What Do We Know So Far About Ventricular Arrhythmias and Sudden Cardiac Death Prediction in the Mitral Valve Prolapse Population? Could Biomarkers Help Us Predict Their Occurrence?

PURPOSE OF THE REVIEW: To summarize currently available data on the topic of mitral valve prolapse (MVP) and its correlation to the occurrence of atrial and ventricular arrhythmias. To assess the prognostic value of several diagnostic methods such as transthoracic echocardiography, transesophageal echocardiography, cardiac magnetic resonance, cardiac computed tomography, electrocardiography, and electrophysiology concerning arrhythmic episodes. To explore intra and extracellular biochemistry of the cardiovascular system and its biomarkers as diagnostic tools to predict rhythm disturbances in the MVP population. RECENT FINDINGS: MVP is a common and mainly benign valvular disorder. It affects 2-3% of the general population. MVP is a heterogeneous and highly variable phenomenon with three structural phenotypes: myxomatous degeneration, fibroelastic deficiency, and forme fruste. Exercise intolerance, supraventricular tachycardia, and chest discomfort are the symptoms that are often paired with psychosomatic components. Though MVP is thought to be benign, the association between isolated MVP without mitral regurgitation (MR) or left ventricle dysfunction, with ventricular arrhythmia (VA) and sudden cardiac death (SCD) has been observed. The incidence of SCD in the MVP population is around 0.6% per year, which is 6 times higher than the occurrence of SCD in the general population. Often asymptomatic MVP population poses a challenge to screen for VA and prevent SCD. Therefore, it is crucial to carefully assess the risk of VA and SCD in patients with MVP with the use of various tools such as diagnostic imaging and biochemical and genetic screening.

Echocardiographic markers of dyssynchrony as predictors of super-response to cardiac resynchronisation therapy - a pilot study.

BACKGROUND: Some patients with congestive heart failure have greater improvement of cardiac remodelling after cardiac resynchronisation therapy (CRT) and they are identified as super-responders (SRs). It remains unclear if echocardiographic markers of dyssynchrony could accuratelly predict super-response to CRT. The aim of this study is to evaluate potential echocardiographic predictors associated with super-response to CRT. METHODS: Fifthy nine CRT patients (mean age 52.9 ± 9.0 years, 88% men) with congestive heart failure (54% ischaemic and 46% non-ischaemic aetiology) II-IV NYHA functional class were enrolled. To assess mechanical dyssynchrony we evaluated interventricular mechanical delay, the maximum delay between peak systolic velocities of the septal and posterior walls of left ventricle, duration of left ventricular pre-ejection period (LVPEP), left ventricular and interventricular dyssynchrony by tissue Doppler imaging and systolic dyssynchrony index by 3D echocardiography. After six months the patients were assessed for response and classified as SRs (reduction in left ventricular end-systolic volume (LVESV) ≥30%, n = 20) and non-SRs (reduction in LVESV < 30%, n = 39) and baseline data were analyzed to identify the predictors. RESULTS: Both groups demonstrated significant improvement in NYHA functional class, increase in left ventricular ejection fraction and reduction in LVESV. All parameters of mechanical dyssynchrony at baseline were significantly higher in SR group. Multiple logistic regression analysis showed that LVPEP (HR 1.031; 95% CI 1.007-1.055; p = 0.011) was an independent predictor for CRT super-response. In ROC curve analysis LVPEP with a cut-off value of 147 ms demonstrated 73.7% sensitivity and 75% specificity (AUC = 0.753; p = 0.002) for the prediction of super-response to CRT. CONCLUSION: Greater mechanical dyssynchrony is associated with super-response to CRT in patients with congestive heart failure. It is probable that an LVPEP > 147 ms can be used as independent predictor of super-response.

Subclinical chronic left ventricular systolic dysfunction resulting from phosphine poisoning.

We present a case of a 32-year-old male crew member of a cargo ship, accidentally exposed to phosphine, a fumigating substance. He and other crew members developed increasing fatigue and digestive disorders 24 h later; two died from acute pulmonary oedema. The patient was admitted to hospital, where bilateral pneumonia, acute nephritis, hepatopathy, electrolyte imbalance and leucopenia were diagnosed. He was discharged from hospital 3 weeks later. He was examined 4 months later for possible chronic consequences of acute phosphine poisoning, which included echocardiography showing normal heart size and cardiac function. However, on advanced quantitative analysis, using two-dimensional speckle tracking echocardiography, depressed global longitudinal strain was found. Our report extends previously published findings of phosphine-induced left ventricular (LV) dysfunction by demonstrating that subclinical myocardial dysfunction resulting from acute phosphine exposure may persist several months after the exposure in an otherwise asymptomatic patient, and potentially may not be entirely reversible. The persistence of subclinical abnormalities of LV longitudinal function can be diagnosed using the advanced quantitative echocardiographic analysis we describe.

Harvesting, Coupling, and Control of Single-Exciton Coherences in Photonic Waveguide Antennas.

We perform coherent nonlinear spectroscopy of individual excitons strongly confined in single InAs quantum dots (QDs). The retrieval of their intrinsically weak four-wave mixing (FWM) response is enabled by a one-dimensional dielectric waveguide antenna. Compared to a similar QD embedded in bulk media, the FWM detection sensitivity is enhanced by up to 4 orders of magnitude, over a broad operation bandwidth. Three-beam FWM is employed to investigate coherence and population dynamics within individual QD transitions. We retrieve their homogenous dephasing in a presence of low-frequency spectral wandering. Two-dimensional FWM reveals off-resonant Förster coupling between a pair of distinct QDs embedded in the antenna. We also detect a higher order QD nonlinearity (six-wave mixing) and use it to coherently control the FWM transient. Waveguide antennas enable us to conceive multicolor coherent manipulation schemes of individual emitters.

Lip print evidence: Poland as the Last Bastion of Practical Cheiloscopy.

Cheiloscopic examinations have long been conducted, and many scientists have reported the usefulness of cheiloscopy for personal identification with a characteristic and individual pattern of furrows on the vermilion lip. For almost 40 years, research conducted in Poland has determined the patterns of these furrows and the separation and development of their individual features. This was the basis for forming expert opinions and presenting them in court as evidence. In Poland, cheiloscopic expertise is performed and the results of precise procedures that are accredited and assessed serve as evidence. Although the legal system in Poland (continental system) is completely different from the American system, cheiloscopic expertise was also assessed in detail according to the American standards of evidence. This narrative review presents the problem of cheiloscopic expertise as a scientific and practical issue and provides a brief historical overview of this field and the foundations of the Polish cheiloscopic identification method. We conclude that Poland has sufficient historical background and a robust development of cheiloscopy in the field on a scientific and legal basis; however, due to its reports being in the Polish language, its absence from the most relevant specialized literature, or simply a lack of cooperation between countries and experts, the country has unfairly been left out of the discussion. We believe that a new look at the Polish contribution to lip print identification is necessary to reinsert this topic into the current discussion of a new identification paradigm.

Bose-Einstein condensation of exciton polaritons.

Phase transitions to quantum condensed phases--such as Bose-Einstein condensation (BEC), superfluidity, and superconductivity--have long fascinated scientists, as they bring pure quantum effects to a macroscopic scale. BEC has, for example, famously been demonstrated in dilute atom gas of rubidium atoms at temperatures below 200 nanokelvin. Much effort has been devoted to finding a solid-state system in which BEC can take place. Promising candidate systems are semiconductor microcavities, in which photons are confined and strongly coupled to electronic excitations, leading to the creation of exciton polaritons. These bosonic quasi-particles are 10(9) times lighter than rubidium atoms, thus theoretically permitting BEC to occur at standard cryogenic temperatures. Here we detail a comprehensive set of experiments giving compelling evidence for BEC of polaritons. Above a critical density, we observe massive occupation of the ground state developing from a polariton gas at thermal equilibrium at 19 K, an increase of temporal coherence, and the build-up of long-range spatial coherence and linear polarization, all of which indicate the spontaneous onset of a macroscopic quantum phase.

Up on the Jaynes-Cummings ladder of a quantum-dot/microcavity system.

In spite of their different natures, light and matter can be unified under the strong-coupling regime, yielding superpositions of the two, referred to as dressed states or polaritons. After initially being demonstrated in bulk semiconductors and atomic systems, strong-coupling phenomena have been recently realized in solid-state optical microcavities. Strong coupling is an essential ingredient in the physics spanning from many-body quantum coherence phenomena, such as Bose-Einstein condensation and superfluidity, to cavity quantum electrodynamics. Within cavity quantum electrodynamics, the Jaynes-Cummings model describes the interaction of a single fermionic two-level system with a single bosonic photon mode. For a photon number larger than one, known as quantum strong coupling, a significant anharmonicity is predicted for the ladder-like spectrum of dressed states. For optical transitions in semiconductor nanostructures, first signatures of the quantum strong coupling were recently reported. Here we use advanced coherent nonlinear spectroscopy to explore a strongly coupled exciton-cavity system. We measure and simulate its four-wave mixing response, granting direct access to the coherent dynamics of the first and second rungs of the Jaynes-Cummings ladder. The agreement of the rich experimental evidence with the predictions of the Jaynes-Cummings model is proof of the quantum strong-coupling regime in the investigated solid-state system.

Increase in plasma plasminogen activators inhibitor type 1 concentration after fibrinolytic treatment in patients with acute myocardial infarction is associated with 4G/5G polymorphism of PAI-1 gene.

BACKGROUND: Preliminary data suggest that plasma concentration of plasminogen activators inhibitor type 1 (PAI-1) is genetically determined and may be related to differential regulation of plasma PAI-1 concentration at baseline and after stimulation. AIM: This study aimed to evaluate whether increase in the plasma PAI-1 antigen concentration or activity after fibrinolytic therapy in patients with acute myocardial infarction is associated with the -675 4G/5G genetic polymorphism in the promoter region of PAI-1 gene. RESULTS & CONCLUSIONS: Our study revealed that a rebound effect is observed in PAI-1 activity (ActPAI-1) and PAI-1 antigen (AgPAI-1) concentration after standard streptokinase treatment with maximal values of 3 h (t3) after the completion of streptokinase infusion. Both ActPAI-1 and AgPAI-1 were significantly higher at t3 compared to the levels before fibrinolytic treatment: 37.3 (20.0-67.7) vs. 10.0 (3.6-26.0) IU L(-1); P = 0.00001 and 29.9 (15.6-42.3) vs. 20.9 (13.0-30.2) ng mL(-1); P = 0.001, respectively. The stratification of the patients by genotype revealed that carriers of the 4G allele had higher concentrations of PAI-1 antigen 3 h after streptokinase infusion: 30.9 vs. 13.8 ng mL(-1); P = 0.019. No significant association between PAI-1 activity and genotype was found. In conclusion, the rebound effect in serum PAI-1 concentration observed after streptokinase treatment may be related to the 4G/5G polymorphism in the PAI-1 gene promoter.

[Prevalence of dangerous arrhythmia during pharmacological stress echocardiography]. / Czestosc wystepowania groznych zaburzen rytmu podczas farmakologicznej echokardiografii obciazeniowej.

UNLABELLED: Pharmacological stress echocardiography (SE) has become a routine diagnostic and prognostic method in patients with ischemic heart disease. However, all stress tests can provoke undesirable adverse effects including dangerous arrhythmia. The aim of the study was to access the prevalence and types of arrhythmia that can appear during SE. MATERIALS AND METHODS: A retrospective study included the cohort of patients studied using SE in our Department of Cardiology between 1995 and 2002. We followed the data of 836 patients (pts) (615 men, aged 52 +/- 5 yrs). Dobutamine SE was performed in 695 pts (83.2%) and dipyridamole SE in a group of 141 pts (16.8%). Additionally, atropine was administrated to achieve submaximal heart rate in a group of 694 pts (83%). 519 pts (62%) underwent SE was performed according to high dose protocol and in 317 pts (35%)--low dose protocol. RESULTS: During SE the following arrhythmia events were observed: one persistent ventricular tachycardia (0.12%) and two paroxysmal atrial fibrillation (0.24%) in dobutamine test. The set of unsustained ventricular tachycardia in six patients (0.72%) 5 patients from dobutamine group and 1 from dipyridamole group). Complex forms of ventricular extrasystoles (as bigeminy and trigeminy) in 46 pts (5.5%) 43 in dobutamine SE and 3 in dipyridamole SE. All arrhythmias were mild and withdrew spontaneously or after beta-blockers administration. CONCLUSIONS: The risk of dangerous arrhythmia during either dobutamine SE or dipyridamole SE is small and similar in both groups. Dobutamine SE tends to provoke of mild arrhythmia (p = 0.075) more often.

Visualization and quantification of myocardial mass at risk using three-dimensional contrast echocardiography.

OBJECTIVE: Three-dimensional echocardiographic assessment of myocardial ischemia using contrast echocardiography has been hampered by limitations of available contrast agents and analytic software. In the study presented, a three-dimensional perfusion imaging method was evaluated in the porcine model of myocardial ischemia using a novel contrast agent. METHODS: Three-dimensional echocardiography was performed in eight open-chested pigs before, during and after left anterior descending (six animals) or circumflex (two animals) coronary artery occlusion. The intramyocardial contrast effect was obtained by left atrial injection of Myomap, a deposit contrast agent. RESULTS: Myocardial opacification was visible in all studies and retained in all three-dimensional datasets. Three-dimensional intensity analysis demonstrated a significant difference, exceeding 20 intensity units in every animal (in 127-level scale), between perfused and non-perfused myocardium. Reperfusion followed by contrast reinjection resulted in homogenous myocardial enhancement. Myocardial mass at risk was clearly delineated in all studies and measured with a mean error of -0.1 +/- 2.0 g against real mass (p = non-significant). Spatial extent of ischemia could be displayed in volume-rendered reconstruction of separate perfusion territories. CONCLUSIONS: Quantitative analysis of myocardial contrast enhancement from three-dimensional datasets is feasible and allows accurate measurement of myocardial mass at risk.

Effect of harmonic imaging without contrast on image quality of transesophageal echocardiography.

Harmonic imaging improves endocardial border delineation during transesophageal echocardiography when compared with conventional imaging (26% improvement vs 2% worsening; p <0.001). This allows better assessment of left ventricular function during cardiac surgery, and suggests a role of harmonic imaging for transesophageal echocardiography.

Usefulness of power Doppler contrast echocardiography to identify reperfusion after acute myocardial infarction.

Microvascular integrity, as seen by myocardial contrast echocardiography (MCE), assesses whether myocardium has been successfully reperfused after an acute myocardial infarction. Until now this has been demonstrated only with intracoronary injection of an ultrasound contrast agent. Power Doppler imaging is a recently developed myocardial contrast echocardiographic method that counts the contrast microbubbles destroyed by ultrasounds and displays this number in color. This study sought to evaluate whether power Doppler MCE is able to visualize myocardial reperfusion during intravenous contrast injection. Thirty patients were evaluated 2 days after their first myocardial infarction during intravenous infusion of perfluorocarbon-exposed sonicated dextrose albumin (PESDA). Coronary artery angiography and single-photon emission computed tomography (SPECT) were used as reference techniques. A 16-segment left ventricular model was used to relate perfusion to coronary artery territories. Sensitivity and specificity of power Doppler MCE for segments supplied by infarct-related arteries were 82% and 95%, respectively. Accuracy of power Doppler MCE and SPECT were similar (90% vs 92% on segmental basis and 98% vs 98% on coronary artery territory basis). Two-dimensional echocardiography was repeated after 6 weeks. Segments recovering wall motion after 6 weeks were defined as stunning myocardium. Dysfunctional but perfused myocardium at day 2 after the infarction showed a better late recovery of wall motion compared with dysfunctional but nonperfused myocardium (p <0.001). In conclusion, harmonic power Doppler imaging is a sensitive and specific method for the identification of myocardial reperfusion early after myocardial infarction. It yields prognostic information for late recovery of ventricular function differentiating stunning (dysfunctional but perfused) from necrotic myocardium (dysfunctional and nonperfused).

Optimal criteria for the diagnosis of coronary artery disease by dobutamine stress echocardiography.

The diagnosis of coronary artery disease (CAD) on the basis of inducible ischemia in > or = 2, rather than 1, segments was suggested to improve specificity of dobutamine stress echocardiography (DSE). However, the impact of using these criteria on the sensitivity and accuracy of DSE was not studied. We studied the accuracy of DSE (up to 40 microg/kg/min) for the diagnosis of CAD in 290 patients with suspected myocardial ischemia using the criteria of > or = 1 and > or = 2 ischemic segments. Ischemia was defined as new or worsening wall motion abnormalities using a 16-segment model. Among the 85 patients without previous myocardial infarction, significant CAD was detected in 51 (60%). Sensitivity, specificity, and accuracy of DSE using > or = 1 ischemic segment were 73%, 85%, and 78%, respectively. Those using > or = 2 segments were 67%, 94%, and 78%, respectively (p = NS). Regional specificity improved by using > or = 2 segments (91% vs 96%, p <0.05) at the expense of an equivalent reduction in regional sensitivity (60% vs 44%, p <0.05), whereas the regional accuracy was similar (80% vs 79% for > or = 1 and > or = 2 segments, respectively). In the 205 patients with previous myocardial infarction, the criterion of ischemia in > or = 1 segment had a higher sensitivity and accuracy for overall diagnosis of CAD (75% vs 64%, p <0.05; 77% vs 68%, p <0.05), infarct-related CAD (64% vs 47%, p <0.005; 70% vs 57%, p <0.01), and remote CAD (74% vs 57%, p <0.005; 78% vs 69%, p <0.05) than the criterion of > or = 2 segments, respectively. It is concluded that in patients without previous myocardial infarction, the use of > or = 2 ischemic segments by DSE for the diagnosis of CAD does not improve the accuracy of DSE compared with the criterion of > or = 1 ischemic segment. Conversely, in patients with previous infarction the use of > or = 2 segments reduces the overall and regional sensitivity and accuracy without a significant improvement in specificity.

Usefulness of three-dimensional transesophageal echocardiographic imaging for evaluating narrowing in the coronary arteries.

Coronary artery (CA) imaging has relied on invasive techniques for diagnosing stenotic lesions. Two-dimensional techniques are limited in obtaining optimal longitudinal views of all segments of the CA because of their spatial orientations. Three-dimensional echocardiography (3DE) may produce any desired cross-sectional views and reconstruct 3-dimensional images from a volumetric data set. Its role in CA imaging has not been fully explored. The aim of this study was to evaluate the potential of 3DE in visualizing CAs and in assessing the severity of stenosis. We performed transesophageal 3DE in 46 patients. Images were collected sequentially with the transducer rotated through 180 degrees. From the 3DE data sets of all 46 patients, cross-sectional views and 3-dimensional images of CAs were reconstructed. For segment-by-segment comparison between CA angiography and 3DE in semiquantitative analysis of coronary stenosis, 5 segments were defined for the proximal CA tree in 20 patients who underwent both procedures. The left main, anterior descending, circumflex, and right CAs were visualized from 3DE in 100%, 100%, 98%, and 72%. The available lengths of these segments from 3DE were 12+/-4 mm (range 4 to 22), 15+/-6 mm (range 6 to 36), 30+/-12 mm (range 13 to 60), and 18+/-9 mm (range 6 to 36), respectively. Comparison between 3DE and CA angiography in semiquantitative estimation of CA stenosis resulted in complete agreement in 83% of the segments (kappa value = 0.7). The sensitivity and specificity of 3DE in detecting significant stenosis (> or =50%) were 84% and 97%. In conclusion, transesophageal 3DE allows imaging of the proximal CA, detection of stenotic lesions, and estimation of the severity of stenosis.

Potentials and limitations of the Valsalva maneuver as a method of differentiating between normal and pseudonormal left ventricular filling patterns.

Pseudonormalization of the left ventricular (LV) filling pattern complicates the Doppler echocardiographic assessment of LV diastolic function in patients with heart failure. The Valsalva maneuver is recommended as a method of differentiating between normal and pseudonormal LV filling patterns. However, neither a standardized Valsalva maneuver nor a healthy control population has been studied so far. Therefore, we studied changes in mitral flow velocities in response to a standardized Valsolva maneuver in 55 heart failure patients with LV systolic dysfunction and 35 control subjects. The study subjects were instructed to elevate their intrathoracic airway pressure to 40 mm Hg for 10 seconds. Doppler mitral flow velocities were recorded at rest and during the Valsalva maneuver. All study subjects had comparable decreases in early mitral flow velocity, but mitral flow velocity at atrial contraction increased rather than decreased in patients with a restrictive LV filling pattern. This markedly abnormal response might be useful in detecting elevated filling pressures and pseudonormal filling patterns. Furthermore, in all but 2 patients and all control subjects with an E/A ratio between 1 and 2, inversion of the E/A ratio occurred. This proves that, in contrast to previous beliefs, inversion of the E/A ratio does not differentiate between normal and pseudonormal LV filling patterns.

Comparison of native and contrast-enhanced harmonic echocardiography for visualization of left ventricular endocardial border.

Our study was designed to compare the utility of fundamental and second harmonic imaging (SH) for visualization of the left ventricular (LV) endocardial border. SH is a new imaging modality using nonlinear acoustic response, which may provide better endocardial border delineation. Standard apical views were studied in 42 patients using fundamental frequency (FF), SH without contrast (1.6- to 1.8-MHz and 2.1- to 2.5-MHz transmission frequencies), and SH after an intravenous injection of 2.5 g of Levovist. The quality of endocardial delineation in 16 standard segments was scored from 0 to 2. The endocardial visualization index was calculated as a mean of the scores. SH with and without contrast significantly improved LV endocardial border detection (endocardial visualization index 1.25+/-0.53, 1.64+/-0.67, 1.55+/-0.69, and 1.73+/-0.28 for fundamental, lower, and higher frequency harmonic and contrast-harmonic mode, respectively, p <0.005). Improvement was found in all LV segments. The number of invisible segments decreased from 142 (FF) to 54, 112, and 61 (in lower, higher, and contrast SH mode, respectively, p <0.001). Endocardial delineation in the apical segments using SH was optimal after contrast injection. In the basal LV area, contrast-enhanced images were less informative because of signal attenuation. Thus, SH significantly improves visualization of the LV endocardial border. Contrast enhancement with Levovist improves imaging of the apical segments but has no additional advantage in the basal segments. SH emerges as first-line modality for studies of LV function.

Measurements and day-to-day variabilities of left ventricular volumes and ejection fraction by three-dimensional echocardiography and comparison with magnetic resonance imaging.

The aim of this study was to assess day-to-day variability of left ventricular (LV) volume and ejection fraction (EF) calculated from 3-dimensional echocardiography (3-DE) and to compare the reproducibility of the measurement with magnetic resonance imaging. Forty-six subjects were examined including 15 normal volunteers (group A) and 31 patients with LV dysfunction (group B). Precordial 3-DE acquisition was performed at 2 degrees rotational intervals and repeated 1 week later. Magnetic resonance imaging was performed at 0.5 T. End-diastolic and end-systolic LV volumes were derived using Simpson's rule by manual endocardial tracing of 8 equidistant parallel LV short-axis slices with 3-DE, whereas 9-mm slices were used with magnetic resonance imaging. The mean +/- SD of end-diastolic and end-systolic LV volumes (ml) and EF (%) from magnetic resonance imaging were 182 +/- 75, 121 +/- 76, and 39 +/- 18, whereas those from 3-DE were 182 +/- 76, 121 +/- 77, and 39 +/- 18 respectively. Day-to-day measurements of end-diastolic and end-systolic LV volumes, and EF on 3-DE were not significantly different as assessed with SEE (2.7, 1.1, and 2.4, respectively). Intra- and interobserver SEE for calculating end-diastolic and end-systolic LV volumes and EF for magnetic resonance imaging were 6.3, 4.7, and 2.1 and 13.6, 11.5, and 4.7, respectively, whereas those for 3-DE were 3.1, 4.4, and 2.2 and 6.2, 3.8, and 3.6, respectively. Day-to-day variability of LV volume and EF calculation on 3-DE were small and not significantly different for normal and dysfunctional left ventricles. Observer variabilities of 3-DE were fewer than those of magnetic resonance imaging. Therefore, 3-DE is recommended for serial assessment of LV volume and EF in normal and abnormally shaped ventricles.

Right ventricular outflow tract obstruction by cardiac metastasis as the first manifestation of follicular thyroid carcinoma.

A 40-year-old man was sent to the echocardiographic laboratory because of a heart murmur. An intracardiac mass, causing obstruction of flow within right ventricle, was diagnosed and the patient was referred to surgery. Histologic examination classified the mass as a metastasis of highly differentiated follicular carcinoma of the thyroid gland. Thyroidectomy was performed and radioiodine treatment instituted. Thus echocardiographic identification of right ventricular outflow obstructing mass was the initial presentation of follicular carcinoma of the thyroid gland. Early detection of this moderately disseminated malignancy allowed for surgical excision and systemic radioactive iodine treatment.

Appropriate 3-dimensional echocardiography data acquisition interval for left ventricular volume quantification: implications for clinical application.

UNLABELLED: Volume-rendered 3-dimensional echocardiography (3DE) acquired with small imaging intervals has been validated for accurate left ventricular (LV) volume measurement. However, its clinical application is often impeded by the lengthy acquisition time. The aim of this study was to examine the accuracy of LV volume measurement from 3DE data acquired at different intervals. METHODS: Transthoracic 3DE LV data sets were acquired at intervals of 2 degrees, 6 degrees, 9 degrees, 12 degrees, 15 degrees, 18 degrees, and 20 degrees in 10 human subjects with various cardiac shapes and function. The LV end-diastolic volume and end-systolic volume were measured from each 3DE data set with the "summation of disks" method. Interobserver and intraobserver variability were also examined. Measurements obtained from data acquired at 2 degrees intervals were used as references for comparison. RESULTS: From 10 subjects a total of 70 3DE data sets were obtained. Data acquisition time decreased from 189 +/- 143 seconds at intervals of 2 degrees to 19 +/- 6 minutes at 20 degrees. No statistically significant difference was found among the measurements derived from data obtained at various intervals. Excellent agreement was obtained between interobserver and intraobserver measurements. CONCLUSION: Data acquired at 12 degrees and 15 degrees intervals remained accurate for LV volume measurement and saved over 80% of time in comparison with data acquired at 2 degrees intervals. A further increase in imaging intervals tended to underestimate LV volumes without significant acceleration of the procedure.