Robert J. Sommer

Use of preformed nitinol snare to improve transcatheter coil delivery in occlusion of patent ductus arteriosus

Abstract Recent studies have reported the efficacy of transcatheter occlusion of the small patent ductus arteriosus (PDA) using a Gianturco Coil1–3 as an alternative to either surgery or Rashkind Umbrella placement.4 This report presents our experience using a preformed nitinol snare, delivered via the venous circulation, to hold and manipulate the coil as it is delivered from the arterial side of the PDA. This modification was designed to aid in the positioning of the coil, and to facilitate coil retrieval in the event of unstable or unfavorable position after delivery.

Usefulness of intermittent monitoring of mixed venous oxygen saturation after stage I palliation for hypoplastic left heart syndrome

Most deaths after stage I palliation for hypoplastic left heart syndrome have occurred within the first 24 hours after surgery. Efforts to improve 1-day survival should therefore have significant impact on improving overall survival. Early death has most often been attributed to low cardiac output and abnormalities of pulmonary to systemic flow ratio (Qp/Qs). Thirteen infants underwent stage I palliation and had a catheter inserted in the high superior vena cava (SVC) for intermittent measurement of SVC oxygen saturation. Calculation of Qp/Qs was achieved using SVC saturation as a mixed venous oxygen saturation, and estimating pulmonary venous oxygen saturation. Eleven patients survived, and 2 patients died within the first 24 hours. Abnormalities in Qp/Qs were noted in 12 of 13 patients after operation. In 10 of these 12 patients, there was a high Qp/Qs, which has been associated with poor outcome. High Qp/Qs was noted even in patients with acceptable arterial oxygen saturations (< 85%). SVC saturation increased in all survivors during the first 24 hours, and was associated with a decrease in Qp/Qs. Measurement of SVC oxygen saturation appears to be a valuable adjuvant in the postoperative management of infants after stage I palliation of hypoplastic left heart syndrome. Major abnormalities in Qp/Qs can be detected even with acceptable arterial saturations. With this information, early ventilator/pharmaceutical adjustments can be made which may improve stage I survival.

Pathophysiology of Congenital Heart Disease in the Adult Part I: Shunt Lesions

Congenital heart disease is common, occurring in ≈8 of 1000 live births.1 With the successes in cardiothoracic surgery over the past 3 decades and the ongoing improvements in the diagnostic, interventional, and critical care skills of pediatric cardiologists, ≈90% of children born with heart defects now survive to adulthood.2 In addition, using improved noninvasive techniques, adult cardiologists are increasingly identifying adults with septal defects that were undiagnosed in childhood. The adult congenital heart disease patients carry a spectrum of disease, from small septal defects and minor valvar obstructions to complex single-ventricle lesions that have been palliated with staged surgical repairs. It is estimated that >1 million adults in the United States now have congenital heart disease, outnumbering their pediatric counterparts for the first time.3,4 While the adult cardiology community struggles with a population that once was the exclusive domain of pediatricians, governmental agencies, national physician associations, and cardiology advisory boards are trying to define the scope of this national healthcare issue and to figure out how to train current and future generations of doctors.5 This specialized cardiac care will require the diagnosis of adult congenital heart disease in patients presenting de novo with new or chronic symptoms, the long-term maintenance of those previously diagnosed, and the ability to recognize when primary or additional interventions are required. As these patients increasingly present to cardiologists’ offices for care, healthcare professionals will need to develop a better level of comfort with adult congenital heart disease. This 3-part series focuses on the pathophysiology of congenital heart lesions, which are seen commonly in adult patients. In this first portion, simple shunt lesions are reviewed. For each, the natural history and common clinical presentations resulting from the shunt are discussed. A discussion of therapeutic options and the literature supporting these options is …

Impact of Low Body Weight on Frequency of Pediatric Cardiac Catheterization Complications

The overall risk of pediatric cardiac catheterization remains low despite the enormous new complexity and potential for complications brought on by the growth of interventional catheterization techniques. For all patients aged < 21 years, balloon interventions carry the highest risk, diagnostic procedures carry more risk than non-balloon interventions, and although weight < or = 5 kg is a significant risk factor for complications, irrespective of the type of procedure performed, weight < or = 2.5 kg did not alter that risk.

Pathophysiology of Congenital Heart Disease in the Adult Part III: Complex Congenital Heart Disease

With the successes in cardiothoracic surgery and pediatric cardiology over the past 3 decades, for the first time, adults with congenital heart disease (CHD) outnumber their pediatric counterparts.1,2 As a result, adult patients with CHD are beginning to appear more frequently in the practices of adult cardiologists. The present series is designed to provide a review of the pathophysiology and natural history of common congenital heart problems that are now being seen by adult cardiologists. In the first 2 parts of the series, simple shunts and congenital obstructive lesions were reviewed. This final chapter will examine the physiology and natural history of and the indications for intervention in common complex congenital cardiac malformations seen in adult patients. These patients include those with singleventricle physiology who are reaching adulthood in significant numbers for the first time, the early survivors of innovative surgical techniques developed a generation ago. The combination of shunts, obstructive lesions, chamber hypoplasia, and abnormal arterial and venous connections that is seen in this group of patients creates some of the most interesting and complex changes in the normal physiology of the heart. Each patient must be considered individually, because small differences in septal defect size or pathway obstruction may have an enormous impact on the overall effectiveness of the circulation and on management of the patient. For the purposes of this article, only the most common types of complex CHD will be considered (those that are most likely to be seen in the adult cardiologist’s office). However, the principles of flow and resistance, as reviewed in the prior 2 portions of this series and as related below, are easily generalized to give the practicing physician insight into the physiological consequences of a myriad of rare cardiac malformations. Adults with complex CHD can be divided into 2 groups: those who have not previously had an intervention and those who have. The former will present with new-onset symptoms in adulthood or may be identified as a result of a physical examination with a new physician, an abnormal ECG, or before they begin a new job. Children in the latter group who have had good outcomes from surgical interventions are frequently lost to follow-up during adolescence. They may return for care in early adulthood with ongoing or new symptoms or for clearance for employment, higher education, insurance, or sports. These patients are often unfamiliar with their diagnoses and their surgical history, have long since stopped taking medication, and have adapted to a lifestyle that fits their level of cardiac function.

Initial experience with percutaneous transhepatic cardiac catheterization in infants and children

Percutaneous transhepatic cardiac catheterization is a straightforward procedure that can be performed by experienced pediatric interventionalists with little additional training. We believe that this technique can be a valuable tool in the treatment of selected patients with complex congenital heart defects.

Pathophysiology of Congenital Heart Disease in the Adult, Part II Simple Obstructive Lesions

With the successes in cardiothoracic surgery over the past 3 decades, adults with congenital heart disease (CHD) outnumber, for the first time, their pediatric counterparts.1,2 As a result, adult patients with CHD are beginning to appear more frequently in the practices of adult cardiologists. This series is designed to provide a review of the pathophysiology and natural history of common congenital heart problems that are now being seen by adult cardiologists. In the first part, simple shunt lesions were reviewed. This section will examine the physiology and natural history of some of the more common congenital obstructive lesions that may be seen by adult cardiologists, as well as indications for intervention. Principally, these lesions will include ventricular outflow obstructions that may or may not have undergone prior intervention. Congenital obstructions of systemic and pulmonary venous return, congenital intra-atrial obstructions, and congenital atrioventricular valve stenosis will not be included in this review because they are far less common and present clinically predominantly in childhood. In the normal circulation, the ventricular outflow tracts, semilunar valves, and great arteries present no obstruction to flow. Congenital narrowing of any of these pathways increases ventricular afterload and in more distal lesions causes maldistribution of flow (see individual defects below). In response to the increased afterload, physiological ventricular hypertrophy occurs, which results in thicker chamber walls, reduced chamber compliance, and higher filling pressures in the atrium. With severe noncompliance (diastolic dysfunction) venous congestion may occur, with exertion or even at rest, which limits cardiac output and physical activity in this population. A reduced stroke volume may also be a direct consequence of increased afterload and may be particularly important in the face of increased demands. All patients with hemodynamically significant obstructions of large ventriculoarterial pathways will present with a heart murmur, the result of the …

Effect of older age en outcome for stage one palliation of hypoplastic left heart syndrome

Abstract In conclusion, in selected infants, stage 1 palliation for hypoplastic left heart syndrome can be performed at an older age without adversely affecting outcome. This includes patients who previously were awaiting cardiac transplantation. Strategies at improving hemodynamic instability preoperatively, such as manipulating inspired gases and measuring mixed venous oxygen saturations to optimize sol Qp Qs and oxygen delivery, should improve survival after stage 1 palliation even further.

Intracardiac shunting in children with ventricular septal defect: Evaluation with Doppler color flow mapping

In children with a ventricular septal defect, transseptal blood flow has been demonstrated angiographically to be bidirectional in all but the smallest defects. To investigate this phenomenon noninvasively, two-dimensional Doppler color flow echocardiography was used in 77 patients (aged 1 day to 15.5 years, mean 24 months). During isovolumetric contraction, flow was seen from the left to the right ventricle in 82 (98%) of 84 studies. During isovolumetric relaxation, right to left flow was noted in 72 (96%) of 75 studies. During early diastole in patients with an isolated defect, flow was initially from the right to the left ventricle and subsequently reversed to become left to right in 29 (91%) of 32 studies. In patients with concomitant right ventricular volume overload, flow across the ventricular defect was from the right to the left ventricle throughout diastole in 30 (86%) of 35 studies. In each of four patients with d-transposition of the great vessels and each of two patients with 1-transposition of the great vessels, blood flow was from the morphologic left ventricle to the morphologic right ventricle during isovolumetric contraction and from the morphologic right ventricle to the morphologic left ventricle during isovolumetric relaxation. These results demonstrate 1) the complex nature of intracardiac shunting in children with ventricular septal defect as previously shown by angiography; 2) an intrinsic functional difference in the contractile and relaxation properties of the morphologic left and right ventricles; and 3) differences in diastolic blood flow patterns between children with an isolated defect and those with a ventricular septal defect and right ventricular volume overload (p = 0.0001).

Acute cyanosis following balloon angioplasty of residual arch obstruction after the Norwood I operation

A 7-month-old child with residual aortic arch obstruction following a modified Norwood I operation developed profound cyanosis with subsequent bradycardia and hypotension immediately after successful balloon angioplasty. This complication of aortic angioplasty is specific to patients with this physiology. The pathophysiology of the event is discussed.