Modified repair of mixed anomalous pulmonary venous connection

A modified repair technique is reported for mixed total or partial anomalous pulmonary venous connection with the right superior pulmonary vein connecting to the superior vena cava, the right inferior pulmonary vein to the right atrium or left atrium, and the left pulmonary veins to the coronary sinus. The superior vena cava is transected above the highest right superior pulmonary vein, its cephalad end is anastomosed to the right atrial appendage, and a pericardial baffle is constructed between the cardiac ostium of the superior vena cava, the ostium of the right inferior pulmonary vein, and the left atrium, including the coronary sinus, which is unroofed. The reported technique may be valuable to avoid pulmonary venous obstruction in complex mixed forms of total or partial anomalous pulmonary venous connection.     

The dorsal mesocardium and development of the pulmonary veins in human embryos

Pulmonary vein development was studied using serial histologic sections of normal human embryos of Carnegie stages 11 to 15. Three-dimensional models were created in the program Swivel 3D on a Macintosh IIfx computer. The position of the mesocardium was found to be an important factor in the placement of the vein. Since the vein grows through a gap in the myoepicardium of the dorsal atrial wall created by the mesocardium, the vein can only grow where the mesocardium is positioned. Displacement of the initially median pulmonary vein ostium into the left atrium appeared to be caused by the formation of the left valve of the sinus venosus. This latter structure displaces the mesocardium to the left from stage 14 and later, carrying the vein to the left as well. The subsequent development of several pulmonary veins from the original single pulmonary vein occurred later, as the apex of the heart rotated to the left and brought the left atrium into a dorsal midline position. The study shows that correct placement of the pulmonary vein in the left atrium is the consequence of the successful execution of a sequence of developmental events in cardiogenesis.     

Atrial septal displacement for repair of anomalous pulmonary venous return into the right atrium

BACKGROUND: In the repair of anomalous connection of the pulmonary veins to the right atrium, the use of a baffle of pericardium to divert the pulmonary venous blood into the left atrium could cause pulmonary venous obstruction as a result of thickening of the pericardial patch. Anomalous pulmonary venous drainage to the right atrium caused by malposition of the atrial septum primum can be repaired by displacing the shifted septum primum to the normal position. METHODS: In 5 patients with total (n=2) or partial (n=3) anomalous pulmonary venous drainage into the right atrium, the septum primum was shifted toward the left atrium and the pulmonary veins drained into the anatomic right atrium despite their normal connection with the posterior wall of the left atrium. This method consisted of incision of the posterior edge of the atrial septum primum and displacement of the incised atrial septum between the anomalous pulmonary veins and both venae cavae. No patch was used. RESULTS: Postoperative echocardiography showed a wide pathway from the pulmonary veins to the left atrium with no stenotic portions. No atrial arrhythmias occurred after the operation. CONCLUSIONS: This technique may be advantageous because it allows for future growth of the route of the pulmonary venous pathway and avoids postoperative supraventricular arrhythmias.     

Development of the cardiac conduction tissue in human embryos using HNK-1 antigen expression: possible relevance for understanding of abnormal atrial automaticity

BACKGROUND: Abnormal atrial automaticity in young patients with structurally normal hearts is often located around the pulmonary veins and in sinus venosus-related parts of the right atrium. We hypothesize that these ectopic pacemaker sites correspond to areas of embryonic myocardium with an early phenotypic differentiation, as indicated by differences in antigen expression during normal cardiac development. METHODS AND RESULTS: In human embryos ranging in age from 42 to 54 days of gestation, the development of the cardiac conduction system was studied with the use of HNK-1 immunohistochemistry. HNK-1 stains the developing atrioventricular conduction system, ie, the bundle branches, His bundle, right atrioventricular ring, and retroaortic ring. In addition, the myocardium around the common pulmonary vein showed transient HNK-1 antigen expression. In the right atrium, 3 HNK-1-positive connections were demonstrated between the sinoatrial node and the right atrioventricular ring. An anterior tract through the septum spurium connects the sinoatrial node with the anterior right atrioventricular ring, and 2 posterior tracts connect the sinoatrial node with the posterior right atrioventricular ring through the right venous valve (future crista terminalis) and sinus septum, encircling the coronary sinus. The medioposterior part of the right atrioventricular ring connected to the His bundle and the medioanterior part form 2 node-like structures. CONCLUSIONS: In patients with abnormal atrial automaticity, the distribution of left and right atrial pacemaker foci correspond to areas of the embryonic myocardium that temporarily express the HNK-1 antigen.     

Successful repair of total anomalous pulmonary venous connection and incomplete endocardial cushion defect associated with left isomerism

Successful repair of a 8-month-old girl with polysplenia was reported. The cardiovascular anomalies were TAPVC (II b), incomplete ECD, interruption of inferior vena cava with hemiazygos continuation, bilateral superior vena cava, and left superior vena cava draining into the coronary sinus. Cardiopulmonary bypass was established with ascending aortic perfusion and caval cannulation. A left superior vena cava was directly cannulated after establishing partial bypass. In this case the left pulmonary vein drained into the right atrium near the orifice of the coronary sinus, so the atrial septal flap was made and sutured between the orifice of the left pulmonary vein and the coronary sinus in order to avoid late pulmonary vein obstruction. Then, atrium was separated by an intraatrial baffle which was sutured to the atrial septal flap. Recently, it becomes possible to surgical repair of polysplenia syndrome according to the advancements of the diagnostic methods, cardiopulmonary bypass, and the technique of the open heart surgery.     

The superior approach for correction of the supracardiac type of total anomalous pulmonary venous return

An alternative approach for correction of supracardiac (type I) total anomalous pulmonary venous return is described. A median sternotomy is used. The posterior wall of the left atrium and the common pulmonary venous trunk are exposed through the transverse sinus. A direct anastomosis between these structures, ligation of the systemic-venous connection (vertical vein), and closure of the interatrial septal defect results in a one-stage repair. In our experience with the supracardiac anomaly in 20 patients, we have found that this approach consistently affords better exposure than other techniques currently in use for surgical correction of this anomaly.     

Identification of atrial septal defects by cross-sectional contrast echocardiography

Cross-sectional echocardiography, combined with injections of contrast into peripheral arm veins, has been used to study 15 patients with atrial septal defects and 10 patients with an intact interatrial septum. Of 11 patients with ostium secundum or sinus venosus atrial septal defects and left-to-right shunts a defect could be visualised in all, and in eight some degree of transfer of contrast from right atrium to left atrium was seen. In three of four patients with a dominant right-to-left shunt a defect was seen and in all there was free transfer of contrast from right atrium to left atrium. Though there may be variable loss of echoes in the septal image in patients with an intact interatrial septum, in general no fixed defect is seen an there is no transfer of contrast from right atrium to left atrium. This is a potentially valuable technique in the assessment of patients in whom an atrial septal defect is suspected.     

Subtotal cor triatrium with left partial anomalous pulmonary venous connection--successful correction in an infant

This report concerns a 10-month-old infant with subtotal cor triatrium associated with left sided partial anomalous pulmonary venous connection to the innominate vein. In the operation, we found that the fossa ovalis existed between the right atrium and the accessory atrial chamber. We performed a radical operation which consisted of a resection of the intra-left-atrial diaphragma and a anastomosis of the vertical vein to the left atrium. His postoperative course was uneventful, and the result was satisfactory. We have presented and reviewed our case, and then discussed the embryogenesis and the hemodynamics. To our knowledge, our case represents the first successful surgical repair of this combination of defects in Japan.     

Unroofed coronary sinus syndrome

Unroofed coronary sinus syndrome or coronary sinus septal defect is a rare congenital cardiac anomaly. We performed corrective operations in 9 patients with such condition. Of them, seven patients had the completely unroofed coronary sinus and persistent left superior vena cava (PLSVC) directly draining into the left atrium (LA). One patient had PLSVC and the partially unroofed terminal portion of the coronary sinus (CS), or sinus ostium open into LA. Another patient had total anomalous pulmonary vein connection and the partially unroofed mid-portion of CS without PLSVC. The operative methods of the unroofed coronary sinus included: ligating PLSVC and repairing ostium primum or secundum atrial septal defects in 4 cases; creating an intra-atrial tunnel from PLSVC to the right atrium (RA) and repairing the atrial septal defect in 2 cases; reconstructing the intra-atrial septal with a patch as a baffle to guide PLSVC or sinus ostium respectively towards RA in 2 cases; enlarging the defect on the coronary sinus roof and repairing the atrial septal defect of the coronary sinus type in one case. No patient died in this group. Because unroofed coronary sinus syndrome has atypical clinical manifestation and usually complicates varied congenital anomalies, its preoperative diagnosis is very difficult in some times and may draw the reliable support from echocardiography and catheterization. The operative program and method must depend not only upon its type but also upon PLSVC presence of absence, and communication between PLSVC and RSVC.     

Haemodynamics after Mustard's operation for transposition of the great arteries

Cardiac catheterization data from 54 investigations after Mustard's procedure were examined to study the influence of the operation on pressure events in the atria, great veins, and pulmonary circulation. Systemic venous atrial pressure tracings were characterized by a rapid, sharp 'y' descent. Pressure gradients between the venae cavae and systemic venous atrium were invariable, whether or not vena caval pathway obstruction was present, the 'y' trough and 'a' wave gradients being greater than the mean gradient. Pulmonary venous atrial pressure tracings were not different from normal except when tricuspid regurgitation was present. It is suggested that the baffle effectively reduces the size and compliance of the systemic venous atrium, but influences the pulmonary venous atrium to a lesser degree. The systolic pressure gradient from the left ventricle to pulmonary artery was decreased postoperatively, suggesting that it may be flow-related; the greatest changes were seen in the group with preoperative ventricular septal defect. The ratio of pulmonary: systemic vascular resistance did not change significantly after operation, and it is suggested that both the pre- and postoperative values were higher than normal. Examination of the left ventricular or pulmonary arterial mean pressure postoperatively should raise the suspicion of a complication, e.g. pulmonary venous obstruction or tricuspid regurgitation.     

Nitric oxide and the intestinal epithelial barrier: does it protect or damage the gut?

The right and left venous valves of the sinoatrial orifice regulate the flow of blood from the sinus venosus to the atrium in pisces, amphibians, and reptiles. In aves, mammals and humans, the venous valve loses its hemodynamic function and hence has become the 'Cinderella' among heart valves, receiving attention only when congenital anomalies occur that are related to it. The right venous valve persists in humans as the crista terminalis, Eustachian and Thebesian valves. An intraluminal muscle band is described located inside the right atrium, and coursing in the line of the crista terminalis between the septum spurium and inferior vena cava. This abnormal band is possibly derived from the right venous valve.     

Soft-tissue considerations in esthetic reconstruction

We describe herein a rare and hitherto not reported variation, found in a Japanese male cadaver, in which a posterior sinus node (SN) artery and an accessory atrioventricular node (AN) artery originate from a common trunk branching from the posterior segment of the circumflex artery. After arising in this manner, the posterior SN artery passed in a clockwise direction around the posterior, lateral, and finally anterior wall of the left atrium to the sinus venosus, giving off a branch to the SN from posteriorly. The accessory AN artery coursed in a counterclockwise direction on the posterior wall of the left atrium as far as the crux of the heart, where it bent anterosuperiorly and continued within the interatrial septum. It entered the AN from superiorly and, crossing deep to the principal AN artery, reached the inferior and superficial portion of this node. It could be considered that the accessory AN artery in this study is a modified version of arteries entering and coursing in the interatrial septum, as exemplified by Kugel's anastomotic artery.     

Revision of previous Fontan connections to extracardiac or intraatrial conduit cavopulmonary anastomosis

BACKGROUND: In patients who have received an atriopulmonary Fontan connection, complications such as right pulmonary vein obstruction, atrial arrhythmias, and thromboembolism are often secondary to right atrial enlargement. When such complications develop despite good ventricular function, there are few management options available. Extracardiac or intraatrial conduit cavopulmonary anastomosis, which improves central systemic venous flow patterns, avoids atrial distention, and does not involve the extensive atrial suturing required by other forms of cavopulmonary anastomosis, may provide relief for this group of patients. METHODS: Between October 1992 and October 1995, 7 patients presented 8 to 20 years after atriopulmonary connection with severe right atrial dilatation (7), Fontan pathway obstruction (4), progressive congestive heart failure (4), atrial tachydysrhythmias (3), right atrial thrombus (1), obstruction of right pulmonary veins by an enlarged right atrium (1), and subaortic stenosis (1). After evaluation of the options, they underwent revision of the atriopulmonary connection to extracardiac (5) or intraatrial (2) conduit cavopulmonary anastomosis. RESULTS: One patient with severe cachexia, in whom transplantation was contraindicated for social reasons, died in the early postoperative period of massive effusions. Two patients eventually required permanent pacing for atrial dysrhythmias (1) or complete heart block secondary to subaortic fibromuscular resection (1), and 2 demonstrated marked improvement in unstable preoperative rhythm disturbances. At a median follow-up of 17 months, 4 of the 6 survivors were functioning at higher New York Heart Association levels than preoperatively, and 1 had recently undergone heart transplantation. CONCLUSIONS: In properly selected patients with atrial complications, revision of a prior Fontan connection to extracardiac or intraatrial conduit cavopulmonary anastomosis appears to be a viable option.     

Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins

BACKGROUND: Atrial fibrillation, the most common sustained cardiac arrhythmia and a major cause of stroke, results from simultaneous reentrant wavelets. Its spontaneous initiation has not been studied. METHODS: We studied 45 patients with frequent episodes of atrial fibrillation (mean [+/-SD] duration, 344+/-326 minutes per 24 hours) refractory to drug therapy. The spontaneous initiation of atrial fibrillation was mapped with the use of multielectrode catheters designed to record the earliest electrical activity preceding the onset of atrial fibrillation and associated atrial ectopic beats. The accuracy of the mapping was confirmed by the abrupt disappearance of triggering atrial ectopic beats after ablation with local radio-frequency energy. RESULTS: A single point of origin of atrial ectopic beats was identified in 29 patients, two points of origin were identified in 9 patients, and three or four points of origin were identified in 7 patients, for a total of 69 ectopic foci. Three foci were in the right atrium, 1 in the posterior left atrium, and 65 (94 percent) in the pulmonary veins (31 in the left superior, 17 in the right superior, 11 in the left inferior, and 6 in the right inferior pulmonary vein). The earliest activation was found to have occurred 2 to 4 cm inside the veins, marked by a local depolarization preceding the atrial ectopic beats on the surface electrocardiogram by 106+/-24 msec. Atrial fibrillation was initiated by a sudden burst of rapid depolarizations (340 per minute). A local depolarization could also be recognized during sinus rhythm and abolished by radiofrequency ablation. During a follow-up period of 8+/-6 months after ablation, 28 patients (62 percent) had no recurrence of atrial fibrillation. CONCLUSIONS: The pulmonary veins are an important source of ectopic beats, initiating frequent paroxysms of atrial fibrillation. These foci respond to treatment with radio-frequency ablation.     

Handedness assessment inventory

A 6 year old boy with a large atrial septal defect, partial anomalous pulmonary venous drainage and unrecognized anomalous insertion of the inferior vena cava into the left atrium had cyanosis after closure of the atrial defect. Repeat study revealed direct drainage of the inferior vena cava into the left atrium with moderate arterial oxygen desaturation. At repeat operation an unusual positioning of the inferior vena cava was seen. After reopening of the atrial defect, the pulmonary venous and systemic venous drainage anomalies were identified. A Dacron patch was inserted so as to divert flow to the proper atrium. Repeat catheterization 3 months after operation revealed a normal heart with no obstruction; arterial oxygen saturation was normal. The child has continued to do well 3 years after operation.     

Changes of venous blood flow velocity waveforms in fetuses with supraventricular tachycardia

Studies in the fetal lamb have shown that atrial pacing beyond a rate of 300-320 beats/min may be associated with dramatic changes of venous blood velocity waveforms, an increase of venous pressure by up to 75%, hydrops, polyhydramnios and placental edema. The aim of our study was to determine the 'critical' heart rate frequency in the human fetus. In 11 fetuses (five with and six without hydrops) with supraventricular tachycardia, pulsed wave Doppler analysis of flow velocity waveforms of the inferior vena cava, the ductus venosus and the left hepatic vein were performed before and after drug treatment. In ten cases cardioversion was achieved by in utero antiarrhythmic drug therapy; in one case treated with digoxin and flecainide the supraventricular tachycardia was decreased to 160-190 beats/min with disappearance of hydrops. Before intrauterine treatment of supraventricular tachycardia, pulsatile reversal of blood flow in the inferior vena cava, ductus venosus and left hepatic vein was visible, with monophasic forward flow during systole and reversed flow during diastole in ten of 11 fetuses. One fetus with supraventricular tachycardia of 195 beats/min showed a normal biphasic forward flow pattern. During drug-induced sinus rhythm, a normal biphasic forward venous blood flow pattern was shown in all ten cases. In five cases pulsatile reversal was demonstrated during a drug-induced reduction of the heart rate from 280 to 210 beats/min and a normal biphasic forward flow velocity waveform appeared during supraventricular tachycardia below 210 beats/min.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrophysiological properties in patients undergoing atrial compartment operation for chronic atrial fibrillation with mitral valve disease

AIMS: Surgical treatment for atrial fibrillation is now feasible in selective cases. The aim of this study was to assess the electrophysiological properties of patients undergoing atrial compartment operation for chronic atrial fibrillation. METHODS AND RESULTS: Electrophysiological studies were performed in 20 mitral valve patients with atrial fibrillation who had been maintained in sinus rhythm for more than 1 year after atrial compartment operation. Intra-cardiac recording and programmed electrical stimulation were performed in various atrial compartments. The parameters studied included sinus node function, atrial conduction and refractoriness, atrioventricular conduction function and inducible arrhythmias if any. Intra-cardiac recordings showed that the rhythm was of sinus origin in all cases, with the earliest atrial activity located in the high right atrium. The mean sinus cycle length was 750 +/- 110 ms, AH time 106 +/- 29 ms, and HV time 53 +/- 7 ms. The sinus node function was normal in 18 patients (90%), and only two patients had prolonged sinus node recovery and sino-atrial conduction. The right atrial appendage compartment was driven by the sinus node in all patients. However, the conduction time from the high right atrium to the right atrial appendage compartment was markedly prolonged in 12 of 15 patients (80%) undergoing the three-compartment operation in which an incision was placed between the high right atrium and right atrial appendage compartments. On the other hand, the electrical activities in the left atrial compartment were much more varied. In 13 of 20 patients (65%), the left atrial compartment was driven by the sinus node; 11 of the 13 patients had a normal or mildly prolonged conduction time (ranged 75 to 146 ms), whereas two patients had a marked delay in conduction (200 ms and 266 ms, respectively). In the remaining seven patients, the left atrial compartments were dissociated from the rest of the heart; five of them had a quiescent left atrium, one a fluttering left atrial rhythm, and one a slow left atrial rhythm. The effective refractory period was longer in the left atrial compartment (242 +/- 47 ms) as compared to that of the high right atrium (224 +/- 26 ms, P < 0.01) and right atrial appendage compartments (219 +/- 25 ms, P < 0.01). Programmed electrical stimulation could not induce atrial fibrillation in any patient, whereas two patients had inducible atrial flutter and three repetitive atrial responses. CONCLUSIONS: (1) Atrial compartment operation does not impair sinus node function in most cases. (2) Elimination of atrial fibrillation while maintaining the electrical connection between different atrial compartments is feasible.     

Cardiac function in total anomalous pulmonary venous return before and after surgery

Cardiac performance was evaluated in 12 infants with isolated total anomalous pulmonary venous return. Four had significant pulmonary venous obstruction and severe pulmonary hypertension (group A). Eight had no obvious venous obstruction, and the pulmonary pressures were lower (group B). In all subjects, right ventricular end-diastolic volume was increased (197% of predicted normal) and its ejection fraction was normal. Left ventricular volume was, generally speaking, still in the normal range (87% of predicted normal); however, its ejection fraction was reduced (0.57 vs normal of 0.73) and left ventricular output was low (3.08 L/min/m2 vs normal of 3.98). Left atrial volume was consistently small (53% of predicted normal) with an appendage of normal size. The infants in group A had smaller chamber volumes/m2 BSA than those in group B. Left atrial function was abnormal, characterized by reduced reservoir function and a greater role as "conduit" from right atrium to left ventricle. Left atrial size was not found to be critical in the surgical repair of TAPVR. Cardiac function is restored to normal following surgery.     

The development of the septum primum relative to atrial septation in the mouse heart

The septum primum in the mouse originates as a thickened primordium with a straight rather than a sickle-shaped ventral border. It is covered on its ventral border by anterior cushion material which is continuous over the roof of the atrium with the principal anterior cushion mass. A process of cavitation thins the septum primum and precedes actual fenestration. This process shifts the membranous septum to the left thereby providing room for the septum secundum to overlap on the right side. The septum primum cannot contact the posterior cushion until closure of the sinus venosus gutter which is described. The closure of the interatrial foramen, later the foramen primum, is accomplished by cell growth of the anterior cushion material. The ventral thick border of the septum primum contributes to the ventral limbus and the caudal thickened boundary of the fossa ovalis with some contribution from the left venous valve. These boundaries as well as the membranous portion of the interatrial septum are derived from the same primordium, namely the septum primum.     

Simultaneous measurement of pulmonary venous flow by intravascular catheter Doppler velocimetry and transesophageal Doppler echocardiography: relation to left atrial pressure and left atrial and left ventricular function

OBJECTIVES: The aim of our study was to compare measurements of pulmonary venous flow velocity obtained either by transesophageal Doppler echocardiography or by intravascular catheter Doppler velocimetry. Furthermore, the relation among pulmonary venous flow velocity, left atrial compliance and left atrial pressure was evaluated. BACKGROUND: Data about the relation between left atrial pressure and pulmonary venous flow velocity are controversial. METHODS: A total of 32 patients undergoing elective open heart surgery for coronary artery bypass grafting were included prospectively in the study. Pulmonary venous flow velocity (Doppler catheter) and left atrial pressure (microtip pressure transducer) were recorded simultaneously with recordings of pulmonary venous flow velocity obtained by transesophageal Doppler echocardiography. RESULTS: Agreement between Doppler catheter and Doppler echocardiographic measurements of pulmonary venous flow velocity (n = 18 patients) was analyzed using the Bland-Altmann technique. The 95% limits of agreement were -0.16 to +0.11 m/s for systolic peak velocity, -0.14 to +0.09 m/s for diastolic peak velocity and -0.12 to +0.10 m/s for atrial peak velocity. The closest agreement between both methods was found for the ratio of systolic to diastolic peak velocity, the ratio of systolic to diastolic flow duration and the time from Q deflection on the electrocardiogram to maximal flow velocity. Mean left atrial pressure was strongly correlated with the ratio of systolic to diastolic peak velocity (r = -0.829), systolic velocity-time integral (r = -0.653), time to maximal flow velocity (r = 0.844) and the ratio of systolic to diastolic flow duration (r = -0.556). The ratio of systolic to diastolic peak velocity and the time to maximal flow velocity were identified as strong independent predictors of mean left atrial pressure. Left atrial compliance was not found to be an independent predictor of mean left atrial pressure. CONCLUSIONS: Flow velocity in the left upper pulmonary vein can be reliably recorded by transesophageal pulsed wave Doppler echocardiography. Our data reveal further evidence that mean left atrial pressure can be estimated by the pattern of pulmonary venous flow velocity.