Summary: The measurement of coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE) with invasive intracoronary Doppler flow wire technique (ICD) was validated and the pathologica...Summary: The measurement of coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE) with invasive intracoronary Doppler flow wire technique (ICD) was validated and the pathological factors which influence CFVR in patients with angiographically normal coronary arteries were analyzed. CFVR was determined successfully in left anterior descending artery (LAD) in 37 of 40 patients with angiographically normal coronary arteries (men 22, women 15, age 20-75 years, mean age 54±12 years). Coronary flow velocity was measured in the distal LAD by TTDE with contrast enhancement at baseline and during intravenous adenosine infusion of 110 μg/ kg per min within 48 h after ICD technique. Average peak velocity at baseline (APVb), average peak velocity during hyperemia (APVh) and CFVR determined from TTDE were correlated closely with those from ICD measurements (APVb: y= 0. 64x+ 5. 04, r=0. 86, P〈0. 001; APVh: y=0. 63x+14. 36, r=0.82, P〈0.001; CFVR: y=0.65xq-0.92, r=0.88, P〈0.001). For CFVR measurements, the mean differences between TTDE and ICD methods were 0. 12±0.39. CFVR in patients with history of hypertension was significantly lower than that in patients without history of hypertension (P〈0.05). Intravascular ultrasound (IVUS) was performed in 34 patients. Plaque formation was found in LAD by IVUS in 17 (50%) patients. No significant difference in CFVR was found between the patients without plaque formation (3. 11±0. 49) and those with plaque formation (2. 76±0.53, P=0. 056). It is suggested that TTDE with contrast enhancement provides reliable measurement of APV and CFVR in the distal I.AD. The early stage of atherosclerosis could be detected by IVUS, which may be normal in angiography. CFVR is impaired in patients with history of hypertension compared with that in patients without history of hypertension.展开更多
Summary: Whether the localized flow acceleration occurs in the resting stenotie left anterior descending coronary artery was explored and its value for detection of coronary stenosis estimated. Blood flow in the left...Summary: Whether the localized flow acceleration occurs in the resting stenotie left anterior descending coronary artery was explored and its value for detection of coronary stenosis estimated. Blood flow in the left anterior descending coronary arteries in 45 patients was detected by transthoratio color Doppler echocardiograph and multipoint pulse Doppler spectrums were recorded in the same segment. The ratio of the maximal peak diastolic velocity to the minimal peak diastolic velocity was calculated. The ratio ≥1.5 was the cutoff value for the presence of localized acceleration flow. There were 23 patients with localized acceleration flow examined by eehoeardiography. Twenty of them were found to have luminal diameter stenosis (60%-98%) in the left anterior descending coronary arteries by coronary angiography and 3 patients were normal. There were 22 patients without localized acceleration flow examined by eehoeardiography. Eighteen of them had no or %60 stenosis. Four patients had serious stenosis (≥95%) or occluded segments in the left anterior descending coronary arteries on coronary angiography. The ratio of the maximal peak diastolic velocity to the minimal peak diastolic velocity was significantly higher in patients with left anterior descending coronary artery stenosis than that in those without stenosis (1.9±0.3 vs 1.3±0.2, P〈0.01) and it correlated significantly with left anterior descending coronary artery stenosis (r=0.77, P〈0.01). The specificity by using the ratio≥1. 5 for stenosis detection was 85.7% (18/ 21), and the sensitivity was 83.3% (20/24). This study demonstrated that local blood flow velocity was increased in the resting stenotie left anterior descending coronary artery. Transthoraeie color Doppler eehoeardiography is a reliable noninvasive method to detect localized acceleration flow in the left anterior descending coronary artery stenosis and it is useful in the noninvasive diagnosis of stenosis in the left anterior descending coronary artery.展开更多
Summary: Transthoracic Doppler echocardiography (TTDE) allows noninvasive flow measurement in the distal left anterior descending artery (LAD). The feasibility of detecting coronary flow by contrast-enhanced TTDE with...Summary: Transthoracic Doppler echocardiography (TTDE) allows noninvasive flow measurement in the distal left anterior descending artery (LAD). The feasibility of detecting coronary flow by contrast-enhanced TTDE with second harmonic technique was assessed, the coronary flow velocity reserve (CFVR) was evaluated in comparison to intracoronary Doppler flow (ICD) analysis and the CFVR after PTCA in LAD was investigated. In 77 (96 %) of 80 patients, CFVR was successfully determined with intravenous adenosine infusion. Doppler signal quality was evaluated in the first 46 patients by use of intravenous Levovist infusion and second harmonic technique. The Doppler flow was not visible in 1 patient only. CFVR determined from TTDE (2.77±0.65) was correlated closely with those from ICD (2.88±0.78) measurements (y=0.73x+0.67, r=0.87, P<0.001). In conclusion, TTDE is a feasible method and provides reliable data on CFVR which can be used for follow-up after PTCA.展开更多
This paper describes a signal processing system in a Pulsed Doppler (PD) radar. It mainly consists of a velocity tracking loop and a digital signal processing auxiliary channel. With many signal processing techniques,...This paper describes a signal processing system in a Pulsed Doppler (PD) radar. It mainly consists of a velocity tracking loop and a digital signal processing auxiliary channel. With many signal processing techniques, the system successfully solves the signal detection and tracking at low SNR and the interference identification and rejection. The idea of system design is introduced in detail. Finally, some simulation and experimental results are presented.展开更多
Echocardiography is the most common diagnostic method for assessing cardiac function but some limitations affect this technique.Until now,visual assessment of wall motion and thickening has allowed only a subjective e...Echocardiography is the most common diagnostic method for assessing cardiac function but some limitations affect this technique.Until now,visual assessment of wall motion and thickening has allowed only a subjective evaluation of myocardial function and requires long-term training.Recently,new echocardiographic techniques have been introduced to evaluate myocardial mechanics.Tissue Doppler imaging(TDI)technique is limited by angle-dependency such that only deformation along the ultrasound beam can be derived from velocities,while myocardium deforms simultaneously in three dimensions.Speckle tracking echocardiography (STE)is a more recent technique that provides a global approach to left ventricular myocardial mechanics,giving information about the three spatial dimensions of cardiac deformation.In this editorial,we describe the physical and pathophysiological concepts of STE,discussing the differences compared to TDI and underlining the pitfalls of this new technique.展开更多
Doppler echocardiography is the gold standard for assessment of diastolic dysfunction, which is increasingly recognised as a cause of heart failure, especially in the elderly. Using a combination of Doppler echocardio...Doppler echocardiography is the gold standard for assessment of diastolic dysfunction, which is increasingly recognised as a cause of heart failure, especially in the elderly. Using a combination of Doppler echocardiography techniques, it is possible to identify grades of dia- stolic dysftmction, estimate left ventricular filling pressures and establish the chronicity of diastolic dysfunction. These physiologi- cally-derived measures have been widely validated against invasive measurements of left heart pressures and have been shown to be prog- nostically valuable in a wide range of clinical settings. This review explores the mechanisms, and approaches to the assessment of diastolic dysfunction in the elderly. The challenge for clinicians is to identify pathophysiological changes from those associated with normal ageing. When used in combination, and taking age into account, Doppler echocardiographic parameters are helpful in the assessment of dyspnoea in older patients and provide prognostic insights.展开更多
We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler(PW) and pulse tissue Doppler imaging(PW-...We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler(PW) and pulse tissue Doppler imaging(PW-TDI).A total of 25 consecutive in-patients with persistent atrial fibrillation,who restored sinus rhythm after ablation procedure,were recruited in our cardiac center.Echocardiography was performed on each patient at 2 hours,1 day,5 days,1 month and 3 months after the ablation therapy,and atrial electromechanical delay was measured simultaneously by PW and PW-TDI.There was no significant difference between PW and TDI in measuring atrial electromechanical delay.However,at postoperative 2 hours,peak A detection rates were mathematically but nonsignificantly greater by PWTDI than by PW.Second,there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months,but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time.Lastly,patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval,by the PW or by PW-TDI,respectively.In patients with persistent atrial fibrillation,atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later,and was significantly related to patients' duration of atrial fibrillation.Atrial electromechanical interval,as a potential predicted factor,is recommended to be measured by either PW or TDI after24 hours,when patients had recovered sinus rhythm by radiofrequency ablation.展开更多
Heart failure is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fi ll with or eject blood.The echocardiogram is the single m...Heart failure is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fi ll with or eject blood.The echocardiogram is the single most performed and useful study in these patients.This article reviews the role of the echocardiogram in the evaluation of the heart failure patient,without focusing on the left ventricle.The discussion includes the use of the echocardiogram in the assessment of the right ventricle and diastolic function and in detecting hemodynamic and morphologic changes in heart failure over a period of time.In addition,we highlight some of the limitations of echocardiography in the assessment of these patients.展开更多
Background Coronary slow flow phenomenon (CSFP) is an important, angiographic clinical entity but is lacking non-invasive detecting techniques. This study aimed to elucidate the value of transthoracic Doppler echoca...Background Coronary slow flow phenomenon (CSFP) is an important, angiographic clinical entity but is lacking non-invasive detecting techniques. This study aimed to elucidate the value of transthoracic Doppler echocardiography (TTDE) in the diagnosis and monitoring of coronary slow flow in left anterior descending (LAD) coronary artery.Methods We consecutively enrolled 27 patients with CSFP in LAD detected by coronary arteriography from August 2009 to April 2010. Thirty-eight patients with angiographically normal coronary flow served as control. Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) was used to document coronary flow velocities. All subjects underwent TTDE within 24 hours after coronary angiography. LAD flow was detected and the coronary diastolic peak velocities (DPV) and diastolic mean velocities (DMV) were calculated.Results Sixty of 65 (92.3%) subjects successfully underwent TTDE. Baseline clinical characteristics were similar between the two groups. Coronary DPV and DMV of LAD were significantly lower in the CSFP group than in the control group ((0.228±0.029) m/s vs. (0.302±0.065) m/s, P=0.000; (0.176±0.028) m/s vs. (0.226±0.052) m/s, P=0.000,respectively). There was a high inverse correlation between CTFC and coronary DPV and DMV (r=-0.727, P=0.000;r=-0.671, P=0.000, respectively). Receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) was less than one half for coronary DPV (AUC=0.104) and DMV (AUC=0.204), respectively.Conclusions In patients with CSFP, there is a high inverse correlation between CTFC and coronary diastolic flow velocities in the LAD coronary artery, as measured by TTDE. The value of TTDE in the monitoring and evaluation of coronary flow in patients with CSFP deserves further investigation.展开更多
Background Turbulent shear stress (TSS) plays an important role in the research of fluid dynamics of heart valves. This study aimed to perform a quantitative study of TSS downstream of porcine artificial mitral valv...Background Turbulent shear stress (TSS) plays an important role in the research of fluid dynamics of heart valves. This study aimed to perform a quantitative study of TSS downstream of porcine artificial mitral valves in order to verify the correlation of hot-film anemometry (HFA) and Doppler echocardiography combined with computer-aided image analysis for the detection of TSS. Methods A porcine model of mitral valve replacement was established. HFA and Doppler ultrasound techniques were used to directly and indirectly measure TSS-relevant parameters of the artificial mitral valve following different mitral valve replacements: different approaches were used to reserve the subvalvular apparatus of the mitral valve. A correlation analysis was then carried out. Results There was a significant correlation between the HFA and Doppler ultrasound combined with computer-aided image analysis of the TSS at the same time and at the same site. No significant difference was found in the TSS measured by the two methods. Conclusions Compared with HFA, Doppler echocardiography combined with computer-aided image analysis is a safe, non-invasive, and real-time method that enables accurate and quantitative detection of TSS downstream in vivo, objectively reflecting the flow field downstream of the artificial mitral valve. Doppler ultrasound combined with computer- aided image analysis can be employed for quantitatively evaluating the downstream hemodynamic performance of the mitral valve.展开更多
Background Pulmonary arterial hypertension(PAH) is a common complication of connective tissue disease(CTD) and confers a worse prognosis. Stress doppler echocardiography(SDE) can detect early pulmonary vasculopathy an...Background Pulmonary arterial hypertension(PAH) is a common complication of connective tissue disease(CTD) and confers a worse prognosis. Stress doppler echocardiography(SDE) can detect early pulmonary vasculopathy and assess right heart function in patients with pulmonary arterial hypertension. In this study, the SDE was applied to analyze the degree of pulmonary vascular lesion and the function of right heart in CTD patients without overt PAH. Methods CTD patients without overt PAH were divided into exercised-induced pulmonary hypertension(EIPH) group and non-EIPH group depending on whether tricuspid regurgitation(TR) exceeded 3.1 m/s during exercise and assessed by echocardiography at rest and during exercise. The data of right ventricular function and the slope of the incremental of the mean pulmonary artery pressure and cardiac output(ΔmPAP/ΔCO) were analyzed. Results Forty-seven CTD patients without overt PAH(35 female, mean age 40.3±12.0 years) were enrolled and divided into EIPH group(n=21) and non-EIPH group(n=26). Patients with systemic sclerosis(SSc) were more likely to have EIPH(47.6% vs. 28.6%, P<0.05) than those with systemic lupus erythematosus(SLE). Patients in EIPH group had a higher value of ΔmPAP/ΔCO than that of the non-EIPH group(4.5±3.1 vs. 2.2±1.3, P<0.05). SSc was more prevalent in CTD patients and the symptoms of dyspnea occurred more often in EIPH group(52.4%), indicating a pressure-flow mismatch induced by exercise. However, the cardiac function demonstrated by left ventricular ejection fraction(LVEF), tricuspid annular plane systolic excursion(TAPSE),DTI-Derived S'-wave velocity(S') and right ventricular fractional area change(RVFAC), as well as functional reserve reflected by the changes of TAPSE, S', RVFAC before and after exercise, did not differ significantly between the two groups. Conclusions Although right ventricular(RV) reserve function does not change much before and after exercise, patients in EIPH group have a higher value of ΔmPAP/ΔCO than that of the non-EIPH group and more likely to have symptoms during exercise. Thus, to assess the potential for pulmonary vascular disease, echocardiography should be performed at rest and during exercise.[S Chin J Cardiol 2019;20(1):31-36]展开更多
A computer simulation method for pulsed Doppler signals from vortices was pro- posed to generate simulated vortex Doppler signals under various given circumstances. The relative waveforms, such as the maximum frequenc...A computer simulation method for pulsed Doppler signals from vortices was pro- posed to generate simulated vortex Doppler signals under various given circumstances. The relative waveforms, such as the maximum frequency waveform, the mean frequency waveform and the bandwidth waveform, were obtained using the short time Fourier analysis of those simulated signals. The relations were studied between several spectrum parameters obtained from these waveforms and given simulation conditions, such as the position and the size of the sample volume, the distance between two vortices, the free stream velocity and the maximum tangent velocity of the vortex. The sensitive parameters were found to detect vortices using the pulsed Doppler techniques.展开更多
Objectives To quantitatively analyze the longitudinal myocardial systolic and diastolic velocities and time intervals of the left ventricle in normal subjects, and to explore the value of pulsed Doppler tissue imaging...Objectives To quantitatively analyze the longitudinal myocardial systolic and diastolic velocities and time intervals of the left ventricle in normal subjects, and to explore the value of pulsed Doppler tissue imaging (DTI) for the assessment of left ventricular systolic and diastolic synchronicity. Methods Twenty and six healthy subjects were studied by pulsed DTI. The septal and lateral, anterior and inferior walls of the left ventricle were displayed respectively, and basal and middle segments of each wall were selected for myocardial motion spectrum sampling. DTI parameters were: peak systolic myocardial velocity (s), regional pre-ejection period (PEP), time to the peak of s wave (Ts), regional ejection time (ET) ; peak early diastolic velocity (e), peak late diastolic velocity (a), e/a ratio, time to the beginning of e wave (QE), time to the peak of e wave (Te) and regional isovolumic relaxation time (IVRT). Results The e and e/a were significantly different among basal segments, and s and e/a were significantly different among middle segments, with the highest value in lateral segments and the lowest value in septal segments. The s, e and a were all significantly higher in basal segments than middle segments. None of the systolic time intervals (PEP, Ts and ET) and diastolic time intervals (QE, Te and IVRT) were significantly different among basal segments and middle segments, neither were they when basal segment was compared with middle segment. Conclusions In normal subjects, the longitudinal myocardial systolic and diastolic velocities of the left ventricle are not homogeneous, but the contraction and relaxation are highly synchronized. Pulsed DTI can be used to quantitatively analyze the systolic and diastolic synchronicity of the heart.展开更多
Background: Heart failure (HF) is a common clinical syndrome mostly due to the impaired ability of the Left Ventricle (LV) to eject blood with reduced cardiac output. Heart failure is called systolic (SHF) if left ven...Background: Heart failure (HF) is a common clinical syndrome mostly due to the impaired ability of the Left Ventricle (LV) to eject blood with reduced cardiac output. Heart failure is called systolic (SHF) if left ventricle ejection fraction on echo-cardiogram is low (LVEF of ≤50%). Aim: To assess the echocardiographic characteristics of patients with SHF with Atrial Fibrillation (AF) and compare with those with Sinus Rhythm (SR) on 12 leads ECG. Furthermore, to evaluate the clinical and biochemical markers for the prediction of AF in SHF. Method: Over two years duration, each patient diagnosed with SHF was enrolled in the study (n = 354) based on admission code. AF or sinus rhythm on 12 leads ECG was documented on each patient. Multiple logistic regression analysis was applied to assess the risk ratio of different clinical and Doppler derived variables for the development of AF in SHF. Results: Out of the total hospital medical admissions of 14,674 patients, there were 354 patients with diagnosis of SHF, a prevalence of 2.4%. The incidence of AF on ECG was 109 (31%) patients in the whole study population and 245 (69%) in SR. M Mode echocardiogram in patients with SHF and AF compared with those in SR showed significant dilation of LV cavity in systole with LVESD of 5.72 ± 0.63 vs. 5.23 ± 0.76 cm, P < 0.001 and in Diastole LVEDD of 6.83 ± 0.51 vs. 6.58 ± 0.63 cm, P < 0.001. Pulsed Doppler echocardiogram showed a severe restrictive-pattern with shorter Decellration Time (DT) of 163.73 ± 7.42 vs. 214.9 ± 31.81msec, P < 0.001 and higher Pulse to Tissue Doppler ratio of E/Em of 14.26 ± 1.34 vs. 9.99 ± 1.27, P , and the serum level of Brain Natriuretic Peptide (BNP) hormone of 723.72 ± 13.45 vs. 686.98 ± 72.57 pg/ml, P < 0.001. The predictive risks (odd ratio) of different clinical variables for the development of AF in SHF were positive for high BNP > 500 pg/ml of 2.8, history of hypertension of 1.8, history of DM of 1.7, BMI > 28 of 1.4, LV hypertrophy on ECG of 1.3. Conclusions: The prevalence of Systolic Heart Failure in the study population was 2.4%. The prevalence of AF in the study population was 31%. The best predictors of AF in SHF were high BNP > 500 pg/ml, history of hypertension, Diabete Mellitus and LV Hypertrophy on ECG.展开更多
文摘Summary: The measurement of coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE) with invasive intracoronary Doppler flow wire technique (ICD) was validated and the pathological factors which influence CFVR in patients with angiographically normal coronary arteries were analyzed. CFVR was determined successfully in left anterior descending artery (LAD) in 37 of 40 patients with angiographically normal coronary arteries (men 22, women 15, age 20-75 years, mean age 54±12 years). Coronary flow velocity was measured in the distal LAD by TTDE with contrast enhancement at baseline and during intravenous adenosine infusion of 110 μg/ kg per min within 48 h after ICD technique. Average peak velocity at baseline (APVb), average peak velocity during hyperemia (APVh) and CFVR determined from TTDE were correlated closely with those from ICD measurements (APVb: y= 0. 64x+ 5. 04, r=0. 86, P〈0. 001; APVh: y=0. 63x+14. 36, r=0.82, P〈0.001; CFVR: y=0.65xq-0.92, r=0.88, P〈0.001). For CFVR measurements, the mean differences between TTDE and ICD methods were 0. 12±0.39. CFVR in patients with history of hypertension was significantly lower than that in patients without history of hypertension (P〈0.05). Intravascular ultrasound (IVUS) was performed in 34 patients. Plaque formation was found in LAD by IVUS in 17 (50%) patients. No significant difference in CFVR was found between the patients without plaque formation (3. 11±0. 49) and those with plaque formation (2. 76±0.53, P=0. 056). It is suggested that TTDE with contrast enhancement provides reliable measurement of APV and CFVR in the distal I.AD. The early stage of atherosclerosis could be detected by IVUS, which may be normal in angiography. CFVR is impaired in patients with history of hypertension compared with that in patients without history of hypertension.
文摘Summary: Whether the localized flow acceleration occurs in the resting stenotie left anterior descending coronary artery was explored and its value for detection of coronary stenosis estimated. Blood flow in the left anterior descending coronary arteries in 45 patients was detected by transthoratio color Doppler echocardiograph and multipoint pulse Doppler spectrums were recorded in the same segment. The ratio of the maximal peak diastolic velocity to the minimal peak diastolic velocity was calculated. The ratio ≥1.5 was the cutoff value for the presence of localized acceleration flow. There were 23 patients with localized acceleration flow examined by eehoeardiography. Twenty of them were found to have luminal diameter stenosis (60%-98%) in the left anterior descending coronary arteries by coronary angiography and 3 patients were normal. There were 22 patients without localized acceleration flow examined by eehoeardiography. Eighteen of them had no or %60 stenosis. Four patients had serious stenosis (≥95%) or occluded segments in the left anterior descending coronary arteries on coronary angiography. The ratio of the maximal peak diastolic velocity to the minimal peak diastolic velocity was significantly higher in patients with left anterior descending coronary artery stenosis than that in those without stenosis (1.9±0.3 vs 1.3±0.2, P〈0.01) and it correlated significantly with left anterior descending coronary artery stenosis (r=0.77, P〈0.01). The specificity by using the ratio≥1. 5 for stenosis detection was 85.7% (18/ 21), and the sensitivity was 83.3% (20/24). This study demonstrated that local blood flow velocity was increased in the resting stenotie left anterior descending coronary artery. Transthoraeie color Doppler eehoeardiography is a reliable noninvasive method to detect localized acceleration flow in the left anterior descending coronary artery stenosis and it is useful in the noninvasive diagnosis of stenosis in the left anterior descending coronary artery.
文摘Summary: Transthoracic Doppler echocardiography (TTDE) allows noninvasive flow measurement in the distal left anterior descending artery (LAD). The feasibility of detecting coronary flow by contrast-enhanced TTDE with second harmonic technique was assessed, the coronary flow velocity reserve (CFVR) was evaluated in comparison to intracoronary Doppler flow (ICD) analysis and the CFVR after PTCA in LAD was investigated. In 77 (96 %) of 80 patients, CFVR was successfully determined with intravenous adenosine infusion. Doppler signal quality was evaluated in the first 46 patients by use of intravenous Levovist infusion and second harmonic technique. The Doppler flow was not visible in 1 patient only. CFVR determined from TTDE (2.77±0.65) was correlated closely with those from ICD (2.88±0.78) measurements (y=0.73x+0.67, r=0.87, P<0.001). In conclusion, TTDE is a feasible method and provides reliable data on CFVR which can be used for follow-up after PTCA.
文摘This paper describes a signal processing system in a Pulsed Doppler (PD) radar. It mainly consists of a velocity tracking loop and a digital signal processing auxiliary channel. With many signal processing techniques, the system successfully solves the signal detection and tracking at low SNR and the interference identification and rejection. The idea of system design is introduced in detail. Finally, some simulation and experimental results are presented.
文摘Echocardiography is the most common diagnostic method for assessing cardiac function but some limitations affect this technique.Until now,visual assessment of wall motion and thickening has allowed only a subjective evaluation of myocardial function and requires long-term training.Recently,new echocardiographic techniques have been introduced to evaluate myocardial mechanics.Tissue Doppler imaging(TDI)technique is limited by angle-dependency such that only deformation along the ultrasound beam can be derived from velocities,while myocardium deforms simultaneously in three dimensions.Speckle tracking echocardiography (STE)is a more recent technique that provides a global approach to left ventricular myocardial mechanics,giving information about the three spatial dimensions of cardiac deformation.In this editorial,we describe the physical and pathophysiological concepts of STE,discussing the differences compared to TDI and underlining the pitfalls of this new technique.
文摘Doppler echocardiography is the gold standard for assessment of diastolic dysfunction, which is increasingly recognised as a cause of heart failure, especially in the elderly. Using a combination of Doppler echocardiography techniques, it is possible to identify grades of dia- stolic dysftmction, estimate left ventricular filling pressures and establish the chronicity of diastolic dysfunction. These physiologi- cally-derived measures have been widely validated against invasive measurements of left heart pressures and have been shown to be prog- nostically valuable in a wide range of clinical settings. This review explores the mechanisms, and approaches to the assessment of diastolic dysfunction in the elderly. The challenge for clinicians is to identify pathophysiological changes from those associated with normal ageing. When used in combination, and taking age into account, Doppler echocardiographic parameters are helpful in the assessment of dyspnoea in older patients and provide prognostic insights.
文摘We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler(PW) and pulse tissue Doppler imaging(PW-TDI).A total of 25 consecutive in-patients with persistent atrial fibrillation,who restored sinus rhythm after ablation procedure,were recruited in our cardiac center.Echocardiography was performed on each patient at 2 hours,1 day,5 days,1 month and 3 months after the ablation therapy,and atrial electromechanical delay was measured simultaneously by PW and PW-TDI.There was no significant difference between PW and TDI in measuring atrial electromechanical delay.However,at postoperative 2 hours,peak A detection rates were mathematically but nonsignificantly greater by PWTDI than by PW.Second,there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months,but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time.Lastly,patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval,by the PW or by PW-TDI,respectively.In patients with persistent atrial fibrillation,atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later,and was significantly related to patients' duration of atrial fibrillation.Atrial electromechanical interval,as a potential predicted factor,is recommended to be measured by either PW or TDI after24 hours,when patients had recovered sinus rhythm by radiofrequency ablation.
文摘Heart failure is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fi ll with or eject blood.The echocardiogram is the single most performed and useful study in these patients.This article reviews the role of the echocardiogram in the evaluation of the heart failure patient,without focusing on the left ventricle.The discussion includes the use of the echocardiogram in the assessment of the right ventricle and diastolic function and in detecting hemodynamic and morphologic changes in heart failure over a period of time.In addition,we highlight some of the limitations of echocardiography in the assessment of these patients.
基金This study was supported by grants from National Natural Science Foundation of China (No. 81070166) and Scientific Research Common Program of Beijing Municipal Commission of Education (No. KM201010025020).Acknowledgement: We are grateful to all staff members of the Department of Cardiology and Catheterization Laboratory, Beijing Anzhen Hospital, Capital Medical University.
文摘Background Coronary slow flow phenomenon (CSFP) is an important, angiographic clinical entity but is lacking non-invasive detecting techniques. This study aimed to elucidate the value of transthoracic Doppler echocardiography (TTDE) in the diagnosis and monitoring of coronary slow flow in left anterior descending (LAD) coronary artery.Methods We consecutively enrolled 27 patients with CSFP in LAD detected by coronary arteriography from August 2009 to April 2010. Thirty-eight patients with angiographically normal coronary flow served as control. Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) was used to document coronary flow velocities. All subjects underwent TTDE within 24 hours after coronary angiography. LAD flow was detected and the coronary diastolic peak velocities (DPV) and diastolic mean velocities (DMV) were calculated.Results Sixty of 65 (92.3%) subjects successfully underwent TTDE. Baseline clinical characteristics were similar between the two groups. Coronary DPV and DMV of LAD were significantly lower in the CSFP group than in the control group ((0.228±0.029) m/s vs. (0.302±0.065) m/s, P=0.000; (0.176±0.028) m/s vs. (0.226±0.052) m/s, P=0.000,respectively). There was a high inverse correlation between CTFC and coronary DPV and DMV (r=-0.727, P=0.000;r=-0.671, P=0.000, respectively). Receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) was less than one half for coronary DPV (AUC=0.104) and DMV (AUC=0.204), respectively.Conclusions In patients with CSFP, there is a high inverse correlation between CTFC and coronary diastolic flow velocities in the LAD coronary artery, as measured by TTDE. The value of TTDE in the monitoring and evaluation of coronary flow in patients with CSFP deserves further investigation.
基金This study was supported by grants from the National Natural Science Foundation of China (No. 30860297) and the United Specialized Foundation of Science and Technology Agency of Yunnan Province and Kunming Medical University (No. 2011FB 185).
文摘Background Turbulent shear stress (TSS) plays an important role in the research of fluid dynamics of heart valves. This study aimed to perform a quantitative study of TSS downstream of porcine artificial mitral valves in order to verify the correlation of hot-film anemometry (HFA) and Doppler echocardiography combined with computer-aided image analysis for the detection of TSS. Methods A porcine model of mitral valve replacement was established. HFA and Doppler ultrasound techniques were used to directly and indirectly measure TSS-relevant parameters of the artificial mitral valve following different mitral valve replacements: different approaches were used to reserve the subvalvular apparatus of the mitral valve. A correlation analysis was then carried out. Results There was a significant correlation between the HFA and Doppler ultrasound combined with computer-aided image analysis of the TSS at the same time and at the same site. No significant difference was found in the TSS measured by the two methods. Conclusions Compared with HFA, Doppler echocardiography combined with computer-aided image analysis is a safe, non-invasive, and real-time method that enables accurate and quantitative detection of TSS downstream in vivo, objectively reflecting the flow field downstream of the artificial mitral valve. Doppler ultrasound combined with computer- aided image analysis can be employed for quantitatively evaluating the downstream hemodynamic performance of the mitral valve.
基金supported by medical science and technology research fund of Guangdong Province(No.A2016131)
文摘Background Pulmonary arterial hypertension(PAH) is a common complication of connective tissue disease(CTD) and confers a worse prognosis. Stress doppler echocardiography(SDE) can detect early pulmonary vasculopathy and assess right heart function in patients with pulmonary arterial hypertension. In this study, the SDE was applied to analyze the degree of pulmonary vascular lesion and the function of right heart in CTD patients without overt PAH. Methods CTD patients without overt PAH were divided into exercised-induced pulmonary hypertension(EIPH) group and non-EIPH group depending on whether tricuspid regurgitation(TR) exceeded 3.1 m/s during exercise and assessed by echocardiography at rest and during exercise. The data of right ventricular function and the slope of the incremental of the mean pulmonary artery pressure and cardiac output(ΔmPAP/ΔCO) were analyzed. Results Forty-seven CTD patients without overt PAH(35 female, mean age 40.3±12.0 years) were enrolled and divided into EIPH group(n=21) and non-EIPH group(n=26). Patients with systemic sclerosis(SSc) were more likely to have EIPH(47.6% vs. 28.6%, P<0.05) than those with systemic lupus erythematosus(SLE). Patients in EIPH group had a higher value of ΔmPAP/ΔCO than that of the non-EIPH group(4.5±3.1 vs. 2.2±1.3, P<0.05). SSc was more prevalent in CTD patients and the symptoms of dyspnea occurred more often in EIPH group(52.4%), indicating a pressure-flow mismatch induced by exercise. However, the cardiac function demonstrated by left ventricular ejection fraction(LVEF), tricuspid annular plane systolic excursion(TAPSE),DTI-Derived S'-wave velocity(S') and right ventricular fractional area change(RVFAC), as well as functional reserve reflected by the changes of TAPSE, S', RVFAC before and after exercise, did not differ significantly between the two groups. Conclusions Although right ventricular(RV) reserve function does not change much before and after exercise, patients in EIPH group have a higher value of ΔmPAP/ΔCO than that of the non-EIPH group and more likely to have symptoms during exercise. Thus, to assess the potential for pulmonary vascular disease, echocardiography should be performed at rest and during exercise.[S Chin J Cardiol 2019;20(1):31-36]
基金This work is supported by the Outstanding Young Teacher Funds of Chinese Ministry of Education.
文摘A computer simulation method for pulsed Doppler signals from vortices was pro- posed to generate simulated vortex Doppler signals under various given circumstances. The relative waveforms, such as the maximum frequency waveform, the mean frequency waveform and the bandwidth waveform, were obtained using the short time Fourier analysis of those simulated signals. The relations were studied between several spectrum parameters obtained from these waveforms and given simulation conditions, such as the position and the size of the sample volume, the distance between two vortices, the free stream velocity and the maximum tangent velocity of the vortex. The sensitive parameters were found to detect vortices using the pulsed Doppler techniques.
文摘Objectives To quantitatively analyze the longitudinal myocardial systolic and diastolic velocities and time intervals of the left ventricle in normal subjects, and to explore the value of pulsed Doppler tissue imaging (DTI) for the assessment of left ventricular systolic and diastolic synchronicity. Methods Twenty and six healthy subjects were studied by pulsed DTI. The septal and lateral, anterior and inferior walls of the left ventricle were displayed respectively, and basal and middle segments of each wall were selected for myocardial motion spectrum sampling. DTI parameters were: peak systolic myocardial velocity (s), regional pre-ejection period (PEP), time to the peak of s wave (Ts), regional ejection time (ET) ; peak early diastolic velocity (e), peak late diastolic velocity (a), e/a ratio, time to the beginning of e wave (QE), time to the peak of e wave (Te) and regional isovolumic relaxation time (IVRT). Results The e and e/a were significantly different among basal segments, and s and e/a were significantly different among middle segments, with the highest value in lateral segments and the lowest value in septal segments. The s, e and a were all significantly higher in basal segments than middle segments. None of the systolic time intervals (PEP, Ts and ET) and diastolic time intervals (QE, Te and IVRT) were significantly different among basal segments and middle segments, neither were they when basal segment was compared with middle segment. Conclusions In normal subjects, the longitudinal myocardial systolic and diastolic velocities of the left ventricle are not homogeneous, but the contraction and relaxation are highly synchronized. Pulsed DTI can be used to quantitatively analyze the systolic and diastolic synchronicity of the heart.
文摘Background: Heart failure (HF) is a common clinical syndrome mostly due to the impaired ability of the Left Ventricle (LV) to eject blood with reduced cardiac output. Heart failure is called systolic (SHF) if left ventricle ejection fraction on echo-cardiogram is low (LVEF of ≤50%). Aim: To assess the echocardiographic characteristics of patients with SHF with Atrial Fibrillation (AF) and compare with those with Sinus Rhythm (SR) on 12 leads ECG. Furthermore, to evaluate the clinical and biochemical markers for the prediction of AF in SHF. Method: Over two years duration, each patient diagnosed with SHF was enrolled in the study (n = 354) based on admission code. AF or sinus rhythm on 12 leads ECG was documented on each patient. Multiple logistic regression analysis was applied to assess the risk ratio of different clinical and Doppler derived variables for the development of AF in SHF. Results: Out of the total hospital medical admissions of 14,674 patients, there were 354 patients with diagnosis of SHF, a prevalence of 2.4%. The incidence of AF on ECG was 109 (31%) patients in the whole study population and 245 (69%) in SR. M Mode echocardiogram in patients with SHF and AF compared with those in SR showed significant dilation of LV cavity in systole with LVESD of 5.72 ± 0.63 vs. 5.23 ± 0.76 cm, P < 0.001 and in Diastole LVEDD of 6.83 ± 0.51 vs. 6.58 ± 0.63 cm, P < 0.001. Pulsed Doppler echocardiogram showed a severe restrictive-pattern with shorter Decellration Time (DT) of 163.73 ± 7.42 vs. 214.9 ± 31.81msec, P < 0.001 and higher Pulse to Tissue Doppler ratio of E/Em of 14.26 ± 1.34 vs. 9.99 ± 1.27, P , and the serum level of Brain Natriuretic Peptide (BNP) hormone of 723.72 ± 13.45 vs. 686.98 ± 72.57 pg/ml, P < 0.001. The predictive risks (odd ratio) of different clinical variables for the development of AF in SHF were positive for high BNP > 500 pg/ml of 2.8, history of hypertension of 1.8, history of DM of 1.7, BMI > 28 of 1.4, LV hypertrophy on ECG of 1.3. Conclusions: The prevalence of Systolic Heart Failure in the study population was 2.4%. The prevalence of AF in the study population was 31%. The best predictors of AF in SHF were high BNP > 500 pg/ml, history of hypertension, Diabete Mellitus and LV Hypertrophy on ECG.