Nitric oxide: lifesaving measure for pulmonary vasospasm after modified Blalock-Taussig shunt.

Pulmonary vasospasm and hypertension may occur after repair or palliation of congenital cardiac defects, and can be fatal in spite of conventional treatment. Nitric oxide has been shown to improve pulmonary hypertension unresponsive to conventional measures after a variety of repairs, but use has infrequently been reported after palliative systemic to pulmonary artery shunts. We report a case of pulmonary hypertension and life threatening desaturation after a modified Blalock-Taussig shunt that responded rapidly to inhaled nitric oxide. Clinical use, further study, and prospective analysis of prophylactic use of nitric oxide appear warranted.

Volume quantification of intracardiac mass lesions by transesophageal three-dimensional echocardiography.

As compared with two-dimensional (2-D) transesophageal echocardiography (TEE), 3-D echocardiography now permits more realistic visualization of cardiac anatomy and of intracardiac lesions. The aim of this study was to apply newer 3-D echocardiographic techniques to quantify volumes of intracardiac masses undergoing surgical resection seen during an intraoperative TEE. The calculated volumes were compared with actual in vitro measurements of surgically resected masses. A total of 14 patients (9 men; 5 women; age range between 21 and 77 years) with intracardiac mass lesions (4 tumors: 3 left atrial myxomas and 1 mitral valve fibroelastoma, and 10 vegetations: 5 aortic valve, 3 mitral valve, 1 tricuspid and 1 pulmonary valve) were studied. Using commercially available 3-D reconstruction software (TomTec v. 4.1), the volumes of intracardiac masses were estimated using both the average rotation (rotation around the long axis, AR) and disk summation (parallel short axis cuts, DS) methods. Volumes of these lesions were also measured in vitro by water submersion. They ranged from 0.20 mL to 24 mL (mean +/- SD = 8.07 +/- 9.21 mL). Both 3-D TEE AR and 3-D TEE DS calculated volumes correlated excellently with in vitro measured volumes (r = 1.00 and r = 0.98, respectively, p = < 0.0001). The correlation between 3-D TEE AR and 3-D TEE DS calculated volumes was also excellent (r = 0.98, p = < 0.0001). In conclusion, the volume assessments by 3-D TEE of intracardiac mass lesions correlated well with in vitro measured volumes of surgical specimens. This technique may prove to be valuable in further defining intracardiac pathology and is a further advancement toward the application of clinically useful 3-D echocardiography.

Hemodynamic evaluation of normally functioning Sulzer Carbomedics prosthetic valves.

The Sulzer Carbomedics prosthetic heart valve (CP) is a commonly used mechanical valve in clinical practice. In the present study, we used conventional and color Doppler echocardiography to assess the hemodynamics of normally functioning CP in the aortic (n = 73) and mitral (n = 127) positions. Our findings demonstrate no significant correlation of Doppler-measured peak and mean pressure gradients and effective orifice area with implanted valve size and actual orifice areas, measured directly by the manufacturer for CPs in both the mitral and aortic positions. However, it is still useful to measure effective orifice area by Doppler because a value in the normal or nonstenotic range points to an unobstructed prosthesis in the aortic or mitral position, in the absence of poor left ventricular ejection fraction. A value in the stenotic range could mean a normally functioning or obstructed prosthesis and, therefore, may need further investigation, such as assessment of valve leaflet motion by transthoracic or transesophageal echocardiography or fluoroscopy. Valve regurgitation as evaluated by color Doppler flow mapping was mild in practically all CPs in the aortic position, and in the majority of CPs in the mitral position.

Transesophageal Three-Dimensional Echocardiographic Assessment of Normal and Stenosed Coronary Arteries.

We describe our preliminary experience in assessing normal and stenosed coronary arteries using transesophageal three-dimensional echocardiography (3-D echo) in 27 adult patients. Multiplane transesophageal two-dimensional images of the coronary arteries (20 left, 3 right, 3 both left and right, and 1 posterior descending) were first acquired in the TomTec computer in 3 degrees sequential increments, from 0 degrees to 180 degrees, and then 3-D reconstruction was performed. The entire left main (LMC, measuring 0.5 to 1.7 cm, mean 1.0 cm) as well as variable lengths of proximal or both proximal and middle segments of the left anterior descending (LAD, measuring 0.2 to 2.5 cm, mean 0.8 cm) and circumflex (LCX, measuring 0.2 to 2.8 cm, mean 0.9 cm) coronary arteries together with some of their branches could be visualized in 3-D in 22 of 23 patients. In the remaining patient, the LMC was absent, and both LAD and LCX could be visualized in 3-D as having separate but adjacent origins from the left sinus of Valsalva (proven by angiography). In two patients, long segments of interventricular and great cardiac veins were also visualized accompanying the LAD and LCX, respectively. The right coronary artery (RCA, measuring 0.7 to 3.0 cm, mean 1.9 cm) was also successfully delineated in 3-D in all six patients in whom an attempt was made to visualize it during echo examination. Using the transgastric approach, a long (1.8 cm) segment of the posterior descending branch (PDA) of RCA was imaged in one patient. In addition, nine significantly stenotic lesions (>50% lumen diameter) were identified by 3-D in eight patients involving LMC (1), proximal LAD (1), mid LAD (1), proximal LCX (2), proximal RCA (3), and mid PDA (1). Eight of these 9 lesions were confirmed by coronary angiography. The remaining lesion (mid PDA) could not be confirmed since the patient did not undergo angiography. Our preliminary study demonstrates the usefulness of transesophageal 3-D echo not only in delineating normal coronary arteries but also diagnosing significant atherosclerotic stenosis in these vessels. (ECHOCARDIOGRAPHY, Volume 13, September 1996)

Transesophageal Three-Dimensional Echo Assessment of Sinus Venosus Atrial Septal Defect.

The incremental value of three-dimensional echocardiography over transesophageal multiplane two-dimensional imaging in the assessment of sinus venosus atrial septal defect is demonstrated in the present study.

Images in geriatric cardiology. Usefulness of live three-dimensional transthoracic echocardiography in aortic valve stenosis evaluation.

Aortic valve stenosis (AS) severity can be estimated by various modalities. Due to some of the limitations of the currently available methods, the usefulness of live three-dimensional transthoracic echocardiography (3D TTE) in the assessment of AS was explored. Live 3D TTE was able to visualize the aortic valve orifice in all 11 patients studied. Live 3D TTE correctly estimated the severity of AS in all 10 patients in whom AS severity could be evaluated at surgery. These included eight patients with severe AS and two with moderate AS. Two of these 10 patients with AS had associated hypertrophic cardiomyopathy and underwent myectomy at the time of aortic valve replacement. Aortic valve orifice area measurements by live 3D TTE correlated well with intraoperative three-dimensional transesophageal echocardiographic reconstruction measurements (r=0.85) but not as well with two-dimensional transesophageal echocardiography measurements (r=0.64). Live 3D TTE measurements of the aortic valve orifice area also did not correlate well with two-dimensional transthoracic echocardiography measurements (r=0.46) but the number of patients studied with two-dimensional transthoracic echocardiography was smaller (only seven) and four of these did not undergo two-dimensional transthoracic echocardiography at the authors' institution. Altogether, four patients with severe AS by live 3D TTE, and subsequently confirmed at surgery, were misdiagnosed as having moderate AS by two-dimensional transthoracic echocardiography. Because it is completely noninvasive and views the aortic valve in three dimensions, 3D TTE could be a useful complement to the existing modalities in the evaluation of AS severity.

Is the "perfect Fontan" operation routinely achievable in the modern era?

OBJECTIVE: In 1990, Fontan, Kirklin, and colleagues published equations for survival after the so-called "Perfect Fontan" operation. After 1988, we evolved a protocol using an internal or external polytetraflouroethylene tube of 16 to 19 millimetres diameter placed from the inferior caval vein to either the right or left pulmonary artery along with a bidirectional cava-pulmonary connection. The objective of this study was to test the hypothesis that a "perfect" outcome is routinely achievable in the current era when using a standardized surgical procedure. METHODS: Between 1 January, 1988, and 12 December, 2005, 112 patients underwent the Fontan procedure using an internal or external polytetraflouroethylene tube plus a bidirectional cava-pulmonary connection, the latter usually having been constructed as a previous procedure. This constituted 45% of our overall experience in constructing the Fontan circulation between 1988 and 1996, and 96% of the experience between 1996 and 2005. Among all surviving patients, the median follow-up was 7.3 years. We calculated the expected survival for an optimal candidate, given from the initial equations, and compared this to our entire experience in constructing the Fontan circulation. RESULTS: An internal tube was utilized in 61 patients, 97% of whom were operated prior to 1998, and an external tube in 51 patients, the latter accounting for 95% of all operations since 1999. At 1, 5, 10 and 15 years, survival of the entire cohort receiving polytetraflouroethylene tubes is superimposable on the curve calculated for a "perfect" outcome. Freedom from replacement or revision of the tube was 97% at 10 years. CONCLUSION: Using a standardized operative procedure, combining a bidirectional cavopulmonary connection with a polytetraflouroethylene tube placed from the inferior caval vein to the pulmonary arteries for nearly all patients with functionally univentricular hearts, early and late survival within the "perfect" outcome as predicted by the initial equations of Fontan and Kirklin is routinely achievable in the current era. The need for late revision or replacement of the tube is rare.

Usefulness of live/real time three-dimensional transthoracic echocardiography in the characterization of ventricular septal defects in adults.

In this report, we present 12 patients (range 14-76 years, mean 40 +/- 22.7 years) who underwent surgical repair of a ventricular septal defect (VSD). Location, size, and surrounding anatomy of the VSD were assessed prior to intervention in all patients with live/real time three-dimensional transthoracic echocardiography (3DTTE). In 9 patients, measurements of maximum dimension, circumference, and area by 3DTTE correlated well with the same measurements from intraoperative three-dimensional transesophageal echocardiographic (3DTEE) reconstruction. 3DTTE measurement of maximum dimension of VSDs also agreed well with maximum dimension by surgery in 10 patients. Live/real time 3DTTE accurately defined VSD location, size, and surrounding anatomy in all patients studied by us. VSD characterization by live 3DTTE agreed well with surgery descriptions and 3DTEE measurements.

Usefulness of live/real time three-dimensional transthoracic echocardiography in the identification of individual segment/scallop prolapse of the mitral valve.

In this report, we present 34 patients in whom surgical intervention was undertaken for severe mitral insufficiency due to mitral valve prolapse (MVP). Location and severity of MVP and regurgitation were assessed preoperatively by live/real time three-dimensional transthoracic echocardiography and closely agreed with the surgical findings.

Live three-dimensional transthoracic echocardiographic assessment of left atrial tumors.

This preliminary study demonstrates the superiority of live three-dimensional transthoracic echocardiography (3D TTE) over two-dimensional (2D) TTE in the assessment of left atrial (LA) tumors in four patients studied by us (three myxomas, one hemangioma, all subsequently pathologically proven). Because of the unique ability of live 3D TTE to systematically section and view the contents of an intracardiac mass, LA myxomas in the three patients studied could be more confidently diagnosed by noting isolated echolucent areas consistent with hemorrhage/necrosis in the tumor mass. On the other hand, a definite echolucent area was found by 2D TTE in only two of the three patients with myxoma. In the fourth patient with a hemangioma, live 3D TTE showed much more extensive and closely packed echolucencies with little solid tissue as compared to a myxoma consistent with a highly vascularized tumor. In contrast, 2D TTE demonstrated only two isolated echolucencies in the tumor suggesting an erroneous diagnosis of myxoma.

Transesophageal three-dimensional echocardiographic demonstration of Ebstein's anomaly.

We report three-dimensional transesophageal echocardiographic findings in an adult patient with Ebstein's anomaly. Using the anyplane technique and multiple views, especially the short-axis view of tricuspid valve, three-dimensional transesophageal echocardiography clearly demonstrated the intermittent tethering of all three leaflets of tricuspid valve to the right ventricular walls giving a "bubble-like" appearance. On the other hand, two-dimensional transesophageal echocardiography demonstrated well the tethering of the septal tricuspid leaflet, but tethering of the other two leaflets was not well seen. To our knowledge, these findings have not been demonstrated by three-dimensional transesophageal echocardiography before.

Three-dimensional transesophageal echocardiographic demonstration of anatomical defects in AV septal defect patients presenting for reoperation.

We present two- and three-dimensional transesophageal echocardiographic findings of two adult patients who presented for reoperation after previous repair of a partial atrioventricular (AV) septal defect. Both patients had a cleft in the left AV valve with severe regurgitation. One patient had an additional 10 x 5 mm defect connecting the left ventricle to the right atrium through the AV junction. Three-dimensional echocardiography was superior to two-dimensional echocardiography in comprehensively delineating the anatomical defects in the left AV valve and the AV junction.

Usefulness of transesophageal three-dimensional echocardiography in the identification of individual segment/scallop prolapse of the mitral valve.

We evaluated the potential usefulness of three-dimensional (3D) transesophageal echocardiography (TEE) in assessing individual scallop/segment prolapse in 36 adult patients with mitral valve prolapse (MVP) undergoing surgical correction. Intraoperative 3D TEE correctly identified the location of scallop/segment prolapse in 34 of 36 patients (94%). However, in 6 of these patients 3D TEE images revealed more scallops or segments with prolapse than the surgeon noted intraoperatively. Prolapse of these areas was less prominent and this could possibly explain the lack of correlation with the surgical findings in these patients. In another 2 patients areas of prolapse seen by the surgeon were missed by 3D TEE because some of those scallops/segments could not be well imaged due to image "drop out" and artifacts. Thus, perfect correlation between 3D TEE and surgery was noted in 28 of 36 (78%) patients. Noncoaptation of the MV was also identified in 2 patients. The prolapsed area of posterior (n = 28 observations) and anterior (n = 9 observations) MV leaflets ranged from 1 cm2 to 9 cm2 (mean 3.50 cm2+/- 2.14) and 1.20 cm2 to 5.99 cm2 (mean 3.21 cm2+/- 1.33), respectively. Interobserver and intraobserver agreement for location and area of MVP was excellent (r = 0.97 and r = 0.99, respectively; all P values are <0.0001). In conclusion, 3D TEE is useful in identifying the location of MVP. It may also be potentially useful in assessing the extent of individual scallop/segment prolapse and identifying sites of MV noncoaptation. This information could aid the surgeon in deciding the extent of MV resection.

Usefulness of live three-dimensional transthoracic echocardiography in the characterization of atrial septal defects in adults.

In this report we present 12 adult patients in whom surgical or percutaneous intervention was considered for repair of atrial septal defect (ASD). Location, size, and surrounding atrial anatomy of the ASD were assessed prior to intervention in all patients with standard and live three-dimensional transthoracic echocardiography (3D TTE). In the four patients in whom intraoperative three-dimensional transesophageal echocardiographic reconstruction (3D TEE) was done, 3D TTE measurements of maximum dimension, maximum circumference, and maximum area of ASD agreed well with 3D TEE. In the seven patients who underwent transcatheter closure device insertion, live 3D TTE measurements of maximum dimension, maximum circumference, and maximum area of ASD agreed well with the sizing balloon. Additionally, since the sizing balloon measures a stretched diameter and area, a live 3D TTE stretched ASD diameter and area (derived from the actual live 3D TTE maximum circumference) were calculated and demonstrated improved agreement with the sizing balloon measurements. In all patients, > or =5 mm of atrial tissue was visualized surrounding the ASD. Further, with the addition of contrast enhancement, characterization of a small patent foramen ovale (<5 mm) was possible in one patient. Live 3D TTE accurately defined ASD location, size, and surrounding atrial anatomy in all patients studied by us. ASD characterization by live 3D TTE agreed well with 3D TEE and sizing balloon measurements.

Quantification of mitral regurgitation by live three-dimensional transthoracic echocardiographic measurements of vena contracta area.

We evaluated 44 consecutive patients who underwent standard two-dimensional (2D) and live three-dimensional (3D) transthoracic echocardiography (TTE), as well as left heart catheterization with left ventriculography. Mitral regurgitant vena contracta area (VCA) was obtained by 3D TTE by systematic and sequential cropping of the acquired 3D TTE data set. Assessment of mitral regurgitation (MR) by ventriculography was compared to measurements of VCA by 3D TTE and to 2D TTE measurements of MR jet area to left atrial area (RJA/LAA), RJA alone, vena contracta width (VCW), and calculated VCA. VCA from 3D TTE closely correlated with angiographic grading (rs=0.88) with very little overlap. VCA of <0.2 cm2 correlated with mild MR, 0.2-0.4 cm2 with moderate MR, and >0.4 cm2 with severe MR by angiography. Ventriculographic grading also correlated well with 2D TTE measurements of RJA/LAA (rs=0.79) and RJA alone (rs=0.76) but with more overlap. Assessment of VCW and calculated VCA by 2D TTE agreed least with ventriculography (rs=0.51 and rs=0.55, respectively). Live 3D TTE color Doppler measurements of VCA can be used for quantitative assessment of MR and is comparable to assessment by ventriculography.

Fluxo coronário desregulado durante reperfusäo pós cardioplegia / Coronary flow response is impaired during post-cardioplegia

Estudaram-se a demanda metabólica e a distribuiçäo do fluxo coronariano na presneça de fibrilaçäo ventricular (FV), durante a reperfusäo pós-cardioplegia. Foram colocados 15 suínos em circulaçäo extracorpórea e submetidos a parada cardíaca cardioplégica sangüínea anterógrada hipotérmica intermitente, durante uma hora, seguida por reperfusäo miocárdica controlada. Os animais foram divididos em três grupos (n=5), conforme estivessem em assistolia (Grupo 1) ou em FV de curta (grupo 2) ou longa duraçäo (Grupo 3), durante os dez primeiros minutos de reperfusäo. Os valores do consumo miocárdico de oxigênio (MVO2), em ml O2/min/g (média + erro padräo) durante a reperfusäo foram de 1,325 + 0,144 (grupo 1); 2,472 + 0,208 (Grupo 2) e 2,469 + 0,228 (Grupo 3). A diferença entre o MVO2 dos coraçöes em assistolia e o dos coraçöes em FV, quer de curta ou longa duraçäo, foi significante (p<0,001). A relaçäo entre os fluxos sangüíneos endo e epicárdico, bem como o fluxo sangüíneo coronário global (ml/mim/100g) foram semelhantes nos 3 grupos. Os valores dessa última variável, em ml/mim/100g, corresponderam a, respectivamente, 169,3 + 11,7; 185,0 + 15,7 e 179,9 + 13,2. Os resultados demonstram que a auto-regulaçäo coronária está alterada durante a fase inicial de reperfusäo pós criocardioplegia, pois a perfusäo miocárdica näo aumentou em resposta à elevaçäo do consumo de oxigênio imposta pela FV. Essa constataçäo, de grande interesse clínico, sugere que a ocorrência de FV durante a fase inicial da reperfusäo possa contribuir para o desenvolvimento de lesöes teciduais em coraçöes cujo fluxo coronário já esteja previamente comprometido, por obstruçäo coronária, distensäo ou hipertrofia ventricular.