Naruto Matsuda

Perioperative changes in plasma brain natriuretic peptide concentrations in patients undergoing cardiac surgery

The plasma concentrations of brain natriuretic peptide (BNP), a cardiac hormone, were measured in 30 consecutive adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) during the perioperative period. BNP concentrations remained unchanged until 6 h after the cessation of bypass, and were elevated 12, 24, and 48 h post-bypass (P<0.0001 versus baseline). They had returned to the baseline values when measured 3 weeks postoperatively. The preoperative plasma BNP concentration correlated significantly with the left ventricular ejection fraction (r=-0.895). The peak plasma BNP concentration 24 h after bypass correlated with the cardiac index (r=-0.64), stroke volume index (r=-0.62), injection rate of dopamine hydrochloride (r=0.65), and aortic crossclamp time (r=0.57). There was also a significant correlation between the preoperative BNP concentration and the plasma BNP concentration 24 h post-CPB. These findings led us to conclude that the plasma concentrations of BNP become markedly and acutely elevated after cardiac surgery with CPB, and reflect the state of left ventricular function. Moreover, the severity of acute heart failure after cardiac surgery can be predicted by the preoperative plasma BNP concentration.

Beneficial actions of acidotic initial reperfusate in stunned myocardium of rat hearts

SummaryThe effects of metabolic acidosis and alkalosis in the initial reperfusate on post-ischemic stunned myocardium were investigated in isolated rat hearts. Metabolic acidosis and alkalosis were produced by altering the doses of artificial buffer (Tris) in place of sodium bicarbonate. All hearts were subjected to global ischemia for 15 min at 37°C. The initial reperfusate under study was given during the subsequent 10 min of reperfusion, just prior to release of the aortic clamp. After that, reperfusion using normal Krebs-Henseleit buffer solution was carried out for 40 min. The acidotic initial reperfusate (pH 6.8) resulted in better protection than the alkalotic initial reperfusate (pH 7.8), as demonstrated by 1) a higher recovery of aortic flow (80.6 % ± 3.8 % vs 32.7 % ± 4.8 %, p < 0.01), 2) a smaller leakage of creatine kinase during the initial reperfusion phase (6.0 ± 0.7 vs 14.6 ± 2.1 IU/10 min/g dry weight, p < 0.05) and during the post-ischemic Langendorff perfusion phase (8.8 ± 1.7 vs 37.3 ±5.2 IU/10 min/g dry weight, p < 0.05), and 3) a lower myocardial water content at the end of reperfusion (84.8 ± 0.2 % vs 85.7 % ± 0.3 %, p < 0.05). Not only Tris buffer system, but also HEPES buffer system indicated that acidotic initial reperfusate was effective to protect against myocardial injury. These results suggest that 1) the extracellular pH during initial reperfusion profoundly influences the reversible myocardial dysfunction (stunned myocardium), and 2) the acidotic initial reperfusate improves post-ischemic myocardial performance.

Congenital pericardial defect associated with ruptured type a aortic dissection

Congenital pericardial defect is a rare and little-known anomaly. Here we describe the unique clinical presentation of a 64-year-old man with partial defect of the left pericardium associated with ruptured acute type A aortic dissection manifesting massive left hemothorax. In this patient, the pericardial defect played the role of a pericardial draining window, which incidentally prevented the heart from cardiac tamponade. Emergent surgery was successfully performed with a prosthetic graft replacement.

Possible involvement of Na+H+ exchange in the early phase of reperfusion in myocardial stunning

Calcium overload during reperfusion after prolonged ischemia has been associated with the Na(+)-Ca2+ exchange system. It has been proposed that the promotion of Na(+)-Ca2+ exchange at reperfusion may be mediated by Na(+)-H+ exchange. To evaluate whether this hypothesis is applicable for stunned myocardium, we examined the influence of temporary suppression of Na(+)-H+ and/or Na(+)-Ca2+ exchange during early reperfusion in isolated rat hearts. Myocardial stunning was produced by global ischemia for 15 min at 37 degrees C. The initial reperfusate was given during the subsequent 10 min after ischemia, and followed by reperfusion with normal Krebs-Henseleit buffer solution for 40 min. Hemodynamic indices, creatine kinase in coronary effluent, and myocardial water content were measured during reperfusion. The functional recovery of stunned myocardium was improved with higher extracellular Na+ concentration and/or lower Ca2+ concentration of the initial reperfusate. Aortic flow recovery of group II (135 mM Na(+)-0.5 mM Ca2+) was 77.0 +/- 3.4%, which was substantially greater (P < 0.05) than that of other groups: group I (control, 135 mM Na(+)-1.5 mM Ca2+), 68.2 +/- 2.4%; group III (25 mM Na(+)-0.5 mM Ca2+), 48.7 +/- 2.9%; group IV (25 mM Na(+)-1.5 mM Ca2+), 21.6 +/- 1.5%. Administration of amiloride, an inhibitor of Na(+)-H+ exchange, in the initial reperfusate ameliorates cardiac damage and improved aortic flow recovery in a dose-dependent manner (10(-6) M, 70.1 +/- 3.7%; 10(-5) M, 77.3 +/- 1.7%; 10(-4) M, 82.0 +/- 2.1% vs control 68.2 +/- 2.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic progression of a subepicardial aneurysm after inferior myocardial infarction

A 62-year-old man presented to hospital with chest oppression. Coronary angiography revealed total occlusion of the right coronary artery and inferior myocardial infarction was diagnosed. He was treated by percutaneous coronary intervention with stenting for myocardial infarction. After four months, echocardiography revealed a huge aneurysm protruding below the inferior surface of the left ventricle. It was considered to be a pseudoaneurysm from the echocardiographic findings. The patient had no symptoms and he refused surgery, so progression of the aneurysm was monitored carefully. At seven months after revascularization, the aneurysm showed a marked increase in size, with a maximal diameter of 48 mm and orifice diameter of 22 mm. Accordingly, the patient agreed to undergo surgical excision. The aneurysm was resected and the defect was closed with a pericardial patch. Pathological examination revealed all of the myocardial elements in the aneurysm wall and thrombus in its lumen. In conclusion, this was a rare case of ventricular subepicardial aneurysm.

Effects of Calcium in Continuous Cardioplegia on Myocardial Protection

The effects of calcium (Ca) on a hyperkalemic cardioplegic solution for continuous cardioplegia were examined in an isolated perfused working rat heart model. The coronary arteries were perfused with a modified Krebs-Henseleit bicarbonate buffer (K-H) solution, containing various concentrations of Ca(0.1, 0.6, 1.2, and 2.5 mmol/l) and a high concentration of potassium (20 mmol/l), for 180 min, after which cardiac arrest was induced at 37°C for 180 min. Cardiac function and creatine kinase (CK) were measured. In the control group, K-H solution was infused in place of the cardioplegic solution, and cardiac arrest was not induced. No significant differences were observed between the groups infused with the K-H solution containing Ca concentrations of 0.6, 1.2, and 2.5 mmol/l in the percent recovery of aortic flow (82.1±2.9%, 80.6±2.0%, and 71.5±3.7% (mean±SEM) respectively) or in the recovery of other indices of cardiac function, or in CK leakage. There were also no significant differences in the recovery of cardiac function and CK leakage between these groups and the control group. In the Ca 0.1 mmol/l group, however, the characteristic Ca paradox was observed. These findings suggest that if the Ca concentration in a cardioplegic solution is higher than 0.6 mmol/l during continuous cardioplegia, excellent cardioprotective effects will be achieved.

Resection of a cardiac tumor extending into the inferior vena cava presenting as Budd-Chiari syndrome

This report describes the successful treatment of a case of cardiac adenocarcinoma with the clinical presentation as Budd-Chiari syndrome. Complete surgical excision of the atriocaval mass was successfully achieved under deep hypothermic circulatory arrest. Histopathological diagnosis of this tumor was tubular adenocarcinoma with positive immunostaining by carcinoembrionic antigen. Subsequent systemic search could not detect any evidence of extra-cardiac primary site and distant metastatic lesion. A 2-year follow-up without any adjuvant therapy revealed no sign of recurrence.

A Case of Endovascular Stent Graft Placement for a Proximal Anastomotic Aneurysm after Abdominal Aortic Aneurysm Surgery

症例は77歳,男性である.腹部大動脈瘤術後9年目に中枢側吻合部瘤のため入院した.吻合部瘤は腎動脈より3cm末梢側に存在し,最大径55mmであった.再手術症例で脳梗塞の既往があり,また解剖学的にも適応があったためステントグラフト内挿術を施行した.術後endoleakやmigrationは認めず,現在外来通院中である.ステントグラフト内挿術は腹部大動脈瘤の再手術症例に対し有効な手段であり,解剖学的に可能であれば積極的に試みるべき治療手技であると考えられた.

Bilateral Persistent Sciatic Artery Associated with Dissecting Aortic Aneurysm: Case Report

A case of bilateral persistence of the sciatic artery in association with a DeBakey type III dissecting aortic aneurysm is presented. Arteriography demon strated a patent persistent left sciatic artery with an aneurysm, and this artery connected to the popliteal artery. The sciatic artery was also present on the right side but had been occluded in the pelvis, so the hypoplastic superficial femoral artery provided the main route to the popliteal artery. Aneurysm or occlusion of a sciatic artery is common. However, the combination of a dissecting aortic aneurysm and a persistent sciatic artery has never been reported previously. When a persistent sciatic artery provides the main blood supply to the lower limb, anticoagulant therapy is recommended to prevent its occlusion.