甲状腺功能减退患者左心室舒张功能研究

应用多普勒超声心动图测定31例甲状腺功能减退(甲减)患者的左心室收缩功能和舒张充盈速率,并与17例对照者比较。甲减时,心率减慢、左心房增大、左心室心肌重量增高和短轴缩短率降低。左心室舒张早期充盈速率下降,舒张早期与舒张晚期充盈速率比值减低。后者与病程相关,病程3年以上者,该比值异常的发生率明显增高。10例经6个月甲状腺素治疗后,心率增快,左心房内径和左心室心肌重量减低和短轴缩短率增高,但舒张充盈速率无明显改变。研究提示,甲减患者常有左心室功能障碍,且治疗后舒张功能的恢复较收缩功能为慢。     

Exercise capacity in hypertrophic cardiomyopathy depends on left ventricular diastolic function.

Some studies have demonstrated that left ventricular (LV) diastolic function is the principal determinant of impaired exercise capacity in hypertrophic cardiomyopathy (HC). In this study we sought the capability of echocardiographic indexes of diastolic function in predicting exercise capacity in patients with HC. We studied 52 patients with HC while they were not on drugs;12 of them had LV tract obstruction at rest. Diastolic function was assessed by M-mode and Doppler echocardiography by measuring: (1) left atrial fractional shortening, and the slope of posterior aortic wall displacement during early atrial emptying on M-mode left atrial tracing; and (2) Doppler-derived transmitral and pulmonary venous flow velocity indexes. Exercise capacity was assessed by maximum oxygen consumption by cardiopulmonary test during cycloergometer upright exercise. Maximum oxygen consumption correlated with the left atrial fractional shortening (r = 0.63, p <0.001), the slope of posterior aortic wall displacement during early atrial emptying (r = 0.55, p <0.001), age (r = -0.50; p <0.001), pulmonary venous diastolic anterograde velocity (r = 0.41, p <0.01), and the systolic filling fraction (r = -0.43; p <0.01). By stepwise multiple linear regression analysis, left atrial fractional shortening and the pulmonary venous systolic filling fraction were the only determinants of the maximum oxygen consumption (multiple r = 0.70; p <0.001). Exercise capacity did not correlate with Doppler-derived transmitral indexes. Thus, in patients with HC, exercise capacity was determined by passive LV diastolic function, as assessed by the left atrial M-mode and Doppler-derived pulmonary venous flow velocities.     

Pulsed Doppler echocardiographic indices of left ventricular diastolic function in normal subjects.

To establish the normal limits for various pulsed Doppler echocardiographic indices of left ventricular diastolic function, 92 healthy volunteers aged from 5 to 75 years were prospectively studied. The influence of various variables including age, gender, body surface area, fractional shortening, and left ventricular mass on these parameters was also assessed. Mean (2SD) values for 15 direct and 11 derived parameters were analyzed from transmitral inflow velocity waveform. No statistically significant differences were observed between males and females for any of these parameters. On stepwise multivariate linear regression analysis, age was found to be an independent strong determinant (p less than 0.001) of peak velocity of early diastolic filling wave, area of atrial filling period, deceleration slope, normalized peak filling rate, and early filling fraction. There was a significant correlation between heart rate and time to peak early diastolic velocity, total diastolic time period, early diastolic period, atrial filling period, and atrial filling fraction. It was further observed that a significant correlation (p less than 0.001) persisted between both age and heart rate with area of early filling period, one-third filling area, one-half filling area, ratio of early to atrial peak velocity and area, atrial filling fraction, and one-third filling fraction. None of the parameters were found to correlate with fractional shortening or left ventricular mass. Thus an effort was made to establish normal limits for various Doppler-derived parameters in healthy volunteers for future comparison in diseased states.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular diastolic dysfunction in patients with COPD in the presence and absence of elevated pulmonary arterial pressure

BACKGROUND: Increased right ventricular afterload leads to left ventricular diastolic dysfunction due to ventricular interdependence. Increased right ventricular afterload is frequently present in patients with COPD. The purpose of this study was to determine whether left ventricular diastolic dysfunction could be detected in COPD patients with normal or elevated pulmonary artery pressure (PAP). METHODS: Twenty-two patients with COPD and 22 matched control subjects underwent pulsed Doppler echocardiography. Left ventricular systolic dysfunction and other causes of left ventricular diastolic dysfunction (eg, coronary artery disease) were excluded in all patients and control subjects. PAP was measured invasively in 13 patients with COPD. RESULTS: The maximal atrial filling velocity was increased and the early filling velocity was decreased in patients with COPD compared to control subjects. The early flow velocity peak/late flow velocity peak (E/A) ratio was markedly decreased in patients with COPD compared to control subjects (0.79 +/- 0.035 vs 1.38 +/- 0.069, respectively; p < 0.0001), indicating the presence of left ventricular diastolic dysfunction. The atrial contribution to total left diastolic filling was increased in patients with COPD. This was also observed in COPD patients with normal PAP, as ascertained using a right heart catheter. The atrial contribution to total left diastolic filling was further increased in COPD patients with PAP. PAP correlated with the E/A ratio (r = -0.85; p < 0.0001). CONCLUSIONS: Left ventricular diastolic dysfunction is present in COPD patients with normal PAP and increases with right ventricular afterload.     

Filling patterns in left ventricular hypertrophy: A combined acoustic quantification and Doppler study

Objectives. The purpose of this study was to evaluate the potential of acoustic quantification compared with Doppler echocardiography for assessment of left ventricular diastolic dysfunction.Background. Diastolic dysfunction usually accompanies left ventricular hypertrophy. Although Doppler echocardiography is widely used, it has known limitations in the diagnosis of diastolic abnormalities. The ventricular area-change waveform obtained with acoustic quantification technology may provide an alternative to assess diastolic dysfunction.Methods. Potential acoustic quantification variables (peak rate of area change and mean slope of area change rate during rapid filling, amount of relative area change during rapid filling and atrial contraction) were obtained and compared with widely used Doppler indexes of ventricular filling (isovolumetric relaxation time, pressure half-time, peak early diastolic velocity/peak late diastolic velocity ratio, rapid filling, atrial contribution to filling) ia 16 healthy volunteers and 30 patients with left ventricular hypertrophy.Results. Criteria for abnormal relaxation were present in 68% of patients by acoustic quantification and in 64% of patients by Doppler echocardiography. However, abnormal relaxation was identified in 89% of patients by one or both methods. Acoustic quantification indicated abnormal relaxation in the presence of completely normalized Doppler patterns and in patients with mitral regurgitation or abnormal rhythm with unreliable Doppler patterns.Conclusions. Acoustic quantification potentially presents a new way to assess diastolic dysfunction. This technique may be regarded as complementary to Doppler echocardiography. The combined use of the methods may improve the diagnosis of left ventricular relaxation abnormalities.     

Left ventricular diastolic function in physiologic and pathologic hypertrophy

BACKGROUND: Patients with hypertensive heart disease and left ventricular hypertrophy demonstrate an impaired left ventricular diastolic filling pattern. The aim of this study was to find out whether physiologic left ventricular hypertrophy induced by endurance training causes disturbances in left ventricular systolic and diastolic filling. METHODS: We examined 49 athletes with left ventricular (LV) hypertrophy due to endurance training, 49 patients with LV hypertrophy due to arterial hypertension, and 26 untrained healthy control subjects by conventional echocardiography. Parameters of LV diastolic filling using pulse wave and color flow Doppler were also assessed. RESULTS: All three study groups showed normal fractional shortening and mid-wall fractional shortening. Conventional echocardiography revealed a higher LV muscle mass index in the two study groups compared with the controls (athletes, 99 +/- 10 g; hypertensive patients, 95 +/- 11 g: controls: 52 +/- 7 g; P < .01 for athletes and hypertensive patients). In patients with arterial hypertension, a diastolic dysfunction consisting of a delayed relaxation pattern with a decrease in maximal early velocity of diastolic filling (0.44 +/- 0.1 m/sec) and a compensatory increase of the maximal late velocity of diastolic filling (0.53 +/- 0.1 m/sec) was demonstrated. In athletes with physiologic LV hypertrophy, a normal LV diastolic filling pattern was documented. CONCLUSIONS: Doppler echocardiographic parameters of LV diastolic function can be of diagnostic importance for discrimination between pathologic and physiologic LV hypertrophy.     

Abnormal diastolic function in patients with type 1 diabetes and early nephropathy

Left ventricular diastolic function was assessed by pulsed Doppler echocardiography in non-diabetic controls (n = 11) and in patients with type 1 diabetes without microvascular disease (n = 16; diabetic controls), with microalbuminuria (n = 9), or with early persistent proteinuria (n = 11). The peak filling velocities during the early and atrial phases of left ventricular diastole and their ratio (E:A ratio) were measured. All patients with diabetes had a normal serum concentration of creatinine and exercise electrocardiogram. The mean E:A ratio was significantly lower in those with proteinuria than in the diabetic controls because of an increase in peak atrial filling velocity; most patients with proteinuria had an abnormal E:A ratio of less than 1.0. Multiple regression analysis showed that systolic blood pressure was the major determinant of both the peak filling velocity during the atrial phase of diastole and also left ventricular mass. Blood pressures were significantly higher in the proteinuria group than in the diabetic controls. Glycaemic control and autonomic function did not influence diastolic filling. The slightly raised blood pressures at the earliest stages of diabetic nephropathy are sufficient to alter left ventricular diastolic compliance--this may reflect early hypertensive heart disease. These data do not preclude a specific heart muscle disease related to diabetes, but suggest that these slightly raised blood pressures contribute significantly to left ventricular dysfunction in these patients, in whom the risk of cardiovascular disease is already greatly increased.     

Abnormal diastolic function in patients with type 1 diabetes and early nephropathy.

Left ventricular diastolic function was assessed by pulsed Doppler echocardiography in non-diabetic controls (n = 11) and in patients with type 1 diabetes without microvascular disease (n = 16; diabetic controls), with microalbuminuria (n = 9), or with early persistent proteinuria (n = 11). The peak filling velocities during the early and atrial phases of left ventricular diastole and their ratio (E:A ratio) were measured. All patients with diabetes had a normal serum concentration of creatinine and exercise electrocardiogram. The mean E:A ratio was significantly lower in those with proteinuria than in the diabetic controls because of an increase in peak atrial filling velocity; most patients with proteinuria had an abnormal E:A ratio of less than 1.0. Multiple regression analysis showed that systolic blood pressure was the major determinant of both the peak filling velocity during the atrial phase of diastole and also left ventricular mass. Blood pressures were significantly higher in the proteinuria group than in the diabetic controls. Glycaemic control and autonomic function did not influence diastolic filling. The slightly raised blood pressures at the earliest stages of diabetic nephropathy are sufficient to alter left ventricular diastolic compliance--this may reflect early hypertensive heart disease. These data do not preclude a specific heart muscle disease related to diabetes, but suggest that these slightly raised blood pressures contribute significantly to left ventricular dysfunction in these patients, in whom the risk of cardiovascular disease is already greatly increased.     

Doppler echocardiographic assessments of left ventricular diastolic filling in patients with amyloid heart disease.

Twenty-eight patients with amyloid heart disease, 9 with primary and 19 with familial amyloidosis, were examined by Doppler echocardiography to characterize transmitral flow velocity patterns and to assess restrictive ventricular hemodynamics. Six of the 28 patients had restrictive ventricular physiology, and the remaining 22 did not. Patients with a restrictive filling process had marked ventricular wall thickening with depressed fractional shortening. The transmitral flow velocity patterns in patients with restriction were characteristically manifested by the increased peak flow velocity and shortening of rapid diastolic filling, which was associated with a reduced flow velocity in atrial systole. In the 22 patients without restriction, the left ventricular filling patterns were subclassified as 1) filling patterns with the prolonged isovolumic relaxation time and reduced early diastolic filling, as well as enhanced atrial contribution to ventricular filling (16 patients with mild echocardiographic abnormalities), 2) normal filling patterns with normal echocardiograms (4 patients), and 3) normal filling patterns, with moderate ventricular wall thickening (2 patients). These findings suggested that restrictive ventricular hemodynamics can be characterized by the transmitral velocity pattern and that patterns of left ventricular diastolic filling are markedly varied depending on the magnitude of myocardial amyloid deposition in patients with amyloid heart disease.     

Doppler echocardiographic analysis of left ventricular filling in treated hypertensive patients

Early detection and prevention of cardiac dysfunction is an important goal in the management of hypertensive patients. In this study, Doppler echocardiography was used to evaluate the pattern of left ventricular diastolic filling in 38 subjects: 18 treated hypertensive patients (blood pressure 141 +/- 17/83 +/- 10 mm Hg, mean +/- SD) without other coronary risk factors and 20 risk-free normotensive subjects of similar age (47 +/- 10 and 49 +/- 13 years, respectively). Peak velocity of late left ventricular filling due to the atrial contraction was greater in hypertensive compared with normotensive subjects (69 +/- 14 versus 52 +/- 13 cm/s; p less than 0.001). Peak velocity of late filling was significantly greater in hypertensive versus normotensive subjects in those aged 50 years or younger and those older than age 50 (65 +/- 12 versus 50 +/- 11; p less than 0.01 and 75 +/- 15 versus 56 +/- 15 cm/s; p less than 0.05, respectively). In hypertensive subjects, peak velocity of late filling did not correlate with routine indexes of hypertensive heart disease (including posterior wall thickness and left ventricular mass), systolic and diastolic blood pressure or duration of hypertension. These results indicate that increased velocity of late left ventricular filling may be independent of left ventricular hypertrophy and persist despite effective blood pressure control.     

Left atrioventricular plane displacement is related to both systolic and diastolic left ventricular performance in patients with chronic heart failure.

AIMS: Left atrioventricular plane displacement is proposed to reflect left ventricular systolic function and is strongly related to prognosis in patients with heart failure. Left atrioventricular plane displacement is a different measure of left ventricular function compared to ejection fraction, and the factors influencing left atrioventricular plane displacement are insufficiently characterized. We wanted to assess any relationship between left atrioventricular plane displacement and left ventricular diastolic performance. METHODS AND RESULTS: Left ventricular diastolic filling, left atrioventricular plane displacement, and fractional shortening were assessed by echocardiography/Doppler in 54 patients with chronic heart failure (age 64 +/- 7 years). Left atrioventricular plane displacement correlated significantly with Doppler variables of left ventricular filling, in particular the inverse logarithm of early transmitral flow deceleration time; log-1 Edt (r = -0.61, P < 0.0001, n = 54). Left atrioventricular plane displacement also correlated with fractional shortening (r = 0.49, P < 0.001, n = 50). However, fractional shortening did not correlate with any Doppler variable. Log-1 Edt, fractional shortening, age, heart rate, left ventricular and atrial size, and degree of mitral regurgitation were included in a multiple regression analysis. Only log-1 Edt (P = 0.001) and fractional shortening (P = 0.03) correlated independently with left atrioventricular plane displacement. Among patients with similar fractional shortening, those with more compromised diastolic performance had lower left atrioventricular plane displacement. CONCLUSION: Left atrioventricular plane displacement was related to both systolic and diastolic left ventricular performance, which may explain some of the discrepancies between left atrioventricular plane displacement and ejection fraction.     

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.     

The role of Doppler echocardiography in the assessment of left ventricular diastolic function

The role of Doppler echocardiography of transmitral filling velocities in the assessment of diastolic function in man has not been adequately defined. It is now appreciated that multiple interacting factors such as loading conditions influence the transmitral velocity profile independent of intrinsic left ventricular diastolic function. Extrapolating the status of diastolic function from the transmitral velocity profile is complicated by these factors. The load dependence of ventricular filling has tempered the initial enthusiasm for the clinical application of the Doppler technique. In the present review, studies examining invasive parameters of diastolic function and Doppler indices of diastolic filling are discussed to gain greater insight and understanding of the role of Doppler echocardiography in the noninvasive assessment of diastolic function. These studies have demonstrated a relatively consistent influence of left ventricular relaxation, chamber stiffness, and left atrial pressure on the transmitral velocity filling profile. Impairment of relaxation impedes early filling and may result in a compensatory increase in atrial contribution to filling. An independent decrease in left atrial pressure from altered loading conditions may also reduce filling in early diastole. Increased left ventricular chamber stiffness (i.e., noncompliant left ventricle) impairs atrial contribution to filling and may enhance early filling. Theoretically, reduced left atrial contractility may decrease atrial contribution to filling. Pulmonic vein flow demonstrating increased retrograde flow during atrial systole helps to exclude impaired left atrial contractility. An increased left atrial pressure from altered loading conditions may also augment early filling. Therefore, an invasive or clinical assessment of left atrial pressure as being increased, decreased, or normal greatly aids in the interpretation of the transmitral filling velocity profile when inferences on the status of diastolic function are being made. Diastolic dysfunction is likely when a given pattern of filling cannot be explained on the basis of left atrial pressure. In situations where reasonable estimates on the status of left atrial pressure cannot be done, striking alterations in the transmitral velocity filling profile may be useful.     

Fasting plasma glucose is an independent determinant of left ventricular diastolic dysfunction in nondiabetic patients with treated essential hypertension.

Left ventricular (LV) hypertrophy and LV diastolic dysfunction are common cardiac changes in hypertensive patients, and these changes are modified by various factors other than blood pressure. The present study was conducted to investigate the influence of mild abnormalities in glucose metabolism on LV structure and function in essential hypertension. In 193 nondiabetic patients with treated essential hypertension, two-dimensional and Doppler echocardiographic examinations were performed, and relative wall thickness (RWT), LV mass index (LVMI), fractional shortening, and the ratio of the peak velocity of atrial filling to early diastolic filling (A/E) were calculated. Fasting plasma glucose (FPG) and HbA1c levels were positively correlated with the A/E ratio and the deceleration time of the E wave. However, these plasma levels had no correlation with RWT, LVMI, or fractional shortening. Peak A wave velocity and the A/E ratio were significantly higher in patients who had FPG of > or = 100 mg/dl (and <126 mg/dl) than those who had FPG of <100 mg/dl, although age, blood pressure, RWT, LVMI, and fractional shortening did not differ between the two groups. In a multiple regression analysis of all subjects, only FPG and age were independent determinants of the A/E ratio. These observations suggest that FPG is a sensitive predictor for LV diastolic dysfunction in nondiabetic patients with treated hypertension. Since a slight increase in plasma glucose levels is associated with abnormalities in diastolic function independent of LV hypertrophy, an early stage of impaired glucose metabolism in hypertensive patients may specifically deteriorate cardiac diastolic function.     

A rapid method to quantify left atrial contractile function: Doppler tissue imaging of the mitral annulus during atrial systole.

AIMS: Assess the value of peak atrial systolic mitral annular velocity (Aann) measured by Doppler tissue echocardiography to quantify left atrial systolic function. METHODS: We studied a total of 61 adults; 10 subjects without history of heart disease and 51 patients with a history of atrial fibrillation or undergoing evaluation for left ventricular systolic or diastolic dysfunction. Aann was obtained by averaging peak atrial systolic mitral annular velocities from the septal, lateral, anterior, and inferior annulus. Left atrial fractional area change (FAC) and fractional volume change (FVC) during atrial systole were calculated. The correlation between peak atrial systolic mitral annular velocity (Aann) and left atrial systolic FAC and FVC was determined. RESULTS: Mean FAC and FVC were 27 +/- 12 and 40 +/- 14%, respectively; mean Aann was 11.2 +/- 3.2 cm/s. Linear regression analysis showed correlation between Aann and FAC (r = 0.71; p<0.001) and between Aann and FVC (r = 0.74; p<0.001). CONCLUSIONS: Peak systolic mitral annular velocity correlates well with left atrial systolic FAC and FVC, thus providing an easy means to assess left atrial systolic function.     

Evaluation of cardiac structures and function in systemic sclerosis by Doppler echocardiography.

Ventricular diastolic filling was investigated in a series of 51 consecutive patients with systemic sclerosis by means of Doppler echocardiography. Peak flow velocity in early (peak E) and late (peak A) diastole, E/A ratio, slope of the early diastolic flow velocity and isovolumic relaxation period were calculated. Nine out of the 51 patients showed abnormalities of ventricular filling dynamics in the absence of left ventricular systolic dysfunction at rest and after provocation. The abnormal diastolic filling pattern in these patients was detected in spite of the absence of systemic hypertension, left ventricular hypertrophy or other clinically evident myocardial disease. These diastolic abnormalities might represent an isolated evidence of the underlying myocardial fibrosis not yet clinically apparent.     

Left ventricular diastolic function in children measured by Doppler echocardiography: normal values and relation with growth.

OBJECTIVES--To determine normal values for variables of left ventricular diastolic function in children measured by Doppler echocardiography and their relations to body surface area (BSA). BACKGROUND--There is increasing interest in echocardiographic assessment of left ventricular diastolic function in children but normal data for children are limited. METHODS--Assessment of left ventricular diastolic function was performed in 130 normal participants (aged from 2.4 months to 19.6 years) from their transmitral flow patterns obtained by pulsed wave Doppler echocardiography. RESULTS--Centile charts for commonly used left ventricular diastolic functional variables plotted against BSA are presented. Peak early diastolic filling velocity and atrial phase filling velocity integral were independent of BSA. Although most other filling indices showed strong relations with BSA, some had more curvilinear relations with BSA due to additional interactions with heart rate. The increase in left ventricular filling with growth is largely achieved by an increase in the early "passive" contribution to filling. The slower heart rates of older children are associated with lower atrial phase filling velocities but increased filling time, so the atrial contribution to filling remains relatively constant. CONCLUSIONS--Normal values of many left ventricular diastolic function variables change with growth in children and cannot be extrapolated from adult data. The data presented are suitable for use in size matched matched comparative studies of left ventricular function in children. Careful standardisation of echocardiographic protocols is necessary to ensure the validity of any comparisons.     

Assessment of left ventricular diastolic function: comparison of Doppler echocardiography and gated blood pool scintigraphy

Although left ventricular diastolic filling patterns can be examined by both Doppler velocity recordings and gated blood pool scintigraphy, few data exist regarding a comparison of these techniques. Therefore, Doppler echocardiography and scintigraphy were compared in 25 patients. Pulsed Doppler echocardiography was performed using an apical four chamber view with the sample volume at the level of the mitral anulus. Doppler measurements included peak velocity of the early diastolic filling wave, time to peak early diastolic velocity from both end-systole and end-diastole, diastolic time period and diastolic integrated velocity (early, atrial and total). The cross-sectional area of the mitral anulus and the left ventricular end-diastolic volume were estimated from measurements made on the apical four chamber view. Scintigraphic measurements included normalized peak filling rate, time to normalized filling rate from both end-diastole and end-systole, diastolic time period and relative diastolic filling during early and atrial filling. Doppler echocardiography and scintigraphy compared favorably in assessment of fractional filling during early diastole (r = 0.84) and atrial systole (r = 0.85), ratio of early to atrial filling (r = 0.83), diastolic filling period (r = 0.94) and interval from end-diastole to peak early diastolic flow (r = 0.88). Normalized peak filling rate and time to normalized peak filling rate from end-systole did not correlate closely by these two techniques. The differences in normalized peak filling rate may be explained by difficulties in estimating mitral anulus cross-sectional area and left ventricular end-diastolic volume.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased left ventricular mass is not associated with impaired left ventricular diastolic filling in normal individuals

BACKGROUND: Hypertensive left ventricular (LV) hypertrophy has been associated with diastolic dysfunction. However, the underlying physiological relationship between LV size and diastolic function remains to be clarified. The aim of this study was to evaluate the relationship between several measures of diastolic filling and LV mass in a population sample. METHODS: We used M-mode and Doppler echocardiography to compare left ventricular mass index (LVMI) and wall thickness with five measures of ventricular diastolic filling (ratio of the peak early mitral inflow velocity to the peak atrial mitral inflow velocity, deceleration time of early mitral inflow, isovolumetric relaxation time, ratio of the peak pulmonary venous systolic to diastolic flow and difference between the durations of the pulmonary venous and mitral inflow atrial waves) in 159 healthy volunteers. RESULTS: LVMI was significantly (P< 0.0001) greater in men (81.3 g/m2, interquartile range: 67-94) than women (59.7 g/m2, interquartile range: 49-74), but no gender differences were observed in diastolic filling. Higher age, blood pressure and heart rate showed significant correlation with diminished diastolic filling. However, no measure of diastolic filling correlated with LVMI or wall thickness in either univariate or multiple regression analyses that adjusted for relevant covariates. CONCLUSIONS: LVMI does not explain physiological differences in diastolic filling. The significant decline in diastolic filling with age reflects changes in the quality rather than the quantity of myocardial tissue.     

Hemodynamic and volume correlates of left ventricular diastolic relaxation and filling in patients with aortic stenosis.

OBJECTIVE. The aim of the present study was to evaluate the hemodynamic and volume correlates of early diastolic filling and isovolumetric relaxation in patients with aortic stenosis. BACKGROUND. Left ventricular diastolic relaxation and filling have been found to be heterogeneous in patients with aortic stenosis. Potential mechanisms underlying this heterogeneity include individual differences in the severity of muscle hypertrophy or systolic dysfunction, or both, in the presence and severity of mitral regurgitation and in the level of left atrial pressure. METHODS. Right (fluid-filled) and left (high fidelity micromanometer) ventricular pressures, left ventricular volumes (contrast angiography) and transmitral inflow dynamics (Doppler echocardiography) were measured in 17 patients with isolated severe aortic stenosis (valve area less than 0.75 cm2). Measurements included left ventricular end-diastolic and end-systolic volumes, left ventricular ejection fraction, peak positive and negative first derivative of left ventricular pressure (dP/dt), the time constant of isovolumetric relaxation (tau), left ventricular end-diastolic pressure, left ventricular mass, left ventricular end-systolic stress, mean capillary wedge pressure and peak early (E) and late (A) transmitral filling velocities. Patients were subclassified according to left ventricular ejection performance at rest and mean capillary wedge pressure. RESULTS. Patients with normal ejection performance and normal mean capillary wedge pressure had a normal rate of isovolumetric left ventricular pressure decay and an abnormal diastolic filling pattern, with diastolic filling occurring primarily during atrial systole. In contrast, in patients with systolic dysfunction and elevated mean capillary wedge pressure, isovolumetric pressure decay was prolonged and diastolic filling occurred essentially during the rapid filling period, with reduced atrial contribution to left ventricular filling and a short isovolumetric relaxation period. Stepwise multiple linear regression analysis identified two variables as independent predictors of transmitral velocity profile and three variables independently predictive of the rate of left ventricular pressure decay. The single most important predictor of transmitral filling pattern was the pulmonary capillary wedge pressure (p less than 0.0001), followed by the left ventricular peak negative dP/dt (p = 0.002). The single most powerful predictor of the rate of reduction in left ventricular pressure was left ventricular mass index (p less than 0.0001), followed by end-systolic volume index (p = 0.0002) and left ventricular peak negative dP/dt (p = 0.0029). CONCLUSIONS. In patients with aortic stenosis, left ventricular filling is essentially determined by left atrial pressure, whereas isovolumetric relaxation more closely depends on the severity of muscle hypertrophy and chamber dilation.