Long-term nitrogen compound removal trends of a hybrid subsurface constructed wetland treating milking parlor wastewater throughout its 7 years of operation

This study evaluated the nitrogen compound removal efficiency of a hybrid subsurface constructed wetland, which began treating milking parlor wastewater in Hokkaido, northern Japan, in 2006. The wetland's overall removal rates of total nitrogen (TN) and ammonium (NH4(+)-N) improved after the second year of operation, and its rate of organic nitrogen (Org-N) removal was stable at 90% efficiency. Only nitrate (NO3(-)-N) levels were increased following the treatment. Despite increased NO3(-)-N (maximum of 3 mg-N/L) levels, TN removal rates were only slightly affected. Removal rates of TN and Org-N were highest in the first vertical bed. NH4(+)-N removal rates were highest in the second vertical bed, presumably due to water recirculation and pH adjustment. Concentrations of NO3(-)-N appeared when total carbon (TC) levels were low, which suggests that low TC prevented complete denitrification in the second vertical bed and the final horizontal bed. In practice, the beds removed more nitrogen than the amount theoretically removed by denitrification, as calculated by the amount of carbon removed from the system. This carbon-nitrogen imbalance may be due to other nitrogen transformation mechanisms, which require less carbon.

Performance of hybrid subsurface constructed wetland system for piggery wastewater treatment

The objective of this study was to evaluate performance of a hybrid constructed wetland (CW) built for high organic content piggery wastewater treatment in a cold region. The system consists of four vertical and one horizontal flow subsurface CWs. The wetland was built in 2009 and water quality was monitored from the outset. Average purification efficiency of this system was 95±5, 91±7, 89±8, 70±10, 84±15, 90±6, 99±2, and 93±16% for biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total carbon (TC), total nitrogen (TN), ammonium-N (NH4-N), total phosphorus (TP), total coliform (T. Coliform), and suspended solids (SS), respectively during August 2010-December 2013. Pollutant removal rate was 15±18 g m(-2) d(-1), 49±52 g m(-2) d(-1), 6±4 g m(-2) d(-1), 7±5 g m(-2) d(-1), and 1±1 g m(-2) d(-1) for BOD5, COD, TN, NH4-N, and TP, respectively. The removal efficiency of BOD5, COD, NH4-N, and SS improved yearly since the start of operation. With respect to removal of TN and TP, efficiency improved in the first three years but slightly declined in the fourth year. The system performed well during both warm and cold periods, but was more efficient in the warm period. The nitrate increase may be attributed to a low C/N ratio, due to limited availability of carbon required for denitrification.

MR imaging-based localized intra-arterial thrombolysis assisted by mechanical clot disruption for acute ischemic stroke due to middle cerebral artery occlusion

BACKGROUND AND PURPOSE

LIT-MCD is used in our institution for acute stroke due to MCA occlusion, with the goal of reducing symptomatic intracranial hemorrhage by maintaining recanalization of the occluded vessels. The purpose of the study was to investigate the safety and efficacy of LIT-MCD and to identify factors associated with a poor outcome in patients undergoing this procedure.

MATERIALS AND METHODS

LIT-MCD for MCA occlusion was performed in 90 of 1907 consecutive patients with acute stroke admitted to our institution. Radiographic data and clinical outcome were evaluated in the 90 patients, and factors predictive of a poor outcome (3-month mRS score, 3-6) were investigated by multivariate analysis.

RESULTS

Recanalization was achieved in 73 of the 90 patients (81%); symptomatic intracranial hemorrhage occurred in 7 (8%); procedure-related complications, in 9 (10%); and a favorable clinical outcome (3-month mRS score, 0-2), in 48 (53%). A high baseline NIHSS score (≥20), a low preprocedural ASPECTS on MR imaging (≤7), proximal M1 occlusion (in the horizontal segment of the MCA at or proximal to the lenticulostriate arteries), and no recanalization were significant predictors of a poor clinical outcome.

CONCLUSIONS

LIT-MCD is a safe and effective treatment for acute stroke due to MCA occlusion. However, further intervention is needed to improve the outcome of patients with proximal M1 occlusion.

Transluminal angioplasty and stenting for intracranial vertebrobasilar occlusive lesions in acute stroke patients

BACKGROUND AND PURPOSE

The clinical outcome is often poor in acute stroke patients with a serious neurological status due to occlusive lesions of the intracranial vertebral and/or basilar artery (IVBA). The purpose of this study was to investigate retrospectively the clinical features and outcome of acute stroke patients who underwent transluminal angioplasty and/or stenting (TAS) for occlusive lesions of the IVBA and to clarify the prerequisites for improvement of outcome.

MATERIALS AND METHODS

Of 1690 consecutive acute ischemic stroke patients admitted to our institution, TAS for occlusive lesions of the IVBA was performed within 7 days after stroke onset in 28 patients. We classified these patients into 2 groups, those with total occlusion (occlusion group) and those with a high-grade stenosis (stenosis group), and compared the preprocedural neurologic status (severe: National Institutes of Health Stroke Scale >20), the rate of technical success, major procedure-related complications, subacute occlusion of the treated vessel, and favorable clinical outcome (0-2 points on a 3-month modified Rankin Scale) between the 2 groups.

RESULTS

In the occlusion group (n = 16) and stenosis group (n = 12), a severe preprocedural neurologic status was seen in 13 and 1 patients, respectively (81% versus 8%; P = .0001); technical success was achieved in 13 and 11 patients, respectively (81% versus 92%; P value not significant [NS]); complications occurred in 6 and 0 patients, respectively (38% versus 0%; P < .05); subacute occlusion was seen in 4 and 1 patients, respectively (25% versus 8%; P = NS); and a favorable clinical outcome was obtained in 3 and 9 patients, respectively (19% versus 75%; P < .01).

CONCLUSION

The clinical outcome of patients who underwent TAS for total occlusion of the IVBA was poor. Improvement of outcome requires reduction of procedure-related complications and subacute occlusion.

Clot removal therapy by aspiration and extraction for acute embolic carotid occlusion

BACKGROUND AND PURPOSE

The purpose of our retrospective study was to investigate the feasibility, safety, and efficacy of clot removal therapy by aspiration and extraction for patients with acute stroke with embolic internal carotid artery (ICA) occlusion.

METHODS

Of 814 consecutive patients with acute ischemic stroke admitted to our institution from March 2003 to April 2005, clot removal therapy was performed for 14. Inclusion criteria were patients (1) presenting within 6 hours of onset of cardioembolic stroke, (2) with serious neurologic symptoms defined by a National Institutes of Health Stroke Scale (NIHSS) score of at least 11, (3) without extensive high signal intensity on diffusion-weighted MR images but with decreased ipsilateral hemispheric cerebral blood flow on perfusion-weighted images (perfusion/diffusion mismatch), and (4) with total ICA occlusion on angiograms. We removed clots by aspiration and extraction with a microsnare through either a guiding or balloon guide catheter. Radiographic results, 7-day NIHSS, 3-month modified Rankin Scale, and procedure-related complications were evaluated.

RESULTS

Of 10 patients treated with the balloon guide catheter to temporarily interrupt proximal flow, 7 obtained complete or partial recanalization. The 4 patients treated with the guiding catheter had no recanalization. Of the 7 patients with recanalization, 6 had favorable 7-day neurologic and 3-month functional outcome; all showed anatomic crossflow via the anterior communicating artery. A procedure-related complication, distal embolization into the ipsilateral anterior cerebral artery, occurred in 1 patient.

CONCLUSION

Balloon guide catheter-assisted clot removal therapy for embolic ICA occlusion may provide a high recanalization rate and good clinical outcome in patients with anatomic crossflow.

Successful Stenting Seven Days After Atherothrombotic Occlusion of the Intracranial Internal Carotid Artery

PURPOSE

To report a case of successful stenting after a subacute stroke.

CASE REPORT

A 75-year-old man presented with sudden onset of right-sided weakness and difficulty speaking. Imaging revealed an occlusion of the left petrous to lacerum internal carotid artery (ICA) segment and slightly decreased cerebral blood flow in the left hemisphere; there were stenoses of the ostial and cavernous ICA segments on the right. On the seventh day after the stroke, he underwent protected carotid angioplasty of the left intracranial ICA occlusion to reduce the high risk of ischemic stroke owing to bilateral disease. An external arteriovenous shunt was established with an occluding balloon in the proximal ICA and a filter in the femoral vein. After protected balloon dilation of the ICA occlusion, a 3.5 x 18-mm balloon-expandable coronary stent was deployed across the residual stenotic segment. An intraluminal filling defect of the petrous ICA segment suggested an arterial dissection or intraluminal thrombus, so another 2 coronary stents were deployed. Macroscopically visible materials were captured in the filter. The patient had a good clinical course and was discharged without neurological deficits on the twelfth day after the stroke. Angiography at 3 months confirmed no restenosis of the stented vessel.

CONCLUSION

This experience suggests that short atherothrombotic intracranial ICA occlusions can be opened in the subacute stroke stage without distal migration of thrombi under proximal protection and flow reversal.

[Ischemic stroke in a young patient with methylephedrine addiction: a case report]

We report a case of a young patient who had an ischemic stroke due to methylephedrine addiction. A 39-year-old man was admitted to our hospital because of right hemiplegia and persistent numbness. Brain diffusion-weighted magnetic resonance images demonstrated multiple hyperintensity spots in the deep and superficial borderzone area of the left hemisphere. The patient had no obvious diseases that might have caused ischemic stroke, including potential cardiac sources of embolism, vasculopathy of the cerebral artery, or abnormalities of blood coagulation. However, we found that the patient had started to abuse methylephedrine at the age of 20 years old, and we suspected that drug abuse might have caused his ischemic stroke. Although previous reports have associated ischemic stroke with ephedrine, no reports have related this condition to methylephedrine. However, our case suggests that methylephedrine abuse may cause ischemic stroke.

Hyperbaric Oxygen Combined With Intravenous Edaravone for Treatment of Acute Embolic Stroke: a Pilot Clinical Trial

The efficacy of hyperbaric oxygen (HBO) therapy combined with intravenous edaravone (free radical scavenger) administration was prospectively investigated in patients with acute embolic stroke involving the anterior cerebral circulation. Patients with acute embolic stroke in the anterior cerebral circulation admitted within 48 hours of onset from August 2001 to March 2002 with National Institutes of Health Stroke Scale (NIHSS) scores on admission of 5 or more were assigned randomly to HBO and control groups. The HBO group underwent HBO therapy combined with intravenous edaravone administration for 7 days, whereas the control group received only conventional treatment. The primary endpoint was the modified Rankin Scale score at 90 days (favorable outcome, score 0 or 1). The secondary endpoint was the NIHSS score at 7 days. Analysis was carried out by intention to treat. Six of the 19 patients in the HBO group, but only one of the 19 patients in the control group, had favorable outcomes at 90 days (p < 0.05), although NIHSS score at 7 days did not differ significantly between the two groups. HBO therapy combined with intravenous edaravone administration appears to be effective for the treatment of patients with acute embolic stroke in the anterior cerebral circulation.

Successful thrombectomy in acute terminal internal carotid occlusion using a basket type microsnare in conjunction with temporary proximal occlusion: a case report

Recanalization therapy is controversial in patients with acute stroke due to terminal internal carotid artery (ICA) occlusion. A 78-year-old man underwent successful percutaneous transarterial microsnare-assisted thrombectomy (PMT) for the treatment of acute terminal ICA occlusion, which was recanalized completely. This case report suggests that PMT is a potential treatment for patients with acute embolic occlusion of the terminal ICA.

Emergency carotid artery stent placement in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

An effective intervention has not yet been established for patients with acute ischemic stroke who present with serious neurologic symptoms due to occlusion or a high-grade stenosis of the internal carotid artery (ICA). The aim of our retrospective study was to investigate the feasibility, safety, and efficacy of emergency carotid artery stent placement to improve neurologic symptoms and clinical outcome.

METHODS

Of 896 consecutive patients with acute ischemic stroke who were admitted to our institution within 7 days of onset from July 2000 to June 2003, 17 patients (1.9%) with occlusion or a high-grade stenosis of the ICA underwent emergency carotid artery stent placement. We reviewed their records for neurologic outcome, per the National Institutes of Health Stroke Scale (NIHSS) score, before and at 7 days after stent placement; clinical outcome, per the modified Rankin Scale score (mRS), at 90 days; frequency of procedure-related complications within 30 days; and recurrence rate of ipsilateral ischemic stroke within 90 days.

RESULTS

Carotid lesions were dilated completely in all patients. Median NIHSS scores before emergency stent placement and at 7 days were 12 and 5, respectively, showing significant improvement (P < .01, Wilcoxon rank sum test). Ten patients (59%) had favorable outcomes (mRS score 0-1) at 90 days. Irreversible complications occurred in two patients (12%): distal embolism in one and intracerebral hemorrhage in the other. No ipsilateral ischemic stroke recurred.

CONCLUSION

Emergency carotid artery stent placement can improve the 7-day neurologic outcome and may improve the 90-day clinical outcome in selected patients with ischemic stroke.

Magnetic noise rejection in the MCG using independent component analysis

In magnetocardiogram (MCG) measurements, the magnetic noise from any magnetic wire, used to suture the sternum after heart surgery, becomes a problem. As one method of noise rejection, independent component analysis is seen here to be effective. In this study, MCG measurements were carried out under conditions where a wire was attached to a normal subject, also where no wire was attached. Signal processing by independent component analysis was carried out in order to reduce the effect of magnetic noise from the wire. From the comparison of the waveforms after this signal processing and the waveforms where the wire was not attached, it was apparent that the magnetic noise from the wire was reduced. Thus, we have shown that independent component analysis is effective for the reduction of magnetic noise from a magnetic wire, in MCG measurements.

[Surgically repaired bilateral giant bullae after long-time follow-up; report of a case]

A 44-year-old male was admitted to our hospital owing to severe dyspnea of sudden onset. Chest X-ray disclosed bilateral giant bullae. His pulmonary function was severely depressed. VC (%) was 2.61 l (66.3%) and FEV1% (%) was 1.47 l (64.5%). Indication of surgical repair of giant bullae are; space occupying lesion more than 25-50% in 1 thorax, progressive dyspnea, enlargement over time irrespective of symptoms, and expectation that re-expand the normal lung. He was conducted two-staged bullectomy using video-assisted thoracoscopic surgery (VATS) with small incisions. First operation was performed to left lung. Pulmonary function improved. VC (%) increased 3.02 l (76.8%) and FEV1% (%) 2.36 l (76.6%). After second operation, which was performed to right lung, VC (%) was 2.40 l (60.5%) and FEV1% (%) was 2.21 l (92.1%). Hugh-Jones grade improved class IV to class I. Postoperative course was uneventful and he was discharged 15 days after second operation. Two-staged bullectomy was appropriate in this case, because he might have suffered from re-expansion pulmonary edema after first surgery. The extent of recovery of pulmonary function was unpredictable. And performing right lung bullectomy just after the left bullectomy may be dangerous, because the patient have to receive anesthesia with his resected left lung. There is some possibility that patient who has bilateral giant bullae shows severe dyspnea during the progress, care should be taken to conduct operation as soon as possible.

Paramyotonia congenita due to a de novo mutation: a case report

A Japanese man with a negative family history of paramyotonia congenita (PMC) was evaluated for symptoms of cold-induced weakness and stiffness. Exercise testing revealed findings characteristic of PMC, and a genetic analysis was therefore performed. A well-known sodium channel mutation for PMC (T1313M) was identified in the patient, but was absent in his biological parents. These data demonstrate the occurrence of a de novo mutation, suggesting that evaluation for PMC should be performed in patients with typical symptoms even if the family history is negative.

Midterm results of conservative repair of the incompetent bicuspid aortic valve

AIM

Repair of the bicuspid aortic valve is not generally considered the treatment of choice. Our success with this procedure leads us to report our immediate and mid-term

RESULTS

METHODS

From August 1993 to December 2000, 19 patients with aortic regurgitation due to congenital aortic valve underwent aortic valve repair (17 men and 2 women with a mean age of 42+/-17 years; range, 16 to 70 years). The mean preoperative aortic regurgitation grade was 3.1+/-0.8 on a scale of 1 to 4. Mean preoperative New York Heart Association functional class was 1.9+/-0.8. Fourteen patients had pure aortic regurgitation, 2 also had infectious endocarditis, 1 had angina pectoris, and 2 had an ascending aortic aneurysm.

RESULTS

There was 1 hospital death (5.2%), and 1 patient required re-operation due to recurrent infectious endocarditis. Mean aortic regurgitation grade at discharge was 1.1+/-0.9, and functional class was 1.1+/-0.2. All patients were followed for a mean duration of 40+/-23 months (range, 0.5 to 84 months). There was 1 late death, and two patients required aortic valve replacement. The 5-year survival rate was 90+/-7%. The 1- and 5-year re-operation-free rates were 87+/-12% and 76+/-23%.

CONCLUSIONS

Bicuspid aortic valve repair is a safe procedure with good early postoperative

RESULTS

However midterm results are not satisfactory. Re-operation is a promising alternative and progress aortic regurgitation were complications. Bicuspid aortic valve repair to valve replacement that requires additional study to individualize treatment.

[Aortic valve repair with minimal access "J" sternotomy]

Recently many cardiovascular operations have been performed with minimally invasive cardiac surgery (MICS). It is reported that MICS is superior to standard full sternotomy in regard to cosmetic and post-operative recovery. In our institution, aortic valve repair operations have been performed to aortic valve insufficiency. This time, we performed aortic valve repair by minimal access "J" sternotomy. A 63-year-old male with degenerative aortic regurgitation underwent aortic valve repair by MICS. He had experienced dyspnea on exertion 7 days before admission. Preoperative transthoracic echocardiogram showed the grade of aortic regurgitation (AR) was severe. Surgery was successful and the grade of AR became trivial. This combined procedure have merits for patients because of freedom from anticoagulation and small incision. Such combined surgery may be indicated in the treatment in a subset of patients with degenerative AR.

[Valvular heart surgery in osteogenesis imperfecta]

Osteogenesis imperfecta is a disease in which fragile bones readily cause fracture. Valvular disease concurrently develops. However, the surgery-related mortality rate is approximately 30%. In this study, we report 2 patients with osteogenesis imperfecta who underwent valvular heart surgery. Patient 1 was a 31-year-old male. He had previously been diagnosed as having osteogenesis imperfecta. Echocardiography suggested aortic valve insufficiency, and aortic valve replacement was performed. Patient 2 was a 59-year-old male. During admission, osteogenesis imperfecta was diagnosed. Echocardiography suggested mitral valve insufficiency, and mitral valve plasty was performed. In the 2 patients, intraoperative hemorrhage was marked. However, there were no fatal complications. We also reviewed the literature.

Selection of surgical methods for infected infrarenal abdominal aortic aneurysms

BACKGROUND

There is no standard treatment for patients with infected abdominal aortic aneurysm (AAA). To determine the basis for selection of a surgical method, we reviewed our experiences with all patients who underwent surgery for infected infrarenal AAA.

METHODS

Between 1993 and 2000, 6 patients with infected infrarenal AAA underwent surgery. Extra-anatomic bypass grafting was performed in 2 of 3 patients with infection extending into the retroperitoneum. In situ grafting was performed in 3 patients with localized infection and in 1 patient with extended infection.

RESULTS

Severe peritonitis occurred in 2 patients with extended infection in the early postoperative phase. One patient, who had undergone in situ grafting, died of sepsis. The other patient, who had undergone extra-anatomic bypass grafting, was treated by continuous irrigation with an electrolyzed strong acid aqueous solution (ESAAS). He recovered gradually and was discharged. After a follow-up period with a mean of 40 months (range: 17-102 months), all 5 patients who survived surgery are alive and asymptomatic.

CONCLUSIONS

It was suggested that the method used for revascularization should be selected based on the degree of diffusion of infection. For a patient with extended infection, postoperative continuous irrigation with ESAAS appears to be effective in eradicating retroperitoneal infection.

[Redo coronary artery bypass grafting using the patent left internal thoracic artery graft as an in flow with composite internal thoracic artery Y grafting; report of a case]

In redo coronary artery bypass grafting (CABG), graft selection and revascularization methods are major problems. We experienced a redo-CABG with occluded previous vein grafts. These grafts were to the circumflex artery and right coronary artery. We conducted operation using cardiopulmonary bypass. We at this operation, chose right internal thoracic artery (RITA) as a conduit and anastomosed it to the side of functioning left internal thoracic artery (LITA) graft, and then diogonal branch, posterolateral branch, and atrioventricular branch were revascularized with the RITA. Post operative course was uneventful. Internal thoracic artery (ITA) is superior to vein graft and other arterial graft as to long term patency. We believe composite Y graft with the use of bilateral ITA can be one of the revascularization strategy in redo CABG.

[Giant coronary artery aneurysm in diagonal artery; report of a case]

We report a giant coronary artery aneurysm occurred in the diagonal artery. A 44-year-old woman was referred to our institution for further examination of chest X-ray abnormality. Computed tomography revealed a 6 cm intracardiac mass adjacent to pulmonary artery. Cardiac catheterization revealed a giant coronary artery aneurysm with the large thrombus in the diagonal artery. A giant aneurysm 6 cm in diameter was exposed through a median sternotomy. Under beating heart with cardiopulmonary bypass, the aneurysm was opened and organized thrombus was removed. The influx and efflux of the aneurysm were identified and ligated. Under arrested heart with cardioplegia, the diagonal artery was bypassed with the left internal thoracic artery. Finally the aneurysm was obliterated with the running suture. The patient discharged at the 17th postoperative day without any complications. Histologic evaluation of the resected aneurysm revealed atherosclerotic change, destruction of vascular layers and infiltration of inflammatory cells. These findings suggested previous history of coronary arteritis. The coronary aneurysm in this case might be resulted from Kawasaki disease.

Vascular relaxant effects of toborinone on the isolated canine internal mammary artery

This study was conducted to evaluate the vascular relaxant effects of toborinone on canine internal mammary ring preparations. We determined the concentration-contraction curves for various vasoconstrictors, namely norepinephrine, serotonin, U46619, endothelin-1, phenylephrine, and KCl in internal mammary artery (IMA) preparations, then assessed the vascular relaxant effects of the test drugs. As models, preparations with and without functional endothelium were used. As vasorelaxants, we used milrinone, papaverine, and nitroglycerin. Toborinone produced concentration-dependent relaxation in preparations precontracted with norepinephrine and serotonin. However, the vascular relaxant effect of toborinone on KCl-induced contraction was weaker than those on norepinephrine- and serotonin-induced contraction. Toborinone produced concentration-dependent relaxation in preparations with, and those without functional endothelium. There was no difference in the potency between the preparations with, and those without functional endothelium. The relaxing effect of toborinone on norepinephrine-induced contraction (EC50 = 1.3 x 10(-6) M) was significantly weaker than that of nitroglycerin (EC50 = 7.8 x 10(-8) M), equal to that of papaverine (EC50 = 2.2 x 10(-6) M), and significantly stronger than that of milrinone (EC50 = 3.3 x 10(-6) M). These results demonstrate that toborinone produces relaxant effects on canine IMA preparations, and that it may be effective in the treatment of IMA malperfusion syndrome.

Plasmapheresis affects T helper type-1/T helper type-2 balance of circulating peripheral lymphocytes

Plasmapheresis not only removes humoral factors, but may also modulate cellular immunity. We investigated whether plasmapheresis influenced T helper type-1/T helper type-2 (Th1/Th2) cytokine-producing-cell balance in 3 patients with neuroimmunological disease. The production of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), and IL-4 in the culture supernatant of peripheral blood mononuclear cells stimulated by anti-CD3 and anti-CD28 was assayed. In 2 of 3 patients, plasmapheresis (immunoadsorption or plasma exchange) reduced Th1/Th2 cytokine ratio. The results may suggest that plasmapheresis induces a shift of Th1/Th2 balance in peripheral blood.

Aortic valve repair of congenital bicuspid aortic valve associated with aneurysm of the ascending aorta

Two unusual cases of congenital bicuspid aortic valve associated with aneurysm of the ascending aorta are reported. One patient with a 7-cm ascending aortic dilatation and aortic regurgitation (AR) (II/IV), and another with a 6-cm ascending aorta and AR (III/IV), presented for treatment. Replacement of the ascending aorta and aortic valve repair were performed in both cases. Aortic valve repair included resection of the raphe, leaflet plication and subcommissural annuloplasty. Both patients had satisfactory results in the early postoperative period. Despite the promising outcomes after surgery in these patients, long-term changes in valve function and durability remain unknown. Additional close observation and monitoring are required before the procedure can be recommended as the standard of care.

Aortic valve repair in dominant aortic regurgitation

OBJECTIVE

We studied immediate and mid-term results after aortic valve repair.

METHODS

Immediate and mid-term results were studied in 63 patients undergoing aortic valve repair, calculating survival and reoperation free rates.

RESULTS

Subjects were 49 men and 14 women aged 15 to 76 years (mean: 53 +/- 17 years). Mean preoperative aortic regurgitation grading of 1 to 4 was 3.2 +/- 0.7. Mean preoperative New York Heart Association functional class was 1.9 +/- 0.8. Two in-hospital deaths occurred. (3.2%) Mean aortic regurgitation grade at discharge was 1.3 +/- 0.8 (p < 0.0001; vs preoperative grade) and functional class was 1.1 +/- 0.2 (p < 0.0001; vs preoperative class),--significantly improved. Overall follow-up was 98.4%, and mean follow-up continued 41.4 +/- 22.1 months. Mean functional class at follow-up was 1.2 +/- 0.4 (n = 49), improved from preoperative class (p < 0.0001). Mean aortic regurgitation grading at follow-up was 1.8 +/- 0.8 (n = 41), improved from preoperative grading (p < 0.0001). Five-year survival was 95.1 +/- 2.8%. One-year reoperation freedom was 96.6 +/- 2.4% and 5-year 77.9 +/- 6.9%.

CONCLUSIONS

Survival after surgery was good, while reoperation was comparable to other reports but less satisfactory compared to reoperation freedom after aortic valve replacement. Based on reoperative findings, a change in indication was made. We believe technical refinements could improve postoperative results.

Annuloaortic repair in the treatment of aortic regurgitation and aortic root pathology

We developed a new technique of aortic root repair which may be able to eliminate the potential problem of leaflet damage, resulting from the direct contact of the aortic leaflets with synthetic vascular grafts during systole. This report describes our technique of annuloaortic repair and the operative results. Between February 1995 and October 1998, 13 patients underwent annuloaortic repair. The patients included 8 males and 5 females (mean age 50 years). Four patients had grade IV/IV aortic regurgitation (AR), 5 had III/IV AR, 2 had II/IV AR, and 1 had no AR preoperatively. Regarding the preoperative functional status, 1 patient was classified as New York Heart Association class IV, 5 were class III, 6 class II, and 1 class I. Concomitant cardiovascular procedures were performed in 12 cases. Aortic valvuloplasty or annuloplasty was performed in 7 patients. Both operative and short-term postoperative results with pre- and postoperative echocardiographic findings were studied retrospectively. The mean total cardiopulmonary bypass time was 212 min. The mean aortic cross-clamp time was 130 min. Circulatory arrest was induced in 5 patients. Postoperatively, 7 patients had no AR. Three patients had grade I/IV AR and 3 had grade II/IV AR. Perioperative changes in aortic annulus, mid-sinus portion, and sinotubular junction diameters were determined echocardiographically in 5 patients. The preoperative diameters were 2.7 +/- 0.4, 5.4 +/- 0.5, and 4.7 +/- 1.0 cm, respectively. The postoperative diameters were 2.3 +/- 0.5, 4.2 +/- 0.5, and 3.5 +/- 0.5cm, respectively. Ten patients were class I and 2 were class II. This technique of annuloaortic repair with or without aortic valvuloplasty is applicable to a certain subset of patients with aortic root disease and AR. Both the indications for this procedure and the long-term results should be confirmed.

Survival and sinus rhythm maintenance after modified Cox/maze procedure and mitral valve operation in patients with chronic atrial fibrillation

OBJECTIVE

Sinus rhythm gained after the Cox/maze procedure concomitant with mitral valve operation has demonstrated long-term attrition during the follow-up, no information exists on whether the type of mitral valve operation--(repair vs. replacement)--affects this sinus rhythm maintenance rate. We retrospectively studied patients undergoing concomitant mitral valve operation and Cox/maze procedure to answer this question.

METHODS

Between April 1993 and August 1995, 87 consecutive patients--35 men and 52 women (mean age: 59.3 years)--with chronic atrial fibrillation and mitral valve disease underwent the modified Cox/maze procedure and concomitant mitral valve operation, with 56 having mitral valve repair (repair group) and 31 mitral valve replacement (replacement group). Patients were followed up and changes in rhythm studied retrospectively.

RESULTS

Follow-up for a mean 51.3 +/- 11.6 months was completed in 82 of 83 long-term survivors (99%). Repair group surgery survival was 98.1 +/- 1.9% at 1 year and 94.2 +/- 3.2% at 5 based on the Kaplan-Meier method. Replacement group surgery survival was 85.7 +/- 5.9% at 1 year and 82.9 +/- 6.4% at 5. Probability in sinus rhythm maintenance for the repair group at 1 year was 88.6 +/- 5.4% and at 5 years was 67.6 +/- 9.1%. Probability in sinus rhythm maintenance for the replacement group at 1 year was 95.7 +/- 4.3% and at 5 years was 65.0 +/- 11.1%.

CONCLUSIONS

Medium-term results after the Cox/maze III procedure concomitant with mitral valve operation are good. The attrition of sinus rhythm maintenance appears similar by the completion of 5-year follow-up.

[A case of aconitine poisoning saved with cardiopulmonary bypass]

"Torikabuto" is a kind of plant which contains deadly poison. Its ingredient is aconitine alkaloids. We report a case of aconitine poisoning with fatal arrhythmia and acute pulmonary edema who was saved with cardio pulmonary bypass. A 41-year-old male ate to mistake "Torikabuto" for wild plant. He developed symptoms of dysarthria and admitted to our hospital. He developed ventricular tachycardia and fibrillation soon after his admission. Then he developed cardiogenic shock. He was resuscitated and supported with a percutaneous cardio pulmonary bypass. Ventricular tachycardia disappeared 24 hours after admittion. About 1 week later, cardio pulmonary bypass was terminated and about 3 months later, he discharged from our hospital.

Reduction of heparin dose is not beneficial to platelet function

BACKGROUND

To clarify the effects of the reduction of heparin dose on platelets, we conducted a prospective trial on patients undergoing cardiopulmonary bypass.

METHODS

Twenty-three patients undergoing coronary artery bypass grafting were studied. The systemic heparin dose was 300 IU/kg in the control group (n = 11) and 200 IU/kg in the low-dose group (n = 12). Heparin-coated cardiopulmonary bypass equipment was used for both the groups. Platelet counts, beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) concentrations were measured and the arterial filters in the circuits were observed by electron microscopy.

RESULTS

Platelet counts were higher in the low-dose group than in the control group (p < 0.01). No significant differences were found in the platelet release reaction (beta-TG and PF4). Electron microscopy demonstrated that cell adhesion on the arterial filters in the control group was significantly more marked than in the low-dose group (p < 0.01) and that most of the cells on the filters were neutrophils.

CONCLUSIONS

We conclude that the reduction of heparin dose with the use of heparin-coated equipment reduces platelet loss, but does not suppress the platelet release reaction. Furthermore, the reduction of heparin dose reduces adherence of leukocytes to the filter surface.

Medium-term results after the modified Cox/Maze procedure combined with other cardiac surgery

OBJECTIVE

Long-term results after the modified Cox/Maze III procedure combined with other cardiac procedure for the treatment of organic heart disease and chronic atrial fibrillation (AF) has not been clarified. This report describes our medium-term results after such operation.

METHODS

Between March 1993 and August 1995, 104 consecutive patients with chronic AF underwent the modified Cox/Maze III procedure combined with other cardiac procedure. There were 100 long-term survivors. There were 45 men and 55 women, with ages ranging from 21 to 77 years (mean 59.7). Patients were followed up and changes in rhythm, need for pacemaker implantation, and the incidence of CNS (central nervous system) complications were retrospectively studied.

RESULTS

The follow-up was complete in 103 patients and 99 long-term survivors (99%). The mean follow-up period was 44.6 +/- 1.1 months. In the immediate postoperative period, 73 patients regained sinus rhythm (SR group), 21 patients were in AF (AF group), and six patients underwent pacemaker implantation because of sick sinus syndrome (SSS). During the follow-up period, eight patients died. One- and 5-year survival rates (Kaplan-Meier) after surgery was 95.1 +/- 2.3 and 87.8 +/- 3.4% for the entire group. Preoperative NYHA class was 2.5 +/- 0.7 and medium-term NYHA class was 1.5 +/- 0.5. (P < 0.001) Changes in rhythm for the SR group were followed. Fifty-two patients of the SR group stayed in SR (72%), 16 patients converted back to AF (22%), and four patients had newly-developed SSS (6%) at follow-up period. Probability in SR maintenance for SR group at 1 year was 88.8 +/- 3.7% and at 5 years was 64.8 +/- 7.5%. Five patients experienced the CNS complication during the follow-up period. Two of the AF group and two of the SR group patients developed cerebral/cerebellar infarction. One of the SR group patients experienced small cerebral bleeding.

CONCLUSIONS

The medium-term results after the modified Cox/Maze III procedure concomitant with other cardiac procedure are good with improved functional status and good survival rate. However, there seems to be gradual but constant attrition in the rate of SR maintenance in SR group.

[Aortic valve papillary fibroelastoma in a patient with mitral valve regurgitation]

Papillary fibroelastoma is a rare cardiac tumour. We describe a patient with mitral valve regurgitation and aortic valve papillary fibroelastoma. The patient was 62-year-old woman. She was referred to us for surgical treatment of mitral valve. Preoperative echocardiography showed rheumatic mitral valve regurgitation (Sellers grade III) and it also demonstrated mobile masses of the aortic valve. At operation, mitral valve was repaired by a posterior annuloplasty. Through the aortotomy, small tumors were found to be attached to each cusps of the aortic valve and they were successfully removed. The histopathologic diagnosis was papillary fibroelastoma of the aortic valve. The postoperative course was uneventful.

Myasthenic crisis with delayed recovery after plasmapheresis

We report on 2 elderly patients with myasthenia gravis in whom recovery from crisis was prolonged despite intensive plasmapheresis (PP). In both patients, the anti-acetylcholine (anti-AChR) titer failed to fall sufficiently after completing PP. These patients might have had antibodies that produced a more pronounced effect on the degradation of AChR, or the synthesis of AChR might have been reduced by aging. The anti-AChR titer did not correlate with a reduction of IgG after PP in 1 patient. Successful treatment was achieved by keeping the anti-AChR titer at a low level via the concomitant use of prednisolone with PP.

AP window and anomalous origin of right coronary artery from the window

Aortopulmonary window (APW) is a rare malformation. We recently operated on a child with APW, ventricular septal defect, right aortic arch, and anomalous right coronary artery from the APW. This patient also had a chromosomal abnormality. He underwent the repair of this complex lesion in a staged operation.

New technique of posterior mitral annuloplasty

We have developed a new technique of mitral annuloplasty applicable in patients with rheumatic mitral regurgitation. This technique is designed to advance anteriorly the posterior annulus and leaflet and to gain more coaptation area. Technical details of this procedure are presented.

Successful treatment of rapidly progressive lupus nephritis associated with anti-MPO antibodies by intravenous immunoglobulins

We report a case of systemic lupus erythematosus (SLE) associated with crescentic glomerulonephritis and myeloperoxidase-specific anti-neutrophil cytoplasmic antibodies (MPO-ANCA). A 34-year-old Japanese female patient diagnosed with SLE developed rapidly progressive renal failure and nephrotic syndrome. Haemodialysis was required to restore renal function. Methylprednisolone pulse therapy followed by plasmapheresis did not suppress the progression of renal failure, so she was treated with high-dose intravenous immunoglobulin (IV-IG) therapy, which was well tolerated and effectively prevented renal failure. A renal biopsy showed diffuse proliferative lupus nephritis (WHO classification IVc) with predominant crescent formation and scant subendothelial immune deposits. These findings indicate that, in addition to lupus nephritis, which usually results from the deposition of circulating or locally formed immune complexes, MPO-ANCA may be involved in the pathogenesis of crescentic glomerulonephritis. Furthermore, we propose that IV-IG is an effective therapy for MPO-ANCA-related renal crisis in lupus nephritis.

Double valve repair and maze procedure for degenerative valvular disease and chronic atrial fibrillation

A 61-year-old male with degenerative aortic valve regurgitation, mitral valve regurgitation and chronic atrial fibrillation underwent a combined reparative procedure consisting of aortic valve repair, mitral valve repair and maze procedure. Surgery was successful and postoperatively the patient is in NYHA class I, without anticoagulation. To the best of our knowledge, this is the first clinical report of this combined reparative surgery. As advances are made in valve repair surgery, it is expected that similar combined procedures will be performed more frequently in future. The benefits of avoiding valve replacement and anticoagulation after such combination treatment is discussed.

[Supervised cardiac rehabilitation for the patients with the disturbance of the motor function after cardiac surgery: the significance of physical therapists' participation]

There are sporadic instances of patients with the motor function disturbance of non-cardiac origin after cardiac surgery, and these patients may need prolonged post-operative cardiac rehabilitation. We established our cardiac rehabilitation program for post-operative patients and a total of 124 patients underwent the post-operative cardiac rehabilitation program (male 73, female 51, average age 60). Among them, 12 patients (9.7%) received the physical therapy for the disturbance of motor function post-operatively. These 12 patients were retrospectively studied. Physical therapies performed were the exercise therapy to improve the range of motion to prevent contracture in 3 patients with peroneal nerve palsy and drop foot, the exercise therapy for pre-operative or post-operative hemiplegia in 6 patients, the instruction of exercise for lumbago in 1 patient with spinal cord disease, respiratory physical therapy in 1 patient, and myotherapy for arthritis in 1 patient. Treatment with physical therapy was very useful in rehabilitating these patients. Active participation of physical therapists in cardiac rehabilitation for patients with the disturbance of motor function after cardiac surgery is possible. It is expected that their participation may improve the quality of life in this subset of patients.

[A case of constrictive pericarditis with atrial fibrillation after mitral valve repair and Maze III procedure]

We report a case of constrictive pericarditis with atrial fibrillation after mitral valve repair and the Maze III procedure. A 66-year-old male underwent mitral valve repair and the Maze procedure for mitral valve regurgitation and chronic atrial fibrillation. About 4 months after discharge, he suffered from shortness of breath. Physical examination revealed a heart rate of 80 beats/min with irregular rhythm, external jugular venous dilatation and abdominal ascites. Electrocardiography revealed atrial fibrillation, and chest X-ray revealed moderate left pleural effusion. Computed tomographic images of the chest showed a that thickened pericardium. A distinct diastolic dip and plateau pattern were recognized on cardiac catheterization. The right atrial, right ventricular end-diastolic, and pulmonary wedge pressures were elevated. Idiopathic pericarditis and recurrent atrial fibrillation were diagnosed and pericardiectomy was performed through a median sternotomy incision. Intraoperatively, the atrial fibrillation converted spontaneously to sinus rhythm. The postoperative hemodynamics improved after pericardiectomy. Total pericardiectomy alone may not convert the rhythm to sinus rhythm in patients with constrictive pericarditis and chronic atrial fibrillation. In this case, atrial fibrillation converted to sinus rhythm during the procedure. This case report suggests that adequate unloading of atrial pressures is necessary for the maintenance of sinus rhythm in patients who have undergone the Maze procedure.

Operative results after the Cox/maze procedure combined with a mitral valve operation

BACKGROUND

There have been few reports on postoperative morbidity and mortality analyses after concomitant mitral valve operation and the Cox/maze procedure.

METHODS

Between April 1993 and August 1995, 87 consecutive patients with chronic atrial fibrillation underwent a mitral valve operation and concomitant Cox/maze procedure at Iwate Medical University. The patients were divided into the replacement group (n = 31) and repair group (n = 56) according to the method of mitral valve replacement. Our initial experience with the combined operative procedures is presented along with the operative mortality and morbidity rates. Univariate analysis on preoperative and intraoperative variables affecting early mortality and morbidity is carried out retrospectively.

RESULTS

Total cardiopulmonary bypass time in all patients was 177.2 +/- 70.1 minutes. Total aortic cross-clamp time was 121.7 +/- 30.8 minutes. Total intensive care unit stay was 5.3 +/- 7.9 days. The average intubation period was 55.5 +/- 187.6 hours. The intensive care unit stay and the intubation period of the replacement group were longer than those of the repair group. There were four operative deaths among the 87 patients (4.6%). All repair group patients survived operation, whereas 4 replacement group patients died after operation. In all patients, the New York Heart Association functional class was higher (p = 0.028) in those who died than in those who survived. The overall restoration rate from atrial fibrillation was 79.5% (66 of 83 survivors). Seventeen patients (20.5%) had persistent atrial fibrillation postoperatively. Sick sinus syndrome occurred in 7 patients (8.4%). In the repair group, the restoration rate was 76.8%, whereas in the replacement group it was 85.2% for the survivors.

CONCLUSIONS

The Cox/maze procedure can be combined with a mitral valve operation with acceptably low operative risk. Analysis of risk factors of early mortality revealed that the type of mitral valve operation (replacement versus repair) and higher preoperative New York Heart Association functional class were associated with mortality. Long-term results from this combined procedure should be clearly demonstrated before its universal acceptance.

Internal thoracic artery malperfusion syndrome after bilateral internal thoracic artery grafting: report of a case

A 58-year-old man with postinfarction unstable angina was referred to the Department of Cardiovascular Surgery at the Saiseikai Kitakami Hospital for urgent coronary revascularization. The bilateral internal thoracic arteries (ITAs) were subsequently utilized to revascularize the myocardium. The left anterior descending artery (LAD) was revascularized with the in situ right ITA and the obtuse marginal artery was revascularized with the in situ left ITA. Although he was successfully weaned from cardiopulmonary bypass, he collapsed hemodynamically 15 min later. Thus, he underwent supplementary vein bypass grafting to the distal LAD and the diagonal artery. Postoperatively, his course was uneventful, apart from the perioperative infarction, and a coronary arteriogram demonstrated patent bilateral ITAs and vein graft. This case report emphasizes the importance of early recognition of this rare syndrome and advocates surgical treatment consisting of supplementary vein grafting.

Clinical experiences of surgical repair for mitral regurgitation secondary to papillary muscle rupture complicating acute myocardial infarction

Mitral regurgitation secondary to ischemic heart disease carries a significant mortality even after emergency open heart surgery. From 1993 to 1997, four patients were operated on for ischemic mitral regurgitation secondary to papillary muscle rupture. These patients were between 58 and 69 years of age and all were in class III or IV of the New York Heart Association Classification. The responsible infarction area was located in the lateral wall in 2 patients, and inferior in others. The interval between the onset of acute myocardial infarction and the appearance of mitral regurgitation was from 1 to 10 days. Three patients had partial rupture (defined as only one or several heads of papillary muscle ruptured), and one had total papillary muscle rupture. Primary mitral plasty was performed in 3 patients, including 1 patient who had undergone patch closure of ventricular septal perforation at the onset of acute myocardial infarction. Mitral plasty combined with coronary artery bypass grafting was performed in 1 patient. Only one case, who had total papillary muscle rupture, required reoperation for recurrence of mitral regurgitation. We suggest that even in the case of ischemic mitral regurgitation, when a papillary muscle rupture is partial, mitral repair is performed because of its potential for improving therapeutic results.

Clinical usefulness of the effective regurgitant orifice area determined by transesophageal echocardiography in patients with eccentric aortic regurgitation

BACKGROUND AND AIMS OF THE STUDY

The aortic regurgitant jet is frequently eccentric, and Doppler color flow mapping techniques of the distal jet is influenced by this eccentricity. The aim of the present study was to determine whether the effective regurgitant orifice area (EROA), determined by the proximal isovelocity surface area (PISA) method using multiplane transesophageal echocardiography (m-TEE), could be used to evaluate the severity of aortic regurgitation (AR) in patients with an eccentric jet.

METHODS

Forty-eight patients with eccentric AR were studied. Values of EROA determined by the PISA method were compared with results from cross-sectional area (CSA), vena contracta (VC) width, aortic angiography, and regurgitant fraction.

RESULTS

Values of EROA correlated well with results from CSA (r = 0.73, p < 0.001), VC (r = 0.74, p < 0.001), angiographic grade (rs = 0.90 p < 0.001), and regurgitant fraction (r = 0.84, p < 0.001) in patients with eccentric aortic regurgitation. Values of EROA > 0.27 cm2 were always associated with a regurgitant fraction > 0.4, while EROA values < 0.27 cm2 were always associated with a regurgitant fraction < 0.4.

CONCLUSIONS

We conclude that, in patients with an eccentric jet, measurement of EROA values by the PISA method using m-TEE is a reliable method of assessing the severity of AR.

Coagulopathy associated with residual dissection after surgical treatment of type A aortic dissection

PURPOSE

This study was performed to evaluate the effects of a residual dissection on coagulation, fibrinolysis, and platelet function after surgical treatment of acute type A aortic dissection.

METHODS

Between 1987 and 1995, 48 consecutive patients underwent emergency surgery for acute type A aortic dissection. Thirty-five of 41 survivors were followed-up for periods ranging from 6 to 112 months (median, 30.3 months). These survivors were classified into three groups by computed tomographic scanning and angiography. Fifteen patients had no residual dissection (group I). Of the 20 patients who had residual dissection, nine had an enlarged aorta greater than 45 mm in maximal diameter (group II), and 11 had an aorta less than 45 mm in maximal diameter (group III). For all patients, blood samples were collected for coagulation, fibrinolysis, and platelet function studies on the same day that the computed tomographic scanning had been performed.

RESULTS

beta-thromboglobulin, thrombin-antithrombin III complex, D-dimer, and alpha 2 plasmin inhibitor-plasmin complex concentrations were significantly higher in group II than in the other two groups. Strong correlations between the maximal diameter of the dissected aorta and beta-thromboglobulin, thrombin-antithrombin III complex, D-dimer, and plasmin inhibitor-plasmin complex concentrations were evident. In contrast, correlations between the length of the dissected aorta and coagulation/fibrinolysis measurements were weak.

CONCLUSIONS

Our findings suggest that the coagulopathy worsened in proportion to the degree of dilatation of the dissected aorta.

Predictors of sinus rhythm restoration after Cox maze procedure concomitant with other cardiac operations

BACKGROUND

There have been sporadic cases of persistent atrial fibrillation and sick sinus syndrome after the maze procedure. The purpose of this study was to identify the predictors of sinus rhythm restoration after operation.

METHODS

Between March 1993 and June 1995, we evaluated retrospectively 96 consecutive patients who underwent the maze procedure (maze III) in combination with another type of cardiac operation. Four patients who died and 6 patients who required permanent pacemaker implantation because of sick sinus syndrome were excluded. Ambulatory electrocardiographic monitoring was evaluated 1 year after operation. Multiple logistic regression analysis was applied to identify the predictors of sinus rhythm restoration.

RESULTS

The final population comprised 86 patients (mean age, 59.8 years; 67 patients with mitral valve disease). Overall, sinus rhythm was restored in 68 of 86 patients (79.1%). The magnitude of the atrial fibrillatory wave positively predicted postoperative sinus rhythm restoration. Conversely, left atrial diameter was inversely related to postoperative sinus rhythm restoration. The odds ratio of having both a fine atrial fibrillatory wave (< 1.0 mm) and enlarged left atrial diameter (> or = 65 mm) for patients with sinus rhythm restoration was 0.04 (95% confidence interval, 0.01 to 0.28).

CONCLUSIONS

Atrial fibrillatory wave and left atrial diameter were independent predictors of sinus rhythm restoration after the maze procedure in patients with chronic atrial fibrillation and organic heart disease.

Can the maze procedure be combined safely with mitral valve repair?

BACKGROUND AND AIMS OF THE STUDY

The safety of combining mitral valve repair with the maze procedure for chronic atrial fibrillation in the surgical management of patients with mitral valve disease is not well elucidated. We present our operative results regarding mortality and morbidity after such combined surgery. As a comparison, our operative results after mitral valve repair in patients without chronic atrial fibrillation are presented.

METHODS

Between April 1993 and December 1994, 39 patients with chronic atrial fibrillation underwent mitral valve repair and concomitant maze procedure (group 1) at the Iwate Medical University. During the same period, 36 patients with sinus rhythm and one patient with DDD pacemaker underwent mitral valve repair (group 2). In order to evaluate the operative risk, morbidity, and mortality of adding the maze procedure to mitral valve repair, total cardiopulmonary bypass time, aortic cross-clamp time, intraoperative blood loss, intubation period, and duration of ICU stay were compared between the groups.

RESULTS

Total cardiopulmonary bypass time and aortic cross-clamp time in group 1 were longer than in group 2 (174.0 +/- 38.8 min versus 150.1 +/- 54.4 min; p = 0.032, 122.5 +/- 30.7 min versus 95.8 +/- 38.2 min; p = 0.0012). However, the duration of ICU stay, intubation period, and intraoperative blood loss were not different between the groups. There were no hospital deaths in either group. Four patients in group 1, and two patients in group 2 required re-exploration for bleeding (p = NS). Two patients in group 1, and none in group 2 required pacemaker implantation postoperatively (p = NS). Two patients in group 2, and none in group 2 had minor cerebral infarction (p = NS). At hospital discharge, 28 patients in group 1 (72%) and 35 patients (97%) in group 2 were in sinus rhythm.

CONCLUSIONS

The maze procedure can be combined with mitral valve repair without adding undue operative risk to patients. Those patients with chronic atrial fibrillation undergoing mitral valve repair may be advised for the possibility of concomitant maze procedure.

Electrocardiographic nature of restored sinus rhythm after Cox maze procedure in patients with chronic atrial fibrillation who also had other cardiac surgery

OBJECTIVE

To characterise heart rate variability and high frequency components of restored sinus rhythm after the maze procedure. The maze procedure for chronic atrial fibrillation may prevent thrombotic events and improve the quality of life. However, the electrocardiographic nature of restored sinus rhythm after the maze procedure has not been fully elucidated.

PATIENTS AND METHODS

Between March 1993 and August 1995, 104 consecutive patients undergoing the maze procedure in combination with other cardiac surgery were studied. There were 100 long-term survivors (78 with mitral valve disease, 9 with aortic valve disease, 8 with congenital heart disease, and 5 others). Twenty age-matched patients with mitral valve disease who were in normal sinus rhythm preoperatively were enrolled as a control group. 30 days after surgery, the presence of arrhythmias and the circadian changes of heart rate variability were estimated by ambulatory electrocardiographic monitoring and the filtered P duration was evaluated by signal-averaged electrocardiogram.

RESULTS

Restoration of sinus rhythm was observed in 73 of 100 cases. Subjects were classified into three groups according to their postoperative ambulatory electro-cardiographic monitoring findings: patients in group 1 (n = 73) (1a: 58 regular sinus rhythm; 1b: 15 sinus rhythm with frequent premature atrial contractions (> 1000/day); patients in group 2 (n = 21) still had persistent atrial fibrillation; and patients in group 3 (n = 6) required permanent pacemaker implantation because of sick sinus syndrome. The success rate of restoration of sinus rhythm was 88.3% if left atrial diameter was small (< 65 mm). Circadian changes in the low frequency to high frequency power ratio in group 1a were significantly diminished compared with control group (P < 0.01). Furthermore, the filtered P duration in group 1a (150 (20) ms) and group 1b (158 (23) ms) were longer than in the control group (122 (11) ms) (P < 0.01).

CONCLUSIONS

The maze procedure may result in a decreased sinus response and non-uniform transmission of impulses in the atrium.

Nonobstructing accessory mitral valve tissue and ventricular septal defect

A 4-month-old boy with ventricular septal defect was found to have accessory mitral valve tissue attached to the anterior leaflet of the mitral valve. Operation was successfully performed to excise the accessory mitral tissue in the left ventricular outflow tract and close the ventricular septal defect. Most previously reported cases with accessory mitral valve tissue were associated with left ventricular outflow tract obstruction. This boy had no pressure gradient across the left ventricular outflow tract. The indications for prophylactic excision of nonobstructing accessory mitral valve tissue in a patient with other forms of congenital cardiac disease are discussed.