Adalia Aubele

Usefulness of a New Miniaturized Echocardiographic System in Outpatient Cardiology Consultations as an Extension of Physical Examination

BACKGROUND The aim of this study was to assess the usefulness of a new miniaturized echocardiographic system (MS) to perform bedside echocardiography in initial outpatient cardiology consultations, in addition to physical examination. METHODS One hundred eighty-nine patients referred for initial cardiology outpatient consultations at two tertiary hospitals in two countries were studied. Each patient was submitted to physical examination followed by MS assessment. Scanning time, the number of examinations with abnormal results after physical examination and the MS, and the information obtained by physical examination alone and followed by the MS (in terms of its importance in reaching a diagnosis, in the necessity of performing routine echocardiography, and in the decision to release the patient from the outpatient clinic) were assessed. RESULTS The scanning time with the MS was 180 ± 86 seconds. Its use after physical examination led to diagnoses in 141 patients (74.6%) and to an additional 37 patients (19.6%) being released from the outpatient clinic. After physical examination followed by MS assessment, only 64 patients (33.9%) were sent to the echocardiography lab. The MS modified the decision of whether to send a patient to the echocardiography lab, with referral determined by the MS in 27 patients (14.3%) and no referral determined by the MS in 58 patients (30.7%). CONCLUSIONS The new MS caused a negligible increase in the duration of consultations. It showed additive clinical value over physical examination, increasing the number of diagnoses, reducing the use of unnecessary routine echocardiography, increasing the number of adequate echocardiographic studies, and determining a large number of releases from the outpatient clinic.

Accuracy of real-time 3-dimensional echocardiography in the assessment of mitral prolapse. Is transesophageal echocardiography still mandatory?

BACKGROUND Segmental analysis in mitral prolapse is important to decide the chances of valvular repair. Multiplane transesophageal echocardiography (TEE) is the only echocardiographic tool validated for this aim hitherto. The aim of the study was to assess if segmental analysis can be performed with transthoracic real-time 3-dimensional (3D) echocardiography as accurately as with TEE, hence representing a valid alternative to TEE. METHODS Forty-one consecutive patients diagnosed with mitral prolapse underwent TEE and a complete 3D echocardiography study, including parasternal and apical real-time; apical full-volume; and 3D color full-volume. Investigators performing TEE were blinded to the 3D results. RESULTS Three-dimensional echocardiogram was feasible in 40 to 41 patients (97.7%). Ages ranged from 15 to 92 years, and all possible anatomical patterns of prolapse were represented. Thirty-seven patients (90.2%) had mitral regurgitation of any degree. The level of agreement was k = 0.93 (P < or = .0001), sensitivity of 96.7%, specificity of 96.7%, likelihood ratio for a positive result of 29.0%, and likelihood ratio for a negative result of 0.03%. Four false positives were found, corresponding to scallops A2 (1), A3 (2), and P3 (1). Four false negatives were found, corresponding to scallops A1 (2) and P1 (2). Sensitivity and specificity in the scallop P2 were 100%. CONCLUSION Segmental analysis in mitral prolapse can be performed with transthoracic real-time 3D echocardiography as accurately as with TEE. False negatives tend to appear around the anterolateral commissure, whereas false positives tend to appear around the posteromedial commissure. Highest accuracy was reached in central scallops.

Contrast agents provide a faster learning curve in dipyridamole stress echocardiography

Aim: Interobserver variability is an important limitation of the stress echocardiography and depends on the echocardiographer training. Our aim was to evaluate if the use of contrast agents during dipyridamole stress echocardiography would improve the agreement between an experienced and a non-experienced observer in stress echo and therefore if contrast would affect the learning period of dypyridamole stress echo. Methods and results: Two independent observers without knowledge of any patient data interpreted all stress studies. One observer was an experienced one and the other had experience in echocardiography but not in stress echo. Two observers analysed 87 non-selected and consecutive studies. Out of the 87 studies, 46 were performed without contrast administration, whereas i.v. contrast (2.5 g Levovist® by two bolus at rest and at peak stress) was administered in 41. In all cases, second harmonic imaging and stress digitalisation pack was used. The agreement between observers showed a κ index of 0.58 and 0.83 without and with contrast administration, respectively. Conclusions: The use of contrast agents provides a better agreement in the evaluation of stress echo between an experienced and a non-experienced observer in stress echo. Adding routinely contrast agents could probably reduce the number of exams required for the necessary learning curve in stress echocardiography.

Isovolumic Contraction Time by Pulsed-Wave Doppler Tissue Imaging in Aortic Stenosis

BACKGROUND Doppler Tissue Imaging (DTI) has been evaluated in ischaemic heart disease and some cardiomyopathies. In patients with aortic stenosis (AS), left ventricular contraction is slowered. This study aimed to evaluate the possible role of the measurement of isovolumic contraction time (ICT) by DTI in the evaluation of AS severity. METHODS The study population constitutes 30 patients: 15 with AS (nine severe and six non-severe) and 15 control subjects. All of them had normal systolic function, sinus rhythm, and absence of ischaemic heart disease of conduction abnormalities. ICT was defined as the time from the onset of the QRS complex to the beginning of the DTI systolic wave. The correlation between ICT and aortic area obtained by continuity equation, as well as the diagnostic value of ICT in the identification of severe AS were studied. RESULTS ICT was significantly increased in patients with severe AS (98+/-27 versus 65+/-21 ms, p=0.024). There was a significant correlation between ICT and aortic area (r=-0.56; p=0.035). The receiver operator characteristic curve of ICT in the identification of severe AS yielded an area under the curve of 0.852 (95% confidence interval: 0.665-1.0). The two best cut-points were >73 ms (88% sensitivity, 77% specificity) and >85 ms (78% sensitivity, 83% specificity). A value of >41 ms had a 100% sensitivity, but only a 17% specificity, and >91 ms showed a 100% specificity, but only a 44% sensitivity. CONCLUSIONS ICT measured by pulsed-wave DTI is increased in patients with aortic stenosis.

Estudio de la deformación miocárdica: predictor de disfunción ventricular a medio plazo tras cirugía en pacientes con insuficiencia mitral crónica

Introduccion y objetivos. El desarrollo de disfuncion ventricular izquierda tras la sustitucion valvular mitral es un problema frecuente en pacientes con insuficiencia mitral grave cronica. El analisis de la deformacion miocardica permite estimar con precision la contractilidad miocardica. Nuestro objetivo fue comparar el valor predictivo de strain (S) y strain rate (SR) preoperatorios obtenidos por speckle-tracking y Doppler tisular (DTI) para predecir la disminucion de la fraccion de eyeccion del ventriculo izquierdo (FEVI) a medio plazo tras la cirugia. Metodos. Treinta y ocho pacientes consecutivos con insuficiencia mitral grave cronica programados para sustitucion valvular mitral fueron incluidos prospectivamente. Se analizo el S y el SR longitudinal del septo interventricular en el periodo preoperatorio mediante speckle-tracking y DTI. La FEVI preoperatoria y postoperatoria se obtuvo por ecocardiografia tridimensional. Los estudios ecocardiograficos se realizaron dentro de las 48 h previas a la cirugia y 6 meses despues de la cirugia. Resultados. La media de edad de los pacientes era 59,9 ± 11,3 anos; 10 pacientes (29,4%) eran varones. Tanto el speckle-tracking como el DTI resultaron predictores de disminucion de la FEVI > 10% a 6 meses. Sin embargo, el valor predictivo del speckle-tracking fue superior al del DTI. El S longitudinal del septo interventricular basal mediante speckle-tracking fue el parametro con mayor poder predictivo, con un area bajo la curva de 0,85 y un punto de corte optimo de -0,11. Conclusiones. El speckle-tracking permite predecir la disminucion de la FEVI a medio plazo tras la sustitucion valvular mitral. Ademas, el speckle-tracking es mas preciso que el DTI para este fin.

Myocardial perfusion in real-time using power modulation: In vivo evidence for microcirculatory damage after acute myocardial infarction

BACKGROUND AND OBJECTIVES In addition to the myocardium, the microvasculature may be also damaged in acute myocardial infarction. The aim was to evaluate the capability of myocardial contrast echocardiography in the detection of microvasculature damage after myocardial infarction. PATIENTS AND METHODS Twelve patients with recent acute myocardial infarction and five control subjects with normal coronary arteries and without history of myocardial infarction were studied. Myocardial contrast echocardiography with power modulation was performed, and quantitative data were measured off-line. Power modulation uses a combination of low (0.1) and high (1.7) mechanical indexes, allowing a real-time evaluation of myocardial perfusion. Contrast agent was administered as a 3-min bolus. The quantitative analysis was performed off-line by a different blinded investigator. The refilling velocity was calculated as the difference between the peak myocardial refilling value and the value at 1 s after the impulse divided by the time from the first second after the impulse to the peak refilling value. RESULTS Eighty-one myocardial segments (75%) were analysed qualitatively and quantitatively in AMI patients, and 18 (60%) in control subjects (P=NS). The peak refilling intensity was not significantly different in patients and control subjects (6.62+/-5.85 vs. 7.53+/-4.06 dB, respectively). However, time to peak refilling intensity was significantly longer (5.25+/-1.57 vs. 4.00+/-0.53, P=0.004) and the velocity of refilling was significantly lower (2.74+/-5.34 vs. 6.58+/-8.02, P=0.028) in patients with myocardial infarction. CONCLUSION There is microvasculature damage after myocardial infarction that is reflected as a delayed velocity of refilling in myocardial contrast echocardiography.

Evaluation of myocardial perfusion with grey-scale ultra-harmonic and multiple-frame triggering. The need for quantification

BACKGROUND AND OBJECTIVE Contrast echocardiography has been recently introduced as a new technique for evaluating myocardial perfusion in a qualitative basis. The objective of this study was to test whether a visual subjective evaluation of myocardial perfusion by myocardial contrast echocardiography adequately matches the data obtained with an off-line quantification of myocardial perfusion. METHODS Sixty-one myocardial segments were evaluated by myocardial contrast echocardiography with Ultra-harmonic and Multiframe Triggering in 11 patients 3-7 days after an anterior myocardial infarction, using SH-U 563A (Levovistâ, Schering AG, Berlin, Germany) as contrast agent. Myocardial perfusion was classified as grade 1 (absent), 2 (patchy or incomplete) and 3 (complete) in each segment. The quantitative analysis was performed off-line by a different investigator blinded to the qualitative evaluation, using a commercially available software. The quantitative data on grey-scale obtained were compared between grade 1, 2 and 3 segments. RESULTS Of the 61 segments, 45 (73.8%) were classified as grade 3, whereas the remaining 16 (26.2%) were considered to be abnormally perfused (grade 2: n=12, 19.6%; grade 1: n=4, 6.6%). Segments with grade 1 perfusion had a significantly higher grey-scale value (123.6 +/- 41.3 vs. 70.1 +/- 34.3, p=0.004). However, there were no significant differences between segments with perfusion grade 2 and 3 (76.8 +/- 33.2 vs. 68.3 +/- 34.8, p=0.452). CONCLUSION Qualitative assessment of myocardial perfusion by Ultra-harmonic and Multiframe Triggering is of limited value, since only myocardial segments with absent perfusion may be reliably identified. This findings support the need of quantification in the evaluation of myocardial perfusion by contrast echocardiography.

Myocardial Contrast Echocardiography in the Assessment of Patients With Chronic Coronary Artery Disease

The development of new contrast agents and new imaging methods has lead to an emerging field of applications for myocardial contrast echocardiography (MCE) in patients suffering from chronic ischemic heart disease. Echo contrast allows the assessment of myocardial perfusion (MP) by imaging the coronary microcirculation. Several echocardiographic modalities are available, the main difference between them being the acoustic power needed to perform the study. MP is evaluated by assessing the changes in myocardial videointensity that occur after intravenous contrast injection. Evaluation of these patients is performed by using different techniques. Evaluation of coronary stenosis may be performed by using stress tests or without its use. Coronary artery stenosis >50% of the coronary luminal diameter reveals a decreased hyperemic response when myocardial oxygen demand is increased. Different methods to evaluate the presence of relevant coronary stenosis have been developed: evaluation of myocardial blood flow reserve, evaluation of myocardial blood volume, and evaluation of the transmural distribution of myocardial blood flow. The combination of wall motion analysis with MCE assessment has been demonstrated to achieve the best balance between sensitivity (86%) and specificity (88%), with the highest accuracy (86%). Without the need of any stress, the ratio systolic/diastolic myocardial blood volume has been described to increase with the presence of a epicardial coronary stenosis and it may be measured by MCE. Myocardial viability is also one of the potentials of MCE. Microvascular integrity, demonstrated by MCE, is an indicator of preserved viability and predicts functional recovery that has been validated in the setting of chronic left ventricular dysfunction secondary to chronic coronary artery disease and in the setting of post acute myocardial infarction left ventricular dysfunction. In conclusion: contrast echocardiography provides an interesting tool that offers the potential of a complete evaluation of patients with chronic coronary artery disease. This includes both diagnostic and prognostic evaluation. (ECHOCARDIOGRAPHY, Volume 20, Supplement 1, 2003)