Cardiovascular Ultrasound - Latest Articles

A novel parasternal transthoracic echocardiographic window for detecting coronary ostial dilation after modified Bentall surgery

Austin Ng — 2013-05-20T00:00:00Z

Background: During the modified Bentall surgery (aortic root replacement), a cuff of native aorta is implanted, together with the coronary ostium, into the aortic graft. Multi-detector computed tomography (MDCT) imaging can accurately assess the coronary ostial anastomosis site post-surgery. In this study, we assessed the feasibility of imaging the coronary ostial anastomosis site using transthoracic echocardiography (TTE). Methods: Patients (n = 14, mean age 65 +/- 12 years, 79% males) with previous Bentall surgery underwent TTE study, with MDCT (64-slice) as the reference standard. TTE used conventional and novel acoustic windows to interrogate the coronary ostia. Results: All coronary ostia (n = 28) were well-visualized with MDCT. The optimum TTE acoustic window for visualizing the coronary ostia was a superiorly positioned parasternal short-axis view with the probe tilted towards the left shoulder, medially angulated for the right coronary artery ostia (RCAos) and laterally angulated for the left main coronary artery (LMAos). In this off-axis position, 10 (71%) LMAos and 13 (93%) RCAos could be visualized. In the conventional parasternal views, only 5 (36%) RCAos and no LMAos could be visualized. TTE underestimated the diameter of the LMAos (10.0 +/- 2.4 mm TTE vs. 13.4 +/- 2.7 mm MDCT, p = 0.007), but was similar to MDCT for the RCAos (9.8 +/- 3.1 mm TTE vs. 11.1 +/- 3.2 mm MDCT, p = 0.10). Conclusions: We report a novel TTE acoustic window to image the coronary ostia of post-Bentall surgery patients. Although TTE underestimates the left coronary ostium size, recognition of the ostial dilation with TTE appears feasible in most patients. Those that cannot be imaged will require alternative imaging modality such as MDCT.

Non invasive evaluation of cardiomechanics in patients undergoing mitraclip procedure

Fabio Guarracino — 2013-05-04T00:00:00Z

Background: In the last recent years a new percutaneous procedure, the MitraClip, has been validated for the treatment of mitral regurgitation. MitraClip procedure is a promising alternative for patients unsuitable for surgery as it reduces the risk of death related to surgery ensuring a similar result. Few data are present in literature about the variation of hemodynamic parameters and ventricular coupling after Mitraclip implantation. Methods: Hemodynamic data of 18 patients enrolled for MitraClip procedure were retrospectively reviewed and analyzed. Echocardiographic measurements were obtained the day before the procedure (T0) and 21 ± 3 days after the procedure (T1), including evaluation of Ejection Fraction, mitral valve regurgitation severity and mechanism, forward Stroke Volume, left atrial volume, estimated systolic pulmonary pressure, non invasive echocardiographic estimation of single beat ventricular elastance (Es(sb)), arterial elastance (Ea) measured as systolic pressure • 0.9/ Stroke Volume, ventricular arterial coupling (Ea/Es(sb) ratio). Data were expressed as median and interquartile range. Measures obtained before and after the procedure were compared using Wilcoxon non parametric test for paired samples. Results: Mitraclip procedure was effective in reducing regurgitation. We observed an amelioration of echocardiographic parameters with a reduction of estimated systolic pulmonary pressure (45 to 37,5 p = 0,0002) and left atrial volume (110 to 93 p = 0,0001). Despite a few cases decreasing in ejection fraction (37 to 35 p = 0,035), the maintained ventricular arterial coupling after the procedure (P = 0,67) was associated with an increasing in forward stroke volume (60,3 to 78 p = 0,05). Conclusion: MitraClip is effective in reducing mitral valve regurgitation and determines an amelioration of hemodynamic parameters with preservation of ventricular arterial coupling.

Transthoracic echocardiography reference values in juvenile and adult 129/Sv mice

Maurícia Vinhas — 2013-05-01T00:00:00Z

Background: In the recent years, the use of Doppler-echocardiography has become a standard non-invasive technique in the analysis of cardiac malformations in genetically modified mice. Therefore, normal values have to be established for the most commonly used inbred strains in whose genetic background those mutations are generated. Here we provide reference values for transthoracic echocardiography measurements in juvenile (3 weeks) and adult (8 weeks) 129/Sv mice. Methods: Echocardiographic measurements were performed using B-mode, M-mode and Doppler-mode in 15 juvenile (3 weeks) and 15 adult (8 weeks) mice, during isoflurane anesthesia. M-mode measurements variability of left ventricle (LV) was determined. Results: Several echocardiographic measurements significantly differ between juvenile and adult mice. Most of these measurements are related with cardiac dimensions. All B-mode measurements were different between juveniles and adults (higher in the adults), except for fractional area change (FAC). Ejection fraction (EF) and fractional shortening (FS), calculated from M-mode parameters, do not differ between juvenile and adult mice. Stroke volume (SV) and cardiac output (CO) were significantly different between juvenile and adult mice. SV was 31.93 ± 8.67 μl in juveniles vs 70.61 ± 24.66 μl in adults, ρ < 0.001. CO was 12.06 ± 4.05 ml/min in juveniles vs 29.71 ± 10.13 ml/min in adults, ρ < 0.001. No difference was found in mitral valve (MV) and tricuspid valve (TV) related parameters between juvenile and adult mice. It was demonstrated that variability of M-mode measurements of LV is minimal. Conclusions: This study suggests that differences in cardiac dimensions, as wells as in pulmonary and aorta outflow parameters, were found between juvenile and adult mice. However, mitral and tricuspid inflow parameters seem to be similar between 3 weeks and 8 weeks mice. The reference values established in this study would contribute as a basis to future studies in post-natal cardiovascular development and diagnosing cardiovascular disorders in genetically modified mouse mutant lines.

Gene therapy for cardiovascular disease mediated by ultrasound and microbubbles

Zhi-Yi Chen — 2013-04-17T00:00:00Z

Gene therapy provides an efficient approach for treatment of cardiovascular disease. To realize the therapeutic effect, both efficient delivery to the target cells and sustained expression of transgenes are required. Ultrasound targeted microbubble destruction (UTMD) technique has become a potential strategy for target-specific gene and drug delivery. When gene-loaded microbubble is injected, the ultrasound-mediated microbubble destruction may spew the transported gene to the targeted cells or organ. Meanwhile, high amplitude oscillations of microbubbles increase the permeability of capillary and cell membrane, facilitating uptake of the released gene into tissue and cell. Therefore, efficiency of gene therapy can be significantly improved. To date, UTMD has been successfully investigated in many diseases, and it has achieved outstanding progress in the last two decades. Herein, we discuss the current status of gene therapy of cardiovascular diseases, and reviewed the progress of the delivery of genes to cardiovascular system by UTMD.

The true cost of cardiovascular imaging: focusing on downstream, indirect, and environmental costs

Larissa Braga — 2013-04-17T00:00:00Z

To develop a more realistic assessment of costs, herein named “true” costs, the extra-cancer from medical radiation, environmental damage from imaging paraphernalia and radioactive wastes must be included as long-term costs from imaging examinations. It is urgent to define the “true” costs across imaging modalities as it interferes on physicians’ decision to request an exam and on research projects such as cost-effectiveness analysis. Cardiology is the specialty that most will benefit from the outcome as cardiovascular exams represent almost 30% of the total exams acquired annually worldwide.

Peak systolic velocity using color-coded tissue Doppler imaging, a strong and independent predictor of outcome in acute coronary syndrome patients

Carl Westholm — 2013-04-01T00:00:00Z

Background: Traditional echocardiographic methods like left ventricular ejection fraction(EF) and wall motion scoring (WMS) and new methods like speckle tracking (ST) based 2D strain carry important prognostic information in acute coronary syndrome (ACS) patients. Parameters from tissue Doppler imaging (TDI), with its high time resolution, may further increase the prognostic value. Peak systolic velocity (PSV) of the basal segments of the left ventricle from TDI is a robust and user independent parameter. The aim was to investigate the prognostic value of PSV compared to EF, WMS, 2D strain and E/e'. Methods: Echocardiographic images were collected and post processed in 227 ACS patients. Additional clinical data was prospectively gathered and patients were followed for 3-5 years regarding the combined endpoint of death or re-admission due to ACS or heart failure. Results: The combined endpoint occurred in 85 (37%) patients. Those with an event had lower median PSV than those without (4,4 cm/s) vs. (5,3 cm/s), (p<0.001). In a ROC analysis, the AUC was larger for PSV (0.75) than for EF (0.68), WMS (0.63), 2D strain (0.67) and E/e'(0.70). The combined endpoint increased with decreasing PSV. When adjusting for differences in baseline characteristics in a COX-regression model, PSV remained independently associated with outcome where the others did not. PSV was also less sensitive to image quality with fewer values missing or unacceptable for analysis. Conclusion: Peak systolic velocity (PSV) is a robust measurement that seems to have a strong and independent association with outcome compared to traditional echocardiographic measurements in ACS patients.

Minimally invasive perventricular device closure of ventricular septal defect in infants under transthoracic echocardiograhic guidance: feasibility and comparison with transesophageal echocardiography

Gui-Can Zhang — 2013-03-11T00:00:00Z

Background: A hybrid approach to minimally invasive perventricular closure of VSD in infants is safe and effective, and has been performed under guidance of transesophageal echocardiography (TEE). We applied transthoracic echocardiographic (TTE) guidance to this hybrid approach, and compare results guided by TTE with those by TEE. Methods: From January 2011 to January 2012, 71 infants with VSD were enrolled to undergo a minimally invasive device closure. After evaluation of VSD by TTE, either TEE or TTE was used to guide the minimally invasive device closure. 30 patients had TEE guidance, and 41 patients had TTE. All patients were followed for 3 months after the operation. Results: The TEE group had a success rate of 93.3% (28/30) for device implantation, compared with 92.7% (38/41) in the TTE group. Two patients in the TEE group turned to surgical closure, one for involvement of the inlet area of VSD demonstrated by TEE, another for moderate aortic regurgitation after device implantation. Two patients in the TTE group also transferred to surgical closure, one for residual shunt, another for failure of the floppy wire across the defect. In addition, one patient in the TTE group experienced dropout of the occluder one day postoperatively. At 3-month follow-up, one patient had mild aortic regurgitation in the TEE group and in two patients in the TTE group. There were no episodes of cardiac block, thromboembolism, or device displacement in either group. Conclusions: TTE-guided VSD closure is feasible in infants, with results similar to those of TEE guidance, although caution is advisable.

Use of echocardiographic pulmonary acceleration time and estimated vascular resistance for the evaluation of possible pulmonary hypertension

Sven-Olof Granstam — 2013-02-27T00:00:00Z

Background: During ultrasound examination, tricuspid regurgitation may be absent or gives a signal that is not reliable for the estimation of systolic pulmonary pressure. The aim of this study was to evaluate the usefulness of acceleration time (AT) from the right ventricular outflow tract (RVOT) as an estimation of the trans-tricuspid valve gradient (TTVG) and to investigate the correlation between estimated and invasive pulmonary vascular resistance (PVR). Methods: The AT was correlated to the TTVG measured with routine standard echocardiography in 121 patients. In a subgroup of 29 patients, systolic pulmonary pressure (SPAP) and mean pulmonary arterial pressure (MPAP) were obtained from recent right heart catheterization (RHC). Results: We found no significant correlation between the estimation of right atrial pressure (RAP) by echocardiography and the RAP obtained by RHC. Estimated SPAP (TTGV + RAP mean from RHC) showed a good linear relation to invasively measured SPAP. TTVG and AT showed a non-linear relation, similar to SPAP and MPAP measured by catheterization and AT. For detection of SPAP above 38 mmHg a cut-off for AT of 100 ms resulted in a sensitivity of 89% and a specificity of 84%. For detection of MPAP above 25 mmHg a cut-off for AT of 100 ms resulted in similar sensitivity and specificity. Invasive PVR and the ratio of TTVG and the time velocity integral of the RVOT (TVI RVOT ) had a strong linear relation. Conclusions: Our study confirms that AT appears to be useful for the evaluation of pulmonary hypertension. In high risk patients, an AT of less than 100 ms indicates a high probability of pulmonary hypertension. Furthermore, PVR estimation by ultrasound seems preferably be done by using the ratio of TTVG and TVI RVOT.

Role of 2D strain in the early identification of left ventricular dysfunction and in the risk stratification of systemic sclerosis patients

Maurizio Cusmà Piccione — 2013-02-03T00:00:00Z

Background: Systemic sclerosis (SSc) is an autoimmune chronic disease characterized by diffuse fibrosis involving several organs, including heart. Aim of our study was to analyze left ventricular (LV) myocardial deformation, by use of 2D strain, in asymptomatic SSc patients with normal LV ejection fraction. Methods: We enrolled 29 SSc patients (28 female, 65±4 years) and 30 controls (23 female, 64±2 years). Echocardiographic study with tissue Doppler imaging (TDI) and 2D strain analysis was performed; moreover, patients were submitted to a two-year follow-up for the occurrence of cardiovascular events. Results: Standard echocardiographic parameters and TDI velocities were comparable between groups. LV longitudinal (LS) and circumferential (CS) strains were lower in patients than in controls (−13.1±4.8 vs −22.6±4.1, p < 0.001; -15.3±6.2 vs −20.4±5.6, p = 0.001), whereas radial strain (RS) was comparable between groups; moreover, a significant correlation of LS and CS with serum levels of Scl-70 antibodies was found (r = 0.74, p = 0.001; r = 0.53, p = 0.025). In addition, patients with cardiovascular events during follow-up showed a greater impairment of LS and CS (−10.3±2.5 vs −14.4±4.1, p = 0.015; -14.2±3.1 vs −20.1±1.6, p = 0.048) and higher values of Scl-70 antibodies serum levels (p = 0.047). Conclusion: The impairment of LV function, often subclinical, worsens prognosis of SSc patients, leading to increased risk of cardiovascular complications. 2D strain, allowing the early detection of LV abnormalities and the identification of patients at greater cardiovascular risk, may be a useful tool in order to provide a more accurate management of SSc patients.

Transesophageal echocardiography measurements of aortic annulus diameter using biplane mode in patients undergoing transcatheter aortic valve implantation

Kambiz Shahgaldi — 2013-01-30T00:00:00Z

Background: Aortic stenosis (AS) is a relevant common valve disorder. Severe AS and symptoms and/or left ventricular dysfunction (EF <50%) have the indication for aortic valve replacement (AVR). Majority of the patients with AS are elderly often with co-morbidities and generally have high preoperative risk. Transcatheter aortic valve implantation (TAVI) is offered in this group. Four different sizes of Corevalve prosthesis are available. Correct measurement of aortic size prior to TAVI is of great important to choose the right prosthesis size to avoid among others paravalvular leak or prosthesis patient mismatch.Aim of the study is to assess the aortic annulus diameter in patients undergoing TAVI by biplane (BP) mode using transesophageal echocardiography (TEE) and compare it to two-dimensional (2D) transthoracic echocardiography (TTE) and 2DTEE using three-dimensional (3D) TEE as reference method. Methods: The study population consisted of 50 patients retrospectively (24 men and 26 women, mean age 85±8 years of age) who all had undergone echocardiography examination prior to TAVI. Results: The mean aortic annulus diameter was 20.4±2.2 mm with TTE, 22.3±2.5 mm with 2DTEE, 22.9±1.9 mm with BP-mode and 23.1±1.9 mm with 3DTEE. TTE underestimated the mean aortic annulus diameter in comparison to transesophageal imaging modalities (p<0.001). Using 3DTEE, 2% of patients were unsuitable for TAVI due to a too-small AoA (n=1). This figure was similar with BP (4%, n=2; p=1.00) but considerably larger with 2DTTE (36%, n=18; p < 0.001) and 2DTEE (12%, n=6; p=0.06). There was a strong correlation between BP-mode and 3DTEE for assessment of aortic annulus diameter (r-value 0.88) with small mean difference (−0.2±0.9 mm) whereas the other modalities showed larger 95% confidence interval and modest correlation (2DTTE vs. 3DTEE, –6.3 to 0.9 mm, r=0.64 and 2DTEE vs. 3DTEE, –4.8 to 3.2 mm, r=0.61). Conclusion: A multi-dimensional method is preferred to assess aortic annulus diameter in TAVI patients since there is risk of underestimation using single plane. Biplane mode is the method of choice in view of speedy post-processing with no need for expensive dedicated software. Lastly, single plane methods lead to misclassification of patients as unsuitable for TAVI. This may be of major clinical importance.