CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation

Benign primary cardiac neoplasms are rare but may cause significant morbidity and mortality. However, they are usually treatable and can often be diagnosed with echocardiography, computed tomography (CT), or magnetic resonance (MR) imaging. Myxomas typically arise from the interatrial septum from a narrow base of attachment. Fibroelastomas are easily detected at echocardiography as small, mobile masses attached to valves by a short pedicle. Cardiac fibromas manifest as a large, noncontractile, solid mass in a ventricular wall at echocardiography and as a homogeneous mass with soft-tissue attenuation at CT. They are usually homogeneous and hypointense on T2-weighted MR images and isointense relative to muscle on T1-weighted images. Paragangliomas usually appear as large, echogenic left atrial masses at echocardiography and as circumscribed, heterogeneous masses with low attenuation at CT. These tumors are usually markedly hyperintense on T2-weighted MR images and iso- or hypointense relative to myocardium on T1-weighted images. Cardiac lipomas manifest at CT as homogeneous, low-attenuation masses in a cardiac chamber or in the pericardial space and demonstrate homogeneous increased signal intensity that decreases with fat-saturated sequences at T1-weighted MR imaging. Cardiac lymphangiomas manifest as cystic masses at echocardiography and typically demonstrate increased signal intensity at T1- and T2-weighted MR imaging. Familiarity with these imaging features and with the relative effectiveness of these modalities is essential for prompt diagnosis and effective treatment.

Influence of ventricular morphology on outcome after the Fontan procedure

The modified Fontan procedure has gained wide acceptance in the treatment of various congenital heart defects. Determination of risk factors for mortality remains an important issue for optimizing patient selection for the Fontan procedure. Conflicting results have been reported about whether ventricular morphology is a risk factor in these patients. Survival free of Fontan takedown or cardiac transplantation was assessed in the first 500 patients undergoing the Fontan procedure at our institution. This survival was correlated with ventricular morphology as evaluated by angiography. Both multivariate and univariate analyses indicated ventricular morphology was predictive of early survival free of Fontan takedown or cardiac transplantation following the procedure. However, there was no statistical evidence for ventricular morphology being a risk factor for mortality in patients alive 6 months after the procedure. Ventricular morphology is a risk factor for early survival in patients undergoing a Fontan procedure, with left ventricular morphology associated with a better early survival than right ventricular morphology.

Telemedicine consultations in congenital heart disease: assessment of advanced technical capabilities

OBJECTIVE

To assess the value of adding remote pointer and dynamic display capabilities to a telemedicine system designed to provide consultative services for patients with congenital heart disease.

MATERIAL AND METHODS

Independent observations by the referring physician and the consulting physician provided the data for the assessment. Fifty-four teleconsultations involving 38 patients with 21 different congenital heart diseases were analyzed. The teleconsultations were based on previously obtained cineangiograms that were digitized and then transmitted by combined satellite and terrestrial-based technology. The observations, recorded by each physician at his workstation at the time of each teleconsultation, were summarized and analyzed statistically.

RESULTS

In 108 observations, the pointer was believed to be helpful in 72 (67%), and dynamic display was helpful in 96 (89%).

CONCLUSION

This study suggests that use of a pointer and dynamic display enhances teleconsultations for patients with congenital heart disease.

Cardiac transplantation for end-stage congenital heart defects: the Mayo Clinic experience. Mayo Cardiothoracic Transplant Team

OBJECTIVE

To review the outcome of cardiac transplantation undertaken in patients with congenital heart defects.

MATERIAL AND METHODS

Between November 1991 and March 1998 at our institution, cardiac transplantation was performed in 16 patients with congenital heart disease (age range, 3 to 57 years; mean, 26.1). Preoperative diagnoses included univentricular heart (N = 4); complete transposition of the great arteries (N = 3); Ebstein's anomaly (N = 2); tetralogy of Fallot (N = 2); levotransposition (N = 2); dextrocardia, corrected transposition, ventricular and atrial septal defects, and pulmonary stenosis (N = 1); double-outlet right ventricle (N = 1); and hypertrophic obstructive cardiomyopathy (N = 1). All patients had undergone from one to five previous palliative operations.

RESULTS

Four patients required permanent pacemaker implantation during the first month postoperatively because of bradycardia; more than 2 years later, another patient required a permanent pacemaker because of sick sinus syndrome. In addition, one patient had an automatic implantable cardioverter-defibrillator. Three patients required reconstruction of cardiovascular structures with use of prosthetic material (Teflon patches or donor tissue) at the time of cardiac transplantation. Actuarial 1-, 2-, and 5-year survival was 86.2 +/- 9.1%. During the first year after transplantation, two deaths occurred--one at 41 days of putative vascular rejection and the second at 60 days of severe cellular rejection. All other patients are alive and functionally rehabilitated; the mean follow-up period has been 26.1 months (range, 2 to 89.6).

CONCLUSION

Cardiac transplantation for patients with congenital heart disease can be accomplished with a low perioperative mortality and an excellent medium-term survival despite the challenges presented by the technical difficulties during invasive diagnostic procedures and at operation and the need for adherence to long-term multiple-drug therapy in this patient population.

Coarctation of the aorta: collateral flow assessment with phase-contrast MR angiography

OBJECTIVE

The purpose of this report is to describe a new use of MR imaging in coarctation of the aorta. The specific question addressed was how well collateral blood flow in intercostal arteries, as determined by phase-contrast MR angiography, correlated with findings during surgery or catheterization in patients with coarctation of the aorta.

CONCLUSION

Phase-contrast MR angiography is an excellent technique for detecting the presence or absence of collateral blood flow in the intercostal arteries of patients with coarctation of the aorta. Knowing whether collateral blood flow is present in patients with narrowing of the juxtaductal aorta should help assess the clinical hemodynamic significance of the coarctation.

Transesophageal echocardiography: unusual case of anomalous pulmonary venous connection to the azygos vein

Partial anomalous pulmonary venous connection, a rare congenital anomaly, most commonly involves the right lung, with one or more pulmonary veins anomalously connecting most frequently to the superior vena cava and less commonly to the right atrium or inferior vena cava. This article describes an unusual case of anomalous pulmonary venous connection of the right lung to the azygos vein in an adult. This anomaly was clearly delineated with angiography, computed tomography of the chest, and transesophageal echocardiography. The transesophageal echocardiographic features of the anomaly are described as a means to prevent further diagnostic misinterpretation.

The Fontan procedure for pulmonary atresia with intact ventricular septum: operative and late results

OBJECTIVES

The goals of the study were to evaluate the operative and late mortality associated with the Fontan procedure in patients with pulmonary atresia and an intact ventricular septum and to obtain follow-up information on the current clinical status of surviving patients.

BACKGROUND

Between 1979 and October 1, 1995, 40 patients with the anomaly had a nonfenestrated Fontan procedure performed at the Mayo Clinic. Because there are no previously published reports involving a series of this size in which the Fontan approach was used for this condition, a review of patient outcomes was thought to be of value.

METHODS

The medical records of the 40 patients were reviewed retrospectively, and 34 were determined to be alive. The status of the survivors as of late 1995 was then ascertained by direct examination, questionnaire or telephone follow-up.

RESULTS

There were three operative deaths and three late deaths. The current ages of the 34 survivors ranged from 4 to 30 years (median 13). Thirty-three of the 34 survivors were thought to be in New York Heart Association functional class I or II, and all but three of these patients, of school age or older, were either full-time students or working full time. The three adults who were not employed thought they were capable of working but were not doing so because of socioeconomic reasons. More than half of the patients were not receiving cardiovascular medications.

CONCLUSIONS

These overall gratifying early and late results encourage continued application of this operation for appropriately selected patients with this complex congenital cardiovascular anomaly.

Angiographic determination of ventricular morphology: correlation with pathology in 36 hearts with single functional ventricles

Among 36 patients with univentricular atrioventricular connections, 27 had left ventricular and 9 right ventricular morphology. None had a common or indeterminate ventricle on autopsy review. Angiographic analysis correctly determined ventricular morphology in 34 (94%) of 36 patients. All 9 patients with right ventricular morphology of the dominant ventricular chamber were correctly identified angiographically. Altogether 25 of 27 patients (93%) with left ventricular morphology of the dominate ventricular chamber were correctly identified angiographically. Two patients with left ventricular morphology and severely dilated ventricles were incorrectly classified as having right ventricular morphology by angiographic assessment. For patients with a single functional ventricle, we conclude that angiographic assessment is an excellent method for determining ventricular morphology.

Dynamic MR digital subtraction angiography using contrast enhancement, fast data acquisition, and complex subtraction

A dynamic MR angiography technique, MR digital subtraction angiography (MR DSA), is proposed using fast acquisition, contrast enhancement, and complex subtraction. When a bolus of contrast is injected into a patient, data acquisition begins, dynamically acquiring a thick slab using a fast gradient echo sequence for 10-100 s. Similar to x-ray DSA, a mask is selected from the images without contrast enhancement, and later images are subtracted from the mask to generate angiograms. Complex subtraction is used to overcome the partial volume effects related to the phase difference between the flowing and stationary magnetization in a voxel. Vessel signal is the enhancement of flow magnetization resulting from the contrast bolus. MR DSA was performed in 28 patients, including vessels in the lungs, brains, legs, abdomen, and pelvis. All targeted vessels were well depicted with MR DSA. Corresponding dynamic information (contrast arrival time ta and duration of the arterial phase tav) was measured: ta/tav = 3.4/4.7 s for the lung, 10.3/4.9 s for the brain, 12.8/19.3 for the aorta, 15.2/12.6 s for the leg. MR DSA can provide dynamic angiographic images using a very short acquisition time.

Successful resection of thoracic aortic aneurysms in Wiskott-Aldrich syndrome

A 23-year-old man with Wiskott-Aldrich syndrome, chronic aortitis, and severe aneurysmal dilatation of the thoracic aorta successfully underwent two-stage graft replacement of the ascending and descending thoracic aorta. Nine years postoperatively, he is asymptomatic and employed full time.

Error in MR volumetric flow measurements due to ordered phase encoding in the presence of flow varying with respiration

Respiratory ordered phase encoding is often employed in MRI studies to reduce image artifacts due to breathing motion. The purpose of this work was to evaluate error caused by the use of respiratory ordering of phase encoding in MR cine phase-contrast (CPC) volumetric flow measurements when the flow rate is sensitive to respiration. It was hypothesized that this effect is due to the systematic biasing of a respiratory-induced phase modulation function in k-space. A theoretical model for the effects of respiration was developed and then tested in flow phantom studies and in normal volunteer studies. In phantom experiments, the use of respiratory ordering induced an error of as much as 13% in CPC volumetric flow measurements. In preliminary volunteer studies, error was as high as 26% in superior vena cava flow measurements versus less than 1% error in the ascending aorta. It is concluded that a potential for error exists in CPC volumetric flow measurements obtained with the use of respiratory ordering schemes. Volunteer studies with larger numbers are warranted. Clinical applications in which this effect may be important include flow measurements in vessels subject to variations in flow due to respiration, such as the venae cavae, pulmonary vasculature, and portal vein.

Outcome of pulmonary and aortic homografts for right ventricular outflow tract reconstruction

To determine late patient outcome and homograft durability, we reviewed 326 patients who received aortic (n = 230) or pulmonary (n = 118) cryopreserved homografts for right ventricular outflow reconstruction between January 1985 and October 1993. Patient survival, including operative mortality, 5 years after the operation was similar between the two groups (pulmonary homograft 86%, aortic homograft 80%; p = not significant by log-rank test). However, 5-year freedom from homograft failure was significantly better for pulmonary homografts (94% versus 70%, p < 0.01 by log-rank test). Late calcification was evaluated by chest roentgenography and echocardiography. Overall, 20% of aortic homografts became moderately or severely calcified compared with 4% of pulmonary homografts (p < 0.01). Twenty-six percent of aortic homografts in children 4 years old or younger had moderate or severe obstruction associated with calcification, whereas only 11% of aortic homografts in patients over 4 years of age had calcific obstruction (p < 0.01). No late deaths among patients receiving pulmonary homografts were related to graft failure; two late deaths in the aortic homograft group were homograft related. Risk factors for patient mortality and homograft failure (defined as either need for homograft replacement because of homograft failure or as homograft-related death) were identified by the Cox multivariate analysis. Aortic type of homograft was a significant risk factor for homograft failure (p < 0.0001), but type of homograft was not correlated with patient mortality. Age 4 years or younger was a significant risk factor for both mortality (p < 0.01) and homograft failure (p = 0.03) in aortic homograft recipients but not in pulmonary homograft recipients. These results indicate that both aortic and pulmonary homografts provided excellent intermediate-term patient survival after right ventricular outflow tract reconstruction, but pulmonary homografts are more durable than aortic homografts with less calcification and obstruction, especially among children 4 years old or younger.

Therapeutic implications of intraoperative pressure measurements after the Fontan operation

Central venous pressure (CVP) and left atrial pressure (LAP) were monitored continuously for the first 72 hours postoperatively in 32 patients who underwent a Fontan operation in whom preoperative measurements of the pulmonary artery index were available. Integrated mean values were generated for each patient for the following time frames: (1) the first 12 hours after operation, (2) the first 24 hours after operation, (3) postoperative day 2, and (4) postoperative day 3. We found no difference in the CVP, LAP, or transpulmonary gradient, derived as CVP-LAP, measured in the operating room at the completion of the operation versus that measured on the third postoperative day: CVP, 18 +/- 2 mmHg versus 19 +/- 3 mmHg; LAP, 10 +/- 2 mmHg versus 10 +/- 3 mmHg; and transpulmonary gradient, 8 +/- 2 mmHg versus 8 +/- 2 mmHg. The combined incidence of hospital mortality and postoperative takedown associated with the Fontan repair was 12.5%. These findings suggest that a poor hemodynamic result from the Fontan operation can be predicted from intraoperative pressure measurements, because the CVP, LAP, and transpulmonary gradient are unlikely to change significantly in the early postoperative period. Therefore, a decision to take down or fenestrate the repair can reasonably be made in the operating room or the early postoperative period.

Coronary artery anatomy in complete transposition of the great arteries

Knowledge of the variations in coronary artery pattern is important in the arterial switch operation for complete transposition of the great arteries (TGA). As autopsy specimens provide the most definitive means of identifying the coronary anatomy, 255 hearts with complete TGA were reviewed by a single pathologist. The age of the patients ranged from 1 day to 34 years (mean, 2.9 years). The origin of the coronary arteries was defined as seen by an observer looking from the pulmonary artery toward the aorta. The usual pattern with the right coronary artery originating from the right hand sinus and the left coronary artery from the left hand sinus (184 cases) and the circumflex coronary artery arising from the right coronary artery (46 cases) accounted for 90% of the cases. Eleven other patterns were identified. The usual coronary artery pattern was more prevalent in TGA with the aorta in a right anterior or anterior position (74.8%) than in TGA with a side-by-side relationship of the great arteries (38.9%). In only 2 cases (0.8%) was an aortic intramural course of the left coronary artery identified. The latter 2 cases confirm our belief that an aortic intramural course of the left coronary artery or the left anterior descending coronary artery must be assumed when the vessel has an aberrant origin from the right sinus or when it is in intimate relationship with the commissure between the right and left sinuses and courses between the great arteries. In the vast majority of specimens a favorable coronary artery pattern with regard to feasibility of the arterial switch operation was encountered.

Imaging strategies for vascular rings

Thirty-nine patients have undergone operation for relief of tracheoesophageal compression resulting from vascular rings and related entities at the Mayo Clinic. Nineteen patients had a double aortic arch, 11 patients had a right aortic arch with an aberrant left subclavian artery, 5 patients had a left aortic arch with an aberrant right subclavian artery, 2 patients had a pulmonary artery sling, 1 patient had a right aortic arch with mirror-image branching and a left ligamentum arteriosum, and 1 patient had a left aortic arch, a right descending aorta, and a right ductus arteriosus. Diagnostic examinations included chest radiography, barium esophagography, angiography, and, more recently, transthoracic echocardiography, computed tomography, and magnetic resonance imaging. A comparison among the various diagnostic techniques used in 12 patients during the last 12 years showed that angiography (n = 7), magnetic resonance imaging (n = 5), and computed tomography (n = 3) were the most reliable, as they always accurately delineated the anatomy. However, in the 6 patients who underwent transthoracic echocardiography, 1 of whom was an older child and 2 of whom were adults, the vascular abnormality was described correctly only once; in the other 5 patients, the results were false-negative or the technique failed to visualize the relevant vascular structures sufficiently. Currently, magnetic resonance imaging is our imaging technique of choice for the delineation of the vascular and tracheal anatomy in patients suspected of having a vascular ring.

Aortic intramural course of the left coronary artery in dextro-transposition of the great arteries

Three patients with dextro-transposition of the great arteries and an aortic intramural left coronary artery are described. A review of our patients with dextro-transposition of the great arteries and those reported in the literature suggests that an aortic intramural course of the left coronary artery or left anterior descending coronary artery must be assumed when the artery arises from the right (posterior) sinus of Valsalva, distal to the right sinotubular junction, or at the commissure between the right and left (anterior) sinuses and courses between the great arteries.

Preoperative diagnosis of coronary artery anatomy in dextrotransposition of the great arteries

BACKGROUND

Preoperative diagnosis of the coronary artery pattern in dextrotransposition of the great arteries is important because deviation from the usual pattern may influence the surgical strategy.

METHODS

For assessment of the value of angiography and echocardiography in this setting, we analyzed the preoperative echocardiographic and angiographic findings in 74 patients with dextrotransposition of the great arteries in whom an arterial switch operation was performed.

RESULTS

Two-dimensional echocardiography established a diagnosis of the coronary artery pattern in 40 of the 74 patients; that diagnosis was correct in 38-30 of 32 (94%) with the usual coronary artery pattern and 8 (100%) with an atypical pattern. Angiography established a diagnosis of the coronary artery pattern in 52 patients; that diagnosis was correct in 50-41 of 42 (98%) with the usual coronary artery pattern and 9 of 10 (90%) with an atypical pattern. The accuracy of echocardiography in diagnosing the coronary artery pattern in dextrotransposition of the great arteries in this series was 95% and that of angiography was 96%.

CONCLUSION

Both echocardiography and angiography can establish the diagnosis of the coronary artery anatomy in most patients. Echocardiography is routinely performed in infants with dextrotransposition of the great arteries and is proving to be increasingly sensitive for diagnosing the coronary artery anatomy; the role of angiography may evolve to be supplementary, especially in cases in which the coronary artery anatomy is not clearly demonstrated by echocardiography.

Radiation exposure and efficacy of exposure-reduction techniques during cardiac catheterization in children

OBJECTIVE

The purpose of this study was to measure radiation exposure levels in children undergoing cardiac catheterization. This information was used to assess methods of reducing exposure and to characterize total exposures.

SUBJECTS AND METHODS

The radiation exposure area product was determined for a total of 175 patients during three study intervals over 10 years. Examinations included biplane fluoroscopy and cineangiography for the diagnosis and treatment of congenital heart disease.

RESULTS

The use of pulsed progressive fluoroscopy was found to reduce patients' fluoroscopic exposure rates by approximately 40% as compared with interlaced mode fluoroscopy. Combining exposures from the frontal and lateral projections, the median fluoroscopic time for diagnostic procedures was 21 min and the median time for cineangiography was 42 sec. Median total exposure area product was 2063 R-cm2 with cineangiography accounting for 44% of the total exposure. For an estimated X-ray beam entrance area of 50-100 cm2, the median total entrance exposure was in the range of 20-40 R. Fluoroscopy times for interventional procedures were found to be 1.5 to 2.5 times longer than for diagnostic procedures, with total exposures approximately three times higher.

CONCLUSION

This study suggests that pulsed progressive fluoroscopy is an effective method of reducing radiation exposure in children undergoing cardiac catheterization.

Surgical treatment of vascular rings: the Mayo Clinic experience

From 1947 through 1992, 37 Mayo Clinic patients underwent operation for the relief of tracheoesophageal obstruction that resulted from vascular rings and related entities. Of the 37 patients, 18 had a double aortic arch, 11 had a right aortic arch with an aberrant left subclavian artery, 4 had a left aortic arch with an aberrant right subclavian artery, 2 had a pulmonary artery sling, 1 had a right aortic arch with mirror-image branching and a left ligamentum arteriosum, and 1 had a left aortic arch, a right descending aorta, and a right ductus arteriosus. Symptoms consisted of stridor, recurrent respiratory infections, and dysphagia. The anomaly was approached through a left thoracotomy in 31 patients, through a right thoracotomy in 4, and through a median sternotomy in 2. Only one early postoperative death (3%) and no late deaths occurred. At long-term follow-up (maximal duration, 45 years), three patients had residual symptomatic tracheomalacia, one of whom required right middle and lower lobectomy for recurrent pneumonia. Magnetic resonance imaging is the imaging technique of choice for accurate delineation of the vascular and tracheal anatomy. When patients are symptomatic, vascular ring should be repaired. The surgical risk is minimal, and the long-term results are excellent.

Modified Fontan operation in the presence of anomalies of systemic and pulmonary venous connection

BACKGROUND

The purpose of this report is to outline technical maneuvers dictated by anomalies of systemic and/or pulmonary venous connection in the performance of the Fontan procedure.

METHODS AND RESULTS

Between 1975 and 1990, 104 patients (60 male, 44 female) with anomalies of systemic and/or pulmonary venous connection underwent a modified Fontan procedure at the Mayo Clinic. Mean age was 9.7 +/- 5.7 years. Isolated anomalies of the systemic venous connection were identified in 46 patients, isolated anomalous pulmonary venous connections in 4, and a combination of the two in 54. Previous palliative operations had been performed in 93 patients. Surgical repair was accomplished by atrial septation or placement of an intra-atrial conduit combined with cavopulmonary anastomosis if required. Survival by Kaplan-Meier, including operative mortality, was 55.7% at 10.3 years, not significantly different from the overall survival of the Fontan population. By the proportional hazards general linear model procedure, insufficiency of the systemic atrioventricular valve, preoperative mean pulmonary pressure greater than 15 mm Hg, and pulmonary artery resistance index greater than 4 U.m2 were associated with higher mortality. Five patients required reoperation for pulmonary venous obstruction (1 patient), revision of the atrial baffle (1 patient), revision of the intra-atrial conduit (2 patients), and replacement of the systemic atrioventricular valve (1 patient).

CONCLUSIONS

We conclude that the modified Fontan operation can be successfully performed in this subset of patients, with long-term results comparable to those obtained in patients with normal systemic and pulmonary venous connection.

Congenital partial and complete absence of the pericardium

Between 1952 and 1991, 15 Mayo patients were found to have partial or complete absence of the pericardium at the time of a cardiovascular surgical procedure. One patient with complete absence of the left pericardium had symptoms possibly related to the pericardial abnormality. This 42-year-old man had severe insufficiency of the tricuspid valve attributable to chordal rupture of the anterior leaflet, possibly precipitated by complete displacement of the heart into the left pleural space. Excision of the ruptured chordae and plication of the anterior flail leaflet rendered a competent tricuspid valve. In two patients, a small defect in the pericardium was repaired. Three patients who underwent operation for complex congenital heart disease died: two early postoperatively and one late after a reoperation. In the other 12 patients, no early or late postoperative complications were encountered. Although rare and usually asymptomatic, complete and partial deficiency of the pericardium may lead to serious complications such as cardiac valvular insufficiency or incarceration of cardiac tissue.

Pulmonary artery size and clinical outcome after the modified Fontan operation

The maximum cross-sectional area of the central pulmonary arteries indexed to the body surface area (pulmonary artery index [PAI]) was measured preoperatively from angiograms in 173 patients evaluated for a Fontan-type operation between 1981 and June 1989. Of these, 34 patients underwent another palliative procedure, 8 primarily on the basis of small pulmonary arteries (PAI, 106 to 167 mm2/m2). The mean PAI of this group was significantly smaller than the mean PAI of the remaining 139 patients who underwent a Fontan operation (136 +/- 20 versus 310 +/- 113 mm2/m2) (p < 0.001). The patients who underwent a Fontan operation were evaluated according to three overlapping end points: (1) hospital death or takedown of repair (12.2%), (2) early failure (cumulative death or takedown of repair within 6 months of operation) (16.5%), and (3) early failure or persistent effusions (33.8%). With regard to these end points, no significant difference in pulmonary artery size could be found between patients having a favorable or unfavorable outcome. However, among a low-risk subset of 30 patients with tricuspid atresia, those with "early failure or persistent effusions" had significantly smaller pulmonary arteries than those with a good outcome (PAI, 185 +/- 47 versus 276 +/- 83 mm2/m2) (p < 0.01). The postoperative transpulmonary gradient of the 8 patients with the smallest pulmonary arteries who underwent a Fontan operation (all PAIs < 170 mm2/m2) was significantly greater than that of the rest of the study group (9.88 +/- 2.3 versus 8.13 +/- 2.3 mm Hg) (p < 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Early and late results of the modified Fontan procedure for double-inlet left ventricle: the Mayo Clinic experience

Between May 1974 and March 1989, 155 patients with double-inlet left ventricle had the Fontan procedure performed at the Mayo Clinic. Age at operation ranged from nearly 2 to 41 years (median 10). The operative mortality rate from 1974 through 1980 (39 patients) was 21%, but from 1981 through 1989 (116 patients) it was reduced to 9%. The 17 late deaths were secondary to reoperation (n = 8), progressive myocardial failure (n = 5), sudden arrhythmia (n = 3) and bleeding varices (n = 1). Neither operative nor late mortality rate was significantly related to age at operation. At follow-up of 6 months to 11 years (mean 4.9 years) in 111 patients, 88% were in good or excellent condition and 12% were in fair or poor condition. The Fontan operation can be performed with a mortality risk of less than 10% in properly selected patients with double-inlet left ventricle. Late results are encouraging when contrasted with the clinical course of patients before this operative approach was utilized.

MR imaging of partial anomalous pulmonary venous connections

Magnetic resonance imaging was performed on 11 patients with partial anomalous pulmonary venous connections (PAPVC). Ten of these patients also had echocardiographic examinations, eight of which included color-flow Doppler studies. The diagnosis of PAPVC was confirmed in each of these patients by surgery or angiography. Fourteen anomalous pulmonary venous connections were identified, 10 involving the right upper lobe pulmonary vein and 4 involving the left upper lobe pulmonary vein. This retrospective review demonstrated that all 14 anomalous venous connections were correctly identified by MR imaging, whereas only 8 of 13 (62%) were identified by echocardiography. With MR, 89% of all the pulmonary veins and 93% of the anomalous pulmonary veins were visualized on axial images, while 41% of all pulmonary veins and 71% of anomalous veins were seen on coronal MR images. There were five atrial septal defects (ASDs), four of the sinus venous type and one of the septum secundum type. All five ASDs were correctly identified with MR imaging; three of four ASDs were identified with echocardiography. We conclude that MR imaging provides an accurate noninvasive method of depicting the anatomic abnormalities associated with PAPVC.

Tissue characterization of an unusual right atrial mass by magnetic resonance imaging

In a 70-year-old man who had angina, exercise-induced ventricular tachycardia, and presyncopal symptoms, transthoracic and transesophageal echocardiography disclosed a large atrial mass that resembled a myxoma. Subsequent evaluation by magnetic resonance imaging identified the mass as an intracardiac lipoma attached to the posterior wall of the right atrium, a diagnosis that was confirmed by surgical intervention. Thus, the diagnostic utility of magnetic resonance imaging as an adjunct to echocardiographic evaluation of intracardiac masses was demonstrated.

Repair of transposition of the great arteries with intact ventricular septum and left ventricular outflow tract obstruction

Repair of transposition of the great arteries in patients with intact ventricular septum and fixed left ventricular outflow tract obstruction has been restricted to atrial baffle procedures, with or without attempts to relieve or bypass the left ventricular outflow obstruction. However, the suboptimal results of these procedures, coupled with excellent functional results with the arterial switch operation in patients without obstruction, has made anatomic correction the goal in repairing these anomalies. We report a technique for the anatomic correction of transposition of the great arteries, intact ventricular septum, and fixed left ventricular outflow tract obstruction. Its consideration in these difficult cases is advocated.

A modification of the Fontan procedure incorporating anomalies of systemic and pulmonary venous return

A modification of the Fontan procedure is described in which separation of anomalous systemic and pulmonary venous pathways is accomplished without the need for construction of a complex intraatrial baffle. The feasibility of this simplified surgical technique is predicated on the presence of a left superior vena cava draining to a coronary sinus. The design of the procedure and results in two patients with polysplenia syndrome and a constellation of systemic and pulmonary venous anomalies are presented. Early and late results have been gratifying, and continued exploration of the technique seems warranted.

MR imaging of fat in and around the heart

MR imaging is useful for characterizing collections of fat in and around the heart. This article illustrates the MR appearance of pericardial fat, epicardial and periaortic fat, intramural fatty involvement and intracavitary fat, with emphasis on the distinctions between fatty and nonfatty tumors.

Effect of pulsed progressive fluoroscopy on reduction of radiation dose in the cardiac catheterization laboratory

The increased application of therapeutic interventional cardiology procedures is associated with increased radiation exposure to physicians, patients and technical personnel. New advances in imaging techniques have the potential for reducing radiation exposure. A progressive scanning video system with a standard vascular phantom has been shown to decrease entrance radiation exposure. The effect of this system on reducing actual radiation exposure to physicians and technicians was assessed from 1984 through 1987. During this time, progressive fluoroscopy was added sequentially to all four adult catheterization laboratories; no changes in shielding procedures were made. During this time, the case load per physician increased by 63% and the number of percutaneous transluminal coronary angioplasty procedures (a high radiation procedure) increased by 244%. Despite these increases in both case load and higher radiation procedures, the average radiation exposure per physician declined by 37%. During the same time, the radiation exposure for technicians decreased by 35%. Pulsed progressive fluoroscopy is effective for reducing radiation exposure to catheterization laboratory physicians and technical staff.

Truncus arteriosus revisited: an angiographic demonstration

The 1965 reclassification of truncus arteriosus by Van Praagh and Van Praagh greatly enhanced our understanding of this interesting anomaly. This brief review article attempts to illustrate the various types of truncus arteriosus identified in this classification by demonstrating their angiographic features. Reemphasis of the usefulness of this classification should help students of congenital heart disease recognize the advantages of a uniform diagnostic approach to this entity.

Complete repair of pulmonary atresia, ventricular septal defect, and severe peripheral arborization abnormalities of the central pulmonary arteries. Experience with preliminary unifocalization procedures in 38 patients

From 1982 to 1987, 38 consecutive patients with pulmonary atresia and ventricular septal defect underwent staged unifocalization procedures in preparation for final intracardiac repair of the anomaly. Thirty-six patients had concordant visceroatrial, atrioventricular, and ventriculoarterial connections. A central pulmonary artery confluence was present in 19 patients and absent in the remaining group. All patients with central pulmonary arteries had inadequate peripheral pulmonary arterial arborization. Systemic collateral arteries were present in all 38 patients. The objectives of the unifocalization procedures were the interruption of extracardiac sources of pulmonary arterial blood flow, the restoration of segmental, lobar, and pulmonary arterial confluence, the replacement of missing central pulmonary arterial branches, and the creation of a central, accessible source of pulmonary arterial blood flow. A total of 54 unifocalization procedures were performed in the 38 patients. These procedures included 85 permanent connecting anastomoses, 15 temporary anastomoses to the ascending aorta, 13 angioplasty procedures, and 15 modified Blalock-Taussig shunts. Three patients died after unifocalization (two early and one late). By the end of the study, eight patients were still waiting for further unifocalization procedures or angiographic assessment. Four patients were rejected for further surgical treatment because of persistent, uncorrectable defects of the pulmonary arterial arborization pattern. Twenty-three patients underwent complete intracardiac repair with two deaths (one early and one late). Postrepair, intraoperative right ventricular/left ventricular systolic pressure ratio after complete surgical repair ranged from 0.4 to 1.0 (mean = 0.63, standard deviation = 0.14). At the end of follow-up, 21 survivors of complete repair were free of significant symptoms. Unifocalization procedures designed to improve the pulmonary arterial arborization pattern of patients with pulmonary atresia and ventricular septal defect with or without central pulmonary arteries can prepare a significant number of these patients for successful intracardiac repair of the anomaly.

Extracardiac vasculature in candidates for Fontan surgery: MR imaging

Magnetic resonance (MR) imaging was performed in 53 patients considered to be candidates for a modified Fontan operation to repair cardiac or extracardiac vascular anomalies. The MR studies were reviewed retrospectively, and the findings with regard to the extracardiac vascular anatomy were compared with the findings from angiography or surgery. The accuracy of MR for the correct identification of the systemic veins was 98%; for pulmonary arteries, 97%; and for pulmonary veins, 95%. For identification of pulmonary veins, MR imaging had a sensitivity of 90% and a specificity of 100%. MR provides excellent demonstration of the extracardiac vascular structures, which are of particular importance in patients being considered for a Fontan procedure.

Optimal display of the coronary arterial tree with an upscan 1,023-line video display system

Differences of opinion exist as to whether visualization of the coronary arterial tree is better with 525-line or 1,023-line video imaging systems. The 1,023-line acquisition has been associated with image degradation; 525-line display, however, has prominent raster lines that may also degrade the image. For evaluation of this issue, identical coronary arterial images were obtained with 525-line acquisition and then displayed with either 525-line or 1,023-line display. The 525-line acquisition with digital upscan 1,023-line display had superior image quality compared with 525-line display. With the use of 525-line acquisition and 1,023-line display, video images were similar to or slightly better than the identical cineangiographic images.

Magnetic resonance imaging of the heart: current status

The favorable technical capabilities of magnetic resonance imaging (MRI) make it well suited for delineating the heart and great vessels. The clinical applications of cardiac MRI have gradually expanded in the past several years. Currently, the most important applications use the modality to provide detailed morphologic information, especially about surgical lesions of the heart. Particularly noteworthy have been applications of MRI in preoperative assessment of patients with certain types of congenital heart disease, cardiac masses, and lesions of the great vessels. Other roles for the modality such as in functional cardiac imaging and nuclear magnetic resonance spectroscopy remain attractive, but these have not yet entered the domain of routine clinical practice.

Caveats of balloon dilation of conduits and conduit valves

The results and complications of percutaneous balloon dilation involving 10 patients with a stenotic right ventricle to pulmonary artery prosthetic conduit and 1 patient with an obstructed right atrium to left pulmonary artery Dacron graft (modified Fontan) are reported. For the 10 patients (14.5 +/- 5 years) with a right ventricle to pulmonary artery conduit, the mean (+/- SD) predilation conduit valve gradient was 57 +/- 22 mm Hg, right ventricular pressure 104 +/- 21 mm Hg and right ventricle to pulmonary artery gradient 75 +/- 23 mm Hg; 2 of the patients had additional pulmonary artery stenosis requiring dilation. In one patient, the balloon could not be advanced across the conduit valve. In 9 of 10 patients in whom dilation was successfully performed, the conduit valve gradient decreased by 59 +/- 13%, right ventricle to pulmonary artery gradient by 43 +/- 22% and right ventricular pressure by 31 +/- 11%. After dilation, right ventricular pressure was less than 65% of systemic pressure in seven patients, although no pressure was less than 40%. In 8 of the 11 patients, surgery was avoided or postponed. Complications included loss of a balloon fragment after rupture during the unsuccessful dilation of the right atrium to left pulmonary artery graft and circumferential balloon rupture requiring catheter retrieval of the distal portion of the balloon from the femoral vein after successful dilation of the right ventricle to pulmonary artery conduit. Conduit valve dilation by balloon can reduce but rarely eliminate conduit obstruction, and balloon rupture may occur and can result in fragment loss or embolization.

Congenital absence of the pericardium and its relationship to the ligamentum arteriosum

An anatomic and embryologic study of congenital absence of the pericardium and the relationship of the ligamentum arteriosum to this defect was carried out by the authors. A case report is presented to clinically correlate the anatomic and radiologic findings in this anomaly. The authors propose that visualization of the ligamentum arteriosum by computed tomography is a characteristic sign for congenital absence of the left pericardium.

Cardiac masses: assessment by MR imaging

The purpose of this study was to assess the role of MR imaging for evaluating suspected cardiac tumors or paracardiac masses involving the heart. Sixty-one patients with clinical or radiologic evidence of cardiac masses were imaged with ECG-gated MR at 1.5 T (22 patients) or 0.15 T (39 patients). Fifty-one patients had echocardiography previously. Among the tissue diagnoses were myxoma (six); fibroma, rhabdomyoma, plasma cell granuloma, lipomatous hypertrophy of the atrial septum, mesothelioma, and thymoma (two each); and leiomyosarcoma, lymphoma, metastatic carcinoid, melanoma, malignant fibrous histiocytoma, hemangiopericytoma, and lung spindle cell sarcoma (one each). MR imaging demonstrated masses in 50 patients (82%); they were centered in the heart in 32, pericardial in nine, and juxtacardiac in nine. MR imaging provided diagnostic information that affected clinical management or surgical planning in 53 patients (87%), including 11 (18%) in whom cardiac mass was excluded by MR. The ability to provide a global view of cardiac anatomy and other unique capabilities of MR imaging give the procedure an important role in the diagnosis and preoperative assessment of cardiac masses.

Accuracy of two-dimensional echocardiography in diagnosing left superior vena cava

Seventy-three consecutive patients with a left superior vena cava evaluated at the Mayo Clinic, Rochester, Minnesota, between 1983 and 1987 underwent cardiac catheterization and two-dimensional echocardiography. Bilateral superior venae cavae were present in 89%. Entry of the left superior venae cavae was into the coronary sinus in 62% (4% were unroofed), a pulmonary venous atrium in 21%, and a common atrium in 17%. Catheterization successfully identified the left superior vena cava in all patients; two-dimensional echocardiography was successful in 68% (group 1) and unsuccessful in 32% (group 2). There was no significant difference between groups with regard to age, sex, diagnosis, or site of drainage. In group 1, 43% had a dilated coronary sinus; in group 2, the coronary sinus was present in 61% but was of normal size. Cineangiograms revealed smaller caliber left superior venae cavae in group 2 than in group 1 (means 7.4 and 11.3 mm, respectively). Thus two-dimensional echocardiography is not totally reliable for the detection of small but possibly significant left superior venae cavae.

The modified Fontan operation for asplenia and polysplenia syndromes

From 1975 through 1986, 49 patients with asplenia (23 patients) or polysplenia (26 patients) syndromes underwent a modified Fontan operation. All patients had anomalous systemic venous return, and 43 (88%) had anomalous pulmonary venous return. The atrioventricular valve anatomy varied: 36 patients had a common atrial chamber and common atrioventricular valve, eight had mitral valve atresia, and five had severe mitral valve hypoplasia. Redirection of systemic venous return was accomplished by (1) atrial baffle (29 patients), (2) intraatrial conduit (19 patients), and (3) extraatrial conduit (one patient). There were 21 (43%) hospital deaths overall. However, since 1985, six of 22 patients (27%) have died. Increased mortality was seen in patients requiring atrioventricular valve repair or replacement (8/11, 73%) and in patients with asplenia (65%). Lower mortality was seen in patients with polysplenia (24%) and those receiving an intraatrial conduit (26%), although this decrease also represents the more recent experience. We conclude: (1) The Fontan operation for patients with asplenia or polysplenia syndromes has resulted in a significant (although recently declining) mortality; (2) mortality is higher in patients with asplenia; (3) patients with atrioventricular valve insufficiency requiring repair or replacement are at higher risk; and (4) intraatrial conduits seem to offer promise for successfully accomplishing this repair.

Technical consideration for a new X-ray video progressive scanning system for cardiac catheterization

The widespread growth of interventional angiographic procedures has expanded the use of X-ray video systems. Reduced radiation exposure to the patient and staff has been recently reported by implementing a new pulsed progressive scanning video system. We have shown that this system, which enables the pulsing of the X-ray generator at 30 pulses per second, results in a 50% reduction in radiation exposure. The technical parameters and implementation of a progressive scanning video system are discussed. Image quality, temporal and spatial resolution, and signal-to-noise ratio (SNR) were assessed using conventional interlaced and progressive video scanning. These comparisons documented improved resolution, no degradation of ejection fraction measurements, improved clinical images, and a 1.0-dB improvement in the SNR with the progressive scanning. Progressive scanning video systems reduce radiation exposure and provide an objective improvement in image quality over conventional scanning video systems.

Blood velocity measurements during selective coronary angiography before and after percutaneous transluminal coronary angioplasty

The velocity of blood flowing down a coronary artery may provide an index of myocardial perfusion, independent of the need for measuring the amount of myocardium supplied by a vessel. The velocity of the leading edge of contrast material was therefore measured before and after percutaneous transluminal coronary angioplasty in 15 patients utilizing digitized images from routine coronary angiography. The velocity (mean +/- SD) before percutaneous transluminal coronary angioplasty in the 15 patients was 11.9 +/- 6.0 cm/s, increasing to 21.7 +/- 8.7 cm/s after (P less than 0.01). There was a correlation between the percent change in velocity and the change in percent stenosis before and after percutaneous transluminal coronary angioplasty (r = 0.65; P less than 0.001). The mean absolute interobserver and intraobserver variabilities for the velocity measurements were 2.1 and 1.8 cm/s, respectively. Measurement of coronary flow velocity from data obtained at the time of routine coronary angiography is an easily performed reproducible technique, which may be used to assess the results of an intervention such as percutaneous transluminal coronary angioplasty.

Right ventricular outflow construction without cardiopulmonary bypass

Establishment of right ventricular-pulmonary arterial continuity without the use of cardiopulmonary bypass was undertaken in 36 patients with different anomalies associated with pulmonary atresia or severe stenosis. Hospital mortality was 11% with no late death. Fourteen of the 27 individuals with pulmonary atresia, ventricular septal defect, and hypoplastic confluent pulmonary arteries had adequate angiographic follow-up, which demonstrated significant pulmonary artery enlargement. Five patients underwent total correction, two after unifocalization operations to establish lobar pulmonary arterial continuity. Symmetric growth of the left and right pulmonary artery was not achieved. However, the enlargement was adequate for potential final repair in all the patients with an unrestricted outflow tract.

Correlation between magnetic resonance imaging of the heart and cardiac anatomy

An understanding of anatomy forms the cornerstone for accurate interpretations of pathologic alterations. In this article, we present cardiac magnetic resonance images and the corresponding sections of normal hearts obtained at autopsy and cut in planes parallel and perpendicular to the ventricular septum in addition to the standard anatomic orthogonal planes (coronal, sagittal, and transverse). This correlation demonstrates the ability of magnetic resonance imaging to display cardiac anatomy accurately and noninvasively. Because magnetic resonance imaging provides excellent contrast between flowing blood and cardiac walls and has the capacity to provide direct images in multiple planes without inherent difficulties, this procedure has advantages over other currently available imaging techniques.

Definitive operation for pulmonary atresia with intact ventricular septum. Results in twenty patients

Definitive operation was performed on 20 patients (aged 25 to 178 months) with pulmonary atresia and intact ventricular septum. All patients had one or more prior preliminary palliative procedures. Right ventricular outflow tract reconstruction with atrial septal defect closure and shunt removal was done on 10 patients. Tricuspid annular circumference was at least 70% of normal in seven patients and between 55% and 70% in three patients. Two patients died during hospitalization. The eight surviving patients were asymptomatic 3 to 145 months after operation. The modified Fontan operation was performed on 10 patients. None of these patients had a tricuspid annular circumference greater than 70% of normal; the circumference was less than 55% in nine patients and between 55% and 70% in one patient. One patient died during hospitalization and one died later. Follow-up 6 to 48 months after operation showed that six patients were in the New York Heart Association Class I and two were in Class II. After effective preliminary palliation of pulmonary atresia with intact ventricular septum, definitive operation can be done with an operative risk of 15% (three of 20 patients) and excellent late results. Right ventricular outflow tract reconstruction can be done as a complete repair for patients who have adequate tricuspid annular size. The modified Fontan operation is the only option for definitive repair when the tricuspid anulus is severely hypoplastic.