Paroxysmal supraventricular tachycardia in identical twins with the same left lateral accessory pathways and innocent dual atrioventricular pathways

We report on 16-year-old, female identical twins who both have atrioventricular reentrant tachycardia caused by the same left lateral atrioventricular accessory pathway. The Kent pathway in twin A was a unidirectional retrograde accessory pathway. A manifest Kent pathway was demonstrated in twin B. Both pathways were successfully ablated by radiofrequency (RF) energy and without recurrence. In addition, innocent dual AV nodal pathways were shown in both patients. These findings suggest that genetic factors may play a role in the pathogenesis of the formation of accessory atrioventricular pathways and dual AV nodal pathways.

Suppression of tumor necrosis factor secretion from white blood cells by synthetic antisense phosphorothioate oligodeoxynucleotides

In this ex vivo, rather than in vitro, experiment, a synthetic antisense oligodeoxynucleotide was tested to suppress tumor necrosis factor - alpha(TNF) secretion from lipopolysaccharide-stimulated white blood cells. Antisense oligomer showed significant and specific suppressive effect to the secretion of TNF at concentrations of 1.0 and 10 microM. At the concentration of 1 microM, there were 68.4 and 63.9% suppression of TNF secretion at 2 and 24 h after resuspension of blood cells. At the concentration of 10 microM, the suppressions were slightly higher than those at 1 microM, which were 71.8 and 76.2%, respectively. A 50%-matched scrambler showed suppressive effect only at 10 microM concentration, and the suppression only occurred at 2 and 24 h after incubation. Sense oligomer showed no suppressive effects at any of the concentrations. The specificity of this oligomer was documented by dose-effect phenomenon, sequence-dependent suppression and absence of effect on the synthesis of another cytokine (interleukin-6). A series of parallel studies was performed and showed that all three oligomers at any concentration tested had no effect on the interleukin-6 secretion after LPS stimulation.In conclusion, properly designed antisense oligodeoxynucleotide can significantly and specifically suppress the secretion of TNF by blood cells in an ex vivo system and it may be a good "information" drug to treat diseases that are caused by over production of TNF.

Turbulence characteristics downstream of bileaflet aortic valve prostheses

This study was focused on a series of in vitro tests on the turbulent flow characteristics of three bileaflet aortic valves: St. Jude Medical (SJM), CarboMedics (CM), and Edwards Tekna (modified Duromedics, DM). The flow fields of the valves were measured in a pulsatile flow model with a laser-Doppler anemometer (LDA) at the aortic sinus area downstream of the valves. The heart rate was set at 70 beats per minute, the cardiac output was maintained at 5 liters per minute, and the aortic pressure wave forms were kept within the physiological range. Cycle-resolved analysis was applied to obtain turbulence data, including mean velocity, Reynolds stresses, autocorrelation coefficients, energy spectral density functions, and turbulence scales. The Reynolds shear stresses of all three valves induced only minor damage to red blood cells, but directly damaged the platelets, increasing the possibility of thrombosis. The smallest turbulence length scale, which offers a more reliable estimate of the effects of turbulence on blood cell damage, was three times the size of red blood cells and five times the size of platelets. This suggests that there is more direct interaction with the blood cells, thus causing more damage.

HeartMate left ventricular assist device for long-term circulatory support

We describe three successful cases of HeartMate left ventricular assist device (LVAD; Thermo Cardiosystems, Woburn, MA, USA) implantation in patients with end-stage heart failure for long-term circulatory support. Patient 1 was a 34-year-old woman with postpartum cardiomyopathy. Patients 2 and 3 were both males with dilated cardiomyopathy, 50 years and 21 years of age, respectively. They all presented in cardiogenic shock with decreased sensorium and anuria. Temporary mechanical support with an intra-aortic balloon pump or extracorporeal membrane oxygenation (ECMO) was needed for life support. Because bleeding and right ventricular failure often occur after HeartMate LVAD implantation, we used a Vascutek tube (Vascutek Ltd, Inchinnan, Scotland) graft to wrap inflow and outflow valve conduits and ECMO as a bridge to HeartMate LVAD implantation. Following surgery, cardiac output increased from 2.70, 2.06 and 2.53 L/min to 4.50, 5.80 and 5.00 L/min in the three patients. HeartMate LVAD can provide safe and stable long-term circulatory support without the need for anticoagulation. One of the patients remained on HeartMate for 287 days before undergoing successful heart transplantation. Patients with HeartMate LVAD are ambulatory and may be discharged while awaiting heart transplantation. Heart function may recover after long-term ventricular unloading with HeartMate LVAD.

Influence of aortopulmonary rotation on the anomalous coronary artery pattern in tetralogy of fallot

Three main patterns of aortic sinus rotation were defined on 517 lateral angiograms of tetralogy of Fallot with 14 cases of anomalous coronary artery pattern occurring only in patients with a right anterior or right lateral aorta. The significant dependence of coronary artery types on the aortic sinus pattern made it possible to predict the predisposing coronary artery pattern in tetralogy of Fallot based on the aortic sinus pattern.

The role of free to total prostate-specific antigen ratio for prostate cancer in screening patients with total serum levels between 4 and 20 ng/ml

BACKGROUND

We retrospectively tried to determine if the free to total prostate-specific antigen (f/t PSA) ratio could improve the specificity of PSA in prostate cancer screening of patients with total serum levels between 4 and 20 ng/ml.

METHODS

Two hundred ninety-five patients with serum PSA levels from 4 to 20 ng/ml had undergone sextant prostate needle biopsy. Each patient had no prior history of prostate cancer, acute urine retention, or prostatitis. Prebiopsy free PSA values were measured in 155 patients. Total PSA levels were determined with the AxSYM enzyme-linked immunosorbent assay. Free PSA levels were measured with the AxSYM microparticle enzyme immunoassay.

RESULTS

Mean f/t PSA ratios were 0.114+/-0.004 in men of the cancer group and 0.161+/-0.008 in men of the benign group (p<0.002). Based on the analysis of sensitivity and specificity in relation to f/t PSA ratios, use of the 18% cutoff point could detect 89% of cancer cases, and at the same time could avoid 35% of unnecessary prostate biopsies. The areas under the receiver-of-characteristic curve for f/t PSA ratio and total PSA were 0.649 and 0.545, respectively.

CONCLUSION

Serum f/t PSA ratios were significantly lower in patients with prostate cancer than in patients with benign disease. The determination of an appropriate f/t PSA ratio should be based on the generated data such as that demonstrated in this study in order to improve diagnostic accuracy and specificity for patients with equivocal PSA values and to avoid conducting unnecessary prostate biopsies.

Simple method of hemostasis in implantation and explantation of HeartMate left ventricular assist device

We described a simple method of hemostasis in implantation and explantation of HeartMate left ventricular assist device. Wrapping of the inflow cannula, outflow conduit and outflow graft with Vascutek tube graft can localize the bleeding due to patient's coagulopathy, imperfect coating and device defect. During explantation, bivalving the tube graft, leaving the graft in place and no-touch of the adhesion between graft and soft tissue can minimize the dissection and prevent the potential bleeding.

Partial left ventriculectomy as a biologic bridge to heart transplantation

Heart failure refractory to medical treatment is consuming an increasingly large proportion of health care resources. Partial left ventriculectomy has recently been used to treat patients with end-stage dilated cardiomyopathy. A 45-year-old man in end-stage heart failure had progressive exertional dyspnea for 3 years. Cardiac catheterization showed dilated cardiomyopathy with severe pulmonary hypertension and severely impaired left ventricular function. After partial left ventriculectomy, cardiac output increased from 2.11 L/min to 5.0 L/min. The left ventricular ejection fraction measured by radionuclide angiography increased from 13% preoperatively to 28% 1 month after the operation. The patient was discharged and monitored at the outpatient clinic. He had an exercise capacity of NYHA functional class II. However, he received heart transplantation 10 months after the partial left ventriculectomy because of recurrent heart failure. Partial left ventriculectomy improves heart function and may be used as a bridge to heart transplantation as an alternative to ventricular assist devices.

Combined heart transplantation and resection of dissecting aneurysm of ascending aorta and aortic arch: a case report

A 21-year-old male patient had suffered from palpitation and exertional dyspnea since October, 1997. He was admitted to our hospital, and a series of examinations were performed. Chest computed tomography (CT) revealed marked dilatation of the ascending aorta (about 7.5 cm at the proximal portion) and aortic annulus, an intimal flap in the ascending aorta and aortic arch was also noted. Cardiac catheterization revealed the pulmonary capillary wedge pressure was 33 mmHg, pulmonary artery pressure was 47/38 mmHg with a mean of 35.4. The cardiac index was 1.01 l/min/m2. Poor left ventricular contractility was shown by a left ventricular ejection fraction (LVEF) of 13.8% and a right ventricular ejection fraction (RVEF) of 5.13% by a radionuclide angiogram (RNA) study. Under the diagnosis of dilated cardiomyopathy and dissecting aortic aneurysm of the ascending aorta and aortic arch, he was put on a waiting list for heart transplantation. On November 11, 1997 he received heart transplantation. Resection of the dissecting aneurysm of the ascending aorta and the aortic arch and replacement with a 26 mm Vascutek graft were performed first under deep hypothermia and retrograde cerebral perfusion. Then while he was rewarming up, heart implantation was performed. He was discharged 30 days after surgery and has been doing well since then. As far as we know, no literature regarding combined heart transplantation and resection of a dissecting aneurysm of the ascending aorta and aortic arch has been reported.

Current status of artificial hearts and ventricular assist devices

Currently available approaches for patients with refractory heart failure include intravenous inotropic therapy, partial left ventriculectomy, dynamic cardiomyoplasty, mechanical circulatory support, and heart transplantation. Heart transplantation is limited by the availability of donor organs, which is never expected to meet the increasing demand. Numerous devices have been developed for circulatory support. Currently available devices differ in configuration, anatomic location, flow characteristics, and durability. Many devices are currently available for mechanical support, and they can generally be categorized as follows: 1) pulsatile or continuous blood flow; 2) internal (implantable) or external (extracorporeal); 3) pneumatically or electrically powered; and 4) for short-term or long-term support. Proper selection of patients for a given therapy has a major impact on clinical outcome. Early implantation of implantable devices, before the onset of multiple or irreversible end-organ failure, is essential. Short-term devices are indicated if myocardial recovery is anticipated, as in cases of postcardiotomy shock and acute myocarditis. Long-term devices are indicated for transitioning patients with end-stage myocardial failure to heart transplantation. Long-term assist devices may, in some selected cases, serve as an alternative to heart transplantation. This alternative will benefit both patients in chronic heart failure competing for a limited donor supply and patients with contraindications to transplantation, such as advanced age, previous malignancies, and renal dysfunction. The next generation of blood pumps to be applied clinically is likely to be axial pumps, which are valveless, miniaturized, intraventricular left ventricular assist devices.

Aorto-right artrial fistula: a rare complication of aortic dissection

We describe the successful surgical repair of an acute aortic dissection that had caused an aorto-right atrial fistula in a 67-year-old man. The patient was admitted to the hospital on an emergency basis because of severe heart failure. The diagnosis of acute aortic dissection with rupture into the right atrium was confirmed by use of intraoperative transesophageal echocardiography, although rupture of a sinus of Valsalva aneurysm into the right atrium had been suggested initially by 2-dimensional and Doppler transthoracic echocardiography. At surgery, we found the patient to have aortic arch dissection with complete separation of the right coronary artery from the sinus of Valsalva and a false lumen that had ruptured into the right atrium. The aortic arch was repaired directly. The ascending aorta was successfully replaced with a composite graft. Aortic dissection with rupture into the right atrium is extremely rare and leads to death rapidly. As shown in this case, such a condition might be mistaken for an aneurysmal rupture of the sinus of Valsalva, with use of transthoracic echocardiography alone. Transesophageal echocardiography is a useful noninvasive method to further define or confirm the diagnosis. Early surgical intervention is necessary in patients with this condition to prevent profound shock and end-organ failure.

Surgical revascularization for acute total occlusion of left main coronary artery

We report our experience with emergency surgical revascularization in 3 patients who were in cardiogenic shock as a result of acute total occlusion of the left main coronary artery. Because they were in profound shock, 2 patients required mechanical support with extracorporeal membrane oxygenation before the operation. Another patient was given moderate inotropic support and treated with an intraaortic balloon pump before surgery, because he had a dominant right coronary artery with extensive collateral circulation to the left coronary artery. All 3 patients underwent surgical revascularization within 20 hours of acute occlusion. Two patients survived, although 1 of them required extracorporeal membrane oxygenation support for 5 days postoperatively. The 3rd patient, despite successful weaning from extracorporeal membrane oxygenation immediately after coronary revascularization, died of hypoxic encephalopathy due to prolonged preoperative resuscitation. Immediate surgical revascularization was an effective treatment in our 3 patients who were in cardiogenic shock due to acute total occlusion of the left main coronary artery. Such factors as abundant collateral vessels from the right coronary artery to the left coronary artery, complete surgical revascularization within 20 hours of acute occlusion, and mechanical circulatory support were deemed important to recovery of left ventricular function. Two of our 3 patients survived.

Heart transplantation in Asia

BACKGROUND

The first clinical heart transplantation in Asia was performed by Wada in 1968. Due to cultural and religious problems, heart transplantation was rarely performed in Asia until 1987 and since then the number of heart transplantation has increased rapidly. This study was undertaken to investigate the results of heart transplantation in Asia.

METHODS

Data was collected through the use of a questionnaire by mail. The questionnaire included information on the year when heart transplantation was started, the number of heart transplantations by year and country population, sex, age and diagnosis of recipients, causes of brain death of the donors, number of centers with an active heart transplantation programs, operative mortality and actuarial survival, brain death and organ transplant legislation.

RESULTS

From July 17, 1987 to December 1996, 380 patients received heart transplantation in Asia. Up to 1996, Taiwan had performed 178 cases of heart transplantation. Thailand also started in 1987 and had 95 cases. South Korea started in 1992 and had 65 cases. Singapore and India each had 12 cases. Hong Kong 8 cases, China 7 cases, and the Philippines 3 cases, all started in the early 1990s. The recipient ages ranged from 1 to 70 years with a male to female ratio of 3 to 1. The one-month operative mortality rate ranged from 0 to 25% with an average of 7.4%. The one-year survival rate ranged from 0 to 84% with an average of 78.8%. The 5-year survival rate ranged from 30 to 74.1% with an average of 67. 5%.

CONCLUSION

Heart transplantation was well-established in most Asian countries, and the number was increasing. The result and survival rate of heart transplantation in Asia were comparable with that of the world series.

Rescue for acute myocarditis with shock by extracorporeal membrane oxygenation

BACKGROUND

Acute myocarditis (AM) complicated with refractory cardiogenic shock carries a very high mortality. We report our experience in treating these patients, who were rescued by extracorporeal membrane oxygenation (ECMO) and intravenous immunoglobulin.

METHODS

Over a 5-year period, 5 patients with AM were rescued with ECMO in our hospital. Femoral venoarterial ECMO was performed in 4 patients, and right atrium-left atrium-aorta ECMO in the other 1 due to ventricular dysfunction. Hemofiltration was applied to 3 patients. Marked elevated creatine kinase, its MB form, and troponin T (TnT) were found before ECMO.

RESULTS

All the patients could be weaned off the ECMO after 140.0+/-57.7 hours of ECMO support. One patient died of multiple organ failure 10 days later after removal of ECMO, resulting in a 20% mortality. Renal function returned to normal in all survivors. The 4 survivors were discharged uneventfully in 23.3+/-8.3 days and resumed functional class I status. The TnT level declined to the low level within 3 days (slope -4.94+/-1.18 ng/mL/day), and might be an indicator of good recovery of myocardium.

CONCLUSIONS

ECMO can provide an effective and simple treatment for critical AM with a satisfactory result and reduce the possibility of progressive cardiomyopathy.

Lung transplantation for patients with end-stage Sauropus androgynus-induced bronchiolitis obliterans (SABO) syndrome

Sauropus androgymus (SA), a vegetable of the Euphorbiaceae family, is a common food source in Malaysia. In Taiwan, over 30 patients have developed progressive respiratory failure after consuming the extract from raw SA leaves as a means of losing weight. Symptoms consistent with a severe obstructive ventilatory defect progressed, despite cessation of SA intake and treatment with bronchodilators, corticosteroids, cytotoxic agents and plasmaphresis. Five patients with end-stage Sauropus androgynus-induced bronchiolitis obliterans (SABO) syndrome underwent lung transplantation. There was no early mortality. One patient died of post-transplant lymphoproliferative disorder and another patient died of bronchial stenosis with infection, 5 and 3.5 months, respectively, post-transplantation. The remaining 3 patients have been followed from 29 to 34 months, with improved general condition and pulmonary function. Perfusion/ventilation scans revealed that these improvements were exclusively attributed to the functional grafts. We believe that lung transplantation is the only effective modality of treatment for patients with end-stage SABO syndrome.

Renal autotransplantation for ureter stricture and renovascular disorders

BACKGROUND

Renal autotransplantation is an established therapy in cases of renal vascular lesions, tumors of the kidney and ureter, complex ureteral lesions, and kidney trauma. It has been a significant technical innovation, aiding the urologist in his great effort to preserve renal function by conserving renal tissue. We report our experience with autotransplantation in 4 patients. The indications, techniques, and results of renal autotransplantation in relation to our own experience are discussed.

METHODS

The patients included 3 women and one man. The average age of the patients was 35 years old, with a range from 20 to 54 years. One patient had Takayasu's arteritis, the second had Nutcracker syndrome with flank pain and hematuria, the third a complicated long ureter stricture, and the fourth patient a renal artery saccular aneurysm.

RESULTS

The average operation time was 7 hours (4.5 to 8.5 hours), and the cold ischemia time was about 88 minutes (45 to 150 minutes). Three of the autografts resumed normal renal perfusion, and in the fourth patient the renal autograft was lost due to vascular thrombosis.

CONCLUSION

Renal autotransplantation is a feasible method for the surgical treatment of renal and ureteral lesions. To avoid postoperative ureteral sloughing and subsequent urinary fistulas, the ureter can be left intact to preserve the ureter blood supply. However, in the case of a complicated vascular reconstruction procedure, it appears to be appropriate to divide the ureter and have the kidney completely free, thus avoiding back-flow perfusion from the intrinsic and intercommunicating blood supply in the ureteral wall, which may result in vascular thrombosis and subsequent autograft failure.

Enterovesical fistula: experiences with 41 cases in 12 years

BACKGROUND

A retrospective analysis of enterovesical fistula treated at Chang Gung Memorial Hospital was conducted to determine the optimal diagnosis and management of this disease.

METHODS

The records of 41 patients who presented from 1984 to 1996 and had a final diagnosis of enterovesical fistula were retrospectively reviewed. The etiology, symptoms on presentation, diagnostic tools, and modality of treatment were analyzed.

RESULTS

The majority of these cases were associated with malignancy (38, 92.7%), and the others with diverticulitis (2, 4.9%) and iatrogenic causes (1, 2.4%). In those with malignancy, 15 patients (39.5%) were found to have tumor recurrence. The most frequent symptom in enterovesical fistula was fecaluria (58.5%), followed by abdominal pain (22%) and dysuria (14.6%). Diagnostic tools included the barium enema, cystography, and cystoscopy; these methods could identify the fistula in 63.2%, 60%, and 53.8% of the patients, respectively. Methods of management included diversion only (39%), one-stage fistula repair (36.6%), and watchful surveillance (24.4%).

CONCLUSION

Enterovesical fistula should be considered if fecaluria, pneumaturia, or persistent non-specific urinary tract infection present as the initial complaint. A thorough surgery for a possible underlying malignancy is mandatory when confronted with enterovesical fistula, since the incidence of inflammatory bowel disease is low in this area. An abdominal computer tomography (CT) scan, barium enema, and cystogram can be useful diagnostic tools. Treatment of this entity should be individualized according to each patients clinical status.

Heart transplantation with marginal recipients and donors

With improvements in surgical techniques and management of postoperative complications, heart transplantation can now be performed with donors and recipients who were previously considered unsuitable. In this study, we report the results of heart transplantation with marginal donors and recipients in our hospital. From June 1993 through June 1998, we performed 79 heart transplantations. Marginal recipients were defined as those with high pulmonary vascular resistance (> 6 Wood units), severe renal impairment (serum creatinine > 2 mg/dL and creatinine clearance < 50 mL/min), or severe hepatic dysfunction (ALT and AST > 100 IU/L or serum bilirubin > 2.5 mg/dL). Marginal donors were those with any of the following conditions: old age (> 40 years), size mismatch (donor/recipient body weight ratio < 0.8), history of chronic alcohol use, previous cardiopulmonary resuscitation and hypotension, hepatitis B or C virus positivity, coronary artery disease, high-dose dopamine (> 10 micrograms.kg-1.min-1), or prolonged allograft ischemic time (> 4 hours). Of the 79 transplantations performed, 45 (58%) involved marginal recipients or donors. The 30-day mortality rate was 5%, and the 1-year and 5-year survival rates were 87% and 83%, respectively. The survival rates did not differ significantly between cases involving marginal donors or recipients and those involving nonmarginal donors and recipients. There were 27 marginal recipients (34%), only one of whom died during surgery. Five of six recipients with severe renal impairment needed short-term hemodialysis after transplantation. Recipients with high pulmonary vascular resistance had a higher incidence of early acute rejection (5/10 vs 22/69). Thirty-three (42%) of the patients received transplants from marginal donors, four of whom died during surgery; two died of acute vascular rejection, one of allograft failure caused by prolonged ischemic time, and one of bleeding secondary to preoperative sepsis and coagulopathy. These results show that heart transplantation may be performed in marginal recipients and donors, with acceptable operative mortality.

Postoperative short-term sedation with propofol in cardiac surgery

We conducted a randomized double-blind study to assess the safety and effectiveness of short-term sedation with propofol in adult patients immediately after cardiac surgery. Sixty hemodynamically stable adult patients who underwent cardiac surgery were randomly assigned to receive propofol postoperatively or no postoperative sedation. The propofol group (n = 30) received propofol infusion (1 mg.kg-1.hr-1) immediately after they awoke postoperatively. The infusion rates were adjusted to maintain a sedation level (Ramsay score) of 3. Nurses assessed the effectiveness of the sedation according to Ramsay scores; the patients also subjectively evaluated sedation. Postoperative pulmonary oxygenation dysfunction (PaO2/FiO2 < 300 mm Hg) was noted in 10 patients receiving propofol and in eight patients in the control group. The dysfunction was greatly improved after overnight ventilator support, and this improvement was not affected by propofol sedation. The propofol group received an average of 13.6 +/- 5.3 hours of propofol infusion, at an average infusion rate of 0.96 +/- 0.16 mg.kg-1.hr-1. Patients receiving propofol remained well sedated (Ramsay score > or = 2) during 99.3% of the study period, while the control patients remained anxious or agitated (Ramsay score, 1) during 12% of the study period. Patients receiving propofol were successfully extubated 9 +/- 4 minutes after cessation of propofol infusion, without complications. The turnover of intensive care unit beds was not delayed by propofol sedation. Subjective evaluations (scored on an analog scale: 0 = nil, 10 = extreme) revealed that patients receiving propofol felt less pain than those in the control group (2.3 +/- 2.7 vs 4.7 +/- 3.1, p < 0.05), had better sleep quality (7.8 +/- 2.9 vs 5.1 +/- 2.9, p < 0.05), and were more satisfied with the care they received (8.3 +/- 2.2 vs 5.8 +/- 3.9, p < 0.05). These findings suggest that propofol infusion is effective for short-term sedation of cardiac surgery patients postoperatively and that an infusion rate adequate to maintain a Ramsay score of 3 may be ideal. Postoperative sedation should be considered for all cardiac surgery patients, not only those with outward signs of anxiety or agitation.