The role of surface charging during the coadsorption of mercaptohexanol to DNA layers on gold: direct observation of desorption and layer reorientation.

We study the coadsorption of mercaptohexanol onto preimmobilized oligonucleotide layers on gold. Monitoring the position of the DNA relative to the surface by optical means directly shows the mercaptohexanol-induced desorption of DNA and the reorientation of surface-tethered strands in situ and in real time. By simultaneously recording the electrochemical electrode potential, we are able to demonstrate that changes in the layer conformation are predominantly of electrostatic origin and can be reversed by applying external bias to the substrate.

Risk stratification analysis of operative mortality in coronary artery bypass surgery.

OBJECTIVE: We assessed the operative mortality of coronary artery bypass grafting (CABG) surgery using risk stratification. METHODS: In 294 consecutive patients who underwent CABG with or without concomitant surgery from August 1994 to December 1999, we compared operative mortality calculated conventionally and by risk stratification. Scores for each patient were calculated using the Parsonnet additive model and stratified based on the probability of operative mortality. RESULTS: Overall crude hospital mortality was 4.8%-4.0% among patients younger than 80 years and 14% among those 80 years of age or older (p = 0.0692). Hospital mortality was 12% in urgent/emergency surgery, and 1.5% in elective surgery (p < 0.0002), and 4.5% in CABG alone and 7.4% in CABG with concomitant surgery (p = 0.3763), and 25% in patients receiving vein grafts only and 3.0% in those receiving at least 1 artery graft (p = 0.0003). Overall patient distribution was 32% good, 20% fair, 20% poor, 11% high-risk, and 16% extremely high-risk. Predicted mortality was 2.2% for patients who were a good risk, 6.7% for fair-risk, 12% for poor-risk, 16% for high-risk, and 25% for extremely high-risk patients. Actual operative mortality was 1.0% for good-risk, 0% for fair-risk, 3.4% for poor-risk, 6.3% for high-risk, and 18% for extremely high-risk patients, making actual mortality significantly lower than that predicted. CONCLUSION: Comparing predicted mortality and actual mortality enabled us to objectively calculate operative results and assess operative quality.

Risk stratification analysis of operative mortality in heart and thoracic aorta surgery: comparison between Parsonnet and EuroSCORE additive model.

OBJECTIVE: Our purpose was to compare the performance of risk stratification model between Parsonnet and European System for Cardiac Operative Risk Evaluation (EuroSCORE) in our patient database. METHODS: From August 1994 to December 2000, 803 consecutive patients have undergone heart and thoracic aorta surgery using cardiopulmonary bypass and scored according to Parsonnet and EuroSCORE algorithm. The population was divided into five clinically relevant risk categories. We compared correlation of predicted mortality and observed mortality between these two models. Score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: Overall hospital mortality was 4.5%. In Parsonnet model, predicted mortality was 2.4% for 0-4% risk, 6.7% for 5-9% risk, 12% for 10-14% risk, 17% for 15-19% risk, 25% for 20% plus risk, and 10.4% for overall patients. Observed mortality was 2.4, 0.4, 5.9, 8.7, 11, and 4.5%, respectively. The thoracic aorta and valve cohort indicated poor correlation between predicted and observed mortality compared to coronary cohort. In the EuroSCORE model, predicted mortality was 1.4% for 0-2% risk, 4.0% for 3-5% risk, 6.7% for 6-8% risk, 9.7% for 9-11% risk, 13% for 12% plus risk, and 5.3% for overall patients. Actual mortality was 0, 1.5, 6.8, 11, 21, and 4.5%, respectively. Each of the thoracic aorta, valve, and coronary cohort indicated good correlation between predicted and observed mortality. Areas under the ROC curves were 0.72 in Parsonnet and 0.82 in EuroSCORE. CONCLUSIONS: The EuroSCORE additive model yielded good predictive value for hospital mortality of Japanese patients undergoing not only cardiac but also thoracic aortic surgery.

[Early and mid-term results after cardiac or thoracic aortic surgery in patients aged 70 years and older--survival and quality of life].

The early and mid-term survival after cardiac or thoracic aortic surgery and influence of age to the operative mortality were examined in 168 consecutive patients aged 70 years and older from August 1994 to December 1998, together with assessment of postoperative quality of life (QOL). The mean age was 74.1 +/- 3.7 years old (70 to 86 years). 80 patients had IHD, 59 had VHD, 28 had TAA. Preoperative risk score was classified in 5 groups (good, fair, poor, high, extremely high) based on Parsonnet method. Current QOL of the survivors was assessed using Asanoi method with questionnaire by a letter. There were 9 early deaths (5.4%). Following the Parsonnet model observed mortality was absolutely lower than predicted mortality. When age score was excluded in the Parsonnet model, the observed mortality became almost equal with the predicted mortality. There were 22 late deaths (6.9%/P-Y). The actuarial survival rate of age 70 to 74 group was significantly higher than the age 75 years and older group (p = 0.0021). The actuarial survival rate of TAA group was significantly lower than the VHD or IHD group (p < 0.02). Postoperative NYHA and activity score of TAA group were better than VHD or IHD group. We got satisfactory answers for operation in 95% current survivors. Patients aged 70 years and older will be undergone cardiac or thoracic aortic surgery at a reasonable risk and well satisfaction.

Successful removal of an infected pacemaker electrode by open heart surgery under extracorporeal circulation.

A 33-year-old male with sick sinus syndrome, who had received a pacemaker implant 18 years earlier, was complicated with a generator infection. Although the infected generator was removed, he was suffered from the recurrent local infection associated with a retained pacemaker lead. After a new pacemaker system implantation from the other side of the subclavian vein, we attempted to remove the lead utilizing a pacemaker removal kit. However, this intervention procedure was unsuccessful, because fibrous adhesions had developed around the lead, accompanied by calcification along its course. As a last resort, we opened the heart under extracorporeal circulation and removed the lead under direct vision. The post-operative course was uneventful. In order to remove a long-term implanted pacemaker lead, the direct surgical procedure with extracorporeal circulation is a favorable mean alternative to conventional intervention techniques.

[Hemodynamic assessment of the Carpentier-Edwards pericardial valve compared with the St. Jude Medical valve in the aortic position using dobutamine-stress echocardiography].

To assess the hemodynamic performance of the prosthetic valve in the aortic position, we examined dobutamine-stress echocardiography (DSE) to the patients underwent AVR with CEP valve or SJM valve. In 23 mm size, there were no significant differences between CEP group and SJM group in Peak velocity of the aortic jet (PV), peak pressure gradient (PPG) and effective orifice area (EOA). On the other hand, in 21 mm size, PV and PPG of the CEP group were significantly lower than those of the SJM group after DSE. The EOA of the CEP group was significantly larger than that of the SJM group after DSE. Our results suggest that the hemodynamic function of the CEP valve is superior to that of the SJM valve especially in small aortic annuli.

Simultaneous repair of cardiovascular disorders and pectus deformity in a patient with Sprintzen-Goldberg syndrome: A case report.

We report a 12-year-old girl with Sprintzen-Goldberg syndrome (SGS) who was complicated with annuloaortic ectasia with aortic regurgitation, mitral valve prolapse with mitral regurgitation, and a severe pectus excavatum. In this patient, aortic root replacement, mitral valve replacement, and sternal elevation were simultaneously performed, and a version of Ravitch's procedure that was technically modified to support the sternum was used for sternal elevation. This modified sternal elevation technique gave excellent operative exposure, and maintained chest wall stability after the operation.

Valve surgery in elderly patients 70 years or older: early and late results.

Between April 1986 and March 1997, 75 patients (Group E) who were 70 years or older underwent valvular operations, and another 73 patients who were under 70 years constituted a comparison group (Group Y). Valve replacement was performed on 131 patients (Group E; 65 patients, Group Y; 66 patients), reparative procedures on 11 patients (Group E; 7, Group Y; 4), and aortic root replacement on 5 (Group E; 3, Group Y; 2). Coronary artery bypass grafting was concomitantly performed on 13 patients (Group E; 7, Group Y; 6). In the elderly patients, preoperative clinical status, including cardiac and non cardiac organ functions, was not necessarily more severe than that in the younger patients, however, perioperative restoration of cardiac and pulmonary functions required a longer time in Group E than Group Y. There were no significant differences in operative mortality rate, long-term survival rate, the probability of freedom from all events related to native and prosthetic valves, and in activity of daily life between Group E and Group Y. These results suggest that valvular operation for elderly patients 70 years or older may be safely performed with operative risks similar to those of younger patients by application of modern surgical techniques.

Aortic valve replacement with a small mechanical valve prosthesis--a clinical and echocardiographic study of a St Jude Medical valve prosthesis.

The use of small aortic valve prostheses raises concerns about harmful effects of residual obstruction to left ventricular outflow. The present study was undertaken to examine long-term clinical and echocardiographic results in 193 patients who underwent isolated aortic valve replacement (AVR) with a St Jude Medical (SJM) valve of 25 mm or smaller. The study subjects comprised 128 male and 65 female patients with a mean age of 54.1 years. The patients were divided into 2 groups according to the size of the valve prosthesis used for AVR. Small valves (19 or 21 mm) were implanted in 49 patients (group S) and large valves (23 or 25 mm) were used in 144 patients (group L). The group S patients were mainly female, older, and had smaller body surface areas. There were no significant differences in early and late mortality in group S as compared with group L. Furthermore, there was no difference in the incidence of valve-related or cardiac, non-valve-related death, including the incidence of sudden death, between the 2 groups, and they enjoy a similar level of daily routine activity regardless of the valve size used. Left ventricular (LV) function (ejection fraction, fractional shortening, LV mass index, LV end-systolic volume index, and LV end-diastolic volume index) measured by echocardiography improved significantly and returned to normal values after AVR in both groups. Moreover, no significant differences were observed in the postoperative variables of the LV function. These results suggest that 19-mm and 21-mm SJM valves can be safely used for AVR in the majority of Japanese patients.

Minimally diluted tepid blood cardioplegia.

BACKGROUND: To evaluate the effects of minimally diluted tepid blood cardioplegia, a prospective, randomized study was undertaken. METHODS: Thirty-seven patients undergoing isolated primary coronary artery bypass grafting were randomized to receive standard 4:1 diluted tepid blood cardioplegia (4:1 group, n = 18) or minimally diluted tepid blood cardioplegia (Mini group, n = 19). Cardioplegic solution was delivered in an intermittent antegrade fashion in both groups. Myocardial oxygen and lactate metabolism, release of the MB isoenzyme of creatine kinase and thiobarbituric acid reactive substances, and cardiac function were measured during and after the operation. RESULTS: Myocardial oxygen consumption was significantly greater and lactate release was significantly lower in the Mini group than in the 4:1 group during cardioplegia. Minimally diluted blood cardioplegia resulted in more prompt resumption of lactate extraction, lower levels of release of the myocardial-specific isoenzyme of creatine kinase and thiobarbituric acid reactive substances during reperfusion, and better postoperative left ventricular function compared with the standard 4:1 cardioplegia. CONCLUSIONS: Minimally diluted tepid blood cardioplegia may provide superior myocardial protection than the standard 4:1 dilution technique by optimizing the aerobic environment through an increase in oxygen supply during intermittent cardioplegia.

[Heart valvular disease in patients 70 years old and older].

From June 1986 to December 1996, 69 patients older than 70 years old underwent AVR (29 cases), MVR (21 cases), MVP (5 cases), DVR (10 cases), aortic root replacement (3 cases), repair of PVL (1 case) in our hospital. There are five (7.2%) operative and hospital deaths. The survival rate was 88.4% at 10 year after surgery and three (4.7%) late deaths. The factors associated with early deaths were renal dysfunction and DVR. Our surgical results suggest that open heart surgery can be performed safely even elderly patients, in spite of their precarious physiologic homeostasis. Not the chronological age but the physiological age is important determinant for surgical indication. If quality of life (QOL) can be expected to be enhanced, we recommend an aggressive surgical approach.

[Combined superior-transseptal approach to left atrial myxoma].

A 60-year-old woman was referred to our hospital for treatment of an intracardiac tumor Echocardiography revealed a 47 x 30 mm tumor in the left atrium which had a short stalk attached to the atrial septum. At operation, a large left atrial myxoma was extirpated using a combine superior transseptal approach. Through this incision, exposure of the left atrial myxoma and it stalk was excellent and removal of the myxoma was easily performed with minimal minpulation. Postoperative arrhythmias related to the operative procedures were not observed. The patient recovered uneventfully. The operative technique and indications of the combined superior transseptal approach to the left atrium are discussed in this paper.

Cineradiographic evaluation of ATS open pivot bileaflet valves.

BACKGROUND AND AIMS OF THE STUDY: Echocardiography and cineradiography are both valuable for the evaluation of prosthetic valve function, especially of mechanical valves. Although Doppler echocardiography data are available for the recently developed ATS valve, cineradiographic evaluation of leaflet movement of the valve has not been performed. MATERIALS AND METHODS: Five patients received aortic and another five mitral valve replacement with the open pivot ATS bileaflet prosthetic valve. There were three men and seven women; mean patient age was 58.8 years. Cineradiographic and Doppler echocardiographic evaluations of the ATS valve were performed early after surgery in all 10 patients. RESULTS: There were no early deaths after surgery or after discharge from the hospital. No valve-related complications were seen, and no clinical symptoms or signs of prosthetic malfunction were observed during the follow up period. Doppler-derived values of the ATS valve were comparable with those previously reported; however, cineradiography of the valve demonstrated that the mean angle enclosed by the two open leaflets was 37.6 degrees (range: 34 degrees to 44 degrees) in the aortic position and 29.7 degrees (range: 20 degrees to 35 degrees) in the mitral position. Mean leaflet mobility was 93.0 degrees (range: 86 degrees to 96 degrees) in the aortic position and 100.0 degrees (range: 92 degrees to 110 degrees) in the mitral position. Thus, the opening of the normally functioning ATS valves in vivo was less than that observed in vitro and reported by the manufacturer. CONCLUSIONS: These results suggest that unevenly distributed blood flows with different velocities through the two side orifices and the central orifice may result in incomplete opening of the ATS leaflets, which respond with great sensitivity to localized blood flow. Our findings appear to be important to avoid the removal of a normally functioning ATS valve only because the leaflet opening appears to be 'restricted'.

Aortic valve replacement for aortic regurgitation due to Kawasaki disease. Report of two cases.

Two cases of severe aortic regurgitation due to Kawasaki disease are reported. Both patients were diagnosed as having Kawasaki disease in their infancy, and were followed up by a pediatrician. Aortic regurgitation was detected 18 months in one case and 36 days in the other case after onset of the illness. With the passage of time, the aortic regurgitation increased and aortic valve replacement was scheduled in both patient at the age of 13. On admission, two-dimensional echocardiography showed thickening of the aortic cusps, and severe aortic regurgitation was detected by color flow Doppler studies. Successful aortic valve replacement was performed, and histological studies of the cusps showed sequelae of valvulitis. In conclusion, aortic regurgitation is a rare complication of Kawasaki disease, and the aortic valve function, especially occurrence of aortic regurgitation, should be carefully observed in patients with a past history of Kawasaki disease.