Effect of burden and origin sites of premature ventricular contractions on left ventricular function by 7-day Holter monitor

Recent studies have shown that premature ventricular contractions （PVCs） could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular （LV） function in patients with PVCs by 7-day Holter electrocardiography （ECG）. From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors＇ affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal pro- brain natriuretic peptide （NT-proBNP） levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction （EF） level and a lower LV end-systolic dimension （ESD） than other PVC foci （P〈0.05）. The high burden group had a higher LV end-diastolic dimension （EDD） and LVESD but lower LVEF than the other two groups （P〈0.05）. Female, older age, physical work, and history of PVCs had a significantly positive correlation with symptoms. Male, older age, physical work, and high burden were positive predictors of enlarged LVEDD, LVESD and higher serum NT-proBNP level, but lower LVEF. Seven-day dynamic ECG Holter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction.

ASSESSMENT OF LEFT VENTRICULAR FUNCTION IN HEALTHY SUBJECTS BY PUSLED WAVE DOPPLER TISSUE IMAGING

Objective To examine the clinical application of pulsed Doppler tissue imaging(DTI)for regional left ventricular function assessment in normal subjects. Methods We examined 50 healthy subjects(range 12-42 years,mean age 28.3 ± 6.9 years)using pulsed Doppler tissue imaging to characterize the diastolic and systolic velocity profiles of mitral annulus. Recordings were made along the long axis in the apical 4-chamber, 2-chamber, and long apical views of 6 sites(posterior-septum, lateral, anterior, inferior, anterior-septum, posterior)at the mitral annulus. Myocardial velocities were determined with use of variance F statistical analysis. Correlation analysis was employed to test the relationship between age and mitral annular velocities. Results Both early diastolic and systolic velocities at the septum were lower than other sites. There were no differences in mitral annulus late diastolic velocities. Mean early diastolic and systolic velocities was negatively correlated with age. Conclusions Doppler tissue imaging can directly reflect regional left ventricular function.

Effect of Fish Oil on Left Ventricular Function in Anes-thetized Rats

The effect of fish oil on the basal left ventricular function and changes of left ventricular function induced by isoproterenol(ISO)were demonstrated in our study. The detennina-tion of cardiac perfonnance in vivo showed that supplementation with fish oil(EPA and DHA,70%,1.4 ml / kg) had no significant effect on basal cardiac perfonnance,while it could significantly inhibit changes of+ dp / dt_(max),V_(pm) and HR induced by ISO(0.4μg/ kg,4.0μg/ kg,40μg/ kg)intrave-nously.The results suggested that supplementation with fish oil perhaps affected the function of β-adrenoceptors on rat myocardial membrane.

EFFECT OF AROTINOLOL ON LEFT VENTRICULAR FUNCTION IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY

Objective To evaluate the efficacy and safety of long-term treatment with arotinolol in patients with idiopathic dilated cardiomyopathy(IDCM).Methods Sixty-three patients with IDCM were evaluated at baseline and after 12-month therapy with arotinolol.The conventional therapy for congestive heart failure was continued throughout the study with arotinolol as the only β-blocker.Left ventricular function was assessed with the New York Heart Association functional class and two-dimensional echocardiography.Results After 12-month arotinolol treatment,there was a significant improvement in left ventricular systolic function.Left ventricular end-systolic dimension significantly decreased from 59.52±8.83 mm to 50.89±8.17 mm(P<0.001).Left ventricular ejection fraction significantly increased from 27.39%±7.94% to 41.13%±9.45%(P<0.001).Left ventricular mass index decreased from 150.47±42.42 g/m2 to 141.58±34.36 g/m2(P<0.01).No adverse events leading to premature discontinuation of study drug occurred.Conclusion In this preliminary study,12-month arotinolol treatment has a favorable effect on left ventricular function in patients with IDCM,and it is safe and well tolerated.

Left Atrial Volume Index in Patients with Dilated Cardiomyopathy—Correlation with Left Ventricular Function

Background: The aim of this study was to determine the relation of left atrial (LA) volume and LA volume index with left ventricular function and to determine the association of duration of symptoms and left atrial volume index in patients with dilated cardiomyopathy. Materials and Methods: This was an observational, single centre study conducted in India. A total of 50 patients who were admitted to department of cardiology from July, 2008 to February, 2009 with diagnosis of dilated cardiomyopathy and an ejection fraction of <40% were included. Results: Of the 50 patients, 34 (68%) were males. 27 (54%) patients were in NYHA class II and 23 (46%) patients were in NYHA class III. LA volume was found to be ≥40 ml in all patients. LV function and LA volume were found to be correlated (r = -0.789, p < 0.01). Similarly, there was a correlation between LV function and LA volume index (r = -0.826, p < 0.01). There was no correlation between LA volume index and duration of symptoms (r = 0.04). Conclusion: It can be concluded that there is a strong inverse correlation between LA volume and left ventricular function and also between LA volume index and left ventricular function. The patients with NYHA class III were having larger left atrial volume than those with NYHA class II. Moreover, the duration of symptoms has no correlation with left atrial volume index.

Tei index evaluates left ventricular function changes after on-pump and off-pump coronary artery bypass surgery

Objective： To compare function recovery of left ventricle after off-pump and on-pump coronary artery bypass （OPCAB and ONCAB） using Tel index. Methods： Twenty-four patients with coronary artery disease were enrolled, twelve of which received OPCAB and the others underwent ONCAB. Left ventricular ejection fraction （LVEF）, E/A ratio at mitral orifice and Tel index were measured using transthoracic echocardiography before surgery and 3-7 days, 1 month, 3 months and 6 months after surgery. Results：Tel index of both groups decreased 3-7 days after surgery, with OPCAB group＇s lower than ONCAB group＇s. The difference between pre-and post-OPCAB was significant （P〈0.01）, but not for ONCAB group （P〈0.05）. Tel index of ONCAB decreased more significant than that of OPCAB 1 month after surgery, there was statistical difference between 3-7 days and 1 month after surgery in ONCAB （P〈0.01）. Afterwards, Tel index of the 2 groups decreased steadily with no significant difference between them at other time points. LVEF and E/A ratio decreased at first, then increased gradually, with no statistical differences between the 2 groups at all time points. Conclusion： The recovery of left ventricular function after OPCAB is earlier than ONCAB. Tel index is more sensitive than LVEF and E/A ratio in detecting cardiac function recoveries and can be considered as an accurate and simple method to evaluate left ventricular systolic and diastolic function.

Viable Myocardium Impact on Left Ventricular Function after Late Revascularization of Infarct-related Artery in Acute Myocardial Infarction

Objectives The long-term benefit of late reperfusion of infarct-related artery （IRA） after acute myocardial infarction （AMI） is controversial, and the benefit mechanisms remain uncertain. Low dose dobutamine stress echocardiography （LDSE） can identify viable myocardium and predict improvement of wall motion after revascularization. Methods Sixtynine patients with first AMI who did not received early reperfusion therapy were studied by LDSE at 5 to 10 days after AMI. Wall motion abnormality and left ventricular size were measured at the same time. Successful PCI were done in all patients at 10 to 21 days after AMI onset. Patients were divided in two groups based on the presence or absence of viable myocardium. Echocardiography was repeated six months later. Results There were 157 motion abnormality segments. 89 segments （57%） were viable during LDSE. 26 patients （38%） with viability and 43 （62%） without. In viable group, left ventricular ejection fraction （LVEF） was increased （P 〈 0.05）, and left ventricular end systolic volume index （LVESVI） and wall motion score （WMS） were decreased （P 〈 0.05 and P 〈 0.01） significantly at 6 months compared with baseline. But in patients without viability, LVEF was decreased （P 〈 0.01）, and LVESVI and left ventricular end diastolic volume index （LVEDVI） were increased （P 〈 0.05） significantly after 6 months, and the WMS did not changed （P 〉 0.05 ）. LVEF increased （P 〈 0.05 ） and WMS decreased （P 〈 0.05） on LDSE during acute phase in patients with viability, but they were not changed in the nonviable group. Conclusions Late revascularization of IRA in patients with presence of viable myocardium after AMI is associated with long-term preservation left ventricular function and less ventricular remodeling. Improvement of left ventricular systolic function on LDSE indicates late phase recovery of left ventricular function after late revascularization.

Evaluation of Left Ventricular Function after Percutaneous Recanalization of Chronic Coronary Occlusions: The Role of Two-Dimensional Speckle Tracking Echocardiography

Background: The recanalization of a chronic total coronary occlusion is the possible way to improve left ventricular (LV) function through the recovery of hibernating myocardium. Aim: The aim of this study is to evaluate the role of 2D speckle tracking in evaluation of the left ventricular (LV) systolic function in chronic total occlusion (CTO) patients before and at 1 day as well as 3 months after percutaneous coronary intervention (PCI). Patients and Methods: A prospective observational study included 40 patients diagnosed with coronary angiography to have a chronic total occlusion. Percutaneous coronary revascularization was performed according to standard practices with the femoral approach. Conventional 2D echocardiography was used to assess LV functions and wall motion abnormalities scoring index (WMAI). Using speckle-tracking echocardiography was to measure global longitudinal strain (GLS) and. Follow-up of patients was done at day 1 and 3 months later after PCI. Results: Forty patients were included in this study, with a mean age of 58.55 ± 7.98 years. GLS and WMAI difference at baseline and follow-up shows a positive correlation with left ventricular ejection fraction (LVEF) changes at baseline and follow-up (p Conclusion: The results of this study provide evidence to support the clinical use of 2D-STE to monitor the early changes of LV function. In patients undergoing CTO revascularization, change in GLS was more sensitive predictors for LV function improvement at 3-month follow-up.

An Overview of the Consequences of Distal Coronary Microembolization on Left Ventricular Function, Perfusion and Viability

Annually, an estimated 1,285,000 in-patient angioplasty procedures, 1,471,000 inpatient diagnostic cardiac catheteri-zations and 68,000 inpatient defibrillator implantations are performed. The direct and indirect cost of cardiovascular diseases for 2007 is approximately $431.8 billion. The occurrence of plaque rupture with subsequent microemboli of atherosclerotic and thrombolytic debris into small coronary vessels has been confirmed. Microinfarction results from microemboli that are shed following coronary interventions. The aims of this review are to: 1) detect heterogeneous microinfarction using viability imaging, 2) characterize the consequences of distal coronary microembolization on left ventricle function and perfusion and 3) illustrate the progress of non-invasive imaging modalities in assessing distal coronary microembolization.

The Relationships between Serum Concentration of IGF-I and Left Ventricular Function as well as Coronary Collateral Circulation in Patients with Coronary Artery Disease

Objective To investigate therelationships between serum concentration of insulin -like growth factor - I (IGF-I) and left ventricular function as well as coronary collateral circulation in patients with coronary artery disease (CAD) . Methods In 41 patients with CAD and 15 control subjects without CAD, the concentrations of serum IGF - I were measured using radioimmunoassay. The relationships between the concentration of serum IGF - I and Leaman coronary artery score, Rentrop grade of coronary collateral circulation, left ventricular ejection fraction (LVEF) as well as left ventricular wall motion Cortina score were assessed. Results 1. There was no significant difference in the mean level of serum IGF -I between the CAD group and the control group (107. 92±44.74 ng/ml vs 113.05 ±33. 65 ng/ml, P> 0. 05), but the IGF - I concentrations in the subgroup with collateral circulation were significantly greater than that in the control group (147. 33 ±29. 92 ng/ml vs 113. 05±33. 65 ng/ml, P < 0. 01) or in the subgroup without collateral circulation (147. 33 ±29. 92 ng/ml vs 80. 01±29. 75 ng/ml , P < 0. 01). 2. The serum concentration of IGF -I had no significant correlation to the Leaman coronary artery score. 3. The serum level of IGF -I had significantly positive correlation to both LVEF ( r = 0. 45, P < 0. 001) and the Rentrop grade of coronary collateral circulation ( r = 0. 74, P < 0. 001), and was negatively related to the left ventricular wall motion Cortina score (r = -0. 53, P < 0. 001). 4. The Leaman coronary artery score had no significant correlation to the Rentrop grade of coronary collateral circulation. 5. The Leaman coronary artery score was related to neither the LVEF nor the Cortina score in the whole CAD group. In the subgroup without coronary collateral circulation, however, the Leaman score had significantly negative correlation to LVEF ( r = - 0. 46, P < 0. 05) and positive correlation to the Cortina score (r = 0. 47, P < 0. 05) . Conclusions The serum concentration of IGF -I was associated with both left ventricular function and coronary collateral circulation in patients with CAD. IGF -I may play a role in promoting coronary collateral circulation and in protecting left ventricular function in patients with coronary artery disease.

Accuracy of left ventricular function from electrocardiographygated myocardial perfusion SPECT by MyoMetrix in Chinese

This work was to determine threshold values for accurate measurements of left ventricular end-diastolic volume(EDV),end-systolic volume(ESV),and ejection fraction(EF) from electrocardiography-gated myocardial perfusion imaging(MPI) in Chinese,and these data were compared with those of echocardiography.A total of 110 patients with definite or suspected coronary artery disease were referred for both gated MPI and echocardiography within 1 week.The EDV,ESV,and EF automatically measured by MyoMetrix and echocardiography were analyzed using Bland-Altman plot correlation and paired t test.The results showed that these parameters quantified by MyoMetrix software were correlated,moderately to highly,with those on echocardiography(ρ,r ≥0.75,P<0.01).However,the EF was not significantly correlated,with post-exercise MPI ESV of <15 mL or resting MPI ESV of <20 mL.At or above this ESV value,EF was underestimated by MyoMetrix(t≥ 4.60,P<0.01).In a word,a small ESV was underestimated by MyoMetrix,which could lead to EF overestimation.On the contrary,a normal or large ESV was overestimated by MyoMetrix,which led to EF underestimation.

Frequency domain cardiography and radionuclide ventriculography for evaluation of left ventricular function in coronary artery disease

Fifty-six patients with chest pain underwent selective coronaryangiography,radionuclide ventriculography (RNV) and frequency domaincardiography (FCG) to evaluate left ventricular function in coronary artery dis-ease (CAD).The sensitivity,specificity and accuracy of FCG were 87.5%,77.8%and 82.9%,respectively,which were slightly less than those of RNV (92.5%,88.9% and 90.8%,respectively).The changes of FCG scores were negatively corre-lated with changes of LVEF (r=-0.586,P【0.01),and TS (r=-0.679,P【0.01).These results indicate that FCG may be useful for the evaluation of leftventricular function in patients with CAD.

The Clinical Association of Left Atrial Function with Left Ventricular Ejection Fraction

The left atrium (LA) has been recognized as a morphophysiological barometer of left ventricular (LV) diastolic dysfunction. Because in the myocardial ischemia cascade where LV diastolic dysfunction often precedes LV systolic dysfunction, the LA which fashions as an early marker of diastolic anomaly, could equally reflect a declining LV function and/or be a good predictor of potential sequelae. We assessed this association of LA function with reduced LV systolic function among hospitalized patients. Among patients with reduced LV ejection fraction, LA passive ejection fraction was lower (0.172 ± 0.12 vs. 0.232 ± 0.14, p = 0.013) whereas LA kinetic energy was higher (6.48 ± 6.3 vs. 4.57 ± 3.5, p = 0.005). Echocardiographic assessment of LA function, therefore, appears correlated with LVEF and could be important when risk stratifying hospitalized patients.

Deep learning echocardiographic intelligent model for evaluation on left ventricular regional wall motion abnormality

Objective To observe the value of deep learning echocardiographic intelligent model for evaluation on left ventricular(LV)regional wall motion abnormalities(RWMA).Methods Apical two-chamber,three-chamber and four-chamber views two-dimensional echocardiograms were obtained prospectively in 205 patients with coronary heart disease.The model for evaluating LV regional contractile function was constructed using a five-fold cross-validation method to automatically identify the presence of RWMA or not,and the performance of this model was assessed taken manual interpretation of RWMA as standards.Results Among 205 patients,RWMA was detected in totally 650 segments in 83 cases.LV myocardial segmentation model demonstrated good efficacy for delineation of LV myocardium.The average Dice similarity coefficient for LV myocardial segmentation results in the apical two-chamber,three-chamber and four-chamber views was 0.85,0.82 and 0.88,respectively.LV myocardial segmentation model accurately segmented LV myocardium in apical two-chamber,three-chamber and four-chamber views.The mean area under the curve(AUC)of RWMA identification model was 0.843±0.071,with sensitivity of(64.19±14.85)%,specificity of(89.44±7.31)%and accuracy of(85.22±4.37)%.Conclusion Deep learning echocardiographic intelligent model could be used to automatically evaluate LV regional contractile function,hence rapidly and accurately identifying RWMA.

Three hours continuous injection of adenosine improved left ventricular function and infarct size in patients with ST-segment elevation myocardial infarction

Background The definitive treatment for myocardial ischemia is reperfusion. However, reperfusion injury has the potential to cause additional reversible and irreversible damage to the myocardium. One likely candidate for a cardioprotection is adenosine. The present study aimed at investigating the effect of intravenous adenosine on clinical outcomes in patients with ST-segment elevation myocardial infarction （STEMI） undergoing primary percutaneous coronary intervention （PCI）. Methods Patients with STEMI within 12 hours from the onset of symptoms were randomized by 1：1：1 ratio to receive either adenosine 50μg-kg-1.min-1 （low-dose group, n=31）, or 70 μg.kg-1.min1 （high-dose group, n=32）, or saline 1 ml/min （control group, n=27） for three hours. Drugs were given to the patients immediately after the guide wire crossed the culprit lesion. Recurrence of no-reflow, TIMI flow grade （TFG） and TIMI myocardial perfusion grade （TMPG）, and collateral circulation were recorded. The postoperative and preoperative ST segment elevation sum of 18-lead electrocardiogram （ECG） and their ratio （STsum-post/STsum-pre） were recorded, as well as the peak time and peak value of CK-MB enzyme. Serial cardiac echo and myocardial perfusion imaging were performed at 24 hours and 6 months post-stenting. The primary endpoint was left ventricular function, and infarct size. The secondary end-point was the occurrence of cardiac and non-cardiac death, non-fatal myocardial infarction, and heart failure. Results A total of 90 STEMI patients were studied. No-reflow immediately after stent procedure was seen in 11 （35.5%） patients in the control group, significantly different from 6.3% in the low-dose group or 3.7% in the high-dose group （both P=0.001）. STsum-post/STsum-pre in the low-dose and high-dose groups was significantly different from the control group （low-dose group vs. control group, P=0.003 and high-dose group vs. control group, P=0.001）, without a dose-dependent pattern （P=0.238）. The peak value of CK-MB enzyme was significantly reduced in the high-dose group compared to the control group （P=-0.024）. Compared to the left ventricular ejection fraction （LVEF） in control group, LVEF in the low-dose group increased by 5.8% at 24 hours （P=0.012） and by 10.9% at 6 months （P=0,007）, LVEF in the high-dose group increased by 9.5% at 24 hours （P=0.001） and by 10.0% at 6 months （P=0.001）, respectively. Significant reduction of infarct size by 24.2% was detected in the high-dose group vs. low-dose or control groups （P=0.008）. There was no significant difference regarding secondary endpoints at 6 months among the treated groups. Cardiac function by NYHA classification in both the low-dose and the high-dose groups was improved significantly （P=0.013, P=0.016）. Conclusion Intravenous adenosine administration might significantly reduce the recurrence of no-reflow, with resultant improved left ventricular systolic function. High-dose adenosine was further associated with significant reduction of infarct size.

Effects of Late Reperfusion on Left Ventricular Function and Its Relationship With Viable Myocardium After Acute Myocardial Infarction in Patients With or Without Diabetes

Objectives To compare the different effects of late successful reperfusion with PCI on left ventricular function and its relationship with viable myocardium after acute anterior wall myocardial infarction in patients with or without diabetes. Methods A total of 125 consecutive subjects with acute anterior wall myocardial infarction were selected, and divided into diabetes mellitus （DM） group （ n = 43） and Non-DM group （ n = 82） according to WHO diabetes diagnosis criteria. All patients received successful PCI at 12 ± 8 days from onset. Ischemic viable myocardium was detected with low-dose dobutamine echocardiography, and left ventricular function and wall motion abnormality were also assessed with echocardiography before PCI. The data of clinical manifestations and angiograms before and after PCI were analyzed. Levels of creatinine kinase-MB （CK-MB）, and troponin T （TnT） before PCI, 6 hours and 24 hours after PCI were assessed. All patients received clinic and echocardiography follow-up for 6 months. Results Higher rate of TIMI 2 flow, and lower rate of TIMI 3 flow in DM group were demonstrated immediately after PCI, and the rate of serum CK-MB and/or TnT levels were higher in DM group, compared with Non-DM group（P 〈 0.05）. 63% of DM patients and 56% of non-DM patients had viable myocardium before PCI（ P 〉 0. 05）. There were no significant differences of left ventricular ejection fraction （LVEF）, left ventricular end diastolic volume index （LVEDVI）, left ventricular end systolic volume index （LVESVI）, and wall motion score （WMS） between two groups at baseline before PCI（P 〉 0.05）. After six months, WMS was decreased and LVEF was increased in Non-DM group, but the WMS and the LVEF did not changed, and the LVEDVI was increased in DM group compared with baseline; the LVEDVI, LVESVI, LVEF, and WMS were significantly different between two groups （P 〈 0.05 or P 〈 0. 01 ）. Conclusions Compared with non-diabetics, delayed successful revascularization with PCI in diabetics patient with acute myocardial infarction has less benefitial effect on the improvement of late phase left ventricular function, and it may be because the insufficient reperfusion or reperfusion injury to myocardium but not the viable myocardium contributing to the poor result. （S Chin J Cardiol 2009; 10（4） ： 196 -203）

Effect of PTCA and stenting on left ventricular diastolic function in patients with CHD

Objective The aim of this study was to determine the effect of successful coronary revascularisation on left ventricular diastolic function.Methods We consecutively studied the diastolic function by Doppler echocardiography in 125 patients with one vessel disease before and 48 hours after selective coronary angioplasty. The following parameters of left ventricular diastolic function were evaluated: peak early (VE, m/s) and peak late diastolic (VA, m/s) flow velocity, E/A ratio, acceleration time (AT, ms), deceleration time (DT, ms) and isovolumetric relaxation time (IVRT, ms). Ejection fraction (EF; %) was determined and used to characterise systolic left ventricular function. Results All of the patients were initially successful treated with coronary angioplasty (residual stenosis <40% ). In 98 patients( 78.4% ) stents were used to improve an inadequate result after coronary angioplasty. Both patient groups (27 patients with coronary angioplasty and 98 patients with combined coronary angioplasty and stent implantation) showed no relevant differences concerning sex, age, atherosclerotic risk factors, exercise capacity and results of exercise electrocardiography. All patients who underwent stent implantation showed an early improvement of left ventricular diastolic function 48 hours after revascularisation. Surprisingly there was no significant short term improvement (48 hours) of diastolic function in patients with initially successful angioplasty.Conclusions We suppose that stent implantation might normalize coronary blood flow faster than that of coronary balloon angioplasty.

Left ventricular regional and global diastolic function assessed using Quantitative Tissue velocity Imaging in patients with hypertrophic cardiomyopathy

Objectives The study was performed to assess the left ventricular (LV) regional and global diastolic function、left ventricular wall motion features in patients with Hypertrophic cardiomyopathy by Quantitative Tissue Velocity Imaging (QTVI). Methods 42 patients with hypertrophic cardiomyopathy and 36 age-matched normal subjects underwent QTVI study. Off-line LV regional muscular tissue velocity Imaging along LV apical long-axis view were obtained. Regional diastolic function was assessed in using peak tissue velocities of LV regional muscular tissue during early diastole (Ve)and LA contraction (Va), Ve/Va ratio, derived from Tissue Velocity Imaging. Global diastolic function was reflected by isovolumic relaxation time(IRT) and mitral valve peak flow velocity ( E/A ) calculated with pulsed wave doppler. The end-diastolic interventricular septal thickness (ⅣSt) was measured by conventional 2 - dimension echocardiography. Results ① Ve、 Va、 Ve/Va in the segments of hypertrophic interventricular septum (IVS) reduced wlhile E/A ratio significantly reduced and IRT markedly prolonged in HCM patients than in normal subjects。 ② Ve、 Ve/Va were significant reduced in the segments of hypertrophic interventricular septum compared with other LV segments in HCM patients . ③ There was a correlation between Ve/Va and E/A in HCM patients with abnormal E/A ratio (r = 0. 70). ④ There was a negative correlation between Ve/Va and ⅣSt in non -obstruction HCM patients (B group , r = -0.61 ) Conclusions QTVI offers a newer method in clinical practice which has a higher sensibility and accuracy in evaluating the LV regional and global diastolic function in HCM patients .

Accuracy of three-dimensional quantification of left ventricular function using magnetic sensor acquisition: a dynamic in vitro model

Objective To evaluate the accuracy of a three-dimensional (3D) magnetic position sensor system in the quantification of ventricular stroke volumes in a dynamic model.Methods A latex balloon model of the left ventricle was suspended in a water bath connected to a pump producing 10 different pulsatile stroke volumes (15-65mi/beat). Scanning was performed using a 5.0 mHz transducer mounted with a Flock of Birds (FOB) magnetic receiver (GE System Five). The probe was scanned to sweep continuously across and over the balloon volume over 3 - 7 seconds. Digital loops were stored on magneto-optical disks and reviewed retrospectively using 3D Echopac software (GE)based on Simpson's method and compared with a two-dimensional (2D) biplane area-length method (1/2L x R) measurements at end systole and end diastole. Both 3D and 2D derived stroke volumes were compared with the reference stroke volume calculated by direct measurement of balloon capacity.Results There was an improved correlation between 3D stroke volume and reference stroke volume ( y = 0.91 x + 0.41, r = 0.97, SEE = 2.83 ml, P = 0.0001 ) compared to 2D stroke volume and reference stroke volume (y=0.49x+8.68, r=0.87, SEE=3.87 ml, P=0.0011, difference between 2D and 3D P＜0.003).Conclusion 3D magnetic FOB scanning is practical, accurate and should facilitate assessment of left ventricular function.

Left ventricular function in rats measured by apical catheterization

Background Evaluation of left ventricular function plays a vital role in the study of hemodynamics in the circulatory system.This study investigated the feasibility of measuring left ventricular function in rats with catheterization at the apex of the heart.Methods Left carotid catheterization was used to monitor artery pressure,then right carotid-ventricular catheterization and apical catheterization were orderly performed in 20 SD rats to observe the changes of left heart function.Heart rate,carotid arterial pressure,left ventricular peak pressure,left ventricular end-diastolic pressure were recorded by the biological function experiment system,and differential calculations analyzed the systolic and diastolic rate of left ventricular pressure.Results The peak left ventricular pressure was statistically different between when measured by right carotid-ventricle catheterization and by catheterization at the apex of heart(120.7±14.46 mmHg vs.114.04±12.01 mmHg,P<0.05).There was a significant difference in the carotid artery pressure between when the left ventricular function was measured by right carotid-ventricular catheterization and by apical catheterization(115.6±11.24 mmHg vs.108.07±12.33 mmHg,P<0.05),while a different statistical scenario existed for the maximum increase rate of left ventricular pressure(6197.89±1123.28 mmHg/s vs.5985.92±1342.81 mmHg/s,P>0.05);30 min later,the left ventricular pressure and the maximum increase rate of left ventricular pressure were not significantly different between the first and second measurement measured by catheterization at the apex of heart(114.04±12.01 mmHg vs.112.06±11.26 mmHg,5985.92±1342.81 mmHg/s vs.5700.86±598.97 mmHg/s,P>0.05).However,the maximum decline rate of left ventricular pressure was slightly lower compared with the previous measurement(5231.14±1302.57 mmHg/s vs.4862.72±610.49 mmHg/s,P<0.05).Conclusions It is feasible to evaluate cardiac function in rats by catheterization at the apex of heart,and it is superior to right carotid catheterization for its simpler operation,less bleeding risk,less operation time,and the measurement can be repeatedly conducted at least once.[S Chin J Cardiol 2021;22(1):50-56]