Alterations of acid-base balance, electrolyte concentrations, and osmolality caused by nonionic hyperosmolar contrast medium during pediatric cardiac catheterization.

OBJECTIVE: This prospective clinical observational study was conducted to investigate the effects of contrast medium on acid-base balance, electrolyte concentrations, and osmolality in children. BACKGROUND: For pediatric cardiac catheterization, high doses of nonionic hyperosmolar contrast medium are widely used. METHODS: Forty pediatric patients (age 0-16 years) undergoing cardiac angiography with more than 3 ml·kg(-1) of nonionic hyperosmolar contrast medium (Iomeprol) were enrolled, and the total amount of the contrast agent given was documented. Before and after contrast medium administration, a blood sample was collected to analyze electrolytes, acid-base parameters, osmolality, hemoglobin, and hematocrit. RESULTS: After cardiac catheterization, pH, hemoglobin, hematocrit, bicarbonate, base excess, sodium, chloride, calcium, anion gap and strong ion difference decreased, whereas osmolality increased significantly (base excess -1.8 ± 1.8 vs -3.4 ± 2.3, sodium 138 ± 2.9 vs 132 ± 4.1 mm, osmolality 284 ± 5.7 vs 294 ± 7.6 mosmol·kg(-1), P < 0.01). Seventy-eight percent of the children developed hyponatremia (sodium <135 mm). No changes were seen in pCO(2) , lactate, and potassium levels. CONCLUSIONS: Regarding the differential diagnosis of metabolic disturbances after pediatric cardiac catheterization, low-anion gap metabolic acidosis and hyponatremia should be considered as a possible side effect of the administered contrast medium.

Transsplenic endovascular therapy of portal vein stenosis and subsequent complete portal vein thrombosis in a 2-year-old child.

A complex catheter intervention for portal vein stenosis and subsequent complete thrombosis after split-liver transplantation was performed using transsplenic access to the portal vein circulation. The combination of intrahepatic, local thrombolysis and extrahepatic portal vein angioplasty performed twice on 2 consecutive days followed by anticoagulation with a high dose of heparin and clopidogrel completely resolved portal vein stenosis and thrombosis. Postinterventional angiographic and serial ultrasound examinations confirmed that the endovascular therapy was successful. In selected patients, percutaneous transsplenic access to the portal vein circulation may be used for diagnostic and therapeutic interventions even in early childhood.

Elevated brain natriuretic peptide and reduced exercise capacity in adult patients operated on for tetralogy of fallot is due to biventricular dysfunction as determined by the myocardial performance index.

Although tetralogy of Fallot (TOF) can be repaired surgically, residual lesions that cause abnormal ventricular load can eventually lead to heart failure. Subclinical biventricular dysfunction in these patients may be detected only by using suitably sensitive indexes. The Tei index determined by the pulsed Doppler method enables the measurement of left ventricular (LV) and right ventricular (RV) function. This study was designed to evaluate the biventricular Tei indexes in adults with operated congenital heart disease and to correlate these indexes with cardiopulmonary capacity and neurohormonal activation. Fifty-nine patients with surgically corrected TOF and 52 patients with operated left-to-right-shunt defects were included in the study. Patients with TOF showed significantly greater LV and RV Tei indexes than those with left-to-right-shunt defects (LV Tei index 0.50 +/- 0.09 vs 0.34 +/- 0.05, RV Tei index 0.37 +/- 0.1 vs 0.25 +/- 0.06; p <0.0001). Peak oxygen uptake was significantly reduced in the patients with TOF (25 +/- 6 vs 32 +/- 6 ml x kg(-1) x min(-1), p <0.0001) and was correlated inversely with the LV Tei index (r = -0.61, p <0.0001). N-terminal-pro-brain natriuretic peptide was significantly increased in patients with TOF (150 +/- 141 vs 57 +/- 39 pg/ml, p <0.0001). In conclusion, in asymptomatic or minimally symptomatic patients with TOF, biventricular dysfunction is detected by the Tei index. Further indexes for heart failure in these patients are increased circulating plasma N-terminal-pro-brain natriuretic peptide and impaired peak oxygen uptake. The combined determinations of these 3 variables enable the identification of congenital heart disease with impaired cardiac function before they become clinically symptomatic.

Relation of systemic ventricular function quantified by myocardial performance index (Tei) to cardiopulmonary exercise capacity in adults after Mustard procedure for transposition of the great arteries.

After Mustard repair for transposition of the great arteries, the right ventricle serves as a chronically overloaded systemic ventricle (SV). Thus, during long-term follow-up, dysfunction of the right ventricle with consecutive heart failure (HF) is not unusual. Early signs and symptoms of HF are depressed parameters of right ventricular (RV) function at rest and exercise intolerance. It was hypothesized that the measurement of RV function parameters, N-terminal pro-brain natriuretic peptide (NT-pro-BNP), and peak oxygen uptake (VO2max) during exercise testing were suitable for the early detection of subclinical HF. In 33 asymptomatic adolescents and adults who had undergone Mustard repair, RV function was analyzed by the myocardial performance index (Tei index). NT-pro-BNP and VO2max were also determined. The corresponding data from 52 patients operated on for left-to-right shunt defects without residual lesions served as reference data. In patients who underwent the Mustard procedure, the Tei index and NT-pro-BNP were elevated (mean Tei index of the SV 0.63 +/- 0.17 vs 0.34 +/- 0.05, p <0.002; mean NT-pro-BNP 240 +/- 230 vs 57 +/- 39 pg/ml, p <0.0001), and VO2max was reduced (27 +/- 6 vs 32 +/- 6 ml x kg(-1) x min(-1), p <0.002). A good correlation was found between the Tei index and VO2max (r = -0.83, p <0.0001). In conclusion, RV function is depressed in most patients with Mustard repair. Ventricular dysfunction in such asymptomatic or minimally symptomatic patients can be detected by measurement of the Tei index, NT-pro-BNP, and VO2max. These parameters are simple and reliable screening methods to stratify patients with impaired cardiac dysfunction before they become symptomatic.

Comparison of late results of arterial switch versus atrial switch (mustard procedure) operation for transposition of the great arteries.

Two decades after surgery for transposition of the great arteries, the clinical status, cardiac function, cardiorespiratory performance, and neurohormonal activity of patients who underwent either atrial switch (Mustard) operations or arterial switch operations (ASOs) were compared. Sixty-two patients with simple transposition of the great arteries who underwent either Mustard (n = 34) or ASO (n = 28) procedures were included in this cross-sectional study. Following the same study protocol, clinical workup including echocardiography, stress testing, and blood work was completed for all patients. Mean ages in the 2 groups were comparable, at 20.6 ± 2.1 and 20.6 ± 3.4 years in the ASO and Mustard groups, respectively. All ASO patients were in New York Heart Association class I, whereas 59% of Mustard patients were in class II or III. Peak oxygen uptake was higher in ASO patients (percentage of predicted 80% vs 69%, p <0.01). Compared with healthy subjects, the mean Tei index for systemic ventricle was high in the 2 groups, but this parameter was significantly higher in Mustard than ASO patients (0.60 ± 0.16 vs 0.47 ± 0.14, p <0.01). The median plasma N-terminal pro-brain natriuretic peptide level in ASO patients was within the normal range, but the Mustard group had significantly higher levels (42 ng/ml [range 18 to 323] vs 172 ng/ml [range 26 to 1,018], p <0.0001). In conclusion, this cross-sectional assessment 2 decades after surgery reveals better clinical status in patients who underwent ASO compared with Mustard patients. This holds in terms of cardiac function, cardiorespiratory performance, and neurohormonal activity.

Removal of temporary pacemaker after cardiac surgery in infants: A harmless procedure?

External pacemakers (PM) via temporary epicardial leads are routinely applied to infants and children during heart surgery, which usually, after an uneventful post surgical course, can be removed without complications. We report about two infants with complex congenital heart defects after cardiac surgery (arterial switch and Mustard operation for Transposition of the great arteries). Intraoperative these patients received temporary epicardial PM wires. Thirteen and 18 days post surgery, respectively, the PM wires were removed under electrocardiogram (ECG) monitoring. The patients showed acute ECG changes in terms of significant ST elevation during and after removing their pacing wires. Clinically, patients were stable and subsequent echocardiographic examination showed no evidence of myocardial dysfunction or pericardial effusion. In the course of time, patients showed no signs of arrhythmia or abnormal ECG changes. The decision to place temporary pacing wires during the cardiac surgery in patients with congenital heart defects should be considered carefully and their removal should occur under ECG monitoring as soon as the situation of the patient allows. It should be taken into consideration that a complication like this case may be related to delayed removal of temporary PM's leads.

QRS duration in Fontan circulation in adults: a predictor of aerobic capacity.

BACKGROUND: The univentricular circulation after a Fontan procedure is characterized by an abnormal cardiorespiratory response being attributable to an inability to increase stroke volume during exercise. In congenital heart disease a broad QRS complex has been related to increased intracardiac volume and mass being associated with poor ventricular function and prognosis. OBJECTIVES: This study investigated the relation between the width of the QRS complex and parameters of cardiorespiratory response in adult patients after a Fontan procedure. METHODS: Clinical data and parameters of cardiorespiratory function of 56 patients (15 women, 41 men, mean age 23.7+/-6.4 years, mean age at operation 10.0+/-7.5 years) were related to the width of the QRS complex. RESULTS: In the whole group the mean QRS duration was 115+/-23 ms. A QRS complex >or= 120 ms was present in 23 patients. These patients were characterized by significantly older age at operation (13.0+/-9.3 versus 7.9+/-5.1; p<0.05). Compared to individuals with smaller QRS complexes they showed a decreased oxygen uptake (PeakVO(2): 21.6+/-5.2 versus 27.7+/-6.6 ml/kg/min; p<0.001), work rate (1.6+/-0.5 versus 2.0+/-0.5 W/kg, p<0.05), maximum blood pressure (p<0.001) and increase in blood pressure (p<0.05). Univariate analysis showed a significant correlation between PeakVO(2) and several other parameters of cardiorespiratory exercise testing (work rate,O(2)-pulse, increase in heart rate and blood pressure, maximum heart rate and blood pressure), maximum enddiastolic diameter of the systemic ventricle, age at operation. Multivariate regression analysis identified QRS duration as the only independent predictor of PeakVO(2) (p=0.05). CONCLUSION: In a Fontan circulation a broad QRS complex is a negative predictor of cardiorespiratory function. Early Fontan operation may be beneficial in terms of exercise capacity.