Comparative study of heart rate variability between healthy human subjects and healthy dogs, rabbits and calves.

Several studies have been performed to assess heart rate variability (HRV) in several species such as humans, dogs, pigs, calves, rabbits and rats. However, haemodynamic parameters are totally different in each animal, and optimal animal models for studying HRV corresponding to human HRV are still unclear. The purpose of this study was to assess HRV in human subjects and to compare those HRV data with canine, bovine and rabbit HRV data. The heart rate in the human subjects (62.8 +/- 7.4 bpm) was significantly lower than that in dogs (124.2 +/- 18.8 bpm, P < 0.001), calves (73.4 +/- 10.5 bpm, P < 0.05), and rabbits (217.3 +/- 21.5 bpm, P < 0.001). The low-frequency waves (LF) (57.9 +/- 65.8 ms(2)/Hz) and high-frequency waves (HF) (33.8 +/- 49.1 ms(2)/Hz) in rabbits were significantly lower than human LF (1216.3 +/- 1220.7 ms(2)/Hz, P < 0.05) and HF (570.9 +/- 581.3 ms(2)/Hz, P < 0.05). Dogs and calves showed similar LF (991.1 +/- 646.1 ms(2)/Hz and 547.0 +/- 256.9 ms(2)/Hz, respectively), HF (702.1 +/- 394.1 ms(2)/Hz and 601.0 +/- 666.6 ms(2)/Hz, respectively) and LF/HF (2.0 +/- 1.3 and 2.5 +/- 1.9, respectively) when compared with the human data. The present study shows that dogs and calves revealed similar HRV values as those which relate to humans. Large deviation of the HRV values in rabbits compared with humans might be considered when conducting animal studies using those animals to reflect human clinical situations.

Hemolysis evaluation of centrifugal pumps using microcapsule suspension.

OBJECTIVES: Bovine and human blood has been widely used for in vitro hemolysis testing to evaluate centrifugal cardiac assist pumps. However, results from such tests are complicated by variations in the susceptibility of individual red blood cells to shear. The objective of this study was to evaluate the use of microcapsule suspension as an alternative to bovine or human blood for hemolysis testing. METHODS: Microcapsule suspensions of 100 micro m maximal diameter (average 79.1 micro m) with a polyurethane membrane were used. Each microcapsule contained a leuco dye, which was used to measure "hemolysis" in the suspension after exposure to mechanical stress. Six centrifugal pumps were used to measure and compare the hemolysis values of microcapsule suspensions, bovine blood and human blood. RESULTS: Correlations were significant between the hemolysis values measured using microcapsule suspensions and those using bovine blood (R = 0.965, p = 0.002) and human blood (R = 0.940, p = 0.005). CONCLUSIONS: Microcapsule suspension can be successfully used instead of blood to compare the relative hemolytic performance of centrifugal blood pumps.

Pulmonary agenesis with congenital heart disease.

The combined anomalies of pulmonary agenesis and congenital heart disease are exceedingly rare and a highly lethal association. We describe four cardiovascular operations in three patients with this association. Open-heart surgery was performed in two patients, and palliative heart surgery was performed in two patients. One patient died 100 days after the operation because of severe tracheal stenosis and renal failure, but the other two patients are doing well. Surgical access through a thoracotomy, instead of a median approach, was adequate in all patients. Careful evaluation and a precise understanding of the anatomy are necessary for the surgical management of these patients.

[A successful thrombolytic therapy for thrombosed ATS valve in the mitral position in a child; report of a case].

We report a successful thrombolytic therapy for thrombosed ATS valve in the mitral position in a child. A 5-year-old girl was underwent mitral valve re-replacement with ATS mechanical valve for prosthetic valve stenosis in the mitral position. The postoperative course was uneventful, but an unilateral thrombosed leaflet of a ATS valve was observed 26 days after the operation by fluoroscopy. Thrombolytic therapy with urokinase was done and the thrombus was successfully dissolved.

Congenital heart disease with hypereosinophilic syndrome.

The idiopathic hypereosinophilic syndrome, common in adults, is a leukoproliferative disorder marked by a predilection to damage specific organs. This report describes a unique case of an infant with tricuspid stenosis, a hypoplastic right ventricle, severe pulmonary stenosis, patent ductus arteriosus, and a patent foramen ovale associated with hypereosinophilic syndrome. Although treatment with high-dose oral steroids failed to decrease the leukocyte counts, a right classic Blalock-Taussig shunt through a right thoracotomy resolved her cyanosis.

Pulmonary agenesis with interrupted aortic arch.

This report describes a unique case of an infant with right pulmonary agenesis associated with interrupted aortic arch, ventricular septal defect, and aortic valvular stenosis. Blalock-Park arterial anastomosis and pulmonary arterial banding were performed without incidence. These techniques were useful for this complicated heart defect with pulmonary agenesis. The postoperative course of the patient was uneventful.

Reoperation for interrupted aortic arch with the use of retrograde cerebral perfusion.

We treated 2 patients with recurrent coarctation after repair of interrupted aortic arch. Because they had been operated on with the use of vascular prostheses, severe scarring was considered prohibitive for safe dissection. We successfully carried out anatomic repair with the use of retrograde cerebral perfusion through a left thoracotomy in both cases.

Anatomically corrective repair of complete atrioventricular septal defects and major cardiac anomalies.

BACKGROUND: Although satisfactory results of corrective surgery for atrioventricular septal defects (AVSDs) with complex lesions such as double-outlet right ventricle (DORV) or atrial isomerism have been reported in recent years, the optimal surgical options for isomerism hearts is still a controversial issue. METHODS: We performed anatomically corrective repair on 13 children with balanced forms of complete AVSDs and associated major cardiac anomalies. Eight of the 13 patients had atrial isomerism (right in 1, left in 7), 5 of whom had DORV. Four others had DORV with trisomy 21, and 1 had tetralogy of Fallot. Atrial septation for isomerism with the placement of an additional prosthesis was performed on 4 patients. RESULTS: Two hospital deaths and one late death occurred only in the isomerism group. Three reoperations were required solely in the left isomerism group: one replacement of the valved external conduit concomitantly with reconstruction of the left ventricular outflow obstruction, one mitral valve replacement for severe regurgitation of left atrioventricular valve, and one relief of progressing left ventricular outflow obstruction. CONCLUSIONS: The results of anatomically corrective surgery for AVSDs with major associated cardiac anomalies in the nonisomerism group were excellent. The optimal surgical options for isomerism heart, however, remain a controversial issue.

Risk factors influencing early and late mortality after total cavopulmonary connection.

OBJECTIVE: Among the later modifications of the Fontan type procedure, a significant alteration was introduced by de Leval and associates when they described the total cavopulmonary connection (TCPC). Although current results of TCPC have encouraged us to extend this procedure to high risk patients, risk factors influencing surgical outcome after TCPC have not been evaluated. We review our experiences with TCPC to identify which risk factors may have had a considerable impact on the outcome of patients undergoing TCPC and to clarify selection criteria of high-risk Fontan candidates for TCPC. PATIENTS AND METHODS: We retrospectively reviewed the medical and surgical records of all 76 patients who underwent TCPC between July 1988 and August 2000. A cross-sectional review of these patients was undertaken. RESULTS: There were eight early deaths and four late deaths. In a Fisher's exact test, the following variables were associated with an increased early mortality after TCPC: systemic ventricular morphology (right ventricle), ejection fraction of the systemic ventricle less than 60%, and prolonged cardiopulmonary bypass time (240 min or longer). The log-rank test demonstrated that heterotaxy syndrome, moderate to severe atrioventricular valve regurgitation, prolonged cardiopulmonary bypass time (240 min or longer), and prolonged aortic cross clamp time (70 min or longer) were associated with late mortality after TCPC. Six deaths occurred in eight (75%) patients who had six or more risk factors, whereas six deaths (9%) occurred in those who had five or fewer. CONCLUSIONS: Patients with complex cardiac anomalies who have six or more risk factors should be excluded from TCPC candidates.

[Reconstruction of the pulmonary outflow tract without external conduit].

Between October 1987 and December 2000, 50 patients underwent reconstruction of the pulmonary outflow tract without external conduit. The primary malformation was tetralogy of Fallot with pulmonary atresia in 37, double outlet of right ventricle in 4, corrected transposition of the great arteries in 4, transposition of the great arteries with ventricular septal defect and pulmonary stenosis in 4, and double outlet of left ventricle in 2. Mean age at operation was 7.2 years, and mean body weight was 18.3 kg. To reconstruct posterior wall of the pulmonary outflow tract, interposition of autologous pericardium was performed in 24, direct anastomosis between pulmonary trunk and ventriculotomy in 13, longitudinal incision from ventriculotomy through pulmonary trunk in 12, and interposition of left atrial appendage in 1. Anterior wall was reconstructed with monocusp valved outflow patch (MVOP). There was one hospital death and no late death. At 10 years, the freedom from reoperation for pulmonary outflow tract obstruction was 100%, and freedom from reoperation for any cause was 86.6%. Transcatheter stenting for peripheral pulmonary stenosis was performed in 6 patients 2 to 10 months after operation.

Repair of total anomalous pulmonary venous connection without cardiopulmonary bypass.

Two infants with asplenia syndrome and pulmonary venous obstruction underwent repair of total anomalous pulmonary venous connection without cardiopulmonary bypass in 1988. Using a side-biting clamp, an anastomosis between the left upper pulmonary vein and left superior vena cava-atrial junction was satisfactorily created without undue instability. Furthermore, both cases had the advantage of efficient growth in the anastomotic site postoperatively.

The effect of cardiomyoplasty on left atrial function in experimental canine models.

BACKGROUND: Cardiomyoplasty utilizes the latissimus dorsi muscle to boost the failing ventricle. However, the mechanism for clinical improvement still remains controversial. We have previously shown that left ventricular contraction was improved in the long-term periods after cardiomyoplasty in the normal canine heart model and in the dilated failing heart model. On the other hand, right ventricular filling was impaired if a rapid volume loading test was employed in the long-term period after cardiomyoplasty. The purpose of the present study was to determine whether cardiomyoplasty impairs the left atrial function and affects ventricular filling. METHOD: Eleven mongrel dogs that had undergone cardiomyoplasty (study group, n = 5) or a sham operation (control group, n = 6) were studied for 12 weeks postoperatively. An IV 4.5% albumin solution (10 mL/kg) was infused into the right atrium, and hemodynamic changes in right cardiac catheterization and left atrial volume (LAV) were obtained by two-dimensional echocardiography. Atrial function was assessed by hemodynamic changes in Doppler echocardiography and hormonal changes. RESULTS: Stroke volume was significantly increased, from 17.0 +/- 4.4 to 21.1 +/- 7.0 mL, respectively, before and 15 min after albumin infusion in the control group (p < 0.05). Heart rate and cardiac output were significantly increased, from 131.2 +/- 18.1 to 152.0 +/- 9.8 beats/min and 2.72 +/- 1.29 to 4.03 +/- 1.67 L/min, respectively, before and 15 min after albumin infusion in the study group (p < 0.05). No changes were observed in mean right atrial pressure and pulmonary capillary wedge pressure. LAV and atrial natriuretic peptide (ANP) levels increased significantly, from 5.8 +/- 2.1 to 8.5 +/- 3.8 mL and 22.5 +/- 7.5 to 44.5 +/- 31.7 pg/mL, respectively, before and 15 min after albumin infusion in the control group (p < 0.05). In the study group, LAV and ANP levels were also increased, from 10.1 +/- 2.4 to 12.7 +/- 2.8 mL and 64.2 +/- 60.6 to 232.6 +/- 272.2 pg/mL, respectively, before and 15 min after albumin infusion (p < 0.05). The peak velocities and the time-velocity integrals in the pulmonary venous flow of the systolic and diastolic waves, as well as their ratios (systolic to diastolic peak velocity ratio and systolic to diastolic time-velocity integral ratio) showed no significant differences between the two groups. CONCLUSIONS: Cardiomyoplasty preserves left atrial filling and transport function; therefore, cardiomyoplasty may also activate ANP production by stimulating the atrium in the long-term period after cardiomyoplasty.

Pulmonary root translocation for biventricular repair of double-outlet left ventricle.

Double-outlet left ventricle is conventionally repaired with an extracardiac conduit when pulmonary stenosis is present. We report the use of pulmonary root translocation to the right ventricle to construct the posterior wall with autologous tissue and a porcine pericardial monocusp ventricular outflow patch anteriorly for 2 patients with double-outlet left ventricle. This technique allows minimization of pulmonary insufficiency, avoids coronary artery ligation with infundibulotomy, and has a major theoretical advantage for growth potential.

Repair of atrial septal defect through a right posterolateral thoracotomy: a cosmetic approach for female patients.

BACKGROUND: Because the operation for atrial septal defect is considered a low-risk procedure, the cosmetic result has become an important issue. Principally for cosmetic reasons, anterolateral thoracotomy is frequently used for closure of atrial septal defect in young female patients. However, in anterolateral thoracotomy, the skin incision frequently crosses the future breast line, which may cause breast and pectoral muscle maldevelopment. METHODS: We review the long-term results of a consecutive series of 126 patients in whom the atrial septal defect was closed through a right posterolateral thoracotomy. The mean age at operation was 7.1 years (range, 1 to 15 years), and the mean body weight was 23.9 kg (range, 6.9 to 56 kg). Defects repaired included 121 ostium secundum (central type), 3 sinus venosus, and 2 ostium secundum without inferior margin. RESULTS: The average cardiopulmonary bypass time was 65 minutes (range, 37 to 130 minutes), with an average fibrillation time of 41 minutes (range, 23 to 70 minutes). There was no operative or late mortality. A majority of patients were pleased with their cosmetic results. There were no other late complications. CONCLUSIONS: Atrial septal defect can be safely repaired through a right posterolateral thoracotomy approach. This approach offers the benefit of a total absence of scarring and cosmetic disfigurement of the anterior chest wall.

Suppression of the secretion of atrial and brain natriuretic peptide after total cavopulmonary connection.

OBJECTIVES: Among the modifications of the Fontan operation currently being used, total cavopulmonary connection offers the greatest potential for optimizing early and long-term postoperative outcomes. Although studies have established that abrupt increases in right atrial pressure elevate the plasma atrial natriuretic peptide level after the Fontan procedure, changes in plasma natriuretic peptide levels after total cavopulmonary connection have not been clarified. Our hypothesis is that secretion of atrial natriuretic peptide may be suppressed in patients undergoing total cavopulmonary connection because the atrium continues to function at low pressure in those patients. In this study, we measured plasma levels of atrial and brain natriuretic peptide before and during the postoperative period in patients undergoing total cavopulmonary connection. METHODS: We evaluated 60 patients: 30 patients underwent total cavopulmonary connection and 30 patients underwent definitive repair for Fallot's tetralogy. Blood samples for measurement of atrial and brain natriuretic peptide were obtained before the operation and in the postoperative period. RESULTS: Plasma levels of atrial and brain natriuretic peptide were significantly lower during the early postoperative period in patients undergoing total cavopulmonary connection than in patients undergoing definitive repair for Fallot's tetralogy. No correlations were identified between the atrial natriuretic peptide levels and central venous pressure after total cavopulmonary connection. CONCLUSION: These results suggest that total cavopulmonary connection attenuates the secretion of atrial and brain natriuretic peptide in the early postoperative period. The suppressed release of atrial and brain natriuretic peptide after total cavopulmonary connection may have clinical importance.

Tension hemothorax caused by a ruptured aneurysm of the descending thoracic aorta: report of a a case.

The rupture of an aneurysm of the descending thoracic aorta into the right thoracic cavity is a comparatively rare event, and it is very difficult to establish a diagnosis immediately and rescue such patients. We describe herein the successful surgical treatment of a patient with this life-threatening emergency by initiating immediate cardiopulmonary bypass. It is mandatory to drain the right thoracic bleeding through a left thoracotomy without delay to release the tension hemothorax. Furthermore, it is necessary to evacuate the right thoracic hematoma through a right thoracotomy because complete removal o f a hugh hematoma through a left thoracotomy cannot be effectively achieved.

Clinical and pathological features of accessory valve tissue.

BACKGROUND: Accessory valve tissue is a rare congenital cardiac malformation causing a variety of clinical features. We describe our experience with the surgical treatment of accessory valve tissue to clarify clinical and pathological features of this anomaly. METHODS: Between December 1990 and February 1999, 11 children underwent resection of accessory valve tissue together with repair of coexisting intracardiac malformations. Eight patients had accessory tricuspid valve, while 3 had accessory mitral valve tissue. Associated intracardiac malformations included tetralogy of Fallot in 6 patients, transposition of the great arteries in 3, coarctation complex in 1, and ventricular septal defect in 1. RESULTS: Accessory valve tissue was completely resected in all but 1 patient with accessory mitral valve and transposition of the great arteries. As total resection of the accessory valve tissue through the pulmonary artery was unsuccessful, partial resection and bidirectional Glenn shunt operation was performed instead of arterial switch operation in this patient. CONCLUSIONS: The clinical signs and symptoms of accessory valve tissue vary according to its location and coexisting cardiac malformations. Congenital heart surgeons should be familiar with the clinical and pathological features of accessory valve tissue, so as not to overlook it during operation.

Availability of omental flap on prevention against muscular atrophy of a latissimus dorsi cardiomyoplasty.

Dynamic cardiomyoplasty (DCMP) has been performed in more than seven hundreds cases world wide. However, despite symptomatic improvement in the majority of patients surviving the procedure, objective hemodynamic effects have not been consistently demonstrated. Previous studies reported that left ventricular function deteriorated and returned to preoperative level in the chronic phase. We previously reported that atrophy of the latissimus dorsi muscular flap (LDMF) was responsible for the effect of DCMP on improvement of cardiac function in the chronic phase. Ischemia of the muscle flap was proved to induce peripheral muscular atrophy of the flap, and thus preservation of the blood flow is important in preventing muscular atrophy. In the present study, we applied omental flap to LDMF, and postulated that the omentum would improve vascularity and perfusion of latissimus dorsi and prevent peripheral muscle atrophy. In dogs, the right and left latissimus dorsi muscles were dissected free from all attachment except for its thoracodorsal pedicles, and omental flap was wrapped around peripheral part of the left LDMF. Tissue blood flow, maximal muscle isotonic strength, morphologic features, and tissue vascular endothelial growth factor (VEGF) were examined in left LDMF with omental flap (OM group) and in the right LDMF served as the control (Control group). In the distal part of the LDMF, tissue blood flow of OM was significantly preserved than Control (86.4 +/- 6.5% in OM and 33.6 +/- 3.4% in Control, p < 0.05). Maximal isotonic tension was significantly higher in OM as compared to Control. Microscopic findings of H and E stained specimen from distal part of LDMF showed that muscle fibers were preserved in OM. And in the distal part, VEGF expression of OM was 49.6 +/- 7.9 pg/100 micrograms protein and significantly higher than that of Control. Our results indicated that induced endogenous VEGF expression in the LDMF by the omental flap preserved blood perfusion and muscular strength of the LDMF, and suggested that dynamic cardiomyoplasty might not lose its long-term direct cardiac assistance when an omental flap applied for the latissimus dorsi muscle flap.

Transaortic video-assisted removal of a left ventricular thrombus.

A mobile and pedunculated left ventricular thrombus was developed after acute myocardial infarction in a 59-year-old man, and was successfully removed surgically through the aortic valve using a video-assisted thoracoscope. Transaortic video-assisted thoracoscopy greatly facilitated exposure of the interior of the left ventricle and preserved left ventricular function by avoiding ventriculotomy.