Epicardial Echocardiograms Research Articles

Intraoperative epicardial echocardiography or transoesophageal echocardiography in CHD: how much does it matter?

Intraoperative imaging determines the integrity of surgical repairs. Transoesophageal echocardiography represents standard care for intraoperative imaging in CHD. However, some conditions preclude its use, and epicardial echocardiography is used alternatively. Minimal literature exists on the impact of epicardial echocardiography versus transoesophageal echocardiography. We aimed to evaluate accuracy between the two modalities and hypothesised higher imaging error rates for epicardial echocardiography. We retrospectively reviewed all epicardial echocardiograms performed over 16 years and compared them to an age- and procedure-matched, randomly selected transoesophageal echocardiography cohort. We detected un- or misidentified cardiac lesions during the intraoperative imaging and evaluated patient outcomes. Data are presented as a median with a range, or a number with percentages, with comparisons by Wilcoxon two-sample test and Fisher's exact test. Totally, 413 patients comprised the epicardial echocardiography group with 295 transoesophageal echocardiography matches. Rates of imaging discrepancies, re-operation, and incision infection were similar. About 13% of epicardial echocardiography patients had imaging discrepancies versus 16% for transoesophageal (p = 0.2352), the former also had smaller body sizes (p < 0.0001) and more genetic abnormalities (33% versus 19%, p < 0.0001). Death/mechanical support occurred more frequently in epicardial echocardiography patients (16% versus 6%, p < 0.0001), while hospitalisations were longer (25 versus 19 days, p = 0.0003). Diagnostic accuracy was similar between patients undergoing epicardial echocardiography and transoesophageal echocardiography, while rates of death and mechanical support were increased in this inherently higher risk patient population. Epicardial echocardiography provides a reasonable alternative when transoesophageal echocardiography is not feasible.

Successful balloon valvuloplasty using direct puncture of the heart for pentalogy of Cantrell with complete ectopia cordis, low birth weight, single ventricle and severe pulmonary stenosis.

We present a 31 gestational weeks' premature baby whose fetal echocardiogram showed ectopia cordis, single ventricle and severe pulmonary stenosis. At 31 gestational weeks, an emergency caesarean section was performed, and his birth weight was 1756 g, SpO2 was 80% on 100% O2. Epicardial echocardiogram showed double inlet right ventricle, severe valvular pulmonary stenosis and no ductus arteriosus. The risk of surgery was very high, so we decided to perform balloon valvuloplasty by direct puncture of the heart. We punctured the apex of the ventricle using a 16-gauge needle under echo guidance, advanced the guidewire to the pulmonary artery and performed balloon valvuloplasty. Soon after the procedure, the cyanosis improved dramatically. This is the first report of a transcatheter procedure performed by direct puncture of the heart for ectopia cordis with complex congenital heart disease.

Implante experimental de una bomba de asistencia circulatoria de flujo continuo en posición valvular aórtica

IntroductionThe implanting of an axial flow pump in an aortic valve position could decrease certain complications in current pumps. It could permit an anterograde blood flow in the heart and the aorta. It could avoid the making of a bag, as well as avoiding the need for inlet and outlet cannulas, and could slow down the scar formation in the cardiac apex. ObjectiveTo study the technical feasibility of the implanting of an axial flow pump in an aortic valve position, as well as to assess the haemodynamic effects and its impact on cardiac structures. MethodsA Jarvik 2000® pump adapted for an intra-valvular implant in 7 pigs was inserted using left anterior thoracotomy and under extracorporeal circulation. The pump was fixed to the aortic ring using sutures. It assisted the subjects for an hour during an assessment was made of the haemodynamic behaviour and the cardiac structures with an epicardial echocardiogram. After euthanasia of the animal, the heart was removed for an examination of its cavities. ResultsAll the procedures were completed with the technique. With the vasoactive drugs and epicardial pacemaker support, the pump was capable of maintaining the haemodynamics of the individuals. The echocardiogram showed adequate filling of the left ventricle and good functioning of the mitral valve. The post-mortem examination showed that the coronary ostia were free and there had not been any clots in the cardiac cavities. ConclusionsIn this animal model, the implanting of an axial flow pump in an aortic valve position was possible. The pump was able to maintain the haemodynamics of the animal without significantly affecting the cardiac structures.

Utility of a standardized postcardiopulmonary bypass epicardial echocardiography protocol for stage I Norwood palliation.

Stage 1 Norwood palliation is one of the highest risk procedures in congenital cardiac surgery. Patients with superior technical performance scores have more favorable outcomes. Intraoperative epicardial echocardiography may allow the surgeon to address residual lesions prior to leaving the operating room, resulting in improved technical performance. The ability of intraoperative epicardial echocardiography to visualize the relevant anatomy and its association with outcomes is not known. A standardized intraoperative epicardial echocardiography protocol was developed and performed at the conclusion of Stage 1 Norwood palliation. Data pertaining to visualization of relevant anatomy, and comparison of intraoperative echocardiogram findings with other postoperative investigations was performed. Clinical outcomes, including technical performance, were collected. A historical cohort who received either no echocardiogram or a nonstandardized examination was used as a comparison group. Thirty on-protocol and 30 preprotocol patients, 22 of whom had a nonstandardized intraoperative epicardial echocardiogram, were studied. Compared with preprotocol, visualization of the relevant anatomy was significantly increased for the Damus-Kaye-Stansel anastomosis (93% vs. 68% P = .03) and branch pulmonary arteries (70% vs. 36%, P = .02). One residual lesion requiring immediate operative reintervention was diagnosed in the preprotocol group. There were 5 patients in each cohort with residual lesions during the postoperative hospitalization that were not appreciated on the intraoperative echocardiogram. Technical performance, rates of reintervention and clinical outcomes were not significantly different between the two groups. Intraoperative epicardial echocardiography is technically feasible and increases visualization of the relevant anatomy. Larger investigations may be warranted to determine if there is clinical benefit to such an approach.

Preliminary evaluation of a microtransesophageal probe in neonates and young infants undergoing surgery for congenital heart disease.

Background:The larger size of the currently available transesophageal echocardiography (TEE) probes limits their use to relatively older infants undergoing cardiac surgery. In very young neonates and infants, epicardial echocardiogram is used to assess postoperative residual defects. Recently, a miniaturized microTEE probe compatible in neonates has been introduced for clinical use. We evaluated the use of this probe in small infants undergoing cardiac surgery.Materials and Methods:Thirty-three consecutive neonates and infants undergoing cardiac surgery at our institution were included in the study. Intraoperative echocardiography with Philips s8-3t microTEE probe done using IE33 platform was utilized to study the preoperative anatomy and assess postoperative results.Results:Thirty-three patients aged 3 days-2 years (mean 5.1 months) and weighing 2.5-11 kg (mean 4.4 kg) underwent perioperative evaluation using the microTEE probe. Good quality two-dimensional and color Doppler images were obtained in all patients. There were no complications related to the probe insertion or manipulation. The findings on microTEE led to revision of surgery in five patients. Certain echocardiographic parameters that could never be recorded with epicardial echocardiogram could be easily seen in microTEE.Conclusion:On preliminary evaluation, the microTEE probe provided good quality images in very small infants who were not amenable for transesophageal echocardiographic evaluation so far. The probe could be used safely in small infants without complications. It appears to be a promising imaging modality in the perioperative assessment of young infants undergoing cardiac surgery, in whom intraoperative epicardial echocardiography is currently the only tool.

Acute Feasibility Study of a Novel Device for the Treatment of Mitral Regurgitation in a Normal Canine Model

: The purpose of this study was to evaluate the implantability of a novel epicardial mitral annuloplasty device and its ability to reduce the septal-lateral (S-L) dimension of the mitral annulus. : The devices were implanted on the beating heart in 2 healthy dogs (the 24-mm long device in dog A and the 27-mm and 24-mm standard devices in dog B) by sliding the anterior arm onto the floor of the transverse sinus and positioning the posterior arm just apical to the atrioventricular groove on the left ventricular posterolateral wall. The devices were secured with titanium helical tacks driven through the device into the ventricular wall. Two-dimensional epicardial echocardiograms were performed before and after device implantation to evaluate the degree of mitral regurgitation (MR) and the S-L dimension. : Device implantation was uneventful, taking only ∼30 seconds to deploy. MR (1+) in both dogs at baseline was reduced to zero after implant. The reductions in S-L dimension in systole for the 24-mm device were 7.5% in dog A and 30.5% in dog B. For the 27-mm device in dog B, S-L reduction in systole was 29.9%. The leaflet coaptation length was increased in both cases. : The new device was effective in reducing S-L dimension and 1+ MR without requiring the use of cardiopulmonary bypass. We are currently evaluating this device for the treatment of MR in a rapid-pacing canine heart failure model.

Comparison of the Tei index with invasive measurements of right ventricular function

The Doppler-derived Tei index has been reported to be clinically useful in assessing global right ventricular function. It could increase in response to combinations of increased pulmonary artery pressure and/or ventricular dysfunction. We compared the Tei index with invasive measurements of right ventricular function during acute pulmonary hypertension. Right and left ventricular pressures, pulmonary and aortic pressures, pulmonary flow and right ventricular volume by sonomicrometry were measured in six anaesthetized sheep. Graded pulmonary arterial hypertension was induced by a mechanical occlusion maneuver. Pressure–volume loops were generated during preload reduction through caval occlusion. Epicardial echocardiograms were also performed. Invasive indexes including preload recruitable stroke work, ventricular diastolic time constant and stiffness constant, and cardiac output were assessed, as were noninvasive echocardiographic indexes including Tei index and E / A ratio. The right ventricular pressure–volume loop became rectangular, with well-defined isovolumic phases. The slope of preload recruitable stroke work was increased significantly during pulmonary pressure of 30 mm Hg. The ventricular time constant showed a significant increase with no change of chamber stiffness during pulmonary pressure of 35 mm Hg. Concomitantly, the Tei index increased significantly from 0.06 ± 0.03 to 0.31 ± 0.06, together with the shortening of the ejection time and a decrease of the E / A ratio ( P < 0.05). Thus, the right ventricular Tei index was noted to be affected by acute graded afterload increase. The alteration in invasive measurements of systolic and diastolic function makes the Tei index a sensitive indicator of right ventricular dysfunction in the settings of acute pulmonary hypertension.

Correlation of the tei index with invasive measurements of ventricular function in a porcine model

Background The Doppler myocardial performance (Tei) index has been reported to be clinically useful in assessing left ventricular systolic and diastolic function in both adults and children. However, there are limited data to compare the Tei index with invasive measurements of ventricular function. We used a porcine model to directly correlate the Tei index with invasive indices of systolic and diastolic function. Methods Pressure volume loops were obtained from 10 pigs (32-45 kg). A micromanometer and a conductance catheter were placed in the left ventricle to record pressure and volume, respectively. A flow probe was placed around the ascending aorta to record cardiac output. Baseline pressure volume loops were generated during preload reduction through caval occlusion. Epicardial echocardiograms were performed just before the caval occlusion. Invasive indices including preload recruitable stroke work, ventricular stiffness constant, and cardiac output were assessed, as were noninvasive echocardiographic indices including Tei index and ejection fraction. An ischemic insult, ventricular fibrillation, was induced to alter ventricular function. After cardioversion and 40 minutes of reperfusion, echocardiographic and invasive measurements were repeated. Results There was a statistically significant inverse relationship between the percent change in Tei and the percent change in preload recruitable stroke work after ventricular fibrillation ( r = −0.70, P = .02), although the correlation between the actual values of Tei and preload recruitable stroke work were not statistically significant. There was a statistically significant inverse relationship between the percent change in Tei and the percent change in cardiac output ( r = −0.65, P = .03). There was a direct correlation between the value of Tei and the ventricular stiffness constant at baseline ( r = 0.63, P < .05). As anticipated, the value of Tei was inversely related to ejection fraction by epicardial echocardiogram at baseline ( r = −0.85, P < .001). The percent change in Tei was inversely related to the percent change in ejection fraction as well ( r = −0.69, P < .05). Conclusions This animal model is one of the first studies to demonstrate a direct correlation between the Tei index and systolic and diastolic invasive measurements of ventricular function. This supports the clinical use of this index as a measure of global ventricular function.

Periventricular closure of ventricular septal defects without cardiopulmonary bypass

Background. Minimally invasive techniques are currently in use to close atrial and ventricular septal defects (VSD). Cardiopulmonary bypass (CPB) is instituted via the femoral vessels, which may cause injury to these vessels, especially in younger patients. The objectives of this study were to demonstrate the feasibility of periventricular closure of muscular VSD (MVSD) and paramembranous VSD (PVSD) without CPB, using the Amplatz VSD device.Methods. Five Yucatan pigs with naturally occurring PVSD (3- to 7-mm diameter) and 5 dogs with surgically created MVSD (6- to 14-mm diameter) were subjects of this study. The VSDs were closed intraoperatively with a 7-French delivery sheath inserted through the free wall of the right (n = 5) or left ventricle (n = 5), under epicardial echocardiogram guidance. The animals were followed for 3 months.Results. There was no operative mortality. All MVSD closed after placement of the device. Closure rate of PVSD was 4 of 5 after placement and 3 of 5 after 3 months. One pig developed aortic incompetence at the last follow-up.Conclusions. Perventricular closure of MVSD and PVSD is feasible. Avoidance of CPB can decrease recovery time, its complications, and trauma to the femoral vessels.

Percutaneous transvenous intracardiac ultrasound imaging in dogs: a new approach to monitor left ventricular function.

To evaluate the feasibility and ability of percutaneous transvenous intracardiac echocardiography (ICE) to image the left ventricle (LV) and monitor its function from the right ventricular (RV) cavity. A 10 MHz catheter was advanced into the RV from the jugular vein and positioned along the septum at the LV papillary muscle level in five dogs. The catheter was manipulated until a stable catheter position along the septum, which provided on-axis images of LV, was obtained. Different states of LV size and systolic function (n = 80) were created with dobutamine or esmolol, both in the presence and absence of coronary stenoses. LV stroke area (cm2) obtained by ICE was measured at the mid-ventricular level and compared with stroke volume (cm3) obtained simultaneously with a transaortic flow probe. LV end diastolic, end systolic, and stroke areas obtained by ICE were also compared with those obtained by short-axis epicardial echocardiography. In 96% of the stages, short axis images of the LV could be obtained and measured by ICE. LV end diastolic, end systolic, and stroke areas measured by ICE were not significantly different from epicardial echocardiographic values. Stroke area correlated with stroke volume in each dog (mean correlation coefficient 0.79 (SEE 0.19) cm2) (P < 0.001). Percutaneous intracardiac ultrasound imaging allows monitoring of LV function from the RV with an accuracy comparable to a short-axis epicardial echocardiogram. The present device can be used in closed chest experimental studies. With the development of lower frequency devices, this technique may be valuable for continuous monitoring of LV function in patients in the intensive care unit or operating room.