A New Endocardial "Over-the-Wire" or Stylet-Driven Left Ventricular Lead:

Transvenous left ventricular (LV) leads are primarily inserted "over-the-wire" (OTW). However, a stylet-driven (SD) approach may be a helpful alternative. A new polyurethane-coated, unipolar LV lead can be placed either by a stylet or a guide wire, which can be inserted into the lead body from both ends. The multicenter OVID study evaluates the clinical performance of this new steroid- and nonsteroid eluting lead. The primary endpoint is the LV lead implant success rate after identification of the coronary sinus (CS). Secondary endpoints include complication rate, short- and long-term lead characteristics, overall procedure and LV lead placement duration, total fluoroscopy time, and lead handling characteristics ratings. To date, 96 patients with heart failure (68 ± 9 years old, 76% men) are enrolled. The CS was identified in 95 patients and, in 85 (88.5%), the LV lead was successfully implanted. The final lead positioning was lateral in 41%, posterolateral in 35%, anterolateral in 18%, and great cardiac vein in 6% of patients. In 70%, the 85 successful implantations, both stylet-driven and guide-wire techniques were used, a stylet only was used in 22%, and a guide wire only in 8%. Mean overall duration of 85 successful procedures was 112 ± 40 minutes, total fluoroscopy time 28 ± 15 minutes, and the duration of LV lead placement was 35 ± 29 minutes. During a 3-month follow-up, the loss of LV capture occurred in three and phrenic nerve stimulation in six patients. The mean long-term pacing threshold is 0.8 V/0.5 ms and pacing impedance is 550 Ω. The OVID data suggest that these new leads are safe and effective. The choice of both OTW and SD techniques during lead implantation offers greater procedural flexibility.     

Atrial Lead Implantation During Atrial Flutter or Fibrillation?

In patients with sinoatrial disease, unexpected atrial flutter (Af) or fibrillation (AF) is a common problem during implantation of atrial-based pacing systems. As an alternative approach to blind atrial lead placement, lead positioning could be optimized by atrial electrogram mapping. It was the object of this study to evaluate if atrial lead implantation according to this approach and during ongoing arrhythmia is reasonable or if it should be postponed until restoration of sinus rhythm (SR). Twenty-nine consecutive patients (group I) with sick sinus syndrome received a dual-chamber pacemaker during an episode of Af (n = 11) or AF (n = 18). All but two atrial leads were of the screw-in type and had bipolar sensing. Atrial lead position was optimized by mapping the electrogram under fluoroscopy to find locations with high potential amplitudes. The patients were followed for 15.1 ± 9.8 months, and atrial sensing threshold (AST), atrial pulse width threshold (PWT) at 2.0 V, the pacing mode programmed, and the clinical outcome (OUT) were recorded. The control group consisted of 30 patients (group II) who equally had a history of AF or Af, but were in SR during implantation. The atrial peak-to-peak potential (APEAK) after final lead placement was lower for AF (median value 2.5 mV, lower-upper quartile: 1.7–3.1 mV) as compared to Af (3.8 mV, 2.7–4.9 mV, P < 0.05) and SR (4.1 mV, 3.3–6.2 mV, P < 0.001). There was a correlation (P < 0.01) between APEAK during Af/AF and the postoperative AST immediately after restoration of SR. No lead in any group had to be corrected due to improper sensing in the postoperative course. Median chronic AST was 2.8 mV (2.0–4.0 mV) in group I and 4.0 mV (2.8–4.0 mV) in group II. Median chronic PWT at 2.0 V was 0.15 ms (0.12–0.26 ms) in group I and 0.15 ms (0.09–0.20 ms) in group II. There was no significant difference in chronic AST and PWT between both groups. All but two patients in group I preserved SR as the basic rhythm. A stable SR was observed in 10 of 29 patients, intermittent Af/AF was documented in 17 of 29 patients, seven of whom were asymptomatic. There was no significant difference in OUT between group I and II. Hence, sinus rhythm is not a prerequisite of atrial lead implantation. Mapping the Af or AF waves appears to be useful to guide lead placement and to achieve sufficient sensing and pacing conditions after conversion to sinus rhythm.     

Cleavage kinetics and anchor linked intermediates in solid phase peptide amide synthesis

Kinetics and cleavage conditions of peptide amide synthesis were studied using the anchor molecules 5-(4′-aminomethyl-3′,5′-dimethoxyphenoxy)valeric acid (4-ADPV-OH) and 5-(2′-aminomethyl-3′,5′-dimethoxyphenoxy)valeric acid (2-ADPV-OH). Unexpectedly the anchor amide alanyl-4-ADPV-NH₂ was isolated and characterized as an intermediate during the cleavage with trifluoroacetic acid (TFA) of alanyl-4-ADPV-alanyl-aminomethyl-polystyrene to yield the alanine amide. As a matter of fact the NH–CH_α bond of the alanyl spacer has to be cleaved to form this intermediate. Using TFA-dichloro-methane (1:9) alanyl-4-ADPV-NH₂ was obtained as a cleavage product in 50% yield within 60min, whereas the isomeric alanyl-2-ADPV-NH₂ was formed more slowly under these mild conditions. At high TFA concentration no difference between the 2- and 4-ADPV anchor was observed in the rate of formation of the free alanine amide. The presence of tryptophan amide in the cleavage mixture resulted in an anchor alkylated tryptophan amide, which remains stable in acidic solution but disappears rapidly in the presence of the resin. A low TFA/high TFA cleavage procedure is recommended for peptide amid synthesis applying the ADPV anchor.     

A double-blind study of the effect of zinc and oxytetracycline in acne vulgaris

With a double-blind technique, the effects of oral zinc and tetracyclines were compared in 37 patients with moderate and severe acne. No difference in effect between the treatments was seen and no side-effects were noted in any group. After 12 weeks of treatment, the average decrease in the acne score was about 70% in both groups.     

A comparative study of three different approaches to the comfortable zone

By means of a screw jack device, applied to thirteen edentulous subjects, the comfortable zone was approached in three different ways, by the central, the internal and the external approaches. Correspondingly, the zonal borders behaved differently. Applying the central approach it was found that the initial height of the screw jack had a lingering effect upon subsequent adjustments of the screw. Moreover, lower border data collected by the external approach distinguished themselves from other zonal border data by showing a significantly lower susceptibility to successive adjustments. The study suggests that muscle activity is a factor on which the perceptual mechanism relies, when a zonal border is assessed subjectively by a patient.     

The effects of lansoprazole on erosive reflux oesophagitis are influenced by CYP2C19 polymorphism

BACKGROUND: The acid suppressive effect of lansoprazole is influenced by the P450 2C19 (CYP2C19) polymorphism. AIM: To investigate whether the CYP2C19 genotype is related to the healing of erosive reflux oesophagitis during treatment with lansoprazole. METHODS: Eighty-eight Japanese patients with erosive reflux oesophagitis were treated with a daily oral dose of 30 mg lansoprazole for 8 weeks. The CYP2C19 genotype, Helicobacter pylori infection status and serum pepsinogen I/II ratio were assessed before treatment. At 4 and 8 weeks, the healing of erosive reflux oesophagitis was evaluated endoscopically. RESULTS: The healing rates were 57.1%, 69.2% and 72.7% at 4 weeks and 77.4%, 95.0% and 100% at 8 weeks in homozygous extensive metabolizers, heterozygous extensive metabolizers and poor metabolizers, respectively. At 8 weeks, the healing rate of erosive reflux oesophagitis was significantly lower in homozygous extensive metabolizers than in the other two groups (P < 0.05). The H. pylori status and serum pepsinogen I/II ratio had less influence than CYP2C19 polymorphism on the healing rate of erosive reflux oesophagitis. CONCLUSIONS: The therapeutic effect of lansoprazole on erosive reflux oesophagitis is influenced by the CYP2C19 genotype status. Therefore, a test of CYP2C19 genotype may be useful for the medical treatment of reflux oesophagitis with lansoprazole.     

A New Steroid-Eluting Screw-In Electrode

A new lead design was tested that combined a small microporous steroid-eluting electrode with an insulated, exposed helix for active fixation. This lead (model 5078, Medtronic, Inc., group I. n = 10) was compared to a conventional model (model Y 60 BP, Biotronik) with a larger surface of polished platinum-iridium, equipped with a fixed, noninsulated screw but without steroid elution (group II, n = 10). The two lead models were studied in the atrial position of dual chamber pacing systems, which all had a tined ventricular lead (model 5024, Medtronic, Inc.), with essentially the same steroid-aluting tip as the new active fixation lead design. Sensing and pacing data were recorded acutely and during 1 year of follow-up, via the telemetry of a Relay pulse generator (Intermedics. Inc.). Intraoperatively, unfiltered atrial electrogram amplitudes did not differ between groups (group I; 7.12 ± 2.56 mV vs group II: 6.42 ± 1.87 mV; P > 0.05), nor did sensing thresholds 1 year after implantation (group I: 5.33 ± 1.70 mV vs group II: 4.26 ± 1.40 mV; P > 0.05). Atrial pacing thresholds as measured during surgery at a pulse width of 0.5 msec were lower in group I (0.49 ± 0.15 V) than in group II (0.68 ± 0.19 V; P < 0.05). From day 5 through day 360 of follow-up, the difference in atrial pacing thresholds was highly significant (P < 0.01). with a smaller peaking of early thresholds and a much lower scattering of data for the steroid screw-in leads than for controls. Chronic thresholds as measured 1 year postimplant in terms of minimum charge delivered for capture were 0.20 ± 0.03 μC in group I versus 0.54 ± 0.11 μC in group II (P < 0.01). There was no difference between groups on the ventricular level, both acutely and during follow-up. If the active fixation atrial lead was compared to its tined ventricular counterpart in group I, pacing thresholds only differed within the early days postimplant, but they were virtually identical from week 3 through 1 year. It is concluded that the novel pacing lead design effectively combines low energy pacing with more versatility in electrode positioning by use of the active fixation mechanism.     

REM syndrome: reticular erythematous mucinosis (round-cell erythematosis), a new entity?

Four patients, three females and one male, were observed in Cologne with sheet- or net-like erythema of the upper chest and of the back, with a tendency to spread to the abdomen. The patients had no symptoms with the exception of itching in one case and itching after sunburn in another. Histo-logically the epidermis was normal, apart from slight hydropic degeneration and some minor degree of spongiosis. The main features were: dilated blood vessels in the dermis, with a more or less pronounced perivascular infiltrate of round cells, and, in addition, deposits of a substance which stained with alcian blue. Oral treatment with Rhetis was of some benefit, otherwise therapy, including corticosteroids, was not successful. Other antimalarial drugs were not used. There was some relation to sun exposure, but the full spectrum of xenon-light did not cause any abnormal reactions. Since it was not possible to relate these findings to any known syndrome, a combination of the main signs, reticular erythema and mucinosis, was used to name this entity REM syndrome.     

The Distribution of the HL-A Antigens and Genes in a German Population

The frequency of HL-A antigens and genes was determined in a population of 600 unrelated German people. The results confirmed the two loci concept for the HL-A system, and showed that the gene frequencies, the phenotype distributions and the haplotype frequencies are very similar to those observed in other Caucasian populations.     

Rate Adaptive Atrial Pacing in the Bradycardia Tachycardia Syndrome

In 42 patients (26 men, 16 women; mean age 69 ± 10 years), who were paced and medicated with antiarrhythmic drugs for the bradycardia tachycardia syndrome, chronotropic response and AV conduction with rapid atrial pacing during exercise were studied. Patients were included if they had no second- or third-degree AV block, no complete bundle branch or bifascicular block, and a PQ interval ≤ 240 ms during sinus rhythm at rest. The interval between the atrial spike and the following Q wave (SQ) was measured in the supine position at rest with an AAI pacing rate of 5 beats/min above the sinus rate (SQ-R+5), and at the end of exercise with 110 beats/min (SQ-E110). Bicycle ergometry was performed using the Chronotropic Assessment Exercise Protocol with the pacemakers being programmed to AAI with a fixed rate of 60 beats/min. Chronotropic incompetence was defined as peak exercise heart rate: (1) < 100 beats/min; (2) < 75% of the maximum predicted heart rate; or (3) the heart rate at half the maximum workload < 60 + 2 beats/min per mL O₂/kg per minute (calculated O₂ consumption). During exercise, one patient developed atrial fibrillation. Chronotropic incompetence was present in 71 % (29/41) of the patients according to definition 2, and in 76% (31/41) according to definition 1 or 3. Ten out of 41 patients (24%) exhibited a second-degree AV block with atrial pacing at 110 beats/min at the end of exercise. Only 9 out of the remaining 31 patients (29%) showed a physiological adaptation of the SQ-E110, and 21 patients (68%) exhibited a paradoxical increase of the SQ interval with rapid atrial pacing at the end of exercise as compared to the SQ-R+5. These observations indicate that the pacing system to be used in most patients paced and medicated for the bradycardia tachycardia syndrome should be dual chamber, and the option of rate adaptation should be considered.