Robert J. Gajarski

Influence of age on the effect of bidirectional cavopulmonary anastomosis on left ventricular volume, mass and ejection fraction

OBJECTIVESnWe sought to identify age-related differences in the ventricular response of patients after bidirectional cavopulmonary anastomosis (CPA) and to compare changes in the ventricular response among children < 3 years of age who underwent CPA with that of age-matched control subjects who had a systemic to pulmonary artery shunt alone.nnnBACKGROUNDnPre-Fontan CPA has been advocated over a systemic to pulmonary artery shunt alone in patients with a single ventricle to facilitate ventricular volume unloading and minimize risk of the Fontan operation.nnnMETHODSnOur study evaluated 23 patients who initially received a systemic to pulmonary artery shunt as an initial procedure before subsequent Fontan palliation. In eight of these patients (group I), bidirectional CPA was performed before age 3 years, and in four (group II), it was performed after age 10 years. The remaining 11 patients (group III, age and weight control group for group I) were maintained with their initial shunt until they underwent Fontan palliation. Serial echocardiographic analysis was used retrospectively to evaluate left ventricular volume and mass and systolic pump function (ejection fraction) before and after bidirectional CPA.nnnRESULTSnThrough 10 months of follow-up, group I patients showed significant decreases in indexed end-diastolic volume both after CPA (120 ml/m1.5 body surface area vs. 78 ml/m1.5, p = 0.001) and in comparison with values in patients in group II and III, who showed no changes in end-diastolic volume (p < 0.001). Indexed ventricular mass decreased moderately after bidirectional CPA in group I (from 228 g/m1.5 body surface area to 148 g/m1.5) but remained unchanged in groups II and III. The differences in trends between groups I and III were significant (p = 0.03). Ejection fraction decreased significantly in group II versus group I patients (0.48 to 0.27 vs. 0.51 to 0.52, p < 0.05) after CPA. Oxygen saturation measurements before and after bidirectional CPA revealed a significant increase in group I (73% to 86%, p < 0.001) and a decrease in group II (82% to 73%, p < 0.01).nnnCONCLUSIONSnBidirectional CPA facilitates ventricular volume unloading and promotes regression of left ventricular mass in younger children (< 3 years) in preparation for a Fontan operation. In contrast, bidirectional CPA is of questionable value in older children as a staging procedure for Fontan palliation.

Intermediate follow-up of pediatric heart transplant recipients with elevated pulmonary vascular resistance index

OBJECTIVESnThis study examined perioperative and intermediate outcomes in pediatric cardiac transplant recipients who had elevated pulmonary vascular resistance indexes preoperatively.nnnBACKGROUNDnElevated pulmonary vascular resistance was associated with poor outcome in previous studies and constitutes a relative contraindication to transplantation. Few studies have evaluated this poor outcome risk factor in pediatric patients.nnnMETHODSnTo evaluate outcomes of nonneonatal transplant recipients, records were reviewed and divided into Group I (preoperative pulmonary vascular resistance index > or = 6 units.m2) and Group II (pulmonary vascular resistance index < 6 units.m2). Donor/recipient weight ratios, ischemic times, length of intensive care unit stay, posttransplantation infection rates, arrhythmia, response to pretransplantation vasodilator infusions and pulmonary vascular resistance indexes at the first and most recent posttransplantation biopsies were analyzed.nnnRESULTSnGroup I (8 patients) had a mean (+/- SEM) pulmonary vascular resistance index of 11.5 +/- 3.5 units,m2; Group II (29 patients) had a mean pulmonary vascular resistance index of 2.3 +/- 0.4 units,m2 (p < 0.002). Pulmonary vascular resistance index decreased from 12.3 +/- 3.9 to 3.9 +/- 0.9 units.m2 (p < 0.05) in 7 Group I patients undergoing vasodilator infusion during pretransplantation catheterization. Thirty-six orthotopic heart transplantations were performed and one heterotopic transplantation. Donor weights exceeded recipient weights by 13% and 31% for Groups I and II, respectively (p > 0.25). Donor ischemic time was 215 min for Group I and 225 min for Group II (p > 0.75). Intensive care unit stay was 11.5 days in Group I and 15.1 days in Group II (p = 0.20). Infection rate was 38% in both groups (p > 0.80). Arrhythmias occurred in 90% of Group I and 42% in Group II (p < 0.03) patients. Pulmonary resistance index in Group I decreased from 11.5 +/- 3.5 to 3.3 +/- 1.2 units.m2 (p < 0.03) by the first posttransplantation biopsy and have not changed subsequently. During 2.3 years (range 0.3 to 8.5) of follow-up, the mortality rate was 25% and 21% for Groups I and II, respectively (p > 0.80).nnnCONCLUSIONSnGroup I patients did not require significantly oversized donors, restricted donor locations or longer intensive care unit stays or have higher infection rates; however, arrhythmias were more frequent. Pulmonary resistance index normalized early after transplantation. Pulmonary vascular reactivity may be more important for survival than absolute resistance index.

Left Ventricular Mechanics and Geometry in Patients With Congenital Complete Atrioventricular Block

BACKGROUNDnRadiographic evidence of cardiomegaly is common in patients with congenital complete atrioventricular block (CCAVB). It has been speculated that left ventricular (LV) remodeling and increased stroke volume counteract the bradycardia, but the effects of slow heart rate and atrioventricular asynchrony on LV dimensions, geometry, wall stress, and function have not been examined in detail.nnnMETHODS AND RESULTSnThirty patients with CCAVB without associated congenital heart disease (mean age, 8.5+/-5.3 years; range, 0.2 to 20 years) were included in a cross-sectional two-institution study. Thirty-five echocardiograms were performed using standard techniques. ECG and 24-hour ECG recordings were reviewed. Seven patients did not receive a pacemaker, whereas 23 patients underwent pacemaker implantation after the echocardiogram. Compared with normal control subjects, LV volume (Z score=1.5+/-1.3) and LV mass (Z=1.2+/-1.5) were significantly increased, whereas LV mass-to-volume ratio (1.1+/-0.3) and geometry (short-axis diameter/length ratio=0.65+/-0.09) were normal. LV end-systolic stress (ESS) (a measure of afterload) was normal (Z score=0.2+/-2.3), whereas shortening fraction (Z=3+/-2.9) and velocity of circumferential fiber shortening (VCF) (Z=3+/-3.1) were increased. The relationship between VCF and ESS (a preload-insensitive and afterload-adjusted index of contractility) was increased (Z=2.2+/-2) with only small increase in preload (Z=1.02+/-1.1). Regression analyses showed no significant change over age in LV mass, volume, geometry, loading conditions, or systolic function. Patients who ultimately met criteria for pacemaker implantation did not differ from those who did not in terms of heart rate or LV function but did have increased LV volume (Z score=1.8+/-1.4 versus 0.4+/-0.9, P=.03) and LV mass (Z score=1.7+/-1.2 versus 0.2+/-1.7, P=.001) compared to the unpaced group.nnnCONCLUSIONSnIn most patients with CCAVB, the LV was enlarged with normal geometry and enhanced systolic function during the first two decades of life. The degree of LV dilation and enhanced function did not significantly change with age. In patients who ultimately underwent pacemaker implantation LV function did not differ from those who remained unpaced, but evidence of a slightly increased load manifested as increased end-diastolic volume and mass.

Fontan palliation versus heart transplantation: A comparison of charges

Surgical approaches to single-ventricle physiologic abnormalities have included Fontan palliation or transplantation. No cost expenditures have been published. This study compared expenditures between the Fontan procedure and heart transplantation. Between 1988 and 1992, records of 82 patients who underwent the Fontan procedure and 26 who underwent transplant were retrospectively reviewed. Charges for Fontan or transplant procedures were accrued from the date of surgical admission until discharge or patient death and included hospital, physician, and diagnostic laboratory charges. Additionally, the frequency and cost of postoperative hospital readmissions, outpatient evaluations, and diagnostic procedures were recorded for each patient. Estimated expenditures for each evaluated parameter were based on 1992 to 1993 dollar charges. The total expenditure (surgery plus yearly follow-up) for transplantation exceeded that for the Fontan procedure (

Echocardiographic Evaluation of Common Atrioventricular Canal Defects: A Study of 206 Consecutive Patients.

96,475 vs

Long-term results of triple-drug-based immunosuppression in nonneonatal pediatric heart transplant recipients.

29,730; p < 0.001). Although both groups had similar follow-up periods and mortality rates, the number of hospital readmissions and postoperative diagnostic tests was higher among transplant recipients. Within 1 postoperative year at least four high-risk patients who had undergone a Fontan procedure required listing for transplantation; the total costs of their combined procedures (approximately

Effect of donor-recipient size mismatch on left ventricular remodeling after pediatric orthotopic heart transplantation

80,000 +

Usefulness of routine surveillance biopsies in children more than one year after orthotopic heart transplantation

3,000 to

Restrictive cardiomyopathies in childhood. Etiologies and natural history.

5,000 annual outpatient charges) was markedly greater than the cost of the Fontan procedure alone. Although the expenditure for heart transplantation far exceeds that for the Fontan procedure, Fontan palliation in high-risk patients is ultimately more costly and increases postoperative morbidity. In this subgroup, we recommend heart transplantation as the initial definitive procedure because it may increase long-term survival rates and minimize health care expenditures.

Cardiac transplantation for pediatric patients. With inoperable congenital heart disease.

An accurate echocardiographic evaluation of common atrioventricular canal (CAVC) requires indepth knowledge of the wide spectrum of morphological and physiological variations in this group of anomalies. In order to evaluate the incidence and morphological distribution of AV canal defects in a large series of patients and to define a systematic approach to the echocardiographic examination, we reviewed the echocardiograms of 206 consecutive patients with CAVC studied at Texas Childrens Hospital over a 32‐month period. The complete form of CAVC was most common (68.4%) and presented at an earlier age (mean ± SD: 1.6 ± 2.4 months). A partial AV canal (ostium primum atrial septal defect [ASD]) was found in 42 patients (20.4%) and their age at presentation was higher (9.2 ± 10 months). Twenty‐three patients (11.2%) had a transitional AV canal. Down syndrome was diagnosed in 34% of patients, the majority of whom (79%) had a complete CAVC. Associated malformations were found in 46% of patients: anomalies of the conotruncus were most frequent (18%), followed by secundum ASD (14.1%), anomalous pulmonary venous connection (11.2%), and heterotaxy syndrome (11.2%). Subaortic obstruction and mitral stenosis were less common. The AV canal was unbalanced in 14.1% of patients, with the right ventricular dominant form being more common than the left ventricular dominant form (10.7% and 3.4%, respectively). Based on our experience, we developed a systematic, segment‐by‐segment approach to the echocardiographic examination in infants with CAVC. Together with detailed anatomical information, Doppler evaluation provides crucial hemodynamic information that allows planning of surgical repair.