Recanalization of Chronically Occluded Coronary Arteries: Single-Center Experience in 400 Cases, Including Long-Term Angiographic Follow-Up

The study presented comprises the initial and angiographic long-term results of a consecutive series of recanaliza-tion procedures in a single center. Between 1988 and 1992, a total of 400 patients underwent transluminal recanalization for total coronary occlusions. In 82% of successfully attempted patients, the occlusion could be passed by a standard guidewire. The overall initial success rate was 75% (298 of 400). The highest success rates could be achieved in the left circumflex artery (84%) and left anterior descending coronary artery (77%). Complications were uncomplicated myocardial infarction in ten patients (2.5%) and death in two patients (0.5%). Angiographic follow-up 3–6 months after recanalization could be achieved in 263 (88%) of 298 patients. Significant restenosis (≥ 50% minimum lumen diameter) was found in 57 (22%) of 263, and reocclusion was present in 38 (14%) of 263 patients, resulting in a total recurrence rate of 36%. In conclusion, recanalization can be performed with an initial success rate of 75% using bare-wire technique under the prerequisite operator experience. If a nearly complete angiographic follow-up is performed, the overall recurrence rate is 36%, which seems to be very acceptable in comparison with PTC A results for incomplete obstructions published so far . (J Interven Cardiol 1996;9:73–79)     

Cerebrospinal fluid and serum prolactin in systemic lupus erythematosus with and without central nervous system involvement

Aim: Recent research has shown that prolactin (PRL) may participate in the pathogenesis of systemic lupus erythematosus (SLE), and hyperprolactinemia may be related to disease activity. The current study investigated both serum and cerebrospinal fluid (CSF) PRL in SLE patients and their possible relationship to central nervous system (CNS) involvement. Methods: Prolactin levels were determined by immunoradiometric assay. Serum PRL levels were detected in 80 patients with SLE and 25 matched healthy controls. Disease activity was scored by SLEDAI. CSF PRL levels were detected in 7 cases of CNS‐involved SLE, eight cases of non‐CNS‐involved inactive SLE and eight cases of non‐SLE CNS disorders. Results: Hyperprolactinemia was present in 40% of SLE patients. Serum PRL levels were significantly correlated with SLEDAI scores. There was no significant difference of serum PRL levels between SLE patients with or without CNS involvement, but the mean CSF PRL levels were higher in CNS‐involved SLE patients than in non‐CNS‐involved SLE and non‐SLE patients. There was no significant correlation between serum and CSF PRL levels. Conclusions: Our results suggest that high serum PRL levels correlate with active disease in SLE, but not with CNS involvement. CSF PRL levels in SLE patients correlate with CNS involvement, which indicates that CSF PRL may be involved in the pathogenesis of CNS‐SLE.     

Slowing of the Ventricular Rate During Atrial Fibrillation by Ablation of the Slow Pathway of AV Nodal Reentrant Tachycardia

Influence of Slow Pathway Ablation on Atrial Fibrillation. Introduction : The mechanisms whereby radiofrequency catheter modification of AV nodal conduction slows the ventricular response are not well defined. Whether a successful modification procedure can be achieved by ablating posterior inputs to the AV node or by partial ablation of the compact AV node is unclear. We hypothesized that ablation of the well-defined slow pathway in patients with AV nodal reentrant tachycardia would slow the ventricular response during atrial fibrillation.
Methods and Results : In 34 patients with dual AV physiology and inducible AV nodal reentrant tachycardia, atrial fibrillation was induced at baseline and immediately after successful slow pathway ablation and at 1-week follow-up. The minimal, maximal, and mean RR intervals during atrial fibrillation increased from 353 ± 76,500 ± 121, and 405 ± 91 msec to 429 ± 84 (P < 0.01), 673 ± 161 (P < 0.01), and 535 ± 98 msec (P < 0.01), respectively. These effects remained stable during follow-up at 1 week. The AV block cycle length increased from 343 ± 68 msec to 375 ± 60 msec (P < 0.05) immediately and to 400 ± 56 msec (P < 0.01) at 1-week follow-up. The effective refractory period of the AV node prolonged from 282 ± 83 msec to 312 ± 89 msec and to 318 ± 81 msec after 1 week (P < 0.05), respectively.
Conclusion : This study shows a decrease in ventricular response to pacing-induced atrial fibrillation after ablation of the slow pathway in patients with AV nodal reentrant tachycardia. Since the AV nodal conduction properties could be defined, this study supports the hypothesis that the main mechanism of AV nodal modification in chronic atrial fibrillation is caused by ablation of posterior inputs to the AV node.     

High Rate of Late Dislodgements of an Active Fixation Atrial Lead

Between May 1985 and May 1991 we implanted 115 DFH-leads as unipolar atrial leads. The active fixation mechanism of this electrode consists of two sickle-shaped anchoring hooks which are placed at a distance of 0.9 mm parallel to the distal flat end of the electrode. All leads were affixed to the free wall of the right atrium. One hundred eight leads (93.9%) were implanted for dual chamber pacing and seven leads (6.1%) for single chamber atrial pacing. Parameters measured at implantation were (mean values): stimulation threshold 1.06 ± 0.42 V at 0.5 msec pulse width, P wave amplitude 5.12 ± 2.04 mV, and lead impedance 560 ± 76.1 Ohms. Within the first week after implantation, three early dislodgements occurred (2.6%). The follow-up period averaged 30.4 ± 16.2 months (range 2–76 months). During this time, 14 late macrodislodgements (12.2%) occurred after a mean period of 18.4 months (range 2–59 months). All of them required reoperation. The active fixation mechanism of the DEH-lead appears to be unreliable, if implanted in the free wall of the right atrium for dual chamber pacing.     

The use of 6-mercaptopurine in treatment of acute leukemia in late pregnancy

More than 115 cases of leukemia associated with pregnancy have been reported in the literature. This case is presented because 6-mercaptopurine was used in the management of this disease in late pregnancy, with a result suggestive that this drug should be added to our armamentarium for treatment of acute leukemia complicating late pregnancy without apparent ill effects on the fetus. Its efficacy in acute leukemia has been previously reported by Dameshek¹ and Buchenal and associates.²     

Radicular cyst affecting a root-filled human tooth: a long-term post-treatment follow-up

Apical periodontitis is caused primarily by microorganisms residing in the root canals of affected teeth. Nevertheless, there is convincing evidence implicating other independent factors that adversely affect the outcome of conventional root canal therapy. In this paper, morphological evidence is presented in support of die potential role of two endogenous factors that may interfere with post-endodontic healing of the periapex. The specimens consisted of a surgical biopsy of an asymptomatic peri-apical lesion which persisted for a follow-up period of 44 months. The biopsy was processed for correlated light and electron microscopy. The lesion was characterized by the presence of a large central lumen lined by a stratified squamous epithelium. The most striking feature of the lesion was the presence of vast numbers of cholesterol crystals which congregated in the connective tissue surrounding the cyst cavity. Extensive light and electron microscopic investigation of the apical part of the root canal and the lesion foiled to reveal the presence of microorganisms. These findings strongly suggest that intrinsic factors like the accumulation of certain tissue break-down products such as cholesterol crystals, and the cystic condition of the lesion itself, can adversely affect the healing process of the periapex following root canal therapy. Consequently, such apical lesions can remain refractory to conventional endodontic therapy for long periods of time.     

The feasibility of using an American National Board examination for the evaluation of Swiss candidates for licensure

A test in Internal Medicine of the American National Board of Medical Examiners was given to Swiss medical students as a graduating examination. This study dealing with the feasibility of such an enterprise describes the technical procedures and investigates the problems of translation and the validity of foreign made items. Comparison of item analyses for the 369 Swiss candidates and for a sample of 370 American candidates reveals that most items are of close comparability in difficulty, discrimination and pattern of response to the distractors. In a cross-national comparison of students' responses to the items no systematic content characteristics can be found for items favouring one group or the other. Swiss experts, in judging the validity of the items for testing Swiss students, could indeed identify in advance some of the items that proved to be less valid and more difficult for their—but also the American—students. It is concluded that a National Board examination can be as valid and suited to examine Swiss candidates for licensure as it is to examine American candidates.