Cardiac output as a predictor in congenital heart disease: Are we stating the obvious?

BACKGROUND: Significant pulmonary regurgitation, declining right-sided ejection fraction, increased right ventricular (RV) volumes as well as left ventricular (LV) dysfunction have all been identified as predictors of poor outcomes in patients with congenital heart disease (CHD). The prognostic value of the cardiac output (CO) in these patients however has never been studied. METHODS: All consecutive ambulatory adult patients with CHD referred for magnetic resonance imaging (MRI) at the Montreal Children's Hospital between June 2007 and May 2009 were included. Right ventricular (RV) and left ventricular (LV) variables including end diastolic and end systolic volumes (EDV, ESV respectively), ejection fractions (EF) and regurgitant volumes were obtained. Cardiac index (CI) was calculated. Patients were followed for cardiac-related hospitalizations and cardiac interventions. RESULTS: Ninety-six patients were included. Median follow up was 3.9 ± 1.4 years. Nineteen percent of patients had a systemic CI<2.4 l/min/m(2). LVEDV, LVEF and RVEF were significantly diminished in the low CI group with a significant increase in RVESV and total regurgitant volume. Best predictors of low CI were LVEF (AUC=0.74), RVEF (AUC=0.71), total RV regurgitant volume (AUC=0.64) and RVESV (AUC=0.563). Low systemic CI was the best predictor of cardiac-related hospitalizations (hazard ratio 3.5, 95% confidence interval 1.5-8.5) and cardiac interventions (hazard ratio 2.2, 95% confidence interval 1.3-4.0), superior to LVEF, RVEF, total regurgitant volume and RVESV parameters. CONCLUSIONS: In patients with congenital heart disease, cardiac index is the best predictor of cardiac hospitalizations and cardiac interventions.

Magnetic resonance of hearts in a jar: breathing new life into old pathological specimens.

BACKGROUND: Specimens of the normal and congenitally abnormal heart have been long preserved, collected, and studied. It is increasingly difficult to add to such pathological collections. These museum pieces are often inaccessible for teaching purposes. Magnetic resonance imaging of old pathological specimens could produce high-resolution unalterable datasets that could be processed to create three-dimensional reconstructions using inexpensive systems that could be used by untrained individuals. To our knowledge, the concept of "Virtual Autopsy" has not been applied to cardiac specimens of museum collections. METHODS: To determine optimal sequences and assure specimen safety, five different pulse sequences designed to create three-dimensional datasets were tried on a uterus specimen suspended in a fluid-filled glass container, using a 1.5 Tesla scanner with an eight-channel phased-array coil. Having found the best sequences and established specimen integrity, we scanned six historical heart specimens in their original fluid-filled glass containers. The datasets were processed on a laptop with a DICOM viewer available as freeware. RESULTS: All specimens were successfully scanned. The best image quality was obtained by using a three-dimensional FSPGR and the BRAVO pulse sequences. High-resolution three-dimensional and multi-planar image processing was possible for all datasets. Detailed examination of the specimens could be easily performed. CONCLUSION: Pathological specimens can successfully be scanned in minutes resulting in unalterable and portable high-resolution three-dimensional datasets that can be processed by using inexpensive readily available software. The final cardiac reconstructions can be widely shared for educational and scientific purposes and ensure a lasting access to pathological specimens.

Can cardiologists distinguish innocent from pathologic murmurs in neonates?

OBJECTIVES: To determine the sensitivity and specificity of the clinical assessment of murmurs in neonates, as performed by pediatric cardiologists, and to identify clinical features that predict the presence of congenital heart disease (CHD) in this population. STUDY DESIGN: Neonates (n = 201) referred for outpatient evaluation of a heart murmur were enrolled consecutively. After a clinical evaluation, the cardiologist documented whether the murmur was "likely innocent" or "likely pathologic." The cardiologist repeated his/her assessment after an electrocardiogram. Echocardiography served as the gold standard. RESULTS: The median age was 12 days (range, 2-31 days). CHD was present in 113 of 201 (56%). Clinical assessment alone identified patients with CHD with a sensitivity of 80.5% (95% CI, 73.2-87.8), specificity of 90.9% (95% CI, 84.9-96.9), positive predictive value of 91.9% (95% CI, 86.6-97.3), and negative predictive value of 78.4% (95% CI, 70.4-86.4). The addition of an electrocardiogram did not improve these test characteristics. Features that were predictive of CHD were murmur quality (P < .0001), location (P = .02), and timing (P = .04). No patients requiring catheter or surgical intervention were missed by clinical assessment. CONCLUSIONS: The prevalence of CHD in this referral population was high. Clinical assessment detected all complex CHD, although some simple lesions were missed. Murmur quality, location, and timing were predictive of CHD.

Iatrogenic cyanosis and clubbing: 25 years of chronic hypoxia after the repair of an atrial septal defect.

A case of sinus venosus atrial septal defect repair of the inferior vena caval type with an unintentional diversion of the inferior vena caval blood to the left atrium is reported. Long-standing, anatomical, right-to-left shunting with cyanosis and hypoxia are associated with systemic and cerebrovascular complications. Cardiac risks depend on the presence or absence of pulmonary hypertension, the associated hematological abnormalities and the degree of anatomical, right-to-left shunting. Cardiac magnetic resonance imaging clarified the etiology of the unexplained cyanosis and delineated the surgical anatomy.

Comparison of surgical and transcatheter treatment for native coarctation of the aorta in patients > or = 1 year old. The Quebec Native Coarctation of the Aorta study.

BACKGROUND: The objectives of this study were to compare, in the current era, the immediate results, complications, and midterm outcomes obtained by surgical repair versus transcatheter treatment of coarctation of the aorta (CoA). METHODS: The study was of retrospective nature and included 80 consecutive patients > or = 1 year old (mean age 12 +/- 10 years) treated for an isolated CoA in 4 university centers in Quebec between 1998 and 2004. Fifty patients underwent aortic angioplasty, with stent implantation in 19, and 30 had surgical repair. Immediate results, procedural complications, clinical events, and the incidence of aortic aneurysm at follow-up were compared between groups. RESULTS: There were no differences between the 2 groups in clinical baseline characteristics. Percentage reduction in peak systolic pressure gradient across the coarctation was similar between the 2 groups (angioplasty 72% +/- 23% vs surgery 75% +/- 18%, P = .55). Procedure-related complications occurred more frequently after surgical repair compared with angioplasty (50% vs 18%, P = .005), and median hospitalization time was longer in the surgical than in the angioplasty group (7 vs 1 day, P < .001). At 38 +/- 21 months' follow-up, no patient in the surgical group and 16 patients in the angioplasty group had at least 1 aortic reintervention (0% vs 32%, P < .0001). The presence of an aortic aneurysm was diagnosed more frequently in the angioplasty group compared with the surgical group (24% vs 0%, P = .01). CONCLUSION: Aortic angioplasty provided comparable immediate hemodynamic results to surgery, with reduced morbidity and hospitalization length for the treatment of CoA in patients > or = 1 year old. However, angioplasty was associated with a higher rate of reintervention and aneurysm formation at a mean follow-up of 3 years.

Berlin Heart ventricular assist device in a child with hypoplastic left heart syndrome.

We report the implantation of a Berlin Heart ventricular assist device (VAD) in a 4-year-old boy with hypoplastic left heart syndrome previously palliated with Norwood and Glenn operations, who presented with progressive ventricular failure and hypoxemia. Insertion of a 30-mL pneumatic pediatric pump with cannulation of the systemic right ventricle and aorta had a salutary effect on cardiac output, improving oxygen saturations. While awaiting heart transplantation, multiple thromboembolic complications developed and he died, despite therapeutic heparinization and aspirin therapy. Important lessons learned about VAD support in Glenn physiology, anticoagulation, and complications of the Berlin Heart are discussed.

Neonatal repair of right interrupted aortic arch, aberrant left subclavian artery, ventricular septal defect and retroaortic innominate vein.

We report a rare case of neonatal biventricular repair of a right interrupted aortic arch (type B), with an aberrant left subclavian artery, ventricular septal defect and retroaortic innominate vein in a 4-week-old, 2.7 kg neonate with DiGeorge syndrome. The patient had an unremarkable postoperative recovery. We discuss the anatomy of this rare congenital anomaly, its surgical implications and issues surrounding the adequacy of the left ventricular outflow tract.

Complete repair of concomitant interrupted aortic arch and partial anomalous pulmonary venous connection.

We report a rare case of concomitant presentation of partial anomalous pulmonary venous connection and type A interrupted aortic arch in a 4-week-old, 2.1 kg newborn. She presented in extremis and was found to have a closed ductus arteriosus with the entire left pulmonary venous return obstructed at its connection with the innominate vein. Emergent operative repair was performed in one-stage, consisting of aortic arch reconstruction and anomalous vein translocation. Postoperative recovery was unremarkable and the patient was discharged from hospital 12 days after operation.

Elucidating the relationship between cardiac preload and renal perfusion under pneumoperitoneum.

INTRODUCTION: Pneumoperitoneum is associated with a well-described decrease in renal blood flow, but it remains unclear whether a decrease in cardiac preload is responsible. Our aim was to characterize the relationship between cardiac preload and renal perfusion during pneumoperitoneum. METHODS: Eleven pigs were submitted to three 30 minute study periods: 1) Baseline (n=11): no interventions, 2) Pneumoperitoneum (n=11): 12 mmHg CO2 pneumoperitoneum, 3) Preload Reduction: pneumoperitoneum and nitroglycerin infusion (n=8); or pneumoperitoneum and hemorrhage to a mean arterial pressure (MAP) of 40 mmHg (n=3). Echocardiographic measurements of left ventricular end-diastolic diameter (LVEDD) were used as an index of preload. Renal cortical perfusion (RCP) was measured using laser doppler flowmetry. RESULTS: LVEDD decreased from 4.2 +/- 0.5 to 4.1 +/- 0.6 cm (p=0.02) with pneumoperitoneum and then to 4.0 +/- 0.5 cm (p=0.03) with the addition of nitroglycerin. There was no statistically significant change in RCP with pneumoperitoneum (33.5 +/- 8.4 to 28.5 +/- 8.4 ml/min/100g tissue, p=0.2), but it decreased to 18.5 +/- 11.3 ml/min/100g tissue (p=0.001) with the addition of nitroglycerin. The correlation between RCP and LVEDD was weak (0.35, p=0.003), whereas correlation between RCP and MAP was superior (R=0.59, p<0.0001). CONCLUSIONS: While decreasing preload under extreme lab conditions also decreases RCP, simply creating a pneumoperitoneum of 12 mmHg does not. The decrease in renal blood flow associated with pneumoperitoneum is likely not solely a function of preload.