Percutaneous transluminal coronary angioplasty using a steerable guiding catheter: a new technique

A new type of steerable guiding catheter is described for use in percutaneous transluminal coronary angioplasty (PTCA). It is simple to use and externally steerable. The catheter incorporates a steering system by means of which the catheter tip can be made to assume the form of either a right or left Judkins catheter or to be fixed in any intermediate configuration, entirely through external manipulation. We used this new guiding catheter to perform PTCA on 15 patients. Single lesions were found in the left anterior descending branch in seven patients, in the right coronary artery in four, and in the circumflex artery in two, whereas stenosis of a coronary bypass graft was found in two patients. Angioplasty was successful in all cases. There were no complications, during either the procedure or the postoperative hospitalization. The steerable guiding catheter described here may prove useful for PTCA in cases where a conventional catheter cannot be placed accurately or in cases with multi-vessel coronary disease.     

Temporary cardiac pacing using a new, steerable, balloon-tipped pacing catheter

A new balloon-tipped, flow-directed, steerable pacing catheter for unipolar temporary ventricular pacing is presented. It was successfully and uneventfully tested in 25 patients with acute myocardial infarction in the coronary care unit. The main advantage of the new catheter is the ease with which a stable contact may be achieved between the pacing electrode and the endocardium.     

Influence of aortic elastic properties on pulse pressure changes induced by rapid ventricular pacing

The mechanism of aortic pulse pressure decline induced by acute rapid ventricular pacing remains incompletely understood. It has been ascribed to changes in stroke volume or aortic compliance. This becomes more complicated by the dependence of aortic compliance on the level of the mean aortic pressure as well as the aortic wall properties. To test the role of such mechanical factors, aortic pressure-diameter hemodynamics, derived from simultaneous tip-micromanometer aortic pressure recordings and high-fidelity ultrasonic intravascular aortic diameter recordings, were measured in 15 normal subjects during and after abrupt cessation of rapid ventricular pacing (up to 160 bpm). Immediately after terminating the pacing, diastolic aortic pressure declined (–9%, from 87.4±1.2 to 79.5±1.7 mmHg,P<0.0001) while systolic aortic pressure increased (+19%, from 109.5±1.6 to 130.1±2.8 mmHg,P<0.0001). Thus, pulse pressure increased from 22.1±2.2 to 50.6±3.1 mmHg,P<0.0001. To quantify systolic and diastolic aortic pressure differences we compared the first postpaced beat (a) and the last paced beat (b). To estimate what the aortic pressure would have been for the paced beats had the aortic diameter differences due to the different heart rate not occurred we calculated the theoretical pressure of the paced beat P_b=E_b·D_a, where E_b was the instantaneous aortic elastance of the paced beat and D_a was the aortic diameter for the postpaced beat. The corrected pressure difference was then calculated by the following: P_cor=(D_a·E_b)–P_a. It was found that systolic P_cor was 25% of systolic P_raw and diastolic P_cor was 89% of diastolic P_raw. P_raw was the pressure difference between paced and spontaneous beat measured from the raw data. P_cor indicates the portion of P_raw that results from a change in aortic stiffness as a consequence of viscous behavior or aorto-ventricular coupling. These data indicate that the majority of diastolic pressure decline after pacing was terminated, may reflect a change in aortic stiffness while the majority of systolic pressure rise, and may be attributable to differences in hemodynamics alone.     

Testicular descent related to growth hormone treatment

An 8.7 year-old boy with cryptorchidism and growth hormone (GH) deficiency due to septooptic dysplasia presented testicular descent related to the commencement of hGH treatment. This case suggests a role for GH in testicular descent.     

Physician confidence and interest in learning more about common geriatric topics: a needs assessment

OBJECTIVE: To assess physicians' confidence in and interest in learning more about 18 specific geriatric topics. DESIGN: Written survey. SETTING: Annual meetings of the American College of Physicians (ACP) and the American Academy of Family Physicians (AAFP). PARTICIPANTS: Seven hundred and fifty-eight physicians (547 ACP members, 211 AAFP members). MEASUREMENTS: For each topic, participants rated their confidence in performance, their peers' need for education, and their interest in learning more, using a five-point Likert scale. RESULTS: Survey participants were on average 16 years out of medical school and 61% were in a community primary care practice that included many geriatric patients on a primarily fee-for-service basis. High levels of interest in learning more about dementia, functional assessment, urinary incontinence, and sensory impairment were found. A substantial correlation (r =.44, P <.0001) between the proportion of seniors reported in the physicians' practice and confidence in performance in the areas surveyed was identified. CONCLUSIONS: These findings provide useful information on the physician-learner's perception of needs, which is important in the design of effective continuing education efforts in geriatrics.     

Somatostatin increases rat locomotor activity by activating sst2 and sst4 receptors in the striatum and via glutamatergic involvement

The involvement of striatal somatostatin receptors (sst₁, sst₂ and sst₄) in locomotor activity was investigated. Male Sprague–Dawley rats, 280–350 g, received in the striatum bilateral infusions of saline, somatostatin, and selective sst₁, sst₂, and sst₄ ligands. Spontaneous locomotor activity was recorded for 60 min. The involvement of excitatory amino acid receptors (AMPA and NMDA) on somatostatin’s actions was also examined. Western blot analysis was employed for the identification of somatostatin receptors in striatal membranes. Somatostatin, sst₂ and sst₄, but not sst₁, selective ligands increased rat locomotor activity in a dose-dependent manner. Blockade of AMPA and NMDA receptors reversed somatostatin’s actions. In conclusion, striatal somatostatin receptor activation differentially influence rat locomotor activity, while glutamatergic actions underlie the behavioral actions of somatostatin.     

Evaluation of the seminar method to improve clinical teaching

The effects of a seminar method to improve the teaching of ward attending physicians were evaluated. Forty-six attending physicians from four institutions were randomly assigned to experimental and control groups. The method was evaluated to assess its effects on attending physicians’ performances and attitudes, and impact on learners. Evaluation methods included ratings of videotapes of ward rounds, teachers’ subjective assessments of both their teaching performances and their experiences in the study, and trainee ratings. Videotape ratings, the teachers’ own assessments, and the trainees’ assessments of the attending physicians’ impact on learning were significantly different, favoring the experimental group (p<0.05). It is concluded that the seminar method can provide the basis for effective and feasible approaches for improving clinical teaching by attending physicians. Received from Stanford University Medical Center and Palo Alto Veterans Administration Medical Center. Supported by the National Fund for Medical Education, the Veterans Administration, and the Kaiser Foundation Research Institute.     

Stents covered by autologous venous grafts: feasibility and immediate and long-term results

BACKGROUND: Previous experimental studies with a new covered stent, the autologous venous graft-covered stent (AVGCS), have shown favorable results. The aim of this study was to evaluate the feasibility and safety of this new technique in human coronary arteries and to compare the long-term outcome with uncovered stents. METHODS AND RESULTS: A venous graft was removed from an upper limb. A conventional stent then was covered by the venous graft. Fifty-eight AVGCS were implanted in 56 patients, including 16 patients with acute coronary syndromes (ACS). Additionally, in 114 patients, 138 uncovered stents were implanted, serving as a control group, including 38 patients with ACS. The procedure was successful in all patients. Stent thrombosis was observed in 3 patients in the control group and in 1 patient with an AVGCS. There was a trend for the minimal luminal diameter to be greater in the AVGCS group at follow-up (P =.07), and statistical significance was observed in patients with ACS (P <.01). The target vessel revascularization and the restenosis rates were similar between the 2 groups. In patients with ACS, the restenosis rate was less (P <.04) and there was a trend for target vessel revascularization to be less in covered stents (P =.09). The event-free survival rate at 4 years was 85% in the AVGCS group versus 81% in the control group (P = not significant); in ACS it was 94% versus 78%, respectively (P = not significant). Stents covered by thicker venous grafts were associated with improved clinical outcome. CONCLUSIONS: Stents covered by autologous venous grafts may be safely prepared without complications. This technique may prove to be a useful means, especially in patients with ACS.