Direct intraoperative measurements of aortic and pulmonary blood flows in patients with severe pulmonary artery hypertension.

BACKGROUND: Evaluate the significance of direct intraoperative measurements of aortic and pulmonary blood flows by electromagnetic flowmeter as an absolute decision basis for operability in patients with ventricular septal defect/complete atrioventricular septal defect and severe pulmonary artery hypertension. EXPERIMENTAL DESIGN: Prospective study. SETTING: Institutional practice. PATIENTS: Eight patients with marginal operability based on preoperative Doppler echocardiography and cardiac catheterization (pulmonary-to-systemic flow ratio=1.1-2.3, pulmonary-to-systemic resistance ratio=0.34-0.91, and pulmonary vascular resistance=4.6-18.2 units x m2) underwent direct intraoperative measurements of aortic and pulmonary blood flows by electromagnetic flowmeter. Operation would be performed according to the results of direct intraoperative measurements in every patient. RESULTS: Aortic flow by direct intraoperative measurements ranged from 0.9 to 3.2 L/min/m2, and pulmonary blood flow from 4.1 to 8.4 L/min/m2. Pulmonary-to-aortic flow ratio was calculated at 2.1-6.6. Pulmonary vascular resistance ranged from 2.6 to 7.7 units x m2. We assessed that all patients still had operability, and performed corrective operations. Postoperative courses corresponded with the data from the direct intraoperative measurements. CONCLUSIONS: When some clinical findings, particularly Doppler echocardiographic findings, of these patients are slightly in favor of reversibility of pulmonary vascular disease despite discrepant data of preoperative cardiac catheterization under a tight control of carbon dioxide tension, we recommend that direct intraoperative measurement of aortic and pulmonary blood flows is especially useful in decision making for the operability of patients with severe pulmonary artery hypertension.

Surgical management of infants with mitral valve stenosis or atresia without diminutive ascending aorta.

The surgical strategy in infants with mitral valve stenosis or atresia without diminutive ascending aorta remains to be established, including the potential for biventricular repair as a definitive operation. Our surgical experience of six infants with mitral valve stenosis (4 patients) or atresia (2 patients) without diminutive ascending aorta was evaluated based on three important factors: left ventricular volume; the nature of the systemic outflow obstruction; and the type of mitral valve anomaly. Two patients with systemic outflow tract diameter less than 65% of normal underwent systemic outflow tract reconstruction, and the other patients with outflow tract diameter more than 68% of normal were able to maintain systemic circulation without repair. Only one patient with mitral valve stenosis without left ventricular outflow tract obstruction underwent a successful open mitral valvotomy as a biventricular repair after first-stage palliation. The left ventricle of the other patients did not grow after first-stage palliation. Due to progressive subaortic narrowing, pulmonary artery banding should be avoided in patients with mitral atresia due to absent atrioventricular connection who are future Fontan candidates. Most patients with this lesion can be expected to become candidates for safe Fontan-type repair.

[A case of reoperation 24 years after repair of absent pulmonary valve syndrome with anomalous origin of the left pulmonary artery].

We experienced a case of a 38-year-old woman with a persistent cough, 24 years after repair of absent pulmonary valve syndrome with anomalous origin of the left pulmonary artery. The right pulmonary artery was massively dilated, thus it caused the compression of the bronchi, which was thought to result in her respiratory symptom. This dilatation of the right pulmonary artery seemed to have progressed because of the following two reasons. The first is the pulmonary hypertension caused by the late reconstruction of the left pulmonary artery. The second is residual pulmonary stenosis and regurgitation after the initial operation without a pulmonary valve insertion. We performed a reoperation consisting of reconstruction of the right ventricular outflow tract using a valved conduit and plication of the right pulmonary artery. Her postoperative course has been without any complications and satisfactory for the past 2 years.

[Effect of amiloride on the early and late stage of postischemic recovery in isolated perfused rat hearts--possible involvement of Na+/H+ and Na+/Ca2+ exchange].

To investigate whether Na+/H+ exchange or Na+/Ca2+ exchange involves in the ischemic-reperfusion injury, we examined the effect of amiloride, a potent inhibitor of Na+/H+ exchange, on the ischemic reperfused rat heart. When, the hearts were loaded with 0.1 mM amiloride preischemically, the recovery of left ventricular developed pressure was significantly improved than that of the control group, whereas the recovery of heart rate was not influenced by amiloride pretreatment at 30 min of reperfusion. Measurement of intracellular cations revealed that intracellular Na+ accumulation in the early stage (within 5 min) of reperfusion was inhibited by amiloride pretreatment. On the other hand, in the late stage (from 5 min to 30 min) of reperfusion, Ca2+ overload was inhibited by amiloride. These results suggest that Na+/H+ exchange mainly participates in the early stage of reperfusion injury and Na+/Ca2+ exchange system, secondary to the Na+/H+ exchange, participates in the late stage of the reperfusion injury. Moreover, pretreatment with amiloride also decreased creatine phosphokinase activity in the coronary effluent and completely abolished the incidence of ventricular arrhythmia during reperfusion. It is assumed that the improvement of postischemic cardiac dysfunction induced by amiloride pretreatment may be attributable to its inhibition on the resultant Ca2+ accumulation during ischemia.

Angiotensin II as a stimulator of Na(+)-dependent Ca2+ efflux from freshly isolated adult rat cardiomyocytes.

In cardiac tissues, angiotensin II causes inotropic and chronotropic effects on the heart. It is indicated that the mechanism of the inotropic effect of angiotensin II is attributed to an increase in cytosolic free calcium ([Ca2+]i) in cardiomyocytes. However, increased [Ca2+]i should be restored to a physiological level because cumulative elevation in [Ca2+]i leads to irreversible injury in cardiomyocytes. Whereas it is known that angiotensin II causes the increase in [Ca2+]i in cardiac cells, little is known about the mechanisms of decrease in [Ca2+]i in cardiomyocytes upon angiotensin II stimulation. In the present study, we examined the effect of angiotensin II on Ca2+ efflux from freshly isolated adult rat cardiomyocytes. Angiotensin II stimulated the efflux of 45Ca2+ from the cells in a concentration-dependent manner (10(-7)-10(-5) M). The 45Ca2+ efflux from the cells was inhibited by type 1 angiotensin II receptor inhibitor. The angiotensin II-stimulated 45Ca2+ efflux was not affected by deprivation of the extracellular Ca2+, but was dependent on the presence of extracellular Na+. These results indicate that angiotensin II stimulates extracellular Na(+)-dependent 45Ca2+ efflux from freshly isolated adult rat cardiomyocytes, probably through its stimulatory effect on the plasma membrane type 1 angiotensin II receptors which may couple to Na+/Ca2+ exchange.

[Surgical experience of two different types of unroofed coronary sinus].

We experienced two cases with uncommon unroofed coronary sinus. The first patient, a 55-year-old man, had a partially unroofed mid-portion of the coronary sinus. His symptoms and physical state were similar to that of atrial septal defect (ASD). Echocardiogram and angiogram revealed that the coronary sinus (CS) communicated with the left atrium (LA). We confirmed that CS had an enlarged orifice and lacked a part of its roof through the right atriotomy and the atrioseptotomy. We directly closed the defect between the LA and the CS. His postoperative course was satisfactory. The second patient, a 46-year-old man, showed mild cyanosis. He had a completely unroofed CS with left superior vena cava (LSVC), absent inferior vena cava (IVC) and hemiazygos continuity. The LSVC directly drained to the LA, and the CS was absent. A part of the posterior wall of the LA was like a groove which laid from the orifice of the LSVC to the coronary sinus ASD. The roof of this groove was covered with fibrous tissue, which was shaped like a network structure. We thought that this network was a residue of the septum between the CS and the LA. Thus we resected this structure, and reconstructed the roof by equine pericardial patch to drain the venous blood from the LSVC to the right atrium. Anomaly in the patient may be the transitional type between the completely unroofed CS and the partially unroofed CS.

Effect of extracellular adenosine 5'-triphosphate on Ca2+ efflux from freshly isolated adult rat cardiomyocytes.

The effect of extracellular adenosine 5'-triphosphate (ATP) on Ca2+ efflux from freshly isolated adult rat cardiomyocytes was examined. ATP stimulated the efflux of 45Ca2+ from the cells in a concentration-dependent manner (0.01-1 mM). The 45Ca2+ efflux from the cells was also stimulated by adenosine-5'-O-(3-thiotriphosphate)(ATP-gammas) and alpha,beta-methylene-ATP and adenosine 5'-diphosphate, but not by adenosine 5'-monophosphate and adenosine. The ATP-stimulated 45Ca2+ efflux was not affected by deprivation of the extracellular Ca2+, but was dependent on the presence of extracellular Na+. These results indicate that ATP stimulates extracellular Na+-dependent 45Ca2+ efflux from freshly isolated adult rat cardiomyocytes, probably through its stimulatory effect on the plasma membrane P2 purinoceptors which may couple to Na+/Ca2+ exchange.

Newborn with congenital arteriovenous fistulas of the abdominal wall complicated by a ductus arteriosus aneurysm.

A case of congestive heart failure in a neonate resulting from a congenital abdominal arteriovenous fistula is described; an aneurysm of the ductus arteriosus was also found in the patient. Abdominal aortography was performed and demonstrated dilated feeding arteries, including the hypogastric arteries, which communicated with a dilated umbilical vein. Ligation of the feeding arteries and the umbilical vein led to resolution of the heart failure. Transient liver dysfunction occurred, however. Symptoms improved dramatically upon removal of the ligature from the umbilical vein. Although there is one previous report of an arteriovenous fistula involving the umbilical vein, we know of no prior report of a congenital arteriovenous fistula in association with a ductus arteriosus aneurysm.

New operative method for tracheal compression in congenital heart disease.

A new technique is described for repairing tracheal compression caused by ascending aorta associated with corrected transposition of the great arteries and pulmonary atresia in a 113-day-old infant. Surgical repair for the tracheal compression was accomplished by suspending the pericardium around the aortic arch to the underside of the sternum. This method seems to be useful for some patients with tracheal compression caused by the ascending aorta.

[A case report of cor triatriatum benefit of MRI for preoperative diagnosis and surgical method].

Cor triatriatum is uncommon in all congenital heart diseases. It is a malformation resulting in a separation of the left atrium or right atrium into two chambers due to a congenitally abnormal diaphragm. We wish to present a case of cor triatriatum in which MRI was found most useful for preoperative diagnosis and surgical procedure. A 2-year-old girl was transferred to us for severe pulmonary congestion as shown on chest X-ray. Echocardiography showed abnormal diaphragm in the left atrium. MRI demonstrated clearly the relationship between left pulmonary vein and the abnormal diaphragm. Therefore we should preoperatively determine type I A according to the Lucas and Schmidt's classification. Cardiac catheterization showed moderate pulmonary hypertension and confirmed cor triatriatum. The resection of the abnormal diaphragm was performed under extracorporeal circulation with moderate hypothermia. The postoperative course was uneventful. MRI is a very useful non-invasive technique in making a diagnosis and in choosing the appropriate surgical procedure for cor triatriatum.

[A case of tetralogy of Fallot associated with isolation of a subclavian artery and partial DiGeorge syndrome].

A month old girl was referred to our hospital for heart murmur and congestive heart failure. After the UCG and angiography, clinical diagnosis was tetralogy of Fallot, right aortic arch, isolation of left subclavian artery (Victorica type I), and a patent ductus arteriosus that originated from left subclavian artery. The direction of blood flow in the patent ductus arteriosus was from a subclavian artery to pulmonary artery, so she was in the condition of pulmonary over flow and appeared congestive heart failure, although she associated with tetralogy of Fallot. With intraoperative and postoperative examinations, we diagnosed the association of partial DiGeorge syndrome. Isolation of subclavian artery is uncommon, but this anomaly was classified by Victorica. Embryology of this anomaly was explained with hypothesis of double arch system. We had seen no reports of DiGeorge syndrome associated with isolation of a subclavian artery. But DiGeorge Syndrome is hypoplasia of branchiogenic organs, and subclavian arteries is differentiated from brachial arteries. So we supposed that this two lesions have the possibility of combination.

[A case of the successful treatment of pulmonary artery pseudoaneurysm after PA banding].

Pulmonary artery pseudoaneurysm after PA banding is a rare complication and its mortality is very high. The authors successfully operated on this sort of lesion. To our knowledge, this is the first successful case in Japanese literature. The second of twins was found to be suffering asplenia, dextro cardia, TAPVC, atrioventricular septal defect, corrected TGA and PDA. On the 19th day of life, increasingly pulmonary congestion forced us to operate. We performed PDA ligation, correction of TAPVC, together with extrathoracically adjustable PA banding. 5 months following this operation, spike fever and swelling of anterior thorax were noted. PA angiography was performed, and it showed that the pulmonary artery had been cut through by the band and a pseudoaneurysm had developed. The PA banding was removed and an end-to-end anastomosis of the PA was performed using cardiopulmonary bypass and deep hypothermia with surface cooling. The diameter of the PA anastomosis was designed to be one half that of her aorta. Staphylococcus aureus was cultured from the specimen of the PA band. It was thought to have contributed to the development of this aneurysm. The post operative course was uneventful.