[Hemodynamic Derangements in Patients With Functional Univentricular Heart: Mechanisms of Development, Possibilities of Treatment].

Heart failure (HF) is a predictable outcome of nearly all cardiovascular diseases including congenital heart diseases (CHD). A special category comprises patients with functional single ventricle (FSV) of the heart because of extreme diversity of anatomical changes of the heart and great vessels, complex mechanisms of development of HF, multistage surgical correction of the defect, presence of arrhythmias, progressive rise of pulmonary vascular resistance, etc. Prevention and treatment of HF in patients with FSV includes surgical optimization of pulmonary blood flow during neonatal period, timely staged surgical correction of the defect, pharmacotherapy, cardiac resynchronization therapy, and in severe cases mechanical cardiac support and heart transplantation. This article contains review of the mechanisms of HF development in patients with FSV as well as analysis of current approaches to recognition and treatment of this condition.

Caval flow reflects Fontan hemodynamics: quantification by magnetic resonance imaging.

INTRODUCTION: Failing Fontan circulation is a multifactorial problem without clear predictors and with uncertain onset. We sought to investigate the correlations between systemic venous flow return and the clinical condition of Fontan patients. METHODS: Flow measurements using phase contrast magnetic resonance imaging (MRI) were performed in the superior and inferior vena cava (SVC, IVC) in 61 Fontan patients. Median postoperative follow-up time was 6.7 (0.6-14.1) years; median age at MRI was 11.6 (4.0-44.6) years. Eight patients were identified clinically as a subgroup with suboptimal hemodynamics. The effective forward flow of combined SVC and IVC flow volume was defined as the venous cardiac index (vCI, l/min/m(2)). SVC flow ratio was defined as SVC flow in relation to vCI. The vCI and flow distribution between the SVC and IVC were investigated in relation to the hemodynamics and patients' age at MRI. RESULTS: Venous flow return through the SVC was 1.1 (0.6-3.4) l/min/m(2) and through the IVC 1.8 (0.6-3.2) l/min/m(2); total vCI was 3 l/min/m(2) (1.2-5.1). Patients with suboptimal Fontan hemodynamics showed significantly lower IVC flow return (median of 1.5 vs. 1.9 l/min/m(2), p = 0.027) and increased SVC flow ratio (0.56 vs. 0.35, p = 0.005) in comparison to those with good clinical condition. The total vCI decrease was correlated with older patient age (r = 0.575, p < 0.001). CONCLUSIONS: Altered systemic venous flow return is associated with suboptimal Fontan hemodynamics and seems to progress with patients' age and long-term follow-up after Fontan operation. Thus, MRI flow volume measurements might help in monitoring Fontan patients before the onset of clinical signs of suboptimal hemodynamics.

Pulmonary and caval blood flow patterns in patients with intracardiac and extracardiac Fontan: a magnetic resonance study.

AIMS: We compared in vivo blood flow and pulsatility after different types of Fontan operation using magnetic resonance imaging. MATERIAL AND METHODS: A total of 37 consecutive patients (mean age 19+/-7.9 years, 7.3+/-3.2 years after Fontan operation), 7 with atriopulmonary anastomosis (APC), 18 with intra-atrial lateral tunnel (LTFO) and 12 with extracardiac Fontan (ECFO) were studied using magnetic resonance phase-contrast velocity mapping. Blood flow (volume flow) in the superior vena cava (SVC), inferior vena cava (IVC) and both pulmonary arteries were measured and a pulsatility index was calculated for each vessel. RESULTS: For all modifications, the blood flow distribution between the SVC and IVC was normal (1:2). Patients with APC had a normal pulsatility, a dilated right atrium, partial backward flow in the IVC and physiological blood flow distribution between the pulmonary arteries. LTFO and ECFO patients had no retrograde flow in the IVC, equal blood flow distribution between the pulmonary arteries and very low or absent pulsatility. CONCLUSIONS: MRI allows hemodynamic quantification and characterization of various types of Fontan modifications and may be a valuable tool to predict Fontan failure. Despite showing normal pulsatility, patients with APC have right atrial dilatation and partial backward flow in the IVC, demonstrating suboptimal Fontan circulation. LTFO and ECFO both produce unidirectional antegrade flow in the IVC but pulsatility is very low or absent, which may promote poor pulmonary artery growth and increase of pulmonary vascular resistance contributing to late Fontan failure.

Early and medium-term results after modified Fontan operation in adults.

OBJECTIVE: Single ventricle palliation is rarely performed in adults and the results are less optimal than in children. In this article we analyze our experience with the modified Fontan operation in this age group. METHODS: Data of 15 consecutive patients with single ventricle with a mean age of 26 (range 16-38) years, who underwent Fontan operation between 3/92 and 1/2000 were retrospectively analyzed. Five patients had previously had an aortopulmonary shunt in childhood and two patients had previously received a bi-directional cavopulmonary shunt as adults. Eleven patients were preoperatively in NYHA class III and four in class II. The main factors for the selection of the patients before surgery were well-developed pulmonary arteries with lower lobe index 120+30 mm/m(2), pulmonary artery pressure <18 mmHg, good cardiac function and enddiastolic systemic ventricular pressure <12 mmHg. The lateral tunnel Fontan operation (LTFO) was performed in ten patients and extracardiac Fontan operation (ECFO) in five. A fenestration 4-5 mm in size was constructed in all patients with LTFO and in three of five patients with ECFO. RESULTS: There was one intraoperative and one late death (total mortality 13%). The mean extubation time and hospital stay were 24 h and 21 days, respectively. Severe postoperative complications were observed in three patients (20%). Two LTFO patients out of a total of eight patients (53%) with perioperative arrhythmias received a permanent pacemaker due to bradyarrhythmia. During the median follow-up of 5.0 (range 2.3-10.1) years, four patients developed arrhythmias; one of them had new onset bradyarrhythmia after LTFO and required permanent pacemaker implantation. The median postoperative oxygen saturation was 93% (range 90-98%). NYHA class improved significantly in 12 survivors. Cardiac catheterization (0.5-4 years postoperatively, n=12) showed excellent Fontan hemodynamics in all patients. CONCLUSIONS: The modified Fontan operation can be performed in adults with acceptable early and midterm mortality and morbidity and leads to either complete or marked relief of cyanosis and enhanced exercise tolerance in all survivors. Postoperative arrhythmias are one of the main drawbacks but the incidence of arrhythmias after ECFO seems to be lower. The long-term follow-up has yet to be established.

Preliminary analysis of arrhythmias after the Fontan operation with extracardiac conduit compared with intra-atrial lateral tunnel.

BACKGROUND: It is to be expected that avoidance of the atrial suture line during extracardiac Fontan operation (ECFO) decreases the risk of postoperative arrhythmias. METHODS: Two groups of consecutive patients (23 with lateral tunnel (LTFO) and 24 with extracardiac conduit) who underwent successful Fontan operations between 5/93 and 10/98 were comparatively analyzed. All patients had postoperatively standard ECG and 24-hour monitoring. During follow-up, all patients had 2 - 8 (mean 3) standard ECG recordings per year and 76 % of the patients a 24-hour Holter ECG once a year. RESULTS: Median follow-up after ECFO and LTFO was 2.4 years and 4.5 years, respectively. The incidence of supraventricular tachyarrhythmias and bradyarrhythmias after ECFO versus LTFO was lower early after operation and during follow-up (p < 0.05). In follow-up, 20 ECFO patients (91 %) versus 11 patients after LTFO (52 %) remained in sinus rhythm (p < 0.01). Pacemaker insertion was required in 7 (33 %) LTFO patients but none of the ECFO patients (p < 0.01). CONCLUSIONS: The extracardiac Fontan operation decreases the incidence of early and medium-term postoperative arrhythmias. Comparative long-term results are not yet available.

A rare complication of laparoscopic surgery: iatrogenic arteriovenous fistula with high-output cardiac failure.

SUMMARY: The authors report a 19-year-old man with cardiomegaly and high-output cardiac failure resulting from a hemodynamically significant arteriovenous fistula that was diagnosed 18 months after laparoscopic surgery for an inguinal hernia. The diagnosis was established on clinical examination and by ultrasonography and was confirmed by cardiac catheterization and angiography. The fistula was closed surgically by direct venous suture and reconstruction of the iliac artery with a polytetrafluoroethylene patch. The surgical repair achieved complete closure of the fistula with rapid normalization of cardiac size and function within 8 days.

Right pulmonary artery-to-left atrium communication: a rare cause of systemic cyanosis.

Direct communication between the right pulmonary artery and the left atrium is a rare congenital vascular malformation. The clinical diagnosis is difficult, and preoperative angiography is essential. We treated this anomaly successfully with surgery and the use of cardiopulmonary bypass in an 11-year-old boy. Surgery provides a complete cure for this anomaly.

Early experience with extracardiac Fontan operation.

BACKGROUND: The extracardiac Fontan (ECFO) operation has gained more widespread use over last decade. In this article we analyze our early experience with ECFO. METHODS: Thirty-three patients underwent ECFO at median age 4.1 years. Normothermic perfusion with the heart beating was used in 24 patients and cardioplegia in 7. Fenestration was not performed in the last 16 patients who underwent surgery without cardioplegia. RESULTS: The hospital mortality was 6% (2 patients). Necessity or duration of inotropic support, duration of mechanical ventilation, intensive care unit and hospital stay, and incidence of prolonged pleural effusions of patients operated on without cardioplegia were shorter and the rate of complications in these patients was lower than in patients who underwent cardioplegia. CONCLUSIONS: Our preliminary experience shows that ECFO can be performed in many patients with normothermic cardiopulmonary bypass and without cardioplegia and fenestration. Avoidance of cardioplegia seems to decrease postoperative morbidity. Incidence of early postoperative arrhythmias is low. Despite encouraging early results, longer follow-up is necessary to prove the real advantages of ECFO.

Optimal conduit size for extracardiac Fontan operation.

BACKGROUND: Lack of conduit growth potential and thrombogenicity are the main drawbacks of the extracardiac Fontan operation (ECFO). Optimal size of the conduit according to the patients age and inferior vena cava diameter has not been established. OBJECTIVES: We set out to ascertain whether the optimal dimensions of the conduit could be determined before an ECFO. METHODS: Actual and expected age-related inferior vena cava diameters were compared with the extracardiac conduit diameter in 20 patients after ECFO. In 50 other pediatric and adult patients, the distance between intrapericardial part of the inferior vena cava and the undersurface of the right pulmonary artery (IVC-RPA) was measured. Cases of conduit thrombosis were analyzed. RESULTS: The actual diameter of the inferior vena cava was variable and has a weak correlation with anthropometric data and expected diameter (R=0.07-0.23, P=0.32-0.76). The IVC-RPA distance correlated with height (R=0.87, P=0.0001), but was also variable. At the age of 2-4 years and body weight 12-15 kg IVC diameter and IVC-RPA distance are equal to 60-80% of adult values. Conduit thrombosis developed in two patients with unfavorable Fontan hemodynamics and oversized conduits. CONCLUSIONS: Considering the inferior vena cava size, ECFO may be performed at the age of 2-3 years and at a body weight 12-15 kg, when a hemodynamically optimal almost adult sized conduit can be implanted. Optimization of the conduit is necessary on the basis of the actual inferior vena cava diameter and IVC-RPA distance. Anticoagulation postoperatively should be considered to prevent conduit thrombosis in patients with suboptimal Fontan circulation

Correction of cor triatriatum sinistrum in a Jehovah's Witness infant.

A cor triatriatum sinistrum was successfully treated by operation in a 14-week-old infant of a Jehovah's Witness family. The child was pretreated with erythropoietin until a hemoglobin level of 14 g/dl was obtained. There was no cardiac catheterization before the operation. The operation was performed with cardiopulmonary bypass. No blood products were transfused and the hemoglobin level after performing modified ultrafiltration was 11.5 g/dl. The infant was extubated on the same day and discharged from our institution on the eighth day after surgery. Two years after surgery the child is in sinus rhythm and is developing well.