic dysfunction in patients with chronic renal failure: impact of diabetes mellitus.

AIMS: Left ventricular (LV) hypertrophy and LV diastolic dysfunction are cardiac changes commonly observed in patients with chronic renal failure (CRF) as well as hypertension. Although the impairment of LV diastolic function in patients with diabetes mellitus has been shown, little is known about the specific effect of diabetes on LV diastolic function in patients with CRF. The present study was designed to investigate the impact of diabetic nephropathy on LV diastolic dysfunction, independent of LV hypertrophy, in CRF patients. METHODS: In 67 patients with non-dialysis CRF as a result of chronic glomerulonephritis (n = 33) or diabetic nephropathy (n = 34), and 134 hypertensive patients with normal renal function, two-dimensional and Doppler echocardiographic examinations were performed, and LV dimension, mass, systolic function, and diastolic function were evaluated. RESULTS: LV mass was increased and LV diastolic dysfunction was advanced in subjects with CRF compared with hypertensive controls. In the comparison of echocardiographic parameters between the two groups of CRF patients, i.e. chronic glomerulonephritis and diabetic nephropathy groups, all indices of LV diastolic function were more deteriorated in the diabetic nephropathy group than in the chronic glomerulonephritis group, although LV structure including hypertrophy and systolic function did not differ between the groups. In a multiple regression analysis, the presence of diabetes (i.e. diabetic nephropathy group) was a significant predictor of LV diastolic dysfunction in CRF subjects, independent of other influencing factors such as age, blood pressure, renal function, anaemia and LV hypertrophy. CONCLUSION: The present findings suggest that LV diastolic dysfunction, independent of LV hypertrophy, is specifically and markedly progressed in patients with CRF as a result of diabetic nephropathy.     

Endothelial-mediated coronary flow reserve and its relation to mitral annular tissue Doppler velocities in offspring of hypertensive parents

Background: Although coronary flow reserve (CFR) is reduced in hypertensive patients, data regarding the endothelial response of coronary vasomotion and its relation to left ventricular (LV) function in their offspring is limited. Objective: To investigate the endothelial response of coronary flow, using cold pressor test (CPT), in offspring of hypertensive parents and its impact on LV diastolic function. Subjects and Methods: The study population consisted of 32 healthy young offspring (mean age 23.5 ± 7.1 years) of hypertensive parents and 26 aged matched volunteers (healthy offspring of normotensive parents) as controls. Coronary blood flow velocities were recorded in all subjects at rest and after CPT; a stimulus that can be considered totally endothelium‐dependent. CFR was calculated as the ratio of hyperemic‐to‐resting diastolic peak velocities. Doppler echocardiographic assessment was performed using both conventional and tissue Doppler assessment. Results: Coronary diastolic peak velocities at rest was comparable between the two groups (27.1 ± 6.2 vs 26.4 ± 5.8; P > 0.05); but the velocities were significantly lower after CPT in offspring of hypertensive parents (P < 0.02), with highly significant lower CFR (P < 0.0001). Conventional echo‐Doppler variables were comparable in both groups, whereas tissue Doppler assessment demonstrated significant LV diastolic dysfunction among offspring of hypertensive parents. The CPT‐CFR was significantly correlated to tissue Doppler diastolic dysfunction in this group (For Em, Am and Em/Am, r was 0.65, 0.59 and 0.61, respectively, and P < 0.001). Conclusion: Offspring of hypertensive parents have coronary endothelial dysfunction that appears in response to physiological stimuli (CPT). The coronary endothelial dysfunction is associated with latent LV diastolic dysfunction. (Echocardiography 2011;28:1113‐1118)     

Effects of verapamil in normal elderly individuals with left ventricular diastolic dysfunction

Treatment with oral verapamil for 3 to 4 days has been found to enhance left ventricular (LV) diastolic filling in elderly subjects as assessed by radionuclide angiography. However, there are no Doppler echocardiographic studies to assess the long-term effect of verapamil in normal elderly subjects. Thirteen healthy elderly subjects (mean age, 64 +/- 7 years; 8 men and 5 women) with LV diastolic dysfunction underwent this placebo-controlled cross-over trial. The effect of verapamil on LV diastolic function was assessed by treadmill exercise test and Doppler echocardiography at baseline, and after each 3-month treatment period (placebo or verapamil 120 mg once daily), separated by a 1-week washout period before cross-over. Blood pressure, heart rate, LV ejection fraction, LV mass, and cardiac output were unaltered by placebo or verapamil. The exercise time was similar at baseline (11.4 +/- 2.4 min) and after placebo treatment (11.4 +/- 2.3 min) but significantly increased (P < 0.05) after verapamil treatment (12.3 +/- 2.0 min). The ratio of mitral A wave duration/pulmonary venous atrial systolic reversal duration increased after verapamil treatment (1.12 +/- 0.08) compared to placebo (0.93 +/- 0.06, P < 0.05) and baseline (0.89 +/- 0.09), which had similar durations. The isovolumic relaxation time (IVRT) was significantly decreased (P < 0.05) from 85 +/- 13 msec at baseline and 87 +/- 13 msec with placebo to 73 +/- 9 msec with verapamil. The results of this study suggest that in normal elderly patients with Doppler evidence of diastolic dysfunction, 3 months treatment with verapamil can increase exercise tolerance and improve LV diastolic function.     

Modern evaluation of left ventricular diastolic function using Doppler echocardiography

The evaluation of left ventricular (LV) diastolic function is an essential component of the echocardiographic examination for dyspneic patients with impaired or preserved LV systolic function. Doppler echocardiography in combination with two-dimensional echocardiographic findings can assist the diagnosis of underlying cardiac dysfunction, give an estimate of LV filling pressures, guide heart failure treatment, and provide important prognostic information. This article reviews the essentials of modern Doppler assessment of diastolic function and highlights recent updates, areas of controversy, and future applications.     

The Natural History of Left Ventricular Filling Abnormalities: Assessment by Two-Dimensional and Doppler Echocardiography

Doppler and two-dimensional echocardiography are being increasingly used for the indirect assessment of left ventricular (LV) diastolic function. In this article the alterations in LV filling patterns that occur in patients with LV diastolic function are reviewed in the context of echocardiographic findings. A progression of LV filling abnormalities is presented in the sequential "stages" in which we believe they occur in most cardiac disease states. Patient symptoms, hemodynamics, pulmonary venous flow velocities, and left atrial function associated with the different LV filling patterns are also discussed.     

Validity of revised Doppler echocardiographic algorithms and composite clinical and angiographic data in diagnosis of diastolic dysfunction

BACKGROUND: Commonly used echocardiographic indices for grading diastolic function predicated on mitral inflow Doppler analysis have a poor diagnostic concordance and discriminatory value. Even when combined with other indices, significant overlap prevents a single group assignment for many subjects. We tested the relative validity of echocardiographic and clinical algorithms for grading diastolic function in patients undergoing cardiac catheterization. METHOD: Patients (n = 115), had echocardiograms immediately prior to measuring left ventricular (LV) diastolic (pre-A, mean, end-diastolic) pressures. Diastolic function was classified into the traditional four stages, and into three stages using a new classification that obviates the pseudonormal class. Summative clinical and angiographic data were used in a standardized fashion to classify each patient according to the probability for abnormal diastolic function. Measured LV diastolic pressure in each patient was compared with expected diastolic pressures based on the clinical and echocardiographic classifications. RESULT: The group means of the diastolic pressures were identical in patients stratified by four-stage or three-stage echocardiographic classifications, indicating that both classifications schemes are interchangeable. When severe diastolic dysfunction is diagnosed by the three-stage classification, 88% and 12%, respectively, were clinically classified as high and intermediate probability, and the mean LV pre-A pressures was >12 mmHg (P < 0.005). Conversely, the mean LV pre-A pressure in the clinical low probability or echocardiographic normal groups was <11 mmHg. CONCLUSION: Use of a standardized clinical algorithm to define the probability of diastolic function identifies patients with elevated LV filing pressure to the same extent as echocardiographic methods.     

Comparison of early diastolic mitral annular velocity and flow propagation velocity in detection of mild to moderate left ventricular diastolic dysfunction.

BACKGROUND: Pulsed wave tissue Doppler echocardiography (PW-TDE) and color M-mode are new Doppler methods for left ventricular (LV) diastolic function assessment. To date, few studies have compared the data obtained by these methods in the same series of patients and compared them to the current clinical reference method of detecting LV diastolic function. AIMS: To determine the utility of PW-TDE and color M-mode parameters in the assessment of LV diastolic function in the typical patient population encountered in daily clinical practice and to compare their discriminating power. METHODS: Early diastolic septal mitral annular velocity (Em) determined by PW-TDE and color M-mode flow propagation velocity (Vp) were measured in 86 male patients and compared to LV filling patterns obtained using standard Doppler indices. Values of Em < 0.08 m s(-1) and Vp < 0.5 m s(-1) were considered as markers of abnormal LV diastolic function. RESULTS: A value of Em < 0.08 m s(-1) distinguished mild to moderate LV diastolic dysfunction with higher sensitivity and specificity than Vp < 0.5 m s(-1) (96% and 87% vs. 73% and 84%, respectively). A comparison of receiver operating characteristic curves showed a significant difference for areas under the curve in favor of Em (P < 0.01). In a stepwise multiple logistic regression analysis, a pseudonormal filling pattern and an EF > 60% were identified as significant predictors of Vp false negative results (p < 0.05). CONCLUSIONS: Em appears to be superior to Vp in the detection of mild to moderate LV diastolic dysfunction. Vp failed to detect abnormal LV diastolic function in particular in patients with preserved LV systolic function and a pseudonormal filling pattern type.     

Reversal E/A value at end-inspiration might be more sensitive and accurate for diagnosing abnormal left ventricular diastolic function

BACKGROUND: It is well known that left ventricular (LV) filling decreases on inspiration and increases on expiration; however, respiratory effects on diastolic function have not been fully investigated. AIM: This study attempted to provide further information on the precise diagnosis of LV diastolic dysfunction when taking respiration into account. METHODS: Fifty-one patients with systemic hypertension and impaired LV diastolic function and 33 normal subjects were recruited. Respiratory transmitral Doppler flow parameters and the early-to-late diastolic tissue velocity ratio of the mitral annulus (e/a ratio) of the septal wall were recorded. The validity of the reversal ratio of early-to-late peak flow velocity (E/A ratio) on inspiration and on expiration for diagnosis of diastolic dysfunction was compared. RESULTS: The E velocity was much higher and its deceleration time was much shorter on expiration compared to that on inspiration, while the A velocity demonstrated no regular respiratory variations both in normal subjects and patients. Ten of the patients displayed a phenomenon characterized with an E/A ratio < 1 on inspiration and > 1 on expiration, eight of whom revealed abnormal LV filling by Tissue Doppler imaging. CONCLUSION: Respiratory effects on transmitral Doppler flow parameters raise the necessity of adjustment of the existing standard for precise diagnosis of diastolic dysfunction, while the characteristic phenomenon reported here indicates that reversal E/A value on end-inspiration is a more sensitive and accurate indicator of abnormal LV diastolic function.     

Diastolic left ventricular dysfunction in ankylosing spondylitis—A systematic review and meta-analysis

Objectives

Ankylosing spondylitis (AS) is associated with increased mortality largely due to cardiovascular disease. Diastolic left ventricular (LV) dysfunction serves as a precursor to chronic heart failure and may cause morbidity and mortality. A systematic literature search was conducted to determine the prevalence of diastolic LV dysfunction in patients with AS.

Methods

We identified all echocardiographic studies investigating diastolic LV function in patients with AS. The initial search yielded 166 studies of which 11 met the inclusion criteria.

Results

Compared to control subjects, AS patients had a worse E/A ratio [mean difference −0.13 m/s (95% CI: −0.19 to −0.07)], a prolonged deceleration time [mean difference 13.90 ms (95% CI: 6.03–21.78)], and a prolonged mean isovolumetric relaxation time [mean difference 8.06 ms (95% CI: 3.23–12.89)], all suggestive of diastolic LV dysfunction. The best way to establish diastolic LV dysfunction, however, is to combine E/A ratio, deceleration time, and isovolumetric relaxation time. The latter has been done in 3 studies, all reaffirming an increased prevalence rate of diastolic LV dysfunction in AS patients as compared with control subjects, i.e., 9% versus 0%, 30% versus 12%, and 45% versus 18%, respectively.

Conclusions

Our observations support the current evidence base for an increased risk of diastolic LV dysfunction in AS. However, larger studies are needed to investigate the exact magnitude of diastolic LV dysfunction and its clinical relevance in patients with AS.     

Assessment of left ventricular diastolic function by three-dimensional transthoracic echocardiography

Doppler echocardiography assessment of left ventricular (LV) filling pressures at rest and during exercise is the most widely used imaging technique to assess LV diastolic function in clinical practice. However, a sizable number of patients evaluated for suspected LV diastolic function show an inconsistency between the various parameters included in the flowchart recommended by current Doppler echocardiography guidelines and results in an undetermined LV diastolic function. Current three-dimensional echocardiography technology allows obtaining accurate measurements of the left atrial volumes and functions that have been shown to improve the diagnostic accuracy and prognostic value of the algorithms recommended for assessing both LV diastolic dysfunction and heart failure with preserved ejection fraction. Moreover, current software packages used to quantify LV size and function provide also volume-time curves showing the dynamic LV volume change throughout the cardiac cycle. Examining the diastolic part of these curves allows the measurement of several indices of LV filling that have been reported to be useful to differentiate patients with normal LV diastolic function from patients with different degrees of diastolic dysfunction. Finally, several software packages allow to obtain also myocardial deformation parameters from the three-dimensional datasets of both the left atrium and the LV providing additional functional parameters that may be useful to improve the diagnostic yield of three-dimensional echocardiography for the LV diastolic dysfunction. This review summarizes the current applications of three-dimensional echocardiography to assess LV diastolic function.     

Newer doppler measures of left ventricular diastolic function

Left ventricular (LV) diastolic dysfunction is an important cause of heart failure, and recent advances in the application of Doppler techniques allow a semiquantitative assessment of LV diastolic performance. This review discusses the use of Doppler echocardiography in the comprehensive assessment of LV diastolic function and performance in terms of the normal mitral and pulmonary venous flow profiles, their physiologic basis, and alteration in diseased states. There is also a discussion on the newer aspects of mitral flows such as relative durations of mitral A and pulmonary vein AR waves, E- and A-wave propagation inside the LV with their hemodynamic correlates, and derivation of ventricular dP/dt and Tau from the mitral regurgitation velocity profile. Analysis of these flow profiles and the other Doppler measures alluded to above allow one to make a fairly precise hemodynamic assessment of a patient in terms of left atrial pressure, LV relaxation and stiffness and the profile of LV diastolic pressure in terms of pre-‘a’ wave and ‘a’ wave pressures and ventricular end-diastolic pressure.     

Concordance between Doppler and pulsed-wave Doppler tissue imaging in estimation of the degree of left ventricular dysfunction and correlating it to the degree of chronic obstructive pulmonary disease

Objective

As a consequence of leftward shift of the interventricular septum and of pericardial restraint, related to the degree of right ventricular dilation, alveolar hypoxia and related pulmonary vascular changes, left ventricular function is influenced by chronic obstructive pulmonary disease (COPD). The aim of this study was to assess the prevalence of echocardiographic abnormalities by conventional echocardiography and Doppler tissue imaging (DTI) in COPD patients according to the degree of disease severity.

Methods

We enrolled forty consecutive patients with COPD and twenty matched control. Twenty of the patients were suffering from mild form of COPD, twenty were suffering from severe form of COPD as decided by pulmonary function test and arterial blood gases and twenty apparently healthy non COPD control persons were subjected to echocardiographic assessment to left ventricular diastolic and systolic functions by conventional echocardiography and DTI at the mitral annulus.

Results

There were no significant statistical difference between the three groups as regards the age and the gender. There were significant statistical differences between the patients and the control as regards the diastolic functions of the left ventricle. E and A waves obtained by conventional Doppler and by DTI showed significant statistical difference between mild, severe forms of COPD and control subjects. The degree of diastolic dysfunction increased significantly with increase of the severity of COPD.

Conclusion

Left ventricular diastolic function is significantly affected in patients with COPD and the degree of affection is related to the severity of COPD.     

Clinical significance of brain natriuretic peptide in patients with postmyocardial infarction

BACKGROUND: Risk stratification after acute myocardial infarction (AMI) includes the evaluation of left ventricular (LV) function. Natriuretic peptides, and particularly brain natriuretic peptide (BNP), emerged as a potential marker of ventricular function and prognosis after AMI. HYPOTHESIS: Brain natriuretic peptide levels are related to ventricular function, either systolic or isolated diastolic, and can give prognostic information in patients surviving AMI. METHODS: In all, 101 patients were enrolled. An echocardiographic (M-mode, two-dimensional, and pulsed Doppler) evaluation was performed and blood samples for BNP measurement were obtained. Clinical events were recorded during 12 months of follow-up. RESULTS: A negative correlation between BNP and LV ejection fraction was observed (r = -0.38; p < 0.001). The BNP levels were higher among patients with LV systolic dysfunction than in patients with isolated diastolic dysfunction (339.1 +/- 249.9 vs. 168.0 +/- 110.5 pg/ml, p = 0.001). The latter had higher levels of BNP than those with normal LV function (68.3 +/- 72.6 pg/ml, p < 0.001). The BNP accuracy to detect LV systolic dysfunction was good (area under the ROC curve [AUC] = 0.83) and increased when isolated diastolic dysfunction was also considered (AUC = 0.87). Brain natriuretic peptide had a very good accuracy in the prediction of death (AUC = 0.95) and the development of heart failure (AUC = 0.90). CONCLUSION: These results extend previous evidence relating BNP to systolic function after AMI. Furthermore, a relationship between BNP levels and diastolic function was found. Brain natriuretic peptide had a very good performance in detecting the occurrence of an adverse event. We conclude that BNP can detect high-risk patients and help select patients for more aggressive approaches.     

Assessment of global and regional left ventricular diastolic function in hypertensive heart disease using automated border detection techniques

Acoustic quantification (AQ) and color kinesis (CK) are techniques that involve automated detection and tracking of endocardial borders. These methods are useful for the evaluation of global and regional left ventricular (LV) systolic function and more recently have been applied to evaluating LV diastolic performance. Assessment of diastolic dysfunction in hypertensive heart disease is a relevant clinical issue in which these techniques have proven useful. The diastolic portion of left atrium and LV AQ area waveforms are frequently abnormal in patients with left ventricular hypertrophy (LVH). Left ventricular AQ curves consistently demonstrate reduced rapid filling fraction (RFF) and peak rapid filling rate (PRFR), elevated atrial filling fraction (AFF), peak atrial filling rate (PAFR), and reductions in the ratio PRFR/PAFR. Acoustic quantification complements traditional Doppler echocardiographic evaluation of global diastolic function. Many patients with significant LVH and normal Doppler diastolic parameters can be identified as having diastolic dysfunction with AQ. In addition, CK has allowed the evaluation of regional diastolic performance in hypertensive patients. Regional filling curves obtained from CK have demonstrated that endocardial diastolic motion is commonly delayed and heterogeneous in patients with LVH.     

Cardiac Manifestations of Exhaustive Exercise in Nonathletic Adults: Does Cardiac Fatigue Occur?

The aim of the study was to examine the impact of prolonged exercise leading to physical exhaustion on left ventricular (LV) systolic and diastolic function in untrained healthy subjects, and to examine cardiovascular determinants of exercise performance. Twenty-four nonathletic healthy adults (14 males, 10 females; mean age 42 +/- 11 years) were exercised on a treadmill at 70% of maximal oxygen consumption until physical exhaustion occurred after an average of 84 +/- 39 minutes. Two-dimensional and Doppler echocardiography was performed before and 15 minutes after exercise to assess LV function and geometry, and right ventricular (RV) systolic function. After prolonged exercise, LV ejection fraction and geometry were unchanged, but LV end-diastolic volume, end-systolic volume, and stroke volume decreased. However, due to a higher heart rate (HR), cardiac output increased at 15 minutes post exercise. RV fractional shortening was unchanged. LV peak early to atrial filling velocity ratio decreased post exercise, with an increase in percent atrial contribution. However, less preload-dependent variables of LV diastolic function such as deceleration time, LV inflow propagation rate, mitral annular tissue Doppler and myocardial performance index were unchanged. Preexercise stroke volume and HR were the only predictors (r = 0.86, P < 0.01) of exercise duration. However, age, resting blood pressure, indices of systolic and diastolic function, and LV geometry were not predictors. Prolonged exercise leading to physical exhaustion is not associated with systolic or diastolic dysfunction. Reduced early LV diastolic filling and the relative increase in left atrial contribution seen with prolonged exercise are likely due to preload reduction rather than true diastolic dysfunction.     

Early diastolic mitral annular velocity and color M-mode flow propagation velocity in the evaluation of left ventricular diastolic function in patients with Fabry disease

Fabry disease is an X-linked genetic disorder characterized by progressive intracellular accumulation of neutral glycosphingolipids. Cardiac involvement is frequent and left ventricular (LV) diastolic dysfunction is present in most of the affected subjects. Pulsed-wave tissue Doppler echocardiography (PW-TDE) and color M-mode are new Doppler methods for LV diastolic function evaluation. Their role in the assessment of Fabry disease-related cardiomyopathy remains to be established. In this study we aimed to determine the utility of PW-TDE and color M-mode-derived parameters in the assessment of LV diastolic function in patients with Fabry disease. Eighty-one echocardiographic examinations performed in 35 patients affected by Fabry disease were retrospectively analyzed. Early diastolic lateral mitral annular velocity (E_m) determined by PW-TDE and color M-mode flow propagation velocity (V_p) were measured and compared to LV filling patterns obtained using standard Doppler indexes. The receiver operating characteristics (ROC) curves method was used to determine the summary measure of relative accuracy for E_m and V_p. A comparison of ROC curves showed a significant difference for areas under the curve in favor of E_m (P < 0.001). Pseudonormal filling pattern, higher LV mass index, higher relative wall thickness, larger left atrial diameter, and older age were more frequent (all P < 0.001) in patients with incorrect diagnosis of normal LV diastolic function based on the measurement of V_p. E_m appears to be superior to V_p in the assessment of LV diastolic function in patients with Fabry disease. V_p fails to detect abnormal LV diastolic function in subjects with pronounced concentric LV remodeling and pseudonormal filling pattern.     

Tissue Doppler imaging describes diastolic function in men prone to develop hypertension over twenty years.

AIMS: Hypertension is one of several risk factors of cardiovascular disease and is associated with left ventricular (LV) systolic and diastolic dysfunction. A method for reliably detecting the onset of LV dysfunction before transition to irreversible damage of the myocardium would be of crucial importance in subjects with essential hypertension. METHODS AND RESULTS: Subjects with clear differences in BP level, development and duration of the hypertensive disease were examined at the age of 60 yrs: normotensives (n = 17), new hypertensives who developed hypertension over a 20 year period (n = 15) and hypertensives (n = 19). Relationships between conventional echocardiographic and tissue velocities imaging (TVI) parameters compared to LV parameters, and TVI as an estimate of LV function were explored. E'(Lat) (TVI peak early diastolic velocity) (P = 0.006) and E/E'(Lat) (P = 0.002) demonstrated differences in diastolic function between the groups. There were no significant differences regarding systolic myocardial velocities. E'(Lat) correlated to S'(Lat) (TDI peak systolic velocity) (r = 0.32, P = 0.026) and was independently predicted by S'(Lat) (R(2) = 0.24, P = 0.025) in multivariate analysis. E'(Lat) correlated negatively to LV mass index (r = -0.34, P = 0.012), also in multivariate regression analysis (R(2) = 0.12, P = 0.032). CONCLUSIONS: Myocardial diastolic velocities and mitral flow to annulus velocity ratio differentiated LV function between the hypertensive and normotensive groups. The parameters probably reflect changes in relaxation, recoil and contraction and parallel changes in LV mass index.     

肥厚型心肌病左室舒张功能及影响因素的研究

目的评价肥厚型心肌病左室舒张功能受损程度及其可能影响因素.方法使用经胸多普勒超声心动图检测56例肥厚型心肌病患者二尖瓣及肺静脉口血流频谱来评价其舒张功能,探讨左室肥厚程度、左室流出道梗阻等因素对舒张功能损害程度有无影响.结果95%肥厚型心肌病患者存在左室舒张功能受损,其中轻、中、重度损害分别占59%、27%、9%,舒张功能损害程度同左室肥厚程度等因素均无关.结论绝大多数肥厚型心肌病患者存在不同程度的左室舒张功能受损,经胸超声联合检测二尖瓣及肺静脉口血流频谱可准确有效地评价舒张功能,肥厚型心肌病左室舒张功能受损同心肌肥厚程度等因素无关.     

超声心动图评估肥胖对心脏结构和舒张功能的影响

目的:研究肥胖对心脏结构和左室舒张功能的影响以及比较左室舒张功能各项评价指标的敏感性。方法:选择100名健康体检者,根据体质指数分为正常体重组(对照组,25例),超重组(45例),肥胖组(30例)。应用常规超声心动图、组织多普勒成像技术和彩色M型多普勒对其进行检测,并对各组的心脏结构和左室舒张功能参数进行对比分析。结果:与对照组比较,超重组与肥胖组的左房、左室增大,室壁增厚,左室重量指数增加,二尖瓣瓣环舒张早期峰值运动速度(Ea)、Ea/二尖瓣瓣环舒张晚期峰值运动速度比值下降,二尖瓣舒张早期血流峰值速度(E)/Ea比值增加(P<0.05);肥胖组E值、E/二尖瓣舒张晚期血流峰值速度(A)比值下降,A值升高,等容舒张时间延长,舒张早期左室血流传播速度减慢(P<0.05)。与超重组比较,肥胖组心脏结构和舒张功能进一步恶化(P<0.05)。结论:肥胖可引起心脏肥大,左室舒张功能下降,且随体质指数的增加改变更明显。肥胖是亚临床左室舒张功能障碍的独立危险因素,在心肌迟缓型左室舒张功能下降阶段,综合多指标分析可提高左室舒张功能评价的准确性。组织多普勒和E/Ea较常规评价左室舒张功能的方法更敏感、有效。     

Correlation between BNP Levels and Doppler Echocardiographic Parameters of Left Ventricle Filling Pressure in Patients with Chagasic Cardiomyopathy

Cardiomyopathy is the most important manifestation of Chagas' disease. Brain natriuretic peptide (BNP) level and Doppler echocardiographic parameters for diastolic dysfunction have shown correlation with left ventricle (LV) filling pressures. Objectives: The purpose of this study is to compare BNP levels with Doppler echocardiographic parameters in patients with chagasic cardiomyopathy. Methods: Forty-three patients (69.8% men; mean age 41.0 ± 10.4 years) were submitted to an echocardiographic study and 39 had their BNP levels measured. Results: BNP levels increased with the deterioration of the diastolic function (P = 0.025). Pulmonary venous flow parameters were correlated with BNP levels, but E/E ' ratio (E ' measured at the inferior mitral annulus) was the only diastolic parameter that remained an independent predictor of elevated BNP levels in the multivariate analysis. The area under the receiver-operating curve for BNP to detect E/E' >15 was 0.875. A BNP value of 280.4 pg/ml had a sensitivity of 96% and a specificity of 75% for predicting E/E' >15. Conclusions: In a group of patients with chagasic cardiomyopathy, BNP levels correlated with diastolic function patterns regardless of systolic function. The E/E ' ratio (inferior wall) was the only isolated parameter of diastolic function that was independently associated with BNP levels.