老年人慢性肾功能衰竭的临床特点─—附53例回顾分析

我院在１９８５年１月－１９９４年１２月共收治慢性肾功能衰竭（ＣＲＦ）患者１８５例，其中老年患者（≥６０岁）５３例（占２８．６％），与同期住院的非老年患者（＜６０岁）１３２例（占７１．４％）进行对比分析，发现老年人ＣＲＦ在其基础疾病，临床表现，实验室检查，并发症及伴发病方面均有许多特点，并对老年人ＣＲＦ的治疗及与预后有关的因素略加讨论。     

Treatment of Patients with Prior Exit Block Using a Novel Steroid-Eluting Active Fixation Lead

An increased interest has developed in active fixation leads for several reasons. Exit block is an uncommon complication that is seen with both active and passive fixation leads. Exit block has not been a significant problem with passive fixation steroid-eluting leads and has been treated with these leads. A new steroid-eluting active fixation lead was examined for its performance in patients in whom exit block had previously occurred. The lead function was evaluated prospectively in 24 patients with a history of exit block (15 ventricular and 9 atrial). The results in patients with atrial exit block are encouraging with an average chronic stimulation threshold of 0.19 msecs at 2.5 volts. Results in the ventricle are less encouraging with 3 occurrences of recurrent exit block in 15 patients; however, the remaining patients had a good mean threshold of 0.21 ±0.11 msecs at 2.5 volts. There were a remarkable number of non–lead related complications suggesting that this is a substantially different group than routine implantations.     

Clinical outcome of patients with venous thromboembolism and recent major bleeding: findings from a prospective registry (RIETE)

BACKGROUND: Patients who have experienced a recent major bleeding episode are usually excluded from clinical studies of venous thromboembolism (VTE) treatment. Therefore, recommendations based on evidence from clinical trials may not be suitable for these patients. The Registro Informatizado de la Enfermedad TromboEmbolica (RIETE) is a multicenter, observational registry designed to gather and analyze data on VTE treatment practices and clinical outcomes in patients with acute VTE. OBJECTIVES: The aim of this analysis was to study outcomes of patients with VTE who had experienced recent major bleeding (< 30 days prior to VTE diagnosis). METHODS: Patients with objectively confirmed symptomatic acute VTE are consecutively enrolled into the RIETE registry. Patient characteristics, details of antithrombotic therapy, and clinical outcomes at 3 months were recorded. RESULTS: Of 6361 patients enrolled up to January 2004, 170 (2.7%) had experienced recent major bleeding: 69 (40.6%) gastrointestinal tract, 60 (35.3%) intracranial, 41 (24.1%) other. The incidences of major bleeding (4.1%) and recurrent pulmonary embolism (PE) (2.4%) were significantly higher in patients with recent major bleeding. Among them, patients with cancer had an increased incidence of major bleeding [odds ratio (OR) 10.0, 95% confidence interval (CI) 2.3, 50; P < 0.001] and fatal PE (OR 4.1, 95% CI 0.98, 17; P < 0.05). CONCLUSIONS: Patients with VTE and recent major bleeding prior to VTE diagnosis (2.7% of total enrolled patients) had poorer clinical outcomes compared with those who had not experienced recent major bleeding. In patients who had recent major bleeding prior to enrollment, those with cancer had a poorer clinical outcome than those without cancer.     

Complications Associated with Pectoral Implantation of Cardioverter Defibrillators

Pectoral placement of ICD pulse generators is now routine after downsizing of these devices. However, the safety of this approach is not well documented. The aim of this study was to evaluate complications in a large cohort of patients undergoing initial pectoral ICD implantation. The subjects for this study were 1,000 consecutive patients receiving a Medtronic Jewel ICD at 93 centers worldwide. Cumulative follow-up for all patients was 634 patient-years, with 64.9% of patients followed for 6 months or longer. The complications evaluated were erosion, pocket hematoma, seroma, wound infection, dehiscence, device migration, lead fracture, and dislodgment. In this series, 1.8% of patients experienced a pocket complication with only 3 (0.3%) erosions and 2 (0.2%) infections. Lead complications were observed in 2.1% of subjects, most commonly early dislodgment of the RV lead. We conclude that pectoral implantation of a downsized ICD system can be performed with a low rate of complications. However, careful attention to anchoring techniques and close early monitoring is important given the 1.7% rate of lead dislodgment that occurred primarily during the first month following implantation.     

Automatic Sensor Adjustment in a Rate Modulated Pacemaker

A new feature (AutoSlope) has been introduced that can automatically adjust the sensor slope based on the chronic activity level of the patient. The algorithm adjusts the slope once per week so that 99% of the sensor response is maintained between the base rate and 23% of the difference between the programmed Base Rate and the Max Sensor Rate. Offsets are available for fine titration of sensor response in individual patients. The AutoSlope feature was evaluated in 93 patients with DDDR pacemakers (Trilogy DR+, Pacesetter). Patients were seen at 1, 3, and 6 months for a total of 178 evaluations. At each evaluation, the AutoSlope value was recorded. Patients then performed a brisk walk at sensor values equivalent to the AutoSlope value. Desired sensor rate was compared to the rate achieved by AutoSlope for the exercise period. Long-term sensor performance was evaluated by analyzing the sensor histogram. AutoSlope provided the desired sensor rate in most patients. Use of AutoSlope offsets allows fine titration of rate modulation in individual patients. Ongoing changes in sensor performance provided by AutoSlope allow patients to achieve a desired sensor rate from one evaluation to another without changes in permanent programmed settings. Programming a low maximum sensor rate may limit sensor response in some patients.     

Initial Experience with a New Single Chamber, Dual Sensor Rate Responsive Pacemaker

In August 1991, a new single chamber pacemaker became available that utilizes information from two sensors, activity and stimulus-to-T wave (QT) interval. We are reporting on the first 90 implants in 21 centers. T wave sensing was adequate at implantation in 88/90 patients, with a safety margin of > 100% in 86/90, Activity sensing was adequate in all patients. The contribution of each sensor fsensor blending) is programmable for each patient. Of 75 patients assessed at 1 month after implant, three have been programmed to "Activity-Only" mode, and 72 to dual sensor mode. Of these, 18 have been programmed to "QT < Activity," 48 to "QT = Activity," and 6 to "QT > Activity." Forty-five patients underwent exercise testing in dual sensor mode and a subgroup of 15 also underwent exercise testing in Activity-Only mode. The dual sensor mode produced a more gradual increase in pacing rate. Sensor Cross Checking^tmsatisfactorily prevented a sustained high pacing rate in tests of false-positive activity sensing (tapping, vibrating pacemaker, or static pressure). The maximum pacing rate on walking downstairs (94.2 ± 7.2 ppm) was similar to that produced by walking upstairs (91.6 ± 5.9 ppm). We conclude that initial assessment of this dual sensor, single chamber, rate responsive pacemaker confirms that the algorithm for combining data from two sensors functions satisfactorily. Dual sensor rate responsive pacing may offer significant advantages over single sensor devices, and further studies of this novel device are indicated.     

A Prospective, Randomized Evaluation of a Nonthoracotomy Implantable Cardioverter Defibrillator Lead System

Nonthoracotomy lead systems for ICDs have been developed that obviate the need for a thoracotomy and reduce the morbidity and mortality associated with implantation. However, an adequate DFT cannot be achieved in some patients using transvenous electrodes alone. Thus, a new subcutaneous "array" electrode was designed and tested in a prospective, randomized trial that compared the DFT obtained using monophasic shock waveforms with a single transvenous lead alone that has two defibrillating electrodes, the transvenous lead linked to a subcutaneous/submuscular patch electrode, and the transvenous lead linked to the investigational array electrode. There were 267 patients randomized to one of the three nonthoracotomy ICD lead systems. All had DFTs that met the implantation criterion of ≤ 25 J. The resultant study population was 82% male and 18% female, mean age of 63 ± 11 years. The indication for ICD implantation was monomorphic VT in 70%, VF in 19%, monomorphic VT/VF in 6%, and polymorphic VT in 4% of the patients, respectively. The mean LVEF was 0.33 ± 0.13. The mean DFT obtained with the transvenous lead alone was 17.5 ± 4.9 J as compared to 16.9 ± 5.5 J with the lead linked to a patch electrode (P = NS), and 14.9 ± 5.6 with the lead linked to the array electrode (array versus lead alone, P = 0.0001; array versus lead/patch, P = 0.007). The results of this investigation suggest that the subcutaneous array may be superior to the standard patch as a subcutaneous electrode to lower the DFT and increase the margin of safety for successful nonthoracotomy defibrillation.     

Once- versus twice-daily administration of controlled-release isosorbide-5-mononitrate 60 mg in the treatment of stable angina pectoris: A randomized, double-blind, cross-over study

Thirty-seven patients with chronic, stable angina pectoris wereincluded in a randomized, double-blind cross-over study to assessthe efficacy of once- and twice-daily dosage regimens of 60mg isosorbide-5-mononitrate, in a controlied release formulation(5-ISMN Durules^® Astra). After 2 weeks of treatment, duringa symptom-limited bicycle ergometer exercise test performed3 h after the dose, the time to 1 mm ST segment depression wasobserved to be longer by once-daily than by a twice-daily dosageregimen (614 ± 165 vs 561 ± 148 s, P<0·01).The time to the end of exercise was also significantly prolongedby once-daily dosage, as compared with placebo (693 ±158 and 645 ± 173 s, respectively; P<0·05),which was not observed with the twice-daily regimen. Both dosageregimens still had a significant effect on the prolongationof the time to onset of angina 9 h after the dose: 420 ±164 s by placebo, 492 ± 161 s by once-daily dosage; P<0·01and 466 ± 154 s by twice-daily dosage; P<0·05.Anginal attack rate and nitroglycerin consumption was significantlylower during the once-daily dosage period as compared with placebo;this difference was not evident during the twice-daily administrationof the drug. Controlled-release 5-ISMN 60 mg given once daily was effectivein angina pectoris patients for at least 9 h after the doseand showed no clinical signs of tolerance after 2 weeks of thetreatment. Attenuation of the clinical effect was observed withthe twice-daily (in 12 h intervals) dosage regimen, presumablycaused by constantly high 5-ISMN plasma concentration.