Determinants of Left Atrial Compliance in the Metabolic Syndrome: Insights from the "Linosa Study".

The association between left atrial (LA) impairment and cardiovascular diseases (CVD) and between dyslipidaemia and CVD are well known. The present study aims to investigate the relationships between metabolic factors and LA dimensions and compliance, as well as test the hypothesis that metabolic factors influence LA function independent from hemodynamic mechanisms. Arterial blood pressure (BP), waist and hip circumference, metabolic indices, and a complete echocardiographic assessment were obtained from 148 selected inhabitants (M/F 89/59; age 20−86 years) of Linosa Island, who had no history of CVD. At enrollment, 27.7% of the subjects met the criteria for metabolic syndrome (MetS) and 15.5% for arterial hypertension (HTN). LA compliance was reduced in subjects with MetS compared to those without (53 ± 27% vs. 71 ± 29%, p = 0.04) and was even lower (32 ± 17%, p = 0.01) in those with MetS and HTN. At multiple regression analysis, the presence of MetS independently determined LA maximal area (r = 0.56, p < 0.001), whereas systolic BP and the total cholesterol/HDL cholesterol ratio determined LA compliance (r = 0.41, p < 0.001). In an apparently healthy population with a high prevalence of MetS, dyslipidaemia seems to independently influence LA compliance. At a 5-year follow-up, LA compliance was reduced in both all-cause and CVD mortality groups, and markedly impaired in those who died of CVD. These findings may contribute to understanding the prognostic role of LA function in CVD and strengthen the need for early and accurate lipid control strategies.

Features of degenerative mitral valve prolapse in the North East of China: repair characteristics, and short-term follow-up results.

BACKGROUND: We aimed to assess the clinical and echocardiographic characteristics of patients who underwent surgery for degenerative mitral valve prolapse (MVP) in our center, and its relation to outcomes. METHODS: We enrolled 117 consecutive patients from North-East China with an echocardiographic diagnosis of MVP related mitral regurgitation (MR) between April 2018 and November 2019. A complexity scoring system was used for valve anatomy, and patients were re-evaluated at 3-6 months after surgery. RESULTS: Most patients (57.3%) were 40-59 years old. Ejection fraction was <60% in one third, and pulmonary hypertension was present in 64.3% of operated patients. Etiology was myxomatous in 58.9%, with flail as main lesion. Leaflet involvement was posterior in 59.8% patients, anterior in 32.5%, bileaflet in 6%, and commissural in 25.6%. Lesion score was intermediate in >50% of patients, and myxomatous lesions scored higher compared to fibroelastic deficiency (FED). Degree of MR left atrial volume and estimated wedge pressure were significantly higher in intermediate and complex lesions. Repair was performed in 93/101 patients (95.8% success rate). No in-hospital major adverse events, nor deaths at follow-up were reported. Residual MR was ≤ mild in 86.7% of patients at follow-up and was associated with FED etiology and complex lesions. CONCLUSIONS: Compared to Western countries, in our sample of Chinese population degenerative severe MR occurred in younger patients. The MVP lesion characteristics are similar, can be accurately detected by non-invasive preoperative evaluation, allowing predictable results. Advanced tailored repair techniques allow excellent immediate and short-term results regardless of the underlying complexity.

Estimation of increased pulmonary wedge pressure by an algorithm based on noninvasively measured pulmonary diastolic pressure in cardiac patients independent of left ventricular ejection fraction.

AIM: Pulmonary artery diastolic pressure (PADP) correlates closely with pulmonary wedge pressure (PAWP); therefore, we sought to evaluate whether an algorithm based on PADP assessment by the Doppler pulmonary regurgitation (PR) end-diastolic gradient (PRG) may aid in estimating increased PAWP in cardiac patients with reduced or preserved left ventricular (LV) ejection fraction (EF). METHODS AND RESULTS: Right heart catheterization, with estimation of PAWP, right atrial pressure (RAP), PADP, and Doppler echocardiography, was carried out in 183 patients with coronary artery disease (n = 63), dilated cardiomyopathy (n = 52), or aortic stenosis (n = 68). One-hundred and seventeen patients had LV EF <50%. We measured the pressure gradients across the tricuspid and pulmonary valves from tricuspid regurgitation (TRV) and PR velocities. Doppler-estimated PADP (e-PADP) was obtained by adding the estimated RAP to PRG. An algorithm based on e-PADP to predict PAWP, that included TRV, left atrial volume index, and mitral E/A, was developed and validated in derivation (n = 90) and validation (n = 93) subgroups. Both invasive PADP (r = .92, P < .001) and e-PADP (r = .72, P < .001) correlated closely with PAWP, and e-PADP predicted PAWP (AUC: 0.85, CI: 0.79-0.91) with a 94% positive predictive value (PPV) and a 55% negative predictive value (NPV), after exclusion of five patients with precapillary pulmonary hypertension. The e-PADP-based algorithm predicted PAWP with higher accuracy (PPV = 94%; NPV = 67%; accuracy = 85%; kappa: 0.65, P < .001) than the ASE-EACVI 2016 recommendations (PPV = 97%; NPV = 47%; accuracy = 68% undetermined = 18.9%; kappa: 0.15, P < .001). CONCLUSIONS: An algorithm based on noninvasively e-PADP can accurately predict increased PAWP in patients with cardiac disease and reduced or preserved LV EF.

Right ventricular total isovolumic time: Reference value study.

BACKGROUND: There is lack of noninvasive indices to detail the right side cardiovascular physiology. Total isovolumic time (tIVT) is a sensitive marker of left ventricular electromechanical efficiency and systolic-diastolic interaction. The aim of the study was to evaluate normal reference value of the right ventricular tIVT with increasing age. METHODS AND RESULTS: One hundred and eighty-one healthy volunteers (51% male) underwent transthoracic echocardiography. The population was divided into four categories according to age: A < 30 years; B 30-39 years; C 40-49 years; and C ≥ 50 years old. tIVT was computed in seconds/minutes as: 60 - (tET + tFT). tET and tFT are the total ejection and filling time adjusted by the heart rate, measured, respectively, from the onset to the end of the right ventricle (RV) forward flow through the pulmonary valve and from the onset of the E-wave and the end of the A-wave at the level of the tricuspid valve. The mean RV tIVT was 7 ± 1.1 s/min and increased significantly with age, from a 3.4 to 9.7 s/min(P < 0.0001). Significant correlation was found between tIVT and trans-tricuspid E/E' (P < 0.0001; 0.78 (95% CI: 0.715-0.831) while weaker between tIVT and E/A (P = 0.001; -0.283 95% CI: -0.413 to -0.143). CONCLUSION: The normal values of RV tIVT increase with age and correlate significantly with Doppler diastolic parameters.

Sustained favourable haemodynamics 1 year after TAVI: improvement in NYHA functional class related to improvement of left ventricular diastolic function.

AIMS: Despite expected improvement in left ventricular (LV) systolic and diastolic function after transcatheter aortic valve implantation (TAVI), the complex relationship between pre-existent LV systolic and diastolic function and changes in LV haemodynamics and clinical symptoms have been scarcely investigated. This study investigated the presence of pre-operative LV diastolic dysfunction and its improvement over time after TAVI alongside improvement in New York Heart Association (NYHA) class in high-risk patients with severe aortic stenosis. METHODS AND RESULTS: The study population (n = 358) was divided into two groups according to baseline LV ejection fraction (LVEF): LVEF < 50% (n = 96) and LVEF ≥ 50% (n = 262). We compared clinical and echocardiographic parameters between groups before TAVI, at 6 and 12 months follow-up. Grade III LV diastolic dysfunction was more frequent in patients with LVEF < 50% compared with patients with LVEF ≥ 50% (50.0 vs. 16.3%, P < 0.001). Systolic and diastolic echocardiographic parameters improved after TAVI together with improvement in NYHA class both in patients with LVEF < 50% (diastolic dysfunction grade ≥2: baseline 100% of patients; 12 months 58.8%, P < 0.001; NYHA III/IV: baseline, 93.8%; 12 months, 9.7%, P < 0.001) and with LVEF ≥ 50% (diastolic dysfunction grade ≥2: baseline, 87.1%; 12 months, 61.2%; NYHA III/IV: baseline, 74.5%; 12 months, 2.6%, P < 0.001). All-cause mortality was comparable between groups. CONCLUSION: TAVI exerts favourable effects on LV systolic and diastolic function with a remarkable improvement in LV diastolic function associated with improvement in NYHA functional class at follow-up. Prognosis at 1 year after TAVI was not influenced by baseline LV diastolic dysfunction both in patients with and without LV systolic dysfunction.

Reliability and feasibility of longitudinal AFI global and segmental strain compared with 2D left ventricular volumes and ejection fraction: intra- and inter-operator, test-retest, and inter-cycle reproducibility.

AIMS: Echocardiographic evaluation of 2D longitudinal peak systolic strain (LPSS) can detect initial impairment of left ventricular (LV) function in heart disease. Global LPSS (GLPSS) variability has been assessed in small groups and segmental LPSS has not been determined. We compared variability of GLPSS and segmental LPSS with that of 2D LV volumes and ejection fraction (EF) in patients with and without heart diseases. METHODS AND RESULTS: 2D speckle tracking analysis was performed on LV apical views using automated function imaging (AFI) software (GE Healthcare). Intra-operator, inter-cycle, and test-retest variability (bias and CR, coefficient of reproducibility; MPE, mean percent error; CV, coefficient of variation) was assessed for GLPSS, 18 segments of LPSS, and LV volumes and EF in 40 patients (720 segments), and inter-operator variability in 250 patients (4500 segments). Feasibility of segmental tracking was 93.1%. Variability of GLPSS increased from a minimum intra-operator CV = -2.6% to a maximum test-retest CV = -5.4% and was lower than that assessed for volumes and EF. Segmental intra-operator LPSS CV ranged from -5.6 to -14.7%, and test-retest from -8 to -22%, and was at worst similar to variability of end-systolic volume. In the 8.3% of segments with the highest variability, this was related to suboptimal imaging, minor changes in scan angulation, and insufficient ROI width. CONCLUSION: Overall, reproducibility of GLPSS is excellent and superior to that of 2D EF, whereas segmental LPSS reproducibility is good and similar to that of LV volumes. Both are suitable for diagnosis and follow-up of LV global and regional systolic function.

Differences between office and ambulatory blood pressures in children and adolescents attending a hospital hypertension clinic.

BACKGROUND AND OBJECTIVES: Information on ambulatory blood pressure monitoring (ABPM) in children is scarce. While in adults office BP (OBP) is higher than ABP and the difference increases as OBP increases, information in children suggests that at this young age ABP is no lower and often higher than OBP. This study was aimed at describing OBP-ABP differences in a cohort of children of different ages and BPs, and investigating whether OBP-ABP differences are dependent on age or OBP level. METHODS: We retrospectively compared OBP and 24-h, daytime and night-time ABP in 433 children and adolescents aged 4-18 years, referred to our hospital clinic. RESULTS: OBP was found to be significantly lower than 24-h and daytime ABP in the low age tertile (4-10 years) but not in the medium and high tertiles. OBP was also lower than ABP in normotensive patients (n = 182), but higher than ABP in untreated hypertensive patients (n = 92) despite similar ages. Continuous analyses showed a weak correlation of OBP-ABP differences with age, and a much stronger correlation with OBP so that 24-h ABP was higher than OBP at OBP values less than 117/73 mmHg and lower than OBP at higher OBP values. Logistic regression analysis indicates that also in children OBP accounts for most of the OBP-ABP difference. CONCLUSION: There is a common relation both in children and adults between OBP and ABP. It is only because high OBP is common in the elderly, and the lowest OBP is usually found in young children that large positive OBP-ABP differences have been associated with old age, and negative differences with childhood. OBP-ABP differences, often defined as white-coat effect, can have different directions and are likely to be largely due to regression to the mean.

Near real-time echocardiography teleconsultation using low bandwidth and MPEG-4 compression: feasibility, image adequacy and clinical implications.

We assessed the feasibility, image adequacy and clinical utility of a tele-echocardiography service which combined video compression with low-bandwidth store-and-forward transmission. Echocardiograms were acquired by a hospital geriatrician, compressed and transmitted using both near real-time (urgent) and delayed (pre-programmed) protocols via an Internet connection to the notebook PC of a remote cardiologist. Clinical utility was evaluated as a change in therapeutic management. During a one-year period, 101 tele-echocardiography consultations were successfully performed (feasibility = 100%) on 95 patients (age 22-95 years), admitted with cardiovascular or neurological diagnoses (24% of the consultations were urgent). In total, 4617 files (1.4 GByte of data) were transmitted, 2669 of which were short video clips. On average, 46 files (13.8 MByte) were transmitted (mean duration 10 min) at each examination. Consultations (both urgent and pre-programmed) were clinically useful in 83% of examinations. Logistic regression analysis showed that both a low left ventricular systolic function and the examination indication were determinants of clinical utility. The transmitted images were considered adequate for diagnosis in 100% of the pre-programmed teleconsultations. Tele-echocardiography using MPEG-4 video compression is a feasible, adequate and clinically useful tool for telemedicine.

Altered cardiac rhythm in infants with bronchiolitis and respiratory syncytial virus infection.

BACKGROUND: Although the most frequent extra-pulmonary manifestations of respiratory syncytial virus (RSV) infection involve the cardiovascular system, no data regarding heart function in infants with bronchiolitis associated with RSV infection have yet been systematically collected. The aim of this study was to verify the real frequency of heart involvement in patients with bronchiolitis associated with RSV infection, and whether infants with mild or moderate disease also risk heart malfunction. METHODS: A total of 69 otherwise healthy infants aged 1-12 months with bronchiolitis hospitalised in standard wards were enrolled. Pernasal flocked swabs were performed to collect specimens for the detection of RSV by real-time polymerase chain reaction, and a blood sample was drawn to assess troponin I concentrations. On the day of admission, all of the infants underwent 24-hour Holter ECG monitoring and a complete heart evaluation with echocardiography. Patients were re-evaluated by investigators blinded to the etiological and cardiac findings four weeks after enrollment. RESULTS: Regardless of their clinical presentation, sinoatrial blocks were identified in 26/34 RSV-positive patients (76.5%) and 1/35 RSV-negative patients (2.9%) (p < 0.0001). The blocks recurred more than three times over 24 hours in 25/26 RSV-positive patients (96.2%) and none of the RSV-negative infants. Mean and maximum heart rates were significantly higher in the RSV-positive infants (p < 0.05), as was low-frequency power and the low and high-frequency power ratio (p < 0.05). The blocks were significantly more frequent in the children with an RSV load of ≥100,000 copies/mL than in those with a lower viral load (p < 0.0001). Holter ECG after 28 ± 3 days showed the complete regression of the heart abnormalities. CONCLUSIONS: RSV seems associated with sinoatrial blocks and transient rhythm alterations even when the related respiratory problems are mild or moderate. Further studies are needed to clarify the mechanisms of these rhythm problems and whether they remain asymptomatic and transient even in presence of severe respiratory involvement or chronic underlying disease.

Validation of an echo-Doppler decision model to predict left ventricular filling pressure in patients with heart failure independently of ejection fraction.

AIMS: To test a decision model for non-invasive estimation of left ventricular filling pressure (LVFP) in patients with left ventricular (LV) dysfunction and a wide range of ejection fractions (EF). METHODS AND RESULTS: In patients with LV dysfunction (n = 270; EF = 42 +/- 16%), classification and regression tree (CART) analysis was used to generate a model for the prediction of elevated LVFP, defined as pulmonary capillary wedge pressure (PCWP) >15 mmHg, in a derivation cohort (n = 178). At each step of the decision tree, nodes including single or multiple criteria connected by Boolean operators were tested to achieve the best information entropy gain. Averaged mitral-to-myocardial early velocities ratio (E/e') > or =13 OR E-wave deceleration time <150 ms was closely associated with elevated LVFP. Alternatively, prediction of PCWP >15 mmHg needed the following criteria to be satisfied: (i) intermediate E/e' (13 > E/e' > 8); (ii) left atrial volume index >40 mL/m(2) OR ratio of mitral E-wave and colour M-mode propagation velocity >2 OR difference in duration of pulmonary vein and mitral flow at atrial contraction >30 ms; (iii) estimated pulmonary artery systolic pressure >35 mmHg. Patients were correctly allocated according to PCWP with an 87% sensitivity and a 90% specificity. Compared with the best single parameter estimating LVFP, a 17% relative increase in accuracy was achieved in patients with EF >50%. The model was prospectively validated in a testing group (n = 92): 80% sensitivity, 78% specificity. CONCLUSION: This sequential testing is useful to non-invasively predict LVFP in patients with LV dysfunction, especially in those with preserved EF.

Real-time three-dimensional transoesophageal echocardiography: a new intraoperative feasible and useful technology in cardiac surgery.

A new generation of transoesophageal echocardiographic probes with a novel matrix array technique has been recently introduced, allowing three-dimensional (3D) presentation of cardiac structures in real-time. This new tool may potentially provide fast and complete 3D information about cardiac structures improving spatial orientation and overcoming limitations of offline 3D technologies. The aim of this study was to demonstrate the feasibility and usefulness of real-time 3D transoesophageal echocardiography (TOE) for the intraoperative evaluation of cardiac surgery procedures. One-hundred patients underwent transoesophageal echocardiographic examination during cardiac surgery as a part of their routine clinical practice. In the intraoperative pre- and post-cardiopulmonary bypass periods complete 2D and 3D transoesophageal examinations were performed. Feasibility and duration of examinations, and immediate additional anatomical value of 3D versus 2D-TOE were annotated intraoperatively. Image quality, additional clinical value of 3D- compared to standard 2D-TOE and the accuracy in the description of mitral valve pathology by a surgeon and an echocardiographer were evaluated off-line. No complications related to transoesophageal examination occurred and successful intubation was achieved in all 100 patients. Therefore, 200 examinations were performed and analysed considering the pre- and post-cardiopulmonary bypass periods. The mean number of acquisitions per patient was 16 +/- 14, including 3D real-time, zoom, full-volume and colour full volume modalities. The duration of the 3D examination was 16 +/- 10 min and the mean image quality score 2.8 +/- 0.7 (in a scale 1-4). In 36 out of 100 cases (36%) 3D-TOE provided additional anatomical information. The surgeon evaluated 3D images easier and more accurately than 2D images (88% vs. 76% in the evaluation of mitral valve scallop). Real-time 3D TOE may be used routinely for the intraoperative evaluation of cardiac surgery. Imaging with this new probe facilitates intraoperative evaluation of several surgical procedures with an additional clinical value in selected cases.

Assessment and analysis of territorial experiences in digital tele-echocardiography.

Nowadays digital ultrasound-cardiovascular devices are able to send out directly digital images and films. Thanks to the large adoption of such devices, the echocardiographic world is facing new ways of exchanging images and collaborating. What we present in this paper is a review of the experimental projects carried in Lombardy, meant to support the work of specialists by means of second opinion and telemedicine services. On the medical point of view echocardiography is a widely used activity where operators are perfectly accustomed to do repetitive operations and steps. Tele-echocardiography (T-E) introduces new methods and technologies into stable and everyday medical practice, causing disruptions either on the side of the specialists' way of working or on the new opportunities and service. Introducing such a service means to properly model it in order to reduce the changes in the operators' way of working while maximizing the benefits. A proper method of modelling the operators' needs is then a key factor which must be correctly addressed. This paper will present some successful projects and the assessment procedure but it will also discuss a possible service modelling method, which has been adopted for the described experiences.

Clinical utility of guideline-based echocardiography: a prospective study of outpatient referral patterns at a tertiary care center.

BACKGROUND: The spread of echocardiography has increased the number of requests for echocardiography and the length of patient waiting lists in National Health Systems. This overuse of echocardiography may also result in a decrease in examination quality because of an excess in workload. The recommended use of guidelines for the requesting of echocardiograms could reduce the demand for this investigation and thus reduce both workload and health care costs. METHODS: In a prospective study of 520 outpatients in a large tertiary referral center, we analyzed adherence by family physicians and cardiovascular specialists to published guidelines for requesting echocardiograms; the use of a written indication justifying the request for the first and subsequent examinations; the diagnostic outcome; and the clinical utility of each echocardiogram performed. RESULTS: Most echocardiograms (72%) were requested by specialists, follow-ups were frequent (72%), and 14% of these proved normal. Among first examinations, 49% of those requested by family physicians and 36% of those requested by specialists were normal (P = not significant [NS]); in both groups 27% of the requests lacked a written indication. Family physicians requested echocardiograms chiefly for arterial hypertension, palpitations, chest pain, and valve disease, whereas specialists most often requested echocardiograms for checking valve prostheses, ischemic heart disease, and valve disease. The rate of adherence to guidelines (54% vs 52%, P = NS) and clinical utility (60% vs 61%, P = NS) was low and similar for family physicians and specialists. Provision of a written indication for the examination by the requesting physician correlated strongly to the clinical utility of the test (P < .001), and adherence of indication to guidelines was the major determinant of clinical utility at logistic regression analysis (P < .001). CONCLUSION: The rate of adherence to guidelines was lower than desirable and similar for family physicians and cardiovascular specialists. Adherence to guidelines and provision of a written specific indication strongly enhanced the value of the echocardiographic investigation.

High-grade video compression of echocardiographic studies: a multicenter validation study of selected motion pictures expert groups (MPEG)-4 algorithms.

BACKGROUND: Large files produced by standard compression algorithms slow down spread of digital and tele-echocardiography. We validated echocardiographic video high-grade compression with the new Motion Pictures Expert Groups (MPEG)-4 algorithms with a multicenter study. METHODS: Seven expert cardiologists blindly scored (5-point scale) 165 uncompressed and compressed 2-dimensional and color Doppler video clips, based on combined diagnostic content and image quality (uncompressed files as references). One digital video and 3 MPEG-4 algorithms (WM9, MV2, and DivX) were used, the latter at 3 compression levels (0%, 35%, and 60%). RESULTS: Compressed file sizes decreased from 12 to 83 MB to 0.03 to 2.3 MB (1:1051-1:26 reduction ratios). Mean SD of differences was 0.81 for intraobserver variability (uncompressed and digital video files). Compared with uncompressed files, only the DivX mean score at 35% (P = .04) and 60% (P = .001) compression was significantly reduced. At subcategory analysis, these differences were still significant for gray-scale and fundamental imaging but not for color or second harmonic tissue imaging. Original image quality, session sequence, compression grade, and bitrate were all independent determinants of mean score. CONCLUSIONS: Our study supports use of MPEG-4 algorithms to greatly reduce echocardiographic file sizes, thus facilitating archiving and transmission. Quality evaluation studies should account for the many independent variables that affect image quality grading.

[Teleconsulting in echocardiography using a standard cable on HDSL]. / Teleconsulto in ecocardiografia con cavo telefonico standard in HDSL.

BACKGROUND: Teleconsultation in echocardiography is complex owing to the heavy images and video files to be exchanged; moreover standards for data acquisition still need to be defined. The aim of this experience was to verify the feasibility to connect two laboratories for teleconsulting using a standard HDSL telephone cable. METHODS: Hardware included one echocardiograph, one PC, video aquisition board and network board, USB webcam, Network router and an HDSL line for data communication. Software includes MS Windows XP and Netmeeting. The live interactivity between the labs was granted by a video streaming in MPEG4 format, directly delivered by the PC communication software. Standard DICOM was used for formal aspects. The platform has been verified during a demo at "National Congress of Cardiovascular Echography" in 2005. RESULTS: The experiment survey collected at the Teleconference gave a consistently good result. Twenty-one subjects filled in the questionnaire: 12 of them (57%) reported a difference between the video streaming and DICOM; whereas 7 of them (33%) did not point out it. Overall findings have been positive, even though 15 members (71%) reported feasibility with some difficulties; 18 members (86%) reported the possibility of really using this technology in the future. The total cost was 145000 euro. CONCLUSIONS: In our opinion, overall cost is more than acceptable especially considering how often to send data is more convenient than moving sick people or consultants.

Clinical validation of different echocardiographic motion pictures expert group-4 algorythms and compression levels for telemedicine.

Tele-echocardiography is not widely used because of lengthy transmission times when using standard Motion Pictures Expert Groups (MPEG)-2 lossy compression algorythms, unless expensive high bandwidth lines are used. We sought to validate the newer MPEG-4 algorythms to allow further reduction in echocardiographic motion video file size. Four cardiologists expert in echocardiography read blindly 165 randomized uncompressed and compressed 2D and color Doppler normal and pathologic motion images. One Digital Video and 3 MPEG-4 compression algorythms were tested, the latter at 3 decreasing compression quality levels (100%, 65% and 40%). Mean diagnostic and image quality scores were computed for each file and compared across the 3 compression levels using uncompressed files as controls. File dimensions decreased from a range of uncompressed 12-83 MB to MPEG-4 0.03-2.3 MB. All algorythms showed mean scores that were not significantly different from uncompressed source, except the MPEG-4 DivX algorythm at the highest selected compression (40%, p=.002). These data support the use of MPEG-4 compression to reduce echocardiographic motion image size for transmission purposes, allowing cost reduction through use of low bandwidth lines.

Echocardiographic determinants of mitral early flow propagation velocity.

Transmitral color Doppler early diastolic flow propagation velocity (Vp) has been correlated with the left ventricular (LV) relaxation time constant tau in dilated cardiomyopathy and ischemic heart disease. The aim of this study was to investigate the independent influence of LV systolic function and geometry, and of LV relaxation, on Vp in an unselected outpatient population. We studied 30 normal subjects and 130 patients (hypertensive LV hypertrophy, aortic valve stenosis or prosthesis, hypertrophic cardiomyopathy, coronary artery disease, dilated cardiomyopathy, aortic or mitral valve regurgitation). In all, we noninvasively measured LV geometry, mass, systolic function, wall motion dyssynergy, and diastolic function (abnormal relaxation or restrictive LV Doppler filling patterns). The Vp was similar in normal subjects and in patients (51 +/- 14 vs 53 +/- 25 cm/s). In normal subjects, the determinants of Vp at multiple regression analysis were isovolumic relaxation time, 2-dimensional cardiac index, and mitral E-wave velocity-time integral. In all, the main determinants were LV ejection fraction, percent of segmental wall dyssynergy, and isovolumic relaxation time and age. The Vp was highest in hypertrophic (75 +/- 25 cm/s, p <0.05 vs normal subjects) and lowest in dilated (35 +/- 13 cm/s, p = NS) cardiomyopathy. During multivariate analysis of variance, percent of wall dyssynergy (but not diffuse LV hypokinesia) independently reduced Vp (p = 0.02). The latter was not influenced by the LV filling pattern. Thus, in an unselected clinical population, prolonged relaxation per se does not influence Vp if LV systolic dysfunction and/or wall dyssynergy is absent-the latter factors are important independent determinants of Vp, which is determined by multiple factors.