Non-invasive assessment of cardiac function

Noninvasive assessment of cardiac function by Doppler echocardiography is reviewed. The heart propels the blood through the repeated sequence of systole and diastole. The systolic function is essential to maintain the biological function of the whole body. However, before the heart ejects the blood during systole, the heart must be filled up with blood during the preceding diastole. Thus, the diastolic function is as important as the systolic function. Although the diastolic function is traditionally assessed by hemodynamic parameters obtained in the cardiac catheterization laboratory, it has routinely been assessed by Doppler echocardiography in the echocardiographic laboratory in recent years. Since the concept of diastolic failure has widely spread, the important role of the transmitral flow in assessing the diastolic function has been well recognized. Besides the transmitral flow, the modalities for clinical assessment of the left ventricular diastolic function have been well developed. For example, the pulmonary venous flow has been easily obtained by a transthoracic approach, and the tissue Doppler technique provides important information about the diastolic function, and furthermore the color M-mode is applied for the flow propagation velocity of the left ventricular inflow. These modalities make it possible to assess the left ventricular diastolic function more precisely by Doppler echocardiography. Also, TEI index, strain rate and strain imaging, and wave intensity are mentioned.     

Effect of flow disturbances remaining at the beginning of diastole on intraventricular diastolic flow and colour M-mode Doppler echocardiograms

A computational model of the fluid dynamics of intraventricular flow was used to investigate the importance of the effects of flow disturbances existing within the left ventricle (LV) at the onset of diastole on a diastolic flow field. The simulation started with a quiescent flow state; it continued for a number of cardiac cycles to obtain a cyclically repeatable flow. After the flow became periodic, the initial diastolic flow was not quiescent: flow disturbances, remnants of a systolic flow, were present within the LV. Nevertheless, they faded away during an acceleration phase of diastole and almost ceased by the end of this phase. Consequently, a flow field during a deceleration phase of diastole, characterised by the formation of a vortex ring, was hardly affected by the initial flow disturbances. The propagation velocity of a colour M-mode Doppler echocardiogram obtained by scanning velocity along the LV long axis was 0.58ms⁻¹ in the case where diastolic flow was initially quiescent and 0.56ms⁻¹ in the case where flow disturbances existed at the beginning of diastole. These results indicated that the colour M-mode Doppler echocardiographic technique captures flow dynamics produced purely by ventricular expansion, with little influence from initial diastolic flow disturbances.     

The role of echocardiographic techniques in connective tissue diseases

Connective tissue diseases (CTD) lead to a high prevalence of common cardiac manifestations (pericarditis and myocarditis) and of ischemic coronary events with a considerable increase in cardiac mortality related to premature atherosclerosis. Although there are several techniques able to detect cardiac involvement in CTD patients, the most useful and non-invasive technique is echocardiographic exam which is able to detect not only valvular abnormalities, pericardial diseases and pulmonary hypertension but also left ventricular (LV) systolic or diastolic (regional or global) wall motion dysfunction. It is also well known that transesophageal echocardiography (TEE) can better identify cardiac abnormalities, vegetations and embolic sources. Symptomatic patients with positive stress echocardiographic exam or dipyridamole thallium imaging test should be referred for possible cardiac catheterization, especially if a large ischemic territory is involved. Until now, the echocardiographic evaluation of coronary artery tree consisted of assessing regional and global left ventricular systolic and diastolic function at rest and during pharmacological stress test. Recently, a new echocardiographic noninvasive method that allows direct assessment of coronary flow velocity in the mid-distal portion of left anterior descending artery (LAD) has been developed and validated. Advanced ultrasound technology (high-frequency broadband transducer with second harmonic capability) has now made possible a direct arterial visualization and measurement of coronary artery flow in left anterior descending in CTD patients with the assessment of coronary flow reserve (CFR).     

Validation of left ventricular end-diastolic volume from stroke volume and ejection fraction

The present study examines an innovative approach to measurement of left ventricular (LV) end-diastolic volume (LVEDV). Measurement of LVEDV is fundamental to the assessment of intraoperative systolic and diastolic LV function. We compared steady state LVEDV values obtained from stroke volume (SV) and ejection fraction (EF) with echocardiographic and postmortem LVEDV measurements. Five anesthetized pigs (40-45 kg) underwent median sternotomy and pericardiotomy. A transit time ultrasonic flow probe was placed on the ascending aorta to provide cardiac output. A micromanometer provided LV end-diastolic pressure. LV short axis cross sectional echocardiograms and electrocardiograms were also obtained. LV end-diastolic area (LVEDA) and end-systolic area (LVESA) were measured to obtain EF. LVEDVsv/ef was calculated from cardiac output, heart rate, and EF. LVEDVecho was determined using a three-plane echocardiography model. Postmortem (LVEDVpm/vv) volumes were also measured. LVEDVsv/ef correlated well with volumes obtained by echocardiography (r2 = 0.92) and postmortem (r2 = 0.73) measurements. Values of p < 0.05 indicated significant linearity of LVEDA-LVEDVsv/ef (r2 =0.93), LVEDA-LVEDVecho (r2 = 0.96), and LVEDA-LVEDVpm/vv (r2 = 0.81) relationships. Determination of LVEDV from SV and EF is valid and may facilitate real-time determination of LV mechanics.     

动物实验模型中多极导管心室除颤系统电除颤对心脏功能的影响

评价新型的双极和三极导管自动心室除颤系统电除颤对左心室收缩和舒张功能的影响。动物麻醉后,在X光机指导下,分别在10只犬心脏内装置双极导管自动除颤系统（组Ⅰ）;在10只猪心脏内装置三极导管自动除颤系统（组Ⅱ）;并行电除颤试验。使用食管超声心动图在电除颤前后记录二维、M型和多谱勒超声图像。组I动物接受4次电除颤,电量为64J;组Ⅱ接受平均8次电除颤,电量为210J。结果显示：左室收缩面积分数、左室等容舒张时间和二尖瓣血流E波与A波速度比值以及时间-流速积分比值等反映左室舒缩功能的指标在两组动物除颤后均无显著改变。研究表明：两种经静脉导管自动心室除颤系统中反复低能量心内膜电除颤对左室舒缩功能无明显损伤作用;研究结果为经静脉多极导管自动心室除颤系统在临床的应用和电生理研究提供了可靠的实验数据。     

Simulation of systolic and diastolic left ventricular dysfunction in a mock circulation: the effect of arterial compliance

Arterial compliance (AC) is expected to play a major role on cardiac efficacy by acute or long-term mechanisms. The aim of this study was to investigate the purely mechanical effect of AC on left ventricular (LV) performance, for different conditions of LV dysfunction (systolic versus diastolic). A hydraulic, Windkessel model of systemic circulation was used. LV function and aortic flow were simulated using a left ventricular assist device (LVAD). Two cases of LV dysfunction were simulated: Case A, systolic and Case B, diastolic dysfunction. In Case A, AC increased from 1.14 to 2.85 ml mm Hg &#109 1 leading to an increase in LVAD stroke volume up to 6%, while no significant effect was observed in Case B. LVAD systolic work was decreased by 4% in systolic and by 11% in diastolic LVAD dysfunction. The purely mechanical effect of AC changes on LVAD function was different between systolic and diastolic dysfunction. It might be expected that even an acute reduction in arterial stiffness could enhance LV performance by different means in systolic compared to diastolic dysfunction.     

Simulation of systolic and diastolic left ventricular dysfunction in a mock circulation: the effect of arterial compliance

Arterial compliance (AC) is expected to play a major role on cardiac efficacy by acute or long-term mechanisms. The aim of this study was to investigate the purely mechanical effect of AC on left ventricular (LV) performance, for different conditions of LV dysfunction (systolic versus diastolic). A hydraulic, Windkessel model of systemic circulation was used. LV function and aortic flow were simulated using a left ventricular assist device (LVAD). Two cases of LV dysfunction were simulated: Case A, systolic and Case B, diastolic dysfunction. In Case A, AC increased from 1.14 to 2.85 ml mm Hg(-1) leading to an increase in LVAD stroke volume up to 6%, while no significant effect was observed in Case B. LVAD systolic work was decreased by 4% in systolic and by 11% in diastolic LVAD dysfunction. The purely mechanical effect of AC changes on LVAD function was different between systolic and diastolic dysfunction. It might be expected that even an acute reduction in arterial stiffness could enhance LV performance by different means in systolic compared to diastolic dysfunction.     

经食管超声评价微创外科房间隔缺损封堵术中患者心功能及血流动力学

目的运用经食管超声对微创外科房间隔缺损封堵术中患者心功能及血流动力学的变化进行评价,探讨超声在微创外科房间隔缺损封堵术中的应用价值。方法门诊筛查选择适合经微创外科封堵术治疗的房间隔缺损患者50例,于术中及手术前后对患者进行经食管超声和经胸超声心动图检查,分别测量左、右室心功能及血流动力学指标,并对手术前后结果进行对照比较。结果术后左、右房室腔的径线与术前比较明显减小（P〈0．05）,右心室舒张末期容积（RVEDV）、右心室每搏输出量（RVSV）、右心排血量（CO）均较封堵前明显减小,左心室舒张末期容积（LVEDV）、每搏输出量（LVSV）及排血量（CO）均较封堵前增加,两者具有显著差异（P〈0．05）。而左心室收缩末期容积（LVESV）和右心室收缩末期容积（RVESV）以及左室和右室射血分数无显著变化。术后肺动脉瓣上最大血流速度、三尖瓣口E峰流速、三尖瓣反流最大流速及肺动脉收缩压与术前比较均显著减小（P〈0．05）,二尖瓣口E峰流速显著增大（P〈0．05）。结论经食管超声可及时反映微创外科房间隔缺损封堵术前后患者心功能及血流动力学变化,为临床评价手术效果提供参考。     

频谱多谱勒技术评价冠心病人心室舒张功能

目的：采用频谱多谱勒技术观察冠心病人心室舒张功能改变。方法：冠状动脉造影确诊为冠心病患者61例，根据左室射血分数（EF）分为EF正常组（Ⅰ组，EF≥50％，33例），EF降低组（Ⅱ组，EF〈50％，28例）。正常对照组32例。频谱脉冲多普勒技术测量各组二尖瓣、三尖瓣血流频谱及肺静脉血流频谱参数；心导管测量冠心病组左室舒张末压（LVEDP）。结果：冠心病Ⅰ组左、右室舒张功能均可出现障碍，多呈松弛功能异常；冠心病Ⅱ组左室舒张功能障碍，多呈假性正常化；PVad-Ad与LVEDP呈正相关（r=0．72，P〈0．01）；以PVad-Ad〉0ms为标准来鉴别二尖瓣频谱假性正常化，敏感性为92％，特异性为80％；左右室舒张功能相关性分析（E／A：r=0．46，DT：r=0．54，P〈0．01）。结论：冠心病早期收缩功能正常时，左、右室舒张功能均可出现障碍；左室收缩功能异常时，左室舒张功能进一步减退，多呈假性正常化；PVad-Ad能准确地鉴别二尖瓣血流频谱假性正常化；冠心病人左右室舒张功能有较显著的相关性。     

Role of left ventricular untwisting in diastolic dysfunction after long duration exercise

Numerous studies have reported that long duration exercise induces transient left ventricular (LV) dysfunction. Using 2D-strain echocardiography, we aimed to describe cardiac mechanics following 2 h of exercise. We focused especially on LV twist since untwisting is crucial in the development of intraventricular pressure gradient, a key element of LV early filling. Twenty healthy males (20–41 years) underwent a resting echocardiography including a 2D-strain evaluation based on velocity vector imaging before and after 2-h of cycling at a moderate intensity. Measurements included LV longitudinal, radial and circumferential strains, and LV rotations and twist. After the prolonged exercise, the depressed diastolic function (peak E: 77.5 ± 11.4 vs. 71.9 ± 10.9, P < 0.01) was associated with a delay in peak untwisting velocity (110 ± 14 vs. 119 ± 14% of systolic duration, P < 0.05), whereas LV peak diastolic strain rates, indexes of LV relaxation, were unchanged. LV global systolic function and LV peak systolic strain rates remained normal after the exercise (fractional shortening: 36.8 ± 2.8 vs. 36.9 ± 5.7, NS). In conclusion, the present study gives new insight into cardiac dysfunction following long duration exercise. It demonstrates that depressed diastolic function is associated with delayed untwisting velocity, but depressed LV relaxation and contractility following exercise remains controversial.     

Dobutamine stress echocardiography for evaluating cirrhotic cardiomyopathy in liver cirrhosis

Background/Aims

The blunted ventricular systolic and diastolic contractile responses to physical and pharmacological stress in cirrhosis are termed cirrhotic cardiomyopathy (CCM). CCM has been known to involve multiple defects in the β-adrenergic signaling pathway. The aim of this study was to determine whether cirrhotic patients have blunted cardiac responses to catecholamine stimulation through dobutamine stress echocardiography (DSE).

Methods

Seventy-one cirrhotic patients with normal left ventricular (LV) chamber size and ejection fraction were enrolled. The LV systolic and diastolic functions were evaluated by two-dimensional and Doppler echocardiography at rest and during peak dobutamine infusion (40 µg/kg/min). An abnormal response was defined as a decrease of less than 10% in LV end-diastolic volume, a decrease of less than 20% in end-systolic volume, and an increase of less than 10% in LV ejection fraction (EF) at peak dobutamine infusion, based on previously used criteria. The early/late diastolic flow (E/A) ratio and diastolic parameters were also measured.

Results

A blunted LV response to dobutamine was observed in 18 of 71 cirrhotic patients (25.4%). The baseline EF was significantly higher in 18 patients with a blunted DSE response than that of those with a normal DSE response (P<0.05). The baseline and peak E/A ratios, which are common diastolic dysfunction markers, were higher in the cirrhosis group than in the control group (P<0.001). No adverse events associated with DSE were observed.

Conclusions

Blunted cardiac responses to dobutamine stimulation, which are implicated in defects in the β-adrenergic signaling pathway, might contribute to the pathogenesis of CCM in patients with cirrhosis.     

二维超声心动图和M型超声心动图评价左心室扩大患者左心室收缩功能的对比研究

目的评价二维超声心动图（2DE）法和M型超声心动图（ME）法测量心瓣膜病中重度二尖瓣和（或）主动脉瓣反流（VR）、扩张型心肌病（DCM）和缺血性心肌病（ICM）患者左心室收缩功能相关指标的一致性及其影响因素。方法用2DE和ME同时测量100例左心室扩大患者（VR35例、DCM32例和ICM33例）的左心室舒张末期内径（LVEDD）、左心室舒张末期容积（LVEDV）和左心室射血分数（LVEF）,分别记为LVEDD2DE、LVEDDME、LVEDV2DE、LVEDVME、LVEF2DE和LVEFME。结果①患者的LVEDD2DE与LVEDDME、LVEDV2DE与LVEDVME差异有统计学意义,LVEF2DE与LVEFME差异无统计学意义,且具有良好的相关性,r=0．869;②组内比较：3组的LVEDD2DE与LVEDDME差异均有统计学意义,VR组LVEDV2DE与LVEDVME差异无统计学意义,其他两组差异有统计学意义,3组的LVEF2DE与LVEFME差异无统计学意义;③组间比较：LVEDD2DE在DCM组与ICM组之间差异有统计学意义,在VR组与ICM组之间差异也有统计学意义,LVEDDME、LVEDV2DE。和LVEDVME有相同的结果,LVEF2DE在3组间差异均有统计学意义,LVEFME在3组间差异也均有统计学意义,2DE和ME法均得到LVEDVVR≈LVEDVDCM〉LVEDVICM和LVEFDCM〈LVEFICM〈LVEFVR的一致结论;④按LVEDD2DE分为〈80mm大左心室组和≥80mm巨大左心室组,两组的LVEDV2DE与LVEDVME差异有统计学意义,LVER2DE与LVEFME各组差异无统计学意义。结论二维法和M型超声评价VR、DCM和ICM患者左心室收缩功能的指标中LVEF一致性较好．较少受左心室形状及节段性室壁运动异常的影响。2DE和ME均得出VR组与DCM组左心室增大的程度相近．但LVEF减低的程度却不同．而ICM组左心室增大的程度小于前两组。但LVEF却较VR组减低明显。     

The relationship between the left atrial volume and the maximum P-wave and P-wave dispersion in patients with congestive heart failure

PURPOSE: A maximum P-wave duration (Pmax) of > or = 110 msec and a P-wave dispersion (PWD) > or = 40 msec are accepted indicators of a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse, respectively. The left atrial (LA) volume has been reported to be strongly associated with a systolic and diastolic dysfunction and is considered to be an index of atrial remodeling. We aimed to investigate the relationship between LA volume and Pmax or PWD in patients with congestive heart failure (CHF). PATIENTS AND METHODS: Sixty-one patients with CHF were enrolled in this study. The study population was classified into four groups: two groups were divided according to the Pmax (> or = 110 msec or < 110 ms), and the other two groups were formed based on the PWD (> or = 40 msec or < 40 msec). The left atrial volume index (LAVi) was measured by three-dimensional (3-D) transthoracic echocardiography. The Pmax and PWD were measured from a 12-lead electrocardiogram. RESULTS: There were significant differences in the ejection fraction (EF), diastolic function, and LAVi between patients with a Pmax > or = 110 ms or a PWD > or = 40 ms and those with a Pmax < 110 ms or a PWD < 40 ms. The LAVi was independently associated with a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse. The LAVi can be used to identify patients with a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse with reasonably good accuracy. CONCLUSION: We concluded that a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse in patients with CHF is associated with an increase in the LA volume and a deleterious systolic and diastolic dysfunction.     

Variable phenotype in murine transverse aortic constriction

BackgroundIn mice, transverse aortic constriction (TAC) is variably characterized as a model of pressure overload-induced hypertrophy (left ventricular [LV] hypertrophy, or LVH) or heart failure (HF). While commonly used, variability in the TAC model is poorly defined. The objectives of this study were to characterize the variability in the TAC model and to define a simple, noninvasive method of prospectively identifying mice with HF versus compensated LVH after TAC.MethodsEight-week-old male C57BL/6J mice underwent TAC or sham and then echocardiography at 3 weeks post-TAC. A group of sham and TAC mice were euthanized after the 3-week echocardiogram, while the remainder underwent repeat echocardiography and were euthanized at 9 weeks post-TAC. The presence of TAC was assessed with two-dimensional echocardiography, anatomic aortic m-mode and color flow, and pulsed-wave Doppler examination of the transverse aorta (TA) and by LV systolic pressure (LVP). Trans-TAC pressure gradient was assessed invasively in a subset of mice. HF was defined as lung/body weight>upper limit in sham-operated mice.ResultsAs compared with sham, TAC mice had higher TA velocity, LVP and LV weight, and lower ejection fraction (EF) at 3 or 9 weeks post-TAC. Only a subset of TAC mice (28%) developed HF. As compared with compensated LVH, HF mice were characterized by similar TA velocity and higher percent TA stenosis, but lower LVP, higher LV weight, larger LV cavity, lower EF and stress-corrected midwall fiber shortening, and more fibrosis. Both EF and LV mass measured by echocardiography at 3 weeks post-TAC were predictive of the presence of HF at 3 or 9 weeks post-TAC.ConclusionsIn wild-type mice, TAC produces a variable cardiac phenotype. Marked abnormalities in LV mass and EF at echocardiography 3 weeks post-TAC identify mice with HF at autopsy. These data are relevant to appropriate design and interpretation of murine studies.     

Atrioventricular plane displacement correlates closely to circulatory dimensions but not to ejection fraction in normal young subjects.

AIMS: Mitral atrioventricular plane displacement (AVPD) provides information about left ventricular systolic function. M-mode of systolic annulus amplitude or tissue Doppler imaging of systolic annulus velocity are the current methods of evaluating AVPD. A correlation to ejection fraction (EF) has been demonstrated in patients with coronary artery disease and left ventricular dysfunction. Our aim was (i) to investigate the mitral AVPD of normal subjects with different physical work capacities and (ii) to further evaluate AVPD as an index of left ventricular systolic function. METHODS AND RESULTS: Twenty-eight healthy men mean age 28 years (20-39) were included: endurance trained (ET) (n=10), strength trained (ST) (n=9) and untrained (UT) (n=9). The systolic AVPD was recorded at four sites, septal, lateral, anterior and posterior, using M-mode. Left ventricular volumes were calculated according to Simpson's rule. Systolic AVPD was higher in endurance trained, 16.9 +/- 1.5 mm, as compared with both strength trained, 13 +/- 1.6 (P<0.001) and untrained, 14 +/- 1.6 (P<0.001). Left ventricular systolic AVPD correlated strongly with end-diastolic volume (r=0.82), stroke volume (r=0.80) and maximal oxygen consumption per body weight (r=0.72). The correlation between AVPD and EF was poor (r=0.22). CONCLUSION: In the subjects studied, with a range of normal cardiac dimensions, AVPD correlated to stroke volume, end-diastolic volume and maximal oxygen consumption per body weight, but not to EF. On theoretical grounds, it also seems reasonable that a dimension like AVPD is related to other cardiac dimensions and volumes, rather than to a fraction, like EF. AVPD is one parameter that is useful for evaluation of left ventricular systolic function but is not interchangeable with other measurements such as EF.     

Association of right ventricular dysfunction and Cheyne-Stokes respiration in patients with chronic heart failure

Cheyne-Stokes respiration (CSR) is present in up to 40% of patients with congestive heart failure (CHF) and is an independent risk factor for increased overall mortality. We examined whether CSR is associated with right ventricular (RV) dysfunction in CHF patients. Parameters of RV function were assessed by two-dimensional echocardiography and tissue velocity imaging in 42 patients (aged 23-75 years) with a left ventricular (LV) ejection fraction below 40%. Respiratory polygraphy revealed CSR with an central apnea-hypopnea index (CAHI) >10 h-1 in 13 of the 42 patients (31%). Demographic characteristics did not differ among the patient groups. The velocity of the tricuspid annular systolic motion (TASM), a parameter reflecting systolic RV function, was significantly reduced in CHF patients with CSR (10.5 +/- 2.3 cm s-1) compared with those without CSR (15.0 +/- 5.1 cm s-1, P = 0.004), and was inversely associated with the CAHI (y = 15.2-0.2x; r = 0.46, P = 0.003). The RV dimensions were significantly increased and the fractional RV area changes significantly reduced in CHF patients with CSR (33 +/- 17 versus 48 +/- 20%; P = 0.04). Doppler parameters of pulmonary artery flow indicate higher pulmonary artery pressures in CSR patients compared with patients without CSR, which is also reflected by an increased RV free-wall thickness in CSR patients (6.5 +/- 1.1 vs. 5.3 +/- 1.3 mm; P = 0.05). Parameters of systolic LV function, forced expiratory volume in 1 s (FEV1), and PaO2 and PaCO2 were not different among patients with or without CSR. In conclusion, CSR is associated with depressed systolic RV function and increased RV dimensions in CHF patients. Future studies will show whether optimized treatment of CSR will improve RV function.     

Assessment of atrial contribution to left ventricular filling during cold pressor test by M-mode echocardiography in patients with coronary artery disease

To determine whether temporarily increased afterload causes changes in left ventricular (LV) diastolic properties, we examined 19 patients with coronary artery disease (CAD) and 14 healthy subjects by M-mode echocardiography during immersion of the left hand in ice water. The M-mode echocardiograms were digitized to assess the percentage of atrial contribution (%AC) to LV filling as a marker of diastolic properties. Six patients and 5 controls had to be excluded owing to inability to clearly define the endocardium in the left ventricle throughout the entire heart cycle. In the control situation, the %AC did not differ significantly between the two groups. During the cold pressor test, the mean %AC at peak systolic and peak diastolic pressures was significantly higher in the CAD group than in the control group (p less than 0.05). Thus, by using M-mode echocardiography during the cold pressor test it is possible to document an increased atrial contribution to LV filling in patients with CAD. It is suggested that the mechanism is increased myocardial stiffness evoked by ischaemia with a resultant increased role of atrial contraction.     

Practical assessment using transmitral Doppler echocardiography for the evaluation of left ventricular filling pressure in patients with systolic ventricular dysfunction

Transmitral flow velocity profiles by Doppler echocardiography are strongly related to left ventricular diastolic properties. The aim of this study was to address the assessment of left ventricular filling pressures by transmitral flow velocity curves in patients with impaired systolic function. 90 patients (23 female, 67 men, age 60.0 +/- 9,9 a) with an ejection fraction < or = 45% either due to coronary artery disease (n = 67) or dilated cardiomyopathy (n = 23) were investigated by Doppler echocardiography prior to left heart catheterization. Early diastolic deceleration time (DT) and ratio of early to late diastolic peak velocities (VE/VA) were measured. Both, DT and VE/VA showed a significant correlation to left ventricular enddiastolic pressures (r = -0.79 respectively r = 0.73, p < 0.001 for all). According to DT three different transmitral flow patterns were identified. All patients with restrictive filling patterns (DT < 160) had elevated left ventricular filling pressures, whereas impaired relaxation (DT > 210) was a strong predictor of normal filling pressures. In patients with pseudonormal transmitral flow patterns (DT 160 to 210) filling pressures could not be predicted. Furthermore DT was strongly related to clinical signs of left heart failure. Doppler echocardiography gives useful additional information on left ventricular filling pressures in patients with systolic dysfunction.     

The effect of hormone replacement therapy on diastolic left ventricular function in hypertensive and normotensive postmenopausal women

Objectives: To evaluate the effect of hormone replacement therapy (HRT) on left ventricular diastolic function in a group of hypertensive and normotensive postmenopausal women. Methods: Left ventricular diastolic function at rest was evaluated by M-mode, two-dimensional and Doppler echocardiography in 19 postmenopausal women with normal blood pressure and 11 postmenopausal women with mild hypertension, before treatment and during 12 months of HRT. Transdermal estradiol was used in women with a surgical menopause and a sequential regimen of transdermal estradiol and peroral medroxyprogesterone acetate in women with a spontaneous menopause. The parameters assessed were: body mass index, heart rate, ejection fraction of the left ventricle (EF), septal (SW) and posterior wall (PW) dimensions, left ventricular end-systolic (LVsd) and end-diastolic (LVdd) dimensions and volumes (ESV, EDV), total diastolic time (DT), duration of the early (Ei) and of the late (Ai) filling phase, peak velocity of the early (E) and late mitral flow (A), A/E velocity ratio and systolic and diastolic blood pressure. Quantitative data were analyzed using unpaired t-test, MANOVA and multiple regression analysis where appropriate. Results: Hypertensive postmenopausal women had significantly higher SW (P<0.05), PW (P<0.05), A/E (P<0.05) and A (P<0.001) than normotensive postmenopausal women, before therapy. After 12 months of HRT a significant decrease in SW, PW, LVsd, ESV and increase in EF, DT, Ei and E was observed in both hypertensive and normotensive postmenopausal women. Heart rate slowed and systolic pressure decreased significantly only in normotensive postmenopausal women on HRT. Conclusion: HRT of 12 months' duration does not deteriorate left ventricular diastolic function of both hypertensive and normotensive postmenopausal women. Improvement in some parameters of diastolic function could be partially explained by the decrease in heart rate and systolic pressure, induced by therapy.     

Age-associated changes in hearts of male Fischer 344/Brown Norway F1 rats

Aging is associated with left ventricular hypertrophy, dilatation, and fibrosis of the heart. The Fischer 344/Brown Norway F1 (F344/BNF1) rat is recommended for age-related studies by the National Institutes on Aging because this hybrid rat lives longer and has a lower rate of pathological conditions than inbred rats. However, little is known about age-associated changes in cardiac and aortic function and structure in this model. This study evaluated age-related cardiac changes in male F344/BNF1 rats using ECHO, gross, and microscopic examinations. Rats aged 6-, 30-, and 36-mo were anesthetized and two-dimensional ECHO measurements, two-dimensional guided M-mode, Doppler M-mode, and other recordings from parasternal long- and short-axis views were obtained using a Phillips 5500 ECHO system with a 12 megahertz transducer. Hearts and aortas from sacrificed rats were evaluated grossly and microscopically. The ECHO studies revealed persistent cardiac arrhythmias (chiefly PVCs) in 72% (13/18) of 36-mo rats, 10% (1/10) of 30-mo rats, and none in 6-mo rats (0/16). Gross and microscopic studies showed left ventricular (LV) dilatation, borderline to mild hypertrophy, and areas of fibrosis that were common in 36-mo rats, less evident in 30-mo rats, and absent in 6-mo rats. Aging was associated with mild to moderate decreases of LV diastolic and systolic function. Thus, male F344/BN F1 rats demonstrated progressive age-related (a) decline in cardiac function (diastolic and systolic indices), (b) LV structural changes (chamber dimensions, volumes, and wall thicknesses), and (c) persistent arrhythmias. These changes are consistent with those in humans. The noninvasive ECHO technique offers a means to monitor serial age-related cardiac failure and therapeutic responses in the same rats over designated time intervals.