Secundum atrial septal defect in adults: a practical review and recent developments

Secundum atrial septal defect (ASDII) is a common congenital heart defect that causes shunting of blood between the systemic and pulmonary circulations. Patients with an isolated ASDII often remain asymptomatic during childhood and adolescence. If the defect remains untreated, however, the rates of exercise intolerance, supraventricular arrhythmias, right ventricular dysfunction and pulmonary arterial hypertension (PAH) increase with patient age, and life expectancy is reduced. Transcatheter and surgical techniques both provide valid options for ASDII closure, the former being the preferred method. With the exception of those with severe and irreversible PAH, closure is beneficial to, and thus indicated in all patients with significant shunts, regardless of age and symptoms. The symptomatic and survival benefits conferred by defect closure are inversely related to patient age and the presence of PAH, supporting timely closure after diagnosis. In this paper we review the management of adult patients with an isolated ASDII, with a focus on aspects of importance to the decision regarding defect closure and medical follow-up.     

Cardiomyocyte apoptosis in the right auricle of patients with ostium secundum atrial septal defect diseases

Ostium secundum atrial septal defect (osASD) is one of the most commonly occurring cardiac malformations. Although some embryological pathways have been elucidated, the molecular etiologies of ASD are not fully understood. Previous microarray analysis in our laboratory identified differentially expressed genes between osASD and normal right auricular myocardium. Of the 1056 differentially expressed genes, 14 genes were related to apoptosis: eight pro-apoptotic genes were up-regulated and six anti-apoptotic genes were down-regulated in ASD patients. In the current study, we utilized semi-quantitative RT-PCR, electron microscopy, TUNEL and flow cytometry to further understand the role of apoptosis in the atrium of osASD patients. RT-PCR results confirmed differential expression data from previous microarray studies. Additionally, while apoptosis was detected in the right auricular myocardium of all osASD patients, it was absent in controls. These data suggested apoptosis may play an important role in the pathogenesis of osASD or possibly occurs as a consequence of volume overload and hemodynamic changes in right atrium of osASD patients.     

Association of cleft lip and atrial septal defect in mice: a preliminary report.

Newborn A/J and CL/Fr mice with congenital cleft lip usually have an atrial septal defect of the secundum type, often associated with cyanosis. Their littermates without cleft lip rarely have a septal defect. The atrial septal defect results from a delay in growth of the atrial septum primum.     

A technical modification for the repair of ventricular septal defect

For the repair of ventricular septal defect, we have devised a technical modification that makes use of a mushroom-shaped patch and a left ventricular buttress. Since 1972, we have applied this technique in 97 patients, most of whom had moderate to severe hypertension before surgery. Twelve early deaths and one late death resulted. The major complications included two cases of permanent heart block, nine cases of temporary heart block, and two suspected cases of residual shunting. The method has proven effective in preventing a recurrence and in lowering the incidence of surgically produced heart block.     

Association between polymorphisms in AXIN1 gene and atrial septal defect

Abstract

Context: AXIN1 is a central component of Wnt signalling pathway which is essential for embryonic development.

Objective: To investigate whether polymorphisms of AXIN1 contribute to ASD susceptibility.

Materials and methods: Three tag SNPs (rs12921862, rs370681 and rs1805105) in AXIN1 were genotyped in 208 ASD patients and 302 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in a Chinese population.

Results: Significantly increased ASD risk was observed to be associated with the A allele of rs12921862 (p?<?0.0001, OR?=?3.096, 95% CI?=?2.037–4.717). Increased ASD risk was observed to be associated with rs370681 in a codominant (p?=?0.043, OR?=?1.52, 95% CI?=?1.04–2.22) and overdominant model (p?=?0.016, OR?=?1.57, 95% CI?=?1.08–2.27).

Conclusion: rs12921862 and rs370681 may contribute to ASD susceptibility.     

Hydrogen peroxide and catalase are inversely related in adult patients undergoing cardiopulmonary bypass: implications for antioxidant protection

Adult patients undergoing cardiopulmonary bypass (CPB) surgery are subjected to increased oxidative stress and show a spectrum of lung injury. Increased levels of hydrogen peroxide (H2O2) are often seen during episodes of oxidative stress, such as the use of high FiO2s, and this molecule plays a key role in the formation of highly damaging oxidants such as the hydroxyl radical. Oxidative damage to plasma proteins was assessed by measuring free thiol groups, and antioxidant protection against H2O2 by measuring catalase activity. CPB patients (n = 39) receiving either 100% or 50% oxygen at the end of bypass were studied by measuring levels of H2O2 in breath condensate and levels of catalase in their plasma, and comparing these to pre-bypass levels. Post-bypass, all CPB patients exhaled significantly lower levels of H2O2 (P < 0.0001) at a time when they had significantly increased activity (0.809 +/- 0.11 versus 1.688 +/- 0.18 U/mg protein) of catalase in their plasma. There were no significant differences in these parameters between the 100% and 50% oxygen groups. At a time when oxidative stress is greatest, there appears to be a corresponding plasma increase in the antioxidant catalase. Whether this change is fortuitous or a response to oxidative stress is at present under consideration.     

Hydrogen peroxide and catalase are inversely related in adult patients undergoing cardiopulmonary bypass: implications for antioxidant protection

Abstract

Adult patients undergoing cardiopulmonary bypass (CPB) surgery are subjected to increased oxidative stress and show a spectrum of lung injury. Increased levels of hydrogen peroxide (H₂O₂)are often seen during episodes of oxidative stress, such as the use of high FiO₂s, and this molecule plays a key role in the formation of highly damaging oxidants such as the hydroxyl radical. Oxidative damage to plasma proteins was assessed by measuring free thiol groups, and antioxidant protection against H₂O₂ by measuring catalase activity. CPB patients (n =39) receiving either 100% or 50% oxygen at the end of bypass were studied by measuring levels of H₂O₂ in breath condensate and levels of catalase in their plasma, and comparing these to pre-bypass levels. Post-bypass, all CPB patients exhaled significantly lower levels of H₂O₂ (P < 0.0001) at a time when they had significantly increased activity (0.809 ± 0.11 versus 1.688 ±18 U/mg protein) of catalase in their plasma. There were no significant differences in these parameters between the 100% and 50% oxygen groups. At a time when oxidative stress is greatest, there appears to be a corresponding plasma increase in the antioxidant catalase. Whether this change is fortuitous or a response to oxidative stress is at present under consideration.     

Autosomal dominant atrial septal defect of ostium secundum type. Report of three families

The authors report on three Sicilian families with 17 individuals (10 females and 7 males) in successive generations affected by atrial septal defect of ostium secundum type (S-ASD) without conduction defect. The anomaly was inherited as an autosomal dominant trait. Cytoplasmic inheritance could be excluded, the anomaly being transmitted also by fathers. Familial S-ASD is probably more frequent than commonly reported since cardiological examination of the relatives is not routinely performed in every case of apparently sporadic ASD.     

Haemodynamic and functional consequences of the iatrogenic atrial septal defect following Mitraclip therapy

Percutaneous MitraClip placement for treatment of severe mitral regurgitation in high surgical risk patients is a commonly performed procedure and requires a transseptal puncture to reach the left atrium. The resulting iatrogenic atrial septal defect (iASD) is not routinely closed, yet the haemodynamic and functional consequences of a persisting defect are not fully understood. Despite positive effects such as acute left atrial pressure relief, persisting iASDs are associated with negative consequences, namely significant bidirectional shunting and subsequent worse clinical outcome. Percutaneous closure of the iASD may therefore be desirable in selected cases. In this review we discuss the available literature on this matter.     

Relation between zinc, copper, and magnesium concentrations following cardiopulmonary bypass and postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting

Atrial fibrillation is the most frequently encountered arrhythmia following cardiac surgery. Since the essential trace elements zinc, copper, and magnesium are suspected to have an effect on postoperative atrial fibrillation, the concentrations of these elements were determined by flame atomic absorption spectrophotometry in the plasma of 60 patients undergoing elective coronary artery bypass grafting. Blood samples were collected every 30 min during cardiopulmonary bypass and postoperatively. Plasma concentrations of copper, zinc, and magnesium were measured with flame atomic absorption spectrophotometry. All patients were monitored by continuous electrocardiography until they became outpatients or immediately after atrial fibrillation had taken place. Atrial fibrillation occurred in 13 of the 60 patients, corresponding to 21.7%. The zinc and copper concentrations at postoperative days 1 and 3 were significantly different (P < 0.05) between patients with and without atrial fibrillation. The concentrations of zinc following cardiopulmonary bypass recovered more slowly in patients with postoperative atrial fibrillation than in patients without it. Whether or not supplemental zinc could lower the incidence of postoperative atrial fibrillation should be evaluated in future prospective randomized clinical trials.     

实时三维超声心动图评价房间隔缺损患者手术前后心室收缩功能

目的 应用实时三维超声心动图(RT-3DE)研究房间隔缺损(ASD)患者行内科介入手术前后左、右室心肌收缩变化的相关关系.方法 应用RT-3DE技术对34例ASD患者术前、术后1周以及35例正常受检者(对照组)的左、右室舒张末期容量(LVEDV/RVEDV),左、右室收缩末期容量(LVESV/RVESV),左、右室每搏量(LVSV/RVSV)及左、右室射血分数(LVEF/RVEF)进行统计分析.结果 术前,ASD患者LVEDV、LVSV、LVEF均小于对照组(均P＜0.05),RVEDV、RVESV、RVSV、RVEF均大于对照组(均P＜0.05);术后1周内,ASD患者LVEDV、LVSV、LVEF均较术前增大(均P＜0.05),RVEDV、RVSV、RVEF均较术前减小(均P＜0.05);ASD患者术后的LVEDV、LVESV、LVSV、LVEF与对照组比较均无统计学意义(均P＞0.05),而RVEDV、RVESV、RVSV均大于对照组(P＜0.05);ASD患者术后左、右室的射血分数变化之间均无相关性.结论 行内科介入的ASD患者术后初期左、右室收缩功能即恢复到正常水平,术后左、右室射血分数的变化之间均无相关性.