Interatrial Shunt Research Articles

The Incidence and Long-Term Clinical Outcome of Iatrogenic Atrial Septal Defects Secondary to Transseptal Catheterization With a 12F Transseptal Sheath

Studies assessing the presence of a residual iatrogenic atrial septal defect (iASD) after transseptal catheterization with 8F transseptal sheaths have suggested that the majority of these iASDs close within 6 months. However, these studies have been limited by small patient numbers and short follow-up. Additionally, there are a number of novel catheter procedures in interventional cardiology and electrophysiology that use larger transseptal sheaths. The objective of this study was to assess the incidence of and complications associated with iASDs in a large cohort of patients undergoing transseptal catheterization with a 12F transseptal sheath. Patients (n=253) without a preexisting interatrial shunt undergoing WATCHMAN implantation as part of the PROTECT AF study were included in this current study. Patients underwent transesophageal echocardiography with echo-contrast immediately after the procedure and at 45 days and 6 months and 12 months. Eighty-seven percent of patients had an iASD immediately after the procedure, the majority of which sealed by 6 months (incidence of iASD, 34% at 45 days, 11% at 6 months, 7% at 12 months). Whereas the majority of iASDs were >3 mm in diameter immediately after the procedure, the minority of iASD were >3 mm during the follow-up period. Additionally, interatrial shunting was predominantly left-to-right when an iASD was present. There was no significant difference in the rate of stroke and/or systemic embolism during the follow-up period in patients with or without iASD. Transseptal catheterization procedures with a large-diameter transseptal sheath have a high spontaneous closure rate of iASDs that is not associated with an increased rate of stroke/systemic embolization during long-term follow-up.

Veno-venous extracorporeal membrane oxygenation with interatrial shunting: A novel approach to lung transplantation for patients in right ventricular failure

This study evaluated the effectiveness of an atrial septostomy with veno-venous extracorporeal membrane oxygenation in alleviating high afterload right ventricular dysfunction while providing respiratory support. This technique could be applied as a bridge to lung transplantation. Sheep (56±3 kg) underwent a clamshell thoracotomy and hemodynamic instrumentation, including right ventricular pressure and cardiac output. Sheep with and without tricuspid insufficiency (n=5 each) were examined. While sheep were on extracorporeal membrane oxygenation, right ventricular failure was established by banding the pulmonary artery until cardiac output was 40% to 60% of baseline. An extracardiac atrial shunt was created with modified vascular grafts to examine the effect of shunt flow on hemodynamics. Hemodynamic data were thus collected at baseline, during right ventricular failure, and for 1 hour at 100% (fully open), 70%, 50%, and 30% of baseline shunt flow. Cardiac output was returned to baseline values (tricuspid insufficiency: 5.2±0.2 L/min, without tricuspid insufficiency: 5.3±1.2 L/min) with 100% shunt flow (tricuspid insufficiency: 4.8±1.1 L/min, without tricuspid insufficiency: 4.8±1.0 L/min; P=.15) but remained significantly lower than baseline at 70% to 30% shunt flow. At 100% shunt flow, tricuspid insufficiency shunt flow was 1.4±0.8 L/min and without tricuspid insufficiency shunt flow was 1.7±0.2 L/min. Right ventricular pressure was significantly elevated over baseline values at all shunt flows (P<.001). In the group without tricuspid insufficiency, all sheep died beginning at the 70% shunt condition, whereas all animals with tricuspid insufficiency survived the entire experiment. Normal arterial blood gases were maintained under all conditions. An atrial septostomy accompanied by veno-venous extracorporeal membrane oxygenation is capable of eliminating right ventricular failure while maintaining normal arterial blood gases if sufficient shunt flows are achieved. The presence of tricuspid insufficiency improves the efficacy of the shunt.

148 Hypoxemia due to right-to-left interatrial shunt with no pulmonary artery hypertension. One centre experience with transcatheter closure including 63 consecutive patients

Hypoxemia related to interatrial right-to-left shunt may have a significant impact on exercise tolerance. We report here one centre experience in transcatheter closure of interatrial RL shunt. From August 1995 to 2009, 63 consecutive patients (37 females and 26 males, mean age 54 ± 24 years), underwent transcatheter closure of interatrial RL shunt because of cyanosis and shortness of breath at exercise. Associated malformations were modified Fontan (n = 4), Ebstein anomaly (n = 1), RV hypoplasia (n = 1), pectus excavatum (n = 2), aortic aneurysm (n = 1). Ten pts had a past history of stroke. A real platypnea-orthodeoxia syndrome was noticed in only 17 pts. The vast majority of patients had cardiac catheterization under local anaesthesia with a sole fluoroscopic control. None of them had pulmonary artery hypertension. Transcatheter closure was performed with a Sideris device (n = 10), a PFO Amplatzer occluder (n = 40), an ASD Amplatzer occluder (n = 8), a Cardioseal device (n = 3), a VSD Amplatzer occluder (n = 2). Device implantation succeeded in all but two (1 Sideris and 1 Cardioseal device). The fluoroscopic time was 12 ± 8 minutes. All patients had better clinical tolerance after closure with an oxygen saturation > 92%. All underwent serial echocardiographic follow-up with bubble study. One month after implantation, no shunt was noticed in all but 6 pts (tiny RL shunt). In 5 of these remaining pts, the 6-month control did not see any residual shunting. Transcatheter closure of interatrial RL shunt responsible of cyanosis is an effective and a safe method. Many devices using a double disk system can be employed and provide excellent results. The classic platypnea-orthodeoxia syndrome is observed in < 25% of this population.

Platypnea-orthodeoxia-like syndrome in a septic newborn with late appearance of right congenital diaphragmatic hernia

Introduction. Cyanosis and dyspnoea with interatrial shunting of blood occurring without change in body position are termed platypnea-orthodeoxia-like syndrome.Case presentation. We describe a female newborn with sepsis, who developed cyanosis. Two weeks after the initial appe-arance of cyanosis she presented with a right-sided diaphragmatic hernia, which was not seen on the initial X-rays. The hernia was surgically repaired. Her postoperative course was uneventful.&nbsp;Conclusions. In our case, interatrial shunting of blood was presumably caused by disturbed intrathoracic pressures. Positive pressure ventilation and sepsis may also contribute to the development of such a syndrome.

Risk and fate of residual interatrial shunting after transcatheter closure of patent foramen ovale: a long term follow up study

BackgroundPercutaneous transcatheter closure of patent foramen ovale (PFO) in cryptogenic stroke is an alternative to medical therapy. There is still debate on different outcome for each currently available device. The impact of residual shunting after PFO-clo- sure on recurrent arterial embolism is unknown.Aims(i) To evaluate the prevalence of residual interatrial shunting after device- closure of PFO, (ii) to identify risk factors predicting residual interatrial shunting after device implantation, and (iii) to investigate the outcome of patients after PFO-closure during long- term follow- up (FU).Methods and resultsBetween 2000- 2005 PFO-closure was performed in 124 patients using four different devices: Amplatzer PFO-(n = 52), CardioSeal (n = 33), Helex (n = 23) and Premere (n = 16) occluder. All patients underwent serial contrast-enhanced transesophageal echocardiography (TEE) for 24 months after PFO- closure; clinical FU was at minimum 5 years up to 9.75 years (mean 6.67 ± 1.31 years). Overall-closure rate was 87% at 2 years, device-specific closure time curves differed significantly (p-logrank = 0.003). Independent risk factors for residual-shunting were implantation of a Helex occluder (hazard ratio [HR] 12.6, 95% confidence interval [CI] 2.6- 57.4, p = 0.002), PFO- canal- lengths (HR 1.2, 95%CI 1.1- 1.3, p = 0.004) and extend of atrial-septal-aneurysm (HR 1.1, 95%CI 0.9- 1.3; p = 0.05). 4 (3.2%) arterial embolic events occurred during a FU-period of 817.2 patient-years, actuarial annual thromboembolic-risk was 0.49%. All ischemic events were not related to residual PFO-shunting or device-related thrombus- formation.ConclusionSuccess rates of PFO- closure are mainly dependent on occluder-type, extend of concomitant atrial-septum-aneurysm and PFO-canal- length. Importantly, residual shunting after PFO-closure was not associated with recurrence of arterial embolism during long-term follow-up.

Platypnoea-orthodeoxia syndrome due to right to left interatrial shunting despite normal intracardiac pressures

Ceylon Medical Journal (CMJ) is a peer-reviewed, open access journal published quarterly by the Sri Lanka Medical Association in the last week of March, June, September and December each year. The mission of the CMJ is to promote the science and art of medicine and betterment of public health. The Journal publishes original papers and commentaries which have relevance to medicine and allied sciences. The CMJ is committed to maintaining and conforming to the editorial and ethical standards recommended by the International Committee of Medical Journal Editors.

Prediction and perinatal management of severely restrictive atrial septum in fetuses with critical left heart obstruction: Clinical experience using pulmonary venous Doppler analysis

Up to 20% of fetuses with critical left heart obstructive lesions have highly restrictive or intact atrial septae. Although this condition is generally tolerated in utero, severe hypoxemia requiring emergency atrial septostomy often develops in newborns with restrictive atrial septum. We have reported that a pulmonary venous Doppler forward/reverse time-velocity integral ratio less than 5 is highly predictive of the need for emergency atrial septostomy. We reviewed our subsequent experience using fetal pulmonary venous Doppler patterns to identify and manage fetuses with critical left heart obstruction and suspected restrictive atrial septum. A retrospective review of neonates with a prenatal diagnosis of critical left heart obstruction was performed. Fetal restrictive atrial septum was defined as a small/absent interatrial shunt on 2-dimensional imaging and a mean forward/reverse time-velocity integral ratio of 5 or less. Available serial pulmonary venous Doppler data were reviewed. The primary outcome was postnatal confirmation of restrictive atrial septum or severe left atrial hypertension. Eight of 39 infants had a forward/reverse time-velocity integral ratio of 5 or less. A restrictive atrial septum was confirmed postnatally in 6 of 8 infants. Overall, a forward/reverse time-velocity integral ratio of 5 or less had a sensitivity of 100% and specificity of 94% for emergency atrial septostomy. Lowering the cutoff value to 3 or less would have eliminated false-positive diagnoses in the current series. Serial data demonstrated that late second trimester values did not change in later gestation with respect to either threshold in 30 of 32 fetuses. In the fetus with critical left heart obstruction, a threshold forward/reverse time-velocity integral ratio of 3 or less optimizes specificity for predicting emergency atrial septostomy. Most late second trimester values will not change over time with regard to threshold levels.

Improvements in exercise performance after surgery for Ebstein anomaly

The purpose of this longitudinal study was to assess improvements in exercise performance and quality of life in patients with Ebstein anomaly after surgical intervention. In 21 patients with Ebstein anomaly (between 6 and 59 years of age; 16 female, 5 male) who underwent surgery for tricuspid regurgitation and, if present, closure of an interatrial shunt, a cardiopulmonary exercise test and a quality-of-life assessment by the Medical Outcomes Study 36 item short form was performed prior to and 6 to 18 months after surgery. After surgery, peak oxygen uptake increased from 68.4% of predicted to 77.3% of predicted (P = .009), and ventilatory efficiency (VE/VCO(2) slope) improved from 32.5 to 29.3 (P = .001). In 14 patients with additional interatrial shunt closure, oxygen saturation improved from 95% to 99% at rest (P = .003) and from 88% to 99% under peak exercise (P = .003). Improvements in VE/VCO(2) slope were similar in patients who had undergone primary surgery (P = .005) or reoperation (P = .018). Increase in exercise capacity was also similar in both groups but failed significance in both (primary surgery, P = .064; reoperation, P = .063). There was no difference between tricuspid valve repair and replacement in the short-term follow-up. Self-estimated quality of life was fairly good prior to and after surgery. Only in the single question about health transition at follow-up did the patients confirm an improved situation after surgery. Patients with Ebstein anomaly and severe tricuspid regurgitation draw clinical benefit from surgical intervention as measured on exercise testing. This holds true for primary surgery and for reoperation.

Complete Intraoperative Transesophageal Echocardiogram Imaging of the Extent of an Inferior Vena Cava Mass Guides Surgical Management

Complete Intraoperative Transesophageal Echocardiogram Imaging of the Extent of an Inferior Vena Cava Mass Guides Surgical Management

Enhanced detection of patent foramen ovale by systematic transthoracic saline contrast echocardiography

ObjectiveWe aimed to evaluate the effectiveness of transthoracic saline contrast echocardiography (TSCE) in detecting patent foramen ovale (PFO). BackgroundTransesophageal echocardiography (TEE) is semi-invasive and not ideal for PFO screening. Methods112 patients (48 males, 46±14years) with suspected PFO received intravenous agitated-saline contrast at rest and stress (strain and release phases of Valsalva maneuver and coughing). The presence of interatrial shunting was defined as >5 bubbles appearing in the left heart within 3 cardiac cycles. The stage of the maneuver at which interatrial shunting occurred was recorded. The TSCE findings were validated by TEE. ResultsTEE identified PFO in 45% of patients. The sensitivities of TSCE in detecting PFO at rest, during strain and release of Valsalva maneuver, and coughing were 12.0%, 38.0%, 80.0% and 94.0% respectively (each p<0.05 when compared to previous stage). Specificities were similar and >95% for all stages. Moreover, the release phase of the maneuver improved the diagnostic accuracy [defined as (number of true positives+true negatives) divided by total in sample] with incremental value over the preceding strain phase (89.2 vs. 70.5%, p<0.001). ConclusionsPatent foramen ovale can be identified confidently with proper conduct of the Valsalva maneuver during the transthoracic saline contrast echocardiography.

Oclusão percutânea de comunicação interatrial pelo sistema único de saúde: uma opção economicamente viável

Atrial septal defect (ASD) is one of the most frequent congenital malformations, representing 5% to 10% of all congenital heart defects. The most common type is the ostium secundum ASD (OS ASD), and represents 75% of these malformations. When diagnosed late or left untreated, in addition to abnormalities in the clinical examination, there may be heart failure, cardiac arrhythmias, mitral insufficiency, right ventricular overload and pulmonary hypertension. In advanced cases with severe pulmonary hypertension and interatrial shunt reversal (right to left), there is cyanosis, which indicates severe cardiopulmonary disease and increased mortality. In the last decades, with the improvement of percutaneous techniques and devices, the possibility of percutaneous treatment of congenital defects has increased dramatically. Several studies have shown excellent early and long-term results of percutaneous atrial septoplasty. In addition to providing greater comfort for patients, lower complication rates, less in-hospital and extra-hospital recovery time and efficacy similar to that of surgical atrial septoplasty in developed countries, it is definitely the most economic option. There is no doubt that in the near future, the cost-effectiveness ratio of this procedure will also be observed in developing countries such as Brazil, where the cost of the prosthesis is, to this day, the major obstacle for the standardization of this procedure and the amounts paid for surgical procedures are outdated.

Mutations in the cardiac transcription factor GATA4 in patients with lone atrial fibrillation

Familial recurrence of atrial fibrillation (AF) is reported in up to 15% of patients with lone AF. Recently, it was proposed that congenital defects in the morphogenesis of the pulmonary vein myocardium are involved in genetic pathogenesis of lone AF. GATA4 is a cardiac transcription factor essentially involved in myocardial development. Mutations in GATA4 are associated with congenital cardiac malformations. To investigate whether GATA4 mutations represent a genetic origin for AF the coding region of GATA4 was sequenced in 96 patients with lone AF. We found a GATA4 mutation (M247T) in a patient with familial lone AF and atrial septal aneurysm without interatrial shunts. The mutation affects a deeply conserved domain adjacent to the first zinc finger domain of GATA4 and was not reported before. A second GATA4 mutation (A411V) was found in a female patient with sporadic lone AF. This variant was previously reported in patients with cardiac septal defects. However, no anomalies of the atrial or ventricular septa were noted in the AF patient harboring A411V. We report for the first time that mutations in the cardiac transcription factor GATA4 may represent a genetic origin of lone AF. The study proposes that lone AF may share a common genetic origin with congenital cardiac malformations.

Unusual treatment of patent foramen ovale after pneumonectomy

To the Editors: As has often been said by Dr Harold C. Urschel Jr, pneumonectomy is “a disease” in itself. It is a major procedure with frequent perioperative complications such as empyema, fistula, cardiac problems or respiratory insufficiency. Besides frequent post-operative cardiac and respiratory complications, long-term sequelae are also seen. After pneumonectomy, anatomical adaptations occur with repositioning of intrathoracic structures. Common changes are elevation of the hemidiaphragm (especially after phrenic nerve damage), mediastinal shift, diminished intercostal space and filling of the postpneumonectomy space with fluid. Infrequently, these adaptations may lead to invalidating complications. The most frequent complication is the so-called post-pneumonectomy syndrome caused by compression of the remaining bronchus against the vertebral column or aorta. Since positioning of the organs may take years, symptoms may occur even after 5–10 yrs. In this letter, we will focus on a rare complication, shunting through a patent foramen ovale (PFO), as a long-term complication of right-sided pneumonectomy or bilobectomy. Only a few cases have been published, although this complication might be under-reported since the diagnosis of PFO is difficult, especially after pneumonectomy. This letter describes three patients who were diagnosed with shunting through a PFO following lung resection. In these patients, right ventricular compression by the elevated right hemidiaphragm was the main cause of PFO and surgical plication of the right hemidiaphragm was sufficient to close the PFO. ### Patient A A 67-yr-old male underwent a right-sided pneumonectomy 14 yrs earlier because of a bronchial carcinoid. Partial resection of the pericardium with transection of the phrenic nerve were needed for complete resection He developed progressive dyspnoea during exercise and when bending down. Echocardiography demonstrated a right-to-left interatrial shunt when increasing intra-abdominal pressure (valsalva manoeuvre) with a shunt fraction of 18%. Further analysis with right heart catheterisation at our institution showed a mean right atrial resting pressure ( P ra …

Patent oval foramen transcatheter closure: results of a strategy based on tailoring the device to the specific patient’s anatomy

Usually the literature results for device-closure of patent oval foramen concern a single type of device or different devices implanted without anatomical preferences. We propose a strategy of device type and selection based on intra-cardiac echocardiography measurements of inter-atrial septum characteristics. We prospectively enrolled 100 consecutive patients with a mean age of 43 plus or minus 15.5 years, 68 females, who had been referred to our centre for catheter-based closure of inter-atrial shunts over a 48-month period. On the basis of intra-cardiac echocardiography findings the operators selected the Amplatzer Occluder family (AGA Medical Corporation) or the Premere Closure System (St Jude Medical Inc.). Determinants of the selection process were presence and extension of atrial septal aneurysm, tunnel length, rims length, and thickness, presence of additional fenestrations. According on intra-cardiac echocardiography study, 26 patients have a long channel patent oval foramen, 44 patients had a large atrial septal aneurysm (more than four RL), 24 patients had a moderate atrial septal aneurysm (more than two RL but less than four right-to-left), and six patients had hypertrophic rims. Thus, the Amplatzer PFO Occluder was selected in 24 patients, the Amplatzer ASD Cribriform Occluder in 44 patients, and the Premere device in 32 cases. No aortic erosions, device thrombosis, or recurrent ischaemic cerebral events were observed. Pre-discharge and follow-up occlusion rates were 91% and 96%, respectively. Our study suggested that such strategy driven from identification and measurements of the right atrium and inter-atrial septum components resulted in low complications and high-success rates, mandatory conditions when facing with otherwise healthy subjects, such as the patients with patent oval foramen.

Transthoracic second harmonic two- and three-dimensional echocardiography for detection of patent foramen ovale

Transoesophageal echocardiography (TEE) with contrast administration is still considered as the reference method for the detection of patent foramen ovale (PFO) with interatrial shunt, but it is a semi-invasive exam. The aim of the present study is to evaluate a role of two- and three-dimensional transthoracic echocardiography (TTE and R3DTE) as a diagnostic alternative to transcranial Doppler ultrasound (TCD) and TEE for detection of atrial right-to-left shunt. Seventy-five patients with history of cerebrovascular events were subjected to four diagnostic examinations: TCD, TTE, R3DTE, and TEE, with bubble contrast. Bubbles in the left atrium within three cardiac cycles were considered diagnostic for PFO and later as a pulmonary shunt. Greater than 20 bubbles in the left atrium were considered a large shunt and <20 a small shunt. Every exam was read blinded to the results of the others. From the 75 enrolled patients, 62 (82.6%) patients showed right-to-left shunt with TEE; the results were also positive in 53 patients using TCD (70.6%), in 53 using R3DTE (70.6%), and in 55 using TTE (73.3%) (P = NS). There is a statistically significant superiority for TEE in the capacity of detecting shunts compared with TCD (P < 0.024), TTE (P < 0.018), and R3DTE (P < 0.018). The TEE presents a superior ability to recognize mild/moderate interatrial shunts respect to other exams (P = 0.003), without differences for shunts of high degree. In comparison to the TEE, the sensitivity is 89% for TTE, 88% for R3DTE, and 85% for TCD; the specificity is 100% for TTE and R3DTE, and 90% for TCD; the positive predictive value is 100% for TTE and R3DTE, and 98% for TCD; and the negative predictive value is 65% for TTE, 65% for R3DTE, and 53% for TCD. Considering only for mild/moderate shunts, the diagnostic accuracy is clearly inferior (sensitivity 63% for TTE, 58% for R3DTE, and 53% for TCD). In this cohort of patients, TEE confirms the role of 'gold standard' exam for the detection of PFO; the non-invasive methods, and the TTE in particular, present a good diagnostic accuracy, but are inferior to the TEE because of the low negative predictive value and the non-optimal detection of small shunts. If the only purpose of TEE is the detection of significative interatrial shunt, TEE can be replaced by TTE. The R3DTE presents a good diagnostic accuracy, provides a better anatomical definition of the interatrial septum, and may have a role in this setting of patients, but does not add a lot to the TTE for the diagnosis.

Population-based Assessment of Familial Inheritance and Neurologic Comorbidities among Patients with an Isolated Atrial Septal Defect

Interatrial shunts, caused by either atrial septal defect (ASD) or patent foramen ovale, have been reported to have a familial association. We sought to examine the familial risk of isolated interatrial shunt and explore associated comorbidities of stroke, transient ischemic attack (TIA), and migraine using a population database. The Utah Population Database is linked to inpatient and outpatient records from the University of Utah Health Science Center. Patients with an interatrial shunt were identified, and those with any other form of congenital heart disease or an inheritable syndrome associated with ASD were excluded. Of the 9452 individuals diagnosed with isolated interatrial shunt, 6179 (65%) had sufficient familial and follow-up data for analysis. Five age/gender matched controls were randomly selected per case. Cases and their relatives were compared with controls to assess the relative risk for each comorbid condition. Relatives of interatrial shunt cases had an increased risk for interatrial shunt: siblings relative risk (RR) 6.98 (95% confidence interval [CI] 5.75-8.48; P < 1.0 x 10(-16)), first-degree RR 5.64 (95% CI 4.76-6.68; P < 1.0 x 10(-16)), and second-degree RR 1.75 (95% CI 1.32-2.32; P= 0.0001). Patients with interatrial shunt were more likely to have a comorbid condition compared with controls (RR 21.3, 95% CI 17.1-26.5; P < 1.0 x 10(-16)). First-degree relatives of cases had an increased risk of TIA (RR 1.70, 95% CI 1.18-2.45; P= 0.0045), but no increase risk of stroke or migraine compared with controls. There is a strong familial inheritance pattern for isolated interatrial shunt, with significantly higher risk of interatrial shunt among affected patients' siblings, first-, and second-degree relatives. Relatives of affected individuals also had a higher risk of TIA, a trend toward an increased risk for stroke, but no increased risk of migraine headache.

Should we close hypoxaemic patent foramen ovale and interatrial shunts on a systematic basis?

Rarely, hypoxaemia is associated with shunt reversal at the atrial level. Closure by interventional catheterization is the treatment of choice but indications and results have been studied insufficiently. To describe our experience with interventional closure of atrial right-to-left shunts described as hypoxaemic and the impact on patient oxygenation and clinical status. Retrospective study in two referral centres, including all patients undergoing closure of interatrial right-to-left shunt associated with hypoxaemia. Since 2001, 21 consecutive patients underwent interventional shunt closure using the "Amplatzer((R)) device"; two patients had atrial septal defect and 19 had patent foramen ovale. Three patients had minor adverse events; two patients have a tiny residual shunt. Transcutaneous oxygen saturation and partial oxygen pressure increased significantly from 86+/-5 to 95+/-3% (p<0.001) and from 49.8+/-6.8 to 82.9+/-30.4mmHg (p=0.001), respectively. Seventeen (80%) patients reported clinical improvement. However, patients with chronic respiratory insufficiency remained more symptomatic, with three deaths after a median follow-up of 35 (6-97) months and 89% remaining in New York Heart Association class III/IV (vs 29% of patients without chronic respiratory insufficiency; p=0.035). Hypoxaemic shunts are treated effectively by transcatheter closure, resulting in functional improvement in patients without respiratory insufficiency. When associated with chronic respiratory insufficiency, hypoxaemia often persists after shunt closure. In such cases, the right-to-left atrial shunt does not seem to be the main cause of hypoxaemia and the indication for closure is questionable.

Should we close hypoxaemic patent foramen ovale and interatrial shunts on a systematic basis?

Summary Background Rarely, hypoxaemia is associated with shunt reversal at the atrial level. Closure by interventional catheterization is the treatment of choice but indications and results have been studied insufficiently. Purpose To describe our experience with interventional closure of atrial right-to-left shunts described as hypoxaemic and the impact on patient oxygenation and clinical status. Method Retrospective study in two referral centres, including all patients undergoing closure of interatrial right-to-left shunt associated with hypoxaemia. Results Since 2001, 21 consecutive patients underwent interventional shunt closure using the “Amplatzer® device”; two patients had atrial septal defect and 19 had patent foramen ovale. Three patients had minor adverse events; two patients have a tiny residual shunt. Transcutaneous oxygen saturation and partial oxygen pressure increased significantly from 86 ± 5 to 95 ± 3% (p Conclusion Hypoxaemic shunts are treated effectively by transcatheter closure, resulting in functional improvement in patients without respiratory insufficiency. When associated with chronic respiratory insufficiency, hypoxaemia often persists after shunt closure. In such cases, the right-to-left atrial shunt does not seem to be the main cause of hypoxaemia and the indication for closure is questionable.

Diagnosis of Inferior Sinus Venosus Atrial Septal Defects Using Transthoracic Three-Dimensional Echocardiography

The authors report the cases of 2 patients with symptoms and signs related to severe pulmonary hypertension. Two-dimensional echocardiography demonstrated defects in the posterior portion of the atrial septum. Transthoracic three-dimensional echocardiography clearly showed inferior sinus venosus atrial septal defects and their relationships with the inferior vena cava, the pulmonary vein, and the muscular border of the fossa ovalis. These 2 cases not only elucidate the potential value of transthoracic three-dimensional echocardiography in delineating the structural characteristics of unusual interatrial shunting but also remind clinicians to be aware of this potentially treatable cardiac defect during workup for pulmonary hypertension.

Interatrial septum puncture in lateral view is the best technique during percutaneous mitral commissurotomy by the Inoue method even in difficult situation

Background There have been no single-center studies that have systematically addressed the acute outcome of Inoue balloon mitral commissurotomy (BMC) performed in a large series of patients. Accordingly, this study sought to examine the impact of operator experience and continuing technical modifications on the success and complication rates of BMC. Methods BMC was performed in 799 patients: 469 patients with pliable mitral valves (group 1) and 330 patients with calcified valves and/or severe subvalvular disease (group 2). Acute complications were examined and compared between groups before and after modifications in BMC techniques. Major modifications included the use of a height-derived balloon sizing method for the selection of an appropriate balloon catheter, a cautionary stepwise dilation technique, and avoidance of traction on the interatrial septum during balloon inflations. Results Technical failures were encountered in 4 (0.5%) patients in our early experience. One patient sustained cardiac perforation and tamponade and was the only case requiring emergency surgery. There were no deaths. Systemic embolic events were observed in 11 (1.4%), all among the first 353 patients before the routine use of pre-BMC transesophageal echocardiography. Severe postprocedure angiographic (≥3+) mitral regurgitation occurred in 4% of patients, 2% in group 1 versus 9% in group 2 (P = .0001). With increased operator experience and technical modifications, this complication was significantly reduced from 5% (7 of 150 patients) to 0% in the last 316 patients in group 1 (P = .0001) and from 11% (26 of 228 patients) to 3% (3 of 101 patients) in group 2 (P = .031). The incidence of significant interatrial shunting (pulmonary-to-systemic flow ratio ≥1.3) was also significantly reduced from 12% to 6% (P = .0034). Conclusion Incremental operator experience and ongoing technical refinements in BMC techniques have resulted in a 100% technical success rate and a significant diminution in complications in patients with a wide spectrum of stenotic mitral valve morphologic features. (Am Heart J 1999;138:114-21.)