Left Ventricle Ejection Time Research Articles

The prognostic value of low-flow in severe aortic stenosis patients undergoing TAVI - should we follow the flow?

Abstract Funding Acknowledgements Type of funding sources: None. Background Low-flow conditions are associated with higher mortality after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (SAS). Two parameters have been described to determine low-flow status – although the most currently used is stroke volume index, transaortic flow rate (FR – stroke volume divided by left ventricle ejection time) was recently suggested as being superior, as it more closely reflects valvular resistance. Purpose Determine the prognostic impact of low-flow conditions in survival of patients undergoing TAVI for SAS, using low-FR and low-SVi definitions. Methods A database comprising all patients treated with TAVI between 2011 and 2019 in a single-centre was retrospectively analyzed, and cases with echocardiograms performed before intervention in our centre were included. Low-flow patients were defined according to a basal FR<200mL/s or SVi<35mL/m2, and compared with normal counterparts. The prognostic impact of flow was tested using Kaplan-Meier curves, log-rank test and Cox proportional hazard model adjusted for EuroSCORE II, using FR or SVi both as categorical and continuous variables. A subsequent analysis compared patients with preserved and reduced ejection fraction (EF, <52%). Primary endpoint was defined as time to all-cause mortality or last follow-up over the five years after TAVI. Results Of 657 TAVI performed, 490 (74.6%) patients were included in the present analysis, over a median follow-up of 56 months. Of these, 59.6% presented low-FR, and 43.3% had low-SVI. Low-flow patients, using each definition, were of higher estimated surgical risk (EuroSCORE and STS), presented a more advanced NYHA class, had a worse estimated creatinine clearance, and more frequently had coronary disease. Additionally, low-FR patients were older and more frequently female. Atrial fibrillation was more common in low-SVi cases. Echocardiographic studies revealed a lower functional aortic valve area in low-flow cases, and low-SVi was associated with lower transaortic gradients, and lower EF before and after TAVI. Low-FR before TAVI was associated with higher mortality over follow-up [Hazard Ratio (HR) 1.43 (1.06–1.92), p = 0.019)], even after adjusting for EuroSCORE II [HR 1.39 (1.03–1.90), p = 0.034], which was not observed for low-SVi (p = 0.06 and p = 0.2 for uni- and multivariable analysis, respectively). When analyzing FR and SVi as continuous variables, a higher SVi, but not FR, was associated with improved survival [HR 0.98 (0.97–1.00), p = 0.018; HR 0.99 (0.97–1.00), p = 0.044 for uni- and multivariable analysis, respectively). When stratifying by preserved or reduced EF, both FR and SVi did not predict mortality. Conclusions About half of SAS patients undergoing TAVI present with a low-flow condition, which is frequently associated with more advanced heart failure symptoms and higher estimated surgical risk. Low-FR negatively impacts survival after intervention. SVi is also prognostic, but not at a <35ml/s cut-off.

Flow-status and survival in severe aortic stenosis treated with TAVI – is flow rate superior to stroke volume index?

Abstract Background Low-flow status, currently defined as a stroke volume index (SVi) <35 mL/m2, is an important prognostic predictor for mortality after Transcatheter Aortic Valve Implantation (TAVI) for severe aortic stenosis (SAS). However, transaortic flow rate (FR) – defined as stroke volume divided by left ventricle ejection time - has recently been suggested to be superior to SVi in defining low-flow states, as it reflects more closely valvular resistance, while being independent of body surface area. Low FR is most consistently defined as FR<200 mL/s. Purpose Determine the prognostic impact of FR and SVi before TAVI in survival after intervention for SAS. Methods A single-centre retrospective database of all TAVI performed between 2011 and 2019 was analyzed, and cases with pre-intervention echocardiograms available were included. Low-flow patients were identified according to basal FR (<200 mL/s) or SVi (<35 mL/m2), and compared with normal-flow cases. The primary endpoint was defined as time to all-cause death or last follow-up. The impact of flow-status (using FR or SVi) in survival was assessed using Kaplan-Meier curves and log-rank test, as well as Cox proportional hazard model adjusted for EuroSCORE II, using FR or SVi either as categorical or continuous variables. A subanalysis further compared patients with preserved and reduced ejection fraction (EF, <52%). p<0.05 was considered statistically significant. Results From 657 TAVI performed, 490 (74.6%) cases were included, with a median follow-up of 43 months. From those, 59.6% were defined as low-flow according to FR, and 43.3% using SVi. Low-flow patients, using each parameter, were of higher surgical risk (EuroSCORE II and STS scores), had more advanced NYHA classes, worse estimated creatinine clearance, and suffered more frequently from coronary artery disease. Low-FR patients were also older, and more predominantly female. Atrial fibrillation was more prevalent among low SVi cases. Functional aortic valve area was lower in low-flow patients using both assessments, but low-SVi was also associated with lower transaortic gradients, as well as lower EF before and after TAVI. Regarding all-cause mortality, low-SVi was associated with worse survival [p=0.02, hazard ratio (HR) 1.43 (1.05–1.94)], but not low-FR (p=0.4). However, low-SVi, when adjusted for EuroScore II, was no longer a predictor of all-cause mortality (p=0.08). When considering FR and SVi as continuous variables, a higher SVi (but not FR) was associated with better survival (HR 0.98, p=0.047) in multivariable analysis adjusted for EuroSCORE II. When stratifying according to preserved and reduced EF, both FR and SVi did not predict all-cause mortality. Conclusions Low-flow states are common in SAS population treated with TAVI, being frequently associated with worse symptoms and higher procedural risk. Low-SVi, but not low-FR, negatively impacts survival after intervention, representing a marker for prognosis after TAVI. Funding Acknowledgement Type of funding sources: None.

Automativ assessment of systolic cardiac performance using PEP/LVET index

Congestive cardiac failure is one of the deadliest diseases in the world, with more than 26 million patients. Echocardiogram and angiography consider as the gold standards for heart failure diagnosis. Nevertheless, they are not commonly used for long-term follow up as they need highly skilled and experienced operator. In this paper, a simple and low-cost system for automatic assessment of systolic cardiac performance using systolic cardiac intervals is presented. The proposed system utilized electrocardiogram (ECG) and phonocardiogram (PCG) to calculate pre-ejection period (PEP) and left ventricle ejection time (LVET). The ratio between PEP and LVET was computed to assess the performance of the systolic cardiac function. ECG and PCG were acquired using a commercial stethoscope which was modified to convert PCG auscultation to electrical signals. ECG and PCG signals were digitized and transferred to a personal computer. A custom MATLAB application was designed to display the acquired ECG and PCG, and to compute PEP, LVET, and PEP/LVET ratio. The system was tested on 17 healthy subjects and results showed high agreement between the systolic heart function status assessed by the proposed system and the corresponding echocardiography results. These results imply that the proposed system could be used for long-term follow up for patients with congestive heart failure.

P2442Myocardial performance index predicts mortality in people with obstructive lung function from the general population

Abstract Background Forced expiratory volume in one second (FEV1) is a significant predictor of mortality in patients with obstructive lung function (OL). Whether echocardiography can be used to identify patients at high risk, and whether it provides incremental prognostic information on mortality in patients with OL, remains unknown. Methods In a large, low-risk general population study, 1873 participants underwent a health examination with spirometry and echocardiography, including tissue Doppler imaging (TDI). The myocardial performance index (MPI) was calculated as the sum of the isovolumic contraction time (IVCT) and the isovolumic relaxation time (IVRT) divided by the left ventricle ejection time (LVET). Spirometry included measurements of (FEV1) and the forced vital capacity (FVC). OL was defined as FEV1/FVC <0.70. The primary endpoint was all-cause mortality. Results The mean age was 59±16 years, 57% were women, 43% had hypertension, 11% had diabetes, and 6% had ischemic heart disease. Of the 1873 included participants, 288 (15%) were classified as having OL at baseline. During follow up (median 13.7 years (IQR 13.2–16.2)), 584 (31%) persons died, hereof 178 (62%) in the subgroup of participants with OL and 406 (26%) in the subgroup of participants with normal lung function. OL was associated with presence of left ventricular hypertrophy (higher left ventricular mass index), impaired diastolic function (lower E, higher A, lower E/A ratio, longer deceleration time, lower e' and higher E/e'), lower global longitudinal strain, and higher MPI. In unadjusted analysis, higher MPI was associated with all-cause mortality for participants with OL (HR=1.18 (1.11–1.26), p<0.001, per 0.1 increase) and for participants with normal lung function (HR=1.42 (1.34–1.50), p<0.001, per 0.1 increase). The predictive value of MPI was significantly modified by the presence of obstructive lung function (p<0.001). After multivariable adjustment for age, sex, FEV1/FVC, heart rate, systolic blood pressure, smoking status, body mass index (BMI), hypertension, diabetes, ischemic heart disease, ischemic stroke and heart failure at baseline, MPI remained an independent predictor of all-cause mortality (HR=1.19 (1.06–1.34), p=0.004, per 0.1 increase) for participants with OL but not for participants with normal lung function (HR=1.02 (0.94–1.11), p=0.598, per 0.1 increase). When adding the MPI to the updated Age, Dyspnea and Obstruction (ADO) index, MPI provided incremental prognostic information beyond the updated ADO index, as determined from a significant increase in the Harrell's C-statistics (0.785 to 0.792, p=0.003). Conclusion Presence of OL is associated with subtle impairment of left ventricular systolic function, impaired left ventricular diastolic function, and higher MPI. MPI is an independent predictor of mortality in people with OL and provides incremental prognostic information regarding all-cause mortality in this population. Acknowledgement/Funding Herlev & Gentofte University Hospital PhD fund

Reference ranges for the left ventricle modified myocardial performance index, respective time periods, and atrioventricular peak velocities between 20 and 36 + 6 weeks of gestation

Objective: To establish reference ranges for the fetal left ventricle (LV) modified myocardial performance index (Mod-MPI), respective time periods, and right and left atrioventricular peak velocities between 20 and 36 + 6 weeks of gestation.Methods: This cross-sectional study evaluated 360 low-risk singleton pregnancies between 20 and 36 + 6 weeks of gestation. The LV Mod-MPI was calculated as (isovolumetric contraction time + isovolumetric relaxation time)/ejection time. Polynomial regression was used to obtain the best-fit using Mod-MPI and atrioventricular peak velocity measurements and gestational age (GA) with adjustments using the coefficient of determination (R2). The intra- and interobserver reliability was evaluated using the concordance correlation coefficient (CCC).Results: LV Mod-MPI (R2 = 0.026, p = .002) and isovolumetric relaxation time (IRT) (R2 = 0.036, p < .001) significantly increased with advancing GA. Isovolumetric contraction time (ICT) and ejection time (ET) did not significantly change with GA. RV and LV E wave, A wave, and E/A ratio significantly increased with GA (p < .001). The mean of each parameter ranged as follows: LV Mod-MPI (0.44–0.47 s), IRT (0.041–0.045 s), ICT (0.032–0.034 s), ET (0.167–0.167 s), RV E (30.2–46.91 cm/s), RV A (47.1–60.7 cm/s), RV E/A (0.65–0.78 cm/s), LV E (27.0–41.4 cm/s), LV A (43.2–53.8 cm/s), and LV E/A (0.63–0.78 cm/s). Only LV A wave measurements demonstrated an intraobserver CCC >0.80. The remaining intra- and interobserver reproducibility parameters demonstrated lower CCC.Conclusions: Reference values were replicated for the fetal LV Mod-MPI and LV and RV transvalvular peak velocities between 20 and 36 + 6 weeks of gestation.

Systolic time ratio measured by impedance cardiography accurately screens left ventricular diastolic dysfunction in patients with arterial hypertension

BackgroundThe use of impedance cardiography (ICG) may play a role in the assessment of cardiac effects of hypertension (HT), especially its hemodynamic features. Hypertensive heart disease involves structural changes and alterations in left ventricular geometry that end up causing systolic and/or diastolic dysfunction. The IMPEDDANS study aims to assess the usefulness of ICG for the screening of left ventricular diastolic dysfunction (LVDD) in patients with HT.MethodsPatients with HT were assessed by echocardiography and ICG. Receiver-operating characteristic curve and the area under the curve were used to assess the discriminative ability of the parameters obtained by ICG to identify LVDD, as diagnosed by echocardiography.ResultsICG derived pre-ejection period (PEP), left ventricle ejection time (LVET), systolic time ratio (STR) and D wave were associated (p < 0.001) with LVDD diagnosis, with good discriminative ability: PEP (AUC 0.81; 95% CI 0.74–0.89), LVET (AUC 0.82; 95% CI 0.75–0.88), STR (AUC 0.97; 95% CI 0.94–1.00) and presence of D wave (AUC = 0.87; 95% CI 0.82–0.93). STR ≥ 0.30 outperformed the other parameters (sensitivity of 98.0%, specificity of 90.2%, positive predictive value of 95.2%, and negative predictive value of 96.1%).ConclusionThe ICG derived value of STR allows the accurate screening of LVDD in patients with HT. It might as well be used for follow up assessment.Trial registrationThe study protocol was retrospectively registered as IMPEDDANS on ClinicalTrials.gov (ID: NCT03209141) on July 6, 2017.

Temporal relationship between instantaneous pressure gradients and peak-to-peak systolic ejection gradient in congenital aortic stenosis

We sought to identify a time during cardiac ejection when the instantaneous pressure gradient (IPG) correlated best, and near unity, with peak-to-peak systolic ejection gradient (PPSG) in patients with congenital aortic stenosis. Noninvasive echocardiographic measurement of IPG has limited correlation with cardiac catheterization measured PPSG across the spectrum of disease severity of congenital aortic stenosis. A major contributor is the observation that these measures are inherently different with a variable relationship dependent on the degree of stenosis. Hemodynamic data from cardiac catheterizations utilizing simultaneous pressure measurements from the left ventricle (LV) and ascending aorta (AAo) in patients with congenital valvar aortic stenosis was retrospectively reviewed over the past 5 years. The cardiac cycle was standardized for all patients using the percentage of total LV ejection time (ET). Instantaneous gradient at 5% intervals of ET were compared to PPSG using linear regression and Bland-Altman analysis. A total of 22 patients underwent catheterization at a median age of 13.7 years (interquartile range [IQR] 10.3-18.0) and median weight of 51.1 kg (IQR 34.2-71.6). The PPSG was 46.5 ± 12.6 mm Hg (mean ± SD) and correlated suboptimally with the maximum and mean IPG. The midsystolic IPG (occurring at 50% of ET) had the strongest correlation with the PPSG ( PPSG=0.97(IPG50%)-1.12, R2 = 0.88), while the IPG at 55% of ET was closest to unity ( PPSG=0.997(IPG55%)-1.17, R2 = 0.87). The commonly measured maximum and mean IPG are suboptimal estimates of the PPSG in congenital aortic stenosis. Using catheter-based data, IPG at 50%-55% of ejection correlates well with PPSG. This may allow for a more accurate estimation of PPSG via noninvasive assessment of IPG.

Right Atrial Dysfunction in the Fetus with Severely Regurgitant Tricuspid Valve Disease: A Potential Source of Cardiovascular Compromise

In severe right heart obstruction (RHO), redistribution of cardiac output to the left ventricle (LV) is well tolerated by the fetal circulation. Although the same should be true of severely regurgitant tricuspid valve disease (rTVD) with reduced or no output from the right ventricle, affected fetuses more frequently develop hydrops or suffer intrauterine demise. We hypothesized that right atrium (RA) function is altered in rTVD but not in RHO, which could contribute to differences in outcomes. Multi-institutional retrospective review of fetal echocardiograms performed over a 10-year period on fetuses with rTVD (Ebstein's anomaly, tricuspid valve dysplasia) or RHO (pulmonary atresia/intact ventricular septum, tricuspid atresia) and a healthy fetal control group. Offline velocity vector imaging and Doppler measurements of RA size and function and LV function were made. Thirty-four fetuses with rTVD, 40 with RHO, and 79 controls were compared. The rTVD fetuses had thelargest RA size and lowest RA expansion index, fractional area of change, and RA indexed filling and emptying rates compared with fetuses with RHO and controls. The rTVD fetuses had the shortest LV ejection time and increased Tei index with a normal LV ejection fraction. RA dilation (odds ratio, 1.27; 95% CI, 1.05-1.54) and reduced indexed emptying rate (odds ratio, 2.49; 95% CI, 1.07-5.81) were associated with fetal or neonatal demise. Fetal rTVD is characterized by more severe RA dilation and dysfunction compared with fetal RHO and control groups. RA dysfunction may be an important contributor to reduced ventricular filling and output, potentially playing a critical role in the worsened outcomes observed in fetal rTVD.

Assessment of cardiac time intervals by wavelet transform of the impedance cardiogram.

Impedance cardiography (ICG) is an inexpensive, noninvasive technique for estimating hemodynamic parameters. ICG can be used to obtain the ejection fraction of the left atrium and to monitor systolic time intervals. Traditional ICG technique does not enable unambiguous detection of the left ventricle ejection time (LVET) and the time relationships between specific marker points. This work aims to approbate a new approach for ICG signal processing using wavelet transform (WT) and to investigate the possibilities of this approach for determination of the parameters which are related to the stroke volume (SV), in particular LVET. Thoracic tetrapolar polyrheocardiography method for simultaneous registration of ECG, ICG and phonocardiograms has been used. A control group consisted of eight healthy men aged 20-25 years. In addition, four patients with essential hypertension participated in the study. Wavelet representation of the ICG data produced local maxima in a two dimensional distribution of the wavelet coefficient. Each extremum point was characterized by the amplitude, scale and time, which determine SV. LVET was defined as the scale corresponding to the E-wave maximum related to the systolic phase of the cardiac cycle. Also, we defined the initial systolic time interval (ISTI) as the time interval between R peak in the ECG and E-wave maximum on the wavelet plane. During functional test LVET and ISTI values defined by WT demonstrated a proper hemodynamic response to loading for the control group and patients with essential hypertension. The proposed approach demonstrates the ability of ICG-WT technique for adequate assessment of SV parameters, including cardiac time intervals.

Myocardial performance index in fetal anemia.

The objective of the study was to examine the correlation between fetal myocardial performance index (MPI) and hemoglobin (Hb) levels. It is a prospective study involving singleton pregnancies at risk of fetal anemia as a result of maternal anti-D alloimmune disease. Right and left ventricle (LV) MPIs were evaluated by ultrasound up to 72 h before cordocentesis. Zeta-score values for fetal MPI and Hb levels were calculated, and correlation was examined with linear regression analysis. Significance level was set as 0.05. Fourteen singleton pregnancies underwent 31 cordocentesis procedures at a mean gestation of 28.2 ± 4.1 weeks. Zeta-score values for LV MPI, isovolumetric relaxation time (IRT), and ejection time (ET) correlated significantly with fetal Hb zeta-score (LV MPI zeta = 3.816 + 0.336 × Hb zeta, r = 0.59, p < 0.001; LV IRT zeta = 2.643 + 0.218 × Hb zeta, r = 0.45, p = 0.01; LV ET zeta = -2.474 - 0.271 × Hb zeta, r = -0.42, p = 0.02). LV isovolumetric contraction time (ICT) zeta-score and right ventricle (RV) MPI did not show significant correlation (LV ICT zeta, r = 0.35, p = 0.054; RV MPI, r = 0.12, p = 0.53). LV myocardial performance not only remains preserved but also is actually enhanced in cases of moderate/severe fetal anemia.

Surgical Myectomy for Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) has been one of the most interesting and controversial disorders in cardiovascular medicine. Although initial descriptions of the pathology of HCM were published over a century ago, it was not until the surgical and pathological observations of Brock and Teare, respectively, that this cardiac entity came to attention in the modern era. HCM is a primary disorder of the myocardium characterized by myocyte hypertrophy and fiber disarray, myocardial fibrosis, and abnormal coronary intramural microvasculature. Although HCM is characterized by tremendous diversity in terms of phenotypic expression, genetic substrate, and clinical presentation, left ventricular outflow tract (LVOT) obstruction is an integral component of the disease, occurring in up to 70% of patients either at rest or with provocation.1 Article see p 209 Dynamic LVOT obstruction has long been recognized as a clinical feature of HCM, but the pathophysiology and clinical significance of intraventricular pressure gradients sparked much controversy and debate. While initially thought to result from early excessive and rapid ejection from a hypercontractile left ventricle (LV) as opposed to true mechanical impedance to blood flow, this hypothesis was later refuted by Wigle and colleagues,2 who demonstrated a prolonged LV ejection time in the presence of such intraventricular pressure gradients. The pathophysiology of LVOT obstruction is now widely accepted to be attributable to an eject-obstruct-leak concept, driven by Venturi and drag forces of the anterior mitral valve leaflet. Echocardiographic and cardiac magnetic resonance studies have documented that reduction in the LVOT cross-sectional area is attributable to morphological features such as narrowing of the LVOT by septal hypertrophy, intrinsic abnormalities of the mitral valve leaflets, anterior displacement of the mitral apparatus, and anterior malposition of the papillary muscles, either alone or in combination. Rapid LV ejection through a narrowed outflow tract results in the anterior mitral leaflet …

Association of the time course of pulmonary arterial hypertension with changes in oxidative stress in the left ventricle

1. This study investigates the time course of pulmonary arterial hypertension (PAH) due to monocrotaline (MCT) and its association with cardiac function and oxidative stress markers in the left ventricle (LV). 2. Male Wistar rats were divided into six groups: 7 days, 21 days, and 31 days for both control and MCT groups. Following echocardiographic analysis, the heart was removed. The LV was separated and homogenized to analyze oxidized-to-total glutathione ratio and thioredoxin reductase (TrxR) activity as well as hydrogen peroxide (H(2) O(2) ) and ascorbic acid levels. 3. There was significant (P < 0.01) cardiac and right ventricle (RV) hypertrophy and pulmonary congestion in the MCT 21 day and 31 day groups. Echocardiography showed a change in the flow wave of the pulmonary artery at 21 days after MCT treatment. There was an increase in the LV ejection time (P < 0.05) at 31 days after MCT. The LV H(2)O(2) concentration was increased (P < 0.05) in the MCT 21 day and MCT 31 day groups compared with controls. There was a reduction (P < 0.05) in the LV ascorbic acid concentration and an increase (P < 0.05) in TrxR activity in the MCT 31 day rats. 4. Our findings showed RV changes due to pulmonary hypertension at 21 days after MCT injection. There was a correlation between the degree of dysfunction and the morphometry of the heart chambers, along with impairment of the antioxidant/pro-oxidant balance in the LV 31 days after the beginning of the protocol. This study suggests that LV changes follow RV dysfunction subsequent to pulmonary hypertension.

Cardiovascular and hormonal responses to static handgrip in young and older healthy men

The purpose of this study was to investigate the effect of age on cardiovascular changes and plasma concentrations of adrenomedullin (ADM), catecholamines, endothelin-1 (ET-1) and plasma renin activity (PRA) in healthy men. A total of 15 young (21 ± 0.3 years) and 15 older (64 ± 0.7 years) healthy men performed two 3-min bouts of static handgrip at 30% of maximal voluntary contraction, alternately with each hand without any break between the bouts. During exercise heart rate (HR), blood pressure (BP), stroke volume (SV) and pre-ejection period (PEP) and left ventricle ejection time (LVET) were measured. Blood samples were taken before exercise, at the end of both exercise bouts and in the fifth minute of the recovery period. The handgrip-induced increases in HR and cardiac output were significantly smaller in older than in young men (p < 0.01). SV decreased only in older men (p < 0.001). There were no differences between groups in BP increases. The baseline plasma ADM and catecholamines were higher in older man compared to young subjects. Handgrip caused increases in plasma ADM, ET-1 and PRA only in older men (p < 0.05). The increases in plasma ADM correlated positively with those of noradrenaline (NA), PRA, ET-1 and LVET and negatively with changes in total peripheral resistance (TPR), SV, PEP and PEP/LVET ratio. The increases in plasma ET-1 correlated positively with those of NA, PRA, TPR, mean BP and SV. These results revealed that ADM, ET-1 and angiotensin II can contribute to maintain vascular tone during static exercise in older but not in younger men.

Relationship between ocular pulse amplitude and systemic blood pressure measurements

This study aimed to determine whether ocular pulse amplitude (OPA) measured with dynamic contour tonometry (DCT) is related to systemic blood pressure (BP) parameters. Blood pressure was measured continuously and simultaneously with OPA in one randomly selected eye in 29 healthy subjects. Systemic parameters of interest were: systolic and diastolic BPs and their difference (BP amplitude), and left ventricle ejection time (LVET; defined as the time between the diastolic trough and the incisural notch in the BP curve). In addition, the axial length (AL) of the eye was measured. Associations between OPA, AL and systemic cardiovascular parameters were analysed in a multivariate regression model. Measurements of OPA ranged from 1.0 mmHg to 4.9 mmHg (mean 2.3 +/- 0.9 mmHg, median 1.9 mmHg). In a univariate analysis with one predictor at a time, means of intraocular pressure (IOP) (p = 0.008), AL (p = 0.046) and LVET (p = 0.037) were significantly correlated with OPA, whereas systolic and diastolic BPs and their amplitude were not. A multiple linear regression analysis showed that mean IOP (p < 0.005), AL (p = 0.01) and LVET (p = 0.002) all independently contributed to OPA. The OPA readings measured with DCT in healthy subjects were not related to BP levels and amplitude. It seems that the OPA strongly depends on the time-course of the cardiac contraction. Regulating mechanisms in the carotid system as well as scleral rigidity may be responsible for dampening the direct effect of BP variations.

Avaliação ecocardiográfica em bezerros da raça Holandesa

Com o objetivo de estabelecer valores de medidas ecocardiográficas em bezerros da raça Holandesa, utilizaram-se 25 animais, com idade entre 8 e 28 dias e peso entre 27 e 57 kg. Procedeu-se o exame ecocardiográfico em modo-B e modo-M para a obtenção dos valores médios dos seguintes parâmetros, em diástole e sístole, respectivamente: diâmetros internos dos ventrículos direito (2,05±0,13cm e 1,59±0,13cm) e esquerdo (3,91±0,09cm e 2,52±0,13cm), espessuras do septo interventricular (1,24±0,04cm e 1,62±0,06cm) e da parede livre do ventrículo esquerdo (0,92±0,04cm e 1,50±0,05cm). Obtiveram-se ainda valores do diâmetro dos átrios direito e esquerdo em sístole (2,97±0,12cm e 4,11±0,21cm, respectivamente), dos volumes diastólico (67,90±3,65ml), sistólico (25,32±3,05ml) e de ejeção (42,58±2,46ml) do ventrículo esquerdo, do débito cardíaco (3857±339ml/min), do diâmetro aórtico (2,52±0,05cm), da distância entre o ponto de maior abertura do folheto anterior da valva atrioventricular esquerda até o septo interventricular (0,65±0,08cm) e tempo de ejeção (0,39±0,02s), das frações de encurtamento (36,27±2,40%) e de ejeção do ventrículo esquerdo (64,67±3,22%). Houve média correlação linear positiva (66,4%, P&lt;0,01) entre diâmetro aórtico e peso dos animais, média correlação linear negativa (P&lt;0,01) entre tempo de ejeção do ventrículo esquerdo e freqüência cardíaca (69,1%) e com o débito cardíaco (62,4%). Observou-se uma tendência dos bezerros em apresentar menor diâmetro da câmara cardíaca esquerda, apesar de mantidas as relações de espessura de parede e índices funcionais do miocárdio.

Reliability of Doppler Methods in the Evaluation of the Left Ventricular Systolic Function in Patients with Idiopathic Dilated Cardiomyopathy

There are many new methods for evaluating the left ventricle (LV) systolic function. The aim of this study was to compare the methods, which evaluate the systolic function such as Simpson's method, myocardial performance index (MPI), systolic S(m) wave, and dp/dt value of the mitral regurgitation. Forty patients (27 male, 13 female, mean age 52.5 +/- 18.2 years) with idiopathic dilated cardiomyopathy and 40 healthy subjects (27 male, 13 female, mean age 49.3 +/- 10.8 years) were included in the study. All patients and controls underwent echocardiographic examination by M-mode, two-dimensional, pulsed-wave (PW) and continuous wave Doppler and tissue Doppler imaging (TDI). The MPI were measured by the summation of the isovolumetric contraction and relaxation times division of the LV ejection time, with both PW and TDI methods. The cardiac chamber dimensions, MPI, and modified MPI were greater, LV ejection fraction and TDI S(m) wave were lower in the patients compared to the controls (P < 0.001). The LV ejection fraction of patients calculated by Simpson's method compared with novel methods. Value of dp/dt (P = 0.010, r = 0.546), MPI (P = 0.002, r =-0.470) and modified MPI (P = 0.038, r =-0.330) were related to the LV ejection fraction. Tissue Doppler Systolic S(m) wave had a modest correlation with LV ejection fraction (P < 0.001, r = 0.604). Doppler and tissue Doppler imaging methods correlate with traditional echocardiographic methods and can be used reliably and safely for left ventricular performance regardless of the patient's echogenity.

Effect of the isolated left bundle branch block on systolic and diastolic functions of left ventricle

We planned this study to evaluate the effects of left bundle branch block (LBBB) on systolic and diastolic functions of left ventricle (LV) that have not previously been investigated in detail. Forty-five cases diagnosed as isolated LBBB according to the standard electrocardiographic criteria (group I, mean age: 60 +/- 12 years) were taken as the case group and 65 cases with normal conduction system (group II, mean age 58 +/- 14 years) were taken as the control group. Echocardiography was performed to all patients and coronary angiography was performed to 21 patients in group I and 35 patients in group II. In addition to standard systolic and diastolic function parameters, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and ejection time (ET) were measured by echocardiography, and the myocardial performance index (MPI) [(IRT+ICT)/ET] was calculated. LV end-diastolic pressure was calculated for the patients undergoing coronary angiography. In group I, LV end-systolic diameter was greater (3.1 +/- 0.4 cm vs 2.8 +/- 0.4 cm, P <.001) and ejection fraction was lower (64% +/- 6% vs 68% +/- 6%, P <.001) than those of group II. Rapid filling deceleration time and rate was markedly different in group I (respectively, 133 +/- 50 ms vs 166 +/- 24 ms, P <.001; 608 +/- 291 cm/s(2) vs 383 +/- 116 cm/s(2), P <.001). In addition, it was found that LBBB caused shortening of LV diastolic period and ET markedly (respectively, 347 +/- 116 ms vs 394 +/- 106 ms, P =.03; 255 +/- 40 ms vs 294 +/- 21 ms, P <.001) and prolongation of IRT and ICT (respectively; 124 +/- 36 ms vs 91 +/- 16 ms, 96 +/- 35 ms vs 38 +/- 9 ms, P <.001). The MPI was predominantly higher in group I (0.89 +/- 0.29 vs 0.40 +/- 0.06, P <.001). Invasively determined LV end-diastolic pressure was found higher in group I (14 +/- 3 mm Hg vs 10 +/- 3 mm Hg, P <.001). A marked elevation of the LV MPI and end-diastolic pressure, parallel to changes of conventional echocardiographic parameters, in patients with isolated LBBB points out that LBBB causes marked deterioration on LV systolic and diastolic functions.

VALUE OF ECHOCARDIOGRAPHY IN THE ASSESSMENT OF PULMONARY RESISTANCE (PR) IN D-TRANSPOSITION OF THE GREAT ARTERIES (DTGA)

The reliability of echocardiography (EC) in predicting PR was Investigated in 20 DTGA (mean age: 20 months). Ten were simple DTGA, among them two had Eisenmenger reaction (ER). Three had VSD with PS, the rest either VSD, PDA or PS alone. All had an atrial septal defect. Three groups of parameters were studied: 10 EC pattern, of the pulmonary valve (PV). 20 Dimensions of cardiac structures: left ventricle (LV), pulmonary artery (PA) and aortic (Ao) diameters and posterior wall thickness of LV. 30 LV and right ventricular (RV) systolic and diastolic time intervals (SDTI). These parameters were correlated with the systolic, mean (MPA) and diastolic (DPA) pressure in the PA.Results show that: 1) EC patterns described in the PV with pulmonary hypertension (PH) are not seen in DTGA. 2) LV volume and thickness are poorly related to the PR. 3) Best correlations are found with the SDTI. The RV pre-ejection period (RVPEP) was always greater than LVPEP when PR and systemic resistance were within normal limits. Changes in the LVPEP over LV ejection time ratio were slightly more closely related to the DPA (r = 0.70) than the MPA (r = 0.65). More significant was the correlation between the LV isometric relaxation time (LVIRT) and the DPA (r = 0.90). All nine patients with an LVIRT lower than 20 msec had DPA lower than 20 mmHg. The two with ER had an LVIRT of 60 msec.