Transseptal Leftventricular Endocardial Pacing is an Alternative Technique in Cardiac Resynchronization Therapy. One Year Experience in a High Volume Center.

INTRODUCTION: In patients receiving cardiac resynchronization therapy (CRT), failure rate to implant the left ventricular (LV) lead by the traditional trans-venous approach is 4-8%. Surgical epicardial implantation is considered as an alternative, but this technique is not without morbidity. Evidence from case documentation and from small trial batches demonstrated the viability of endocardial LV lead implantation where surgical epicardial lead placement is not applicable. MATERIAL AND METHODS: Four patients were implanted with endocardial LV lead using the transseptal atrial approach after unsuccessful transvenous implantation. Implantation of an endocardial active fixation LV leads was successful in all patients with stable electrical parameters immediately after implantation and over the follow-up period. All patients received anticoagulation therapy in order to target the international normalized ratio of 2.5-3.5 and have not experienced any thromboembolic, hemorrhagic events, or infection. RESULTS: Follow-up echocardiography indicated significant improvement of LV systolic function (24 + 4.9 to 32 + 5.1 %, P = 0.023) with a notable improvement of the functional status. CONCLUSIONS: Endocardial left ventricular lead implantation can be a valuable and safe alternative technique to enable LV stimulation in high surgical risk patients where standard coronary sinus implant is unsuccessful.

Brain image segmentation for virtual endoscopy.

This paper presents an algorithm for fuzzy segmentation of MR brain images. Starting from the standard FCM and its bias-corrected version BCFCM algorithm, by splitting up the two major steps of the latter, and by introducing a new factor gamma, the amount of required calculations is considerably reduced. The algorithm provides good-quality segmented 2-D brain slices a very quick way, which makes it an excellent tool to support a virtual brain endoscope.

The cardiotonic effects of levosimendan in guinea pig hearts are modulated by beta-adrenergic stimulation.

The effects of the Ca2+-sensitiser levosimendan alone or in combination with beta-adrenergic stimulation on the contractile function were studied in various guinea pig cardiac preparations. Echocardiography in narcotised animals indicated that a maximal dose of levosimendan (50 microg x kg(-1)) increased the left ventricular posterior wall movement velocity during systoles and diastoles by 25 +/- 3% (mean +/- S.E.M.) and 17 +/- 2%, respectively. In Langendorff hearts, a saturating concentration of levosimendan (0.3 micromol x l(-1) for 5 min) increased +dP/dt(max) and dP/dt(max) by 28 +/- 3% and 14 +/- 2%, respectively. Further, the Ca2+-sensitising potential of levosimendan in Triton-skinned cardiomyocytes (EC50: 5 +/- 3 nmol x l(-1)) was illustrated by a maximal increase in the isometric force production by 51 +/- 5% (at pCa 6.2). However, following stimulation by isoproterenol, when the level of troponin I phosphorylation was elevated, no significant additional increase in the contractile parameters could be demonstrated upon levosimendan administration. Moreover, the levosimendan-induced increase in force production in isolated skinned myocytes could be prevented by incubation with the catalytic subunit of protein kinase A (100 U x ml(-1) for 40 min). These data indicate that thin filament-targeted Ca2+-sensitisation by levosimendan is modulated by phosphorylation of the contractile filaments, an effect that should be considered during combination therapy with levosimendan.

Effects of smoking on acoustic startle and prepulse inhibition in humans.

RATIONALE: Prepulse inhibition of the acoustic startle response (PPI) is a paradigm in which a startle response to an auditory stimulus is reduced when that stimulus is preceded by a lower intensity, non-startling stimulus (prepulse). PPI is used as an operational measure of sensorimotor gating in both humans and other mammals. Acute administration of nicotine enhances PPI in rats, an effect that has been recently demonstrated in humans. OBJECTIVES: We compared PPI in 12 male smokers and 14 male non-smokers tested in four repeat startle sessions across 2 test days in order to examine further the effects of smoking and smoking withdrawal on acoustic startle and PPI. METHODS: In a crossover design, the smokers smoked ad lib or abstained from smoking overnight prior to 9 a.m. testing. These 2 test days were in randomized order. On both days, smokers were immediately retested after smoking three cigarettes. Non-smokers were tested twice on each of 2 separate days. RESULTS: Across sessions, the smokers had reduced startle to pulse alone stimuli in the first block of each session when compared to the non-smokers. The non-smokers had no change in gating across their four test sessions. For the smokers, the abstinence condition produced a non-significant reduction in PPI compared to that of the ad lib smoking day. During the smoking abstinence session, smokers had comparable gating to non-smokers. Smoking immediately after washout produced a significant improvement in PPI such that gating in the smokers exceeded that of the non-smokers. CONCLUSION: Smoking after overnight washout from cigarettes enhanced sensorimotor gating compared to pre-smoking values and compared to gating in non-smokers.

Clinical and sensorimotor gating effects of ketamine in normals.

The clinical similarities between PCP psychosis and schizophrenia have contributed importantly to the development of the glutamate hypothesis of schizophrenia. Sensory gating, as measured by prepulse inhibition of the acoustic startle reflex (PPI), is impaired in patients with schizophrenia. In animals, the noncompetitive NMDA antagonists PCP and ketamine disrupt PPI in a way that resembles the defect seen in schizophrenia. The purpose of this work is to investigate the modulation of sensory gating in humans by subanaesthetic doses of ketamine. 16 healthy male subjects received a 60-min infusion of ketamine (0.5 mg/kg) or normal saline on two separate days in a randomized double-blind crossover design. Clinical ratings and PPI were done during the infusion on both days. Ketamine produced robust clinical effects. Dissociative symptoms as measured by the CADSS increased from 0 +/- 0.0 to 29.3 +/- 14.3; negative symptoms (Affect Rating Scale) increased from 17.2 +/- 0.8 to 24.8 +/- 3.1; and total BPRS scores increased from 18.3 +/- 0.8 to 26.4 +/- 5.1. ANOVAs for these ratings were all significant at the p <.000 level, although BPRS increases were not in the range seen in decompensated schizophrenic patients. The amplitudes of the startle responses to pulse-alone stimuli were not significantly different on ketamine and placebo days. Ketamine did not cause disruption in PPI as expected. On the contrary, in the first block of the PPI session ketamine significantly enhanced PPI (ANOVA; F=6.15, p =.026). These results indicate that the clinical effects of ketamine are not coupled with schizophrenic-like disruption of PPI in normal controls.

Crystallization of the haptoglobin-hemoglobin complex.

Two orthorhombic forms of crystals of the haptoglobin-hemoglobin complex were obtained using polyethylene glycol as precipitant. These crystals did not diffract well enough for data collection and work on the complex is no longer continued. However, the description of the crystallization conditions may be useful in future endeavors to obtain suitable crystals.

[Pulse oximetry in the study of the viability of the intestines and the microcirculation in intestinal anastomoses (preliminary report)]. / Pulsoxymetria a belek életképességének és az intestinalis anastomosisok microcirculatiójának vizsgálatára (Elözetes közlemény).

The author introduces a new intraoperative procedure suitable to examine the viability of the bowel using pulsoxymetry which has not yet been applied in abdominal surgery, but is widely used in anesthesiological practice. Shortly the writer introduces the importance of the method and its practical measurements. At the moment he is accounting for just six months' experience from the method. The method gives diagnostical assistance to urgent surgical interventions such as destructive and vascular ileus. To obtain accurate measurements the author feels it is necessary to construct a special probe adapted to the bowel. Since pulsoxymeter used to examine decisive parameters of viability--is a part of anesthesiological monitoring system- its application in every surgical theater is a possibility at hand, without any special financial investment.

[Necrosis of the colon and rectum as a complication of aortic reconstruction surgery]. / Aorta reconstructiós mütétek szövödményeként kialakult bal oldali colon- és rectumnecrosis.

The author reports on two patients operated on for necrosis of left colon after aorta-bifemoral by-pass reconstruction and presents another by whom ischemic rectum necrosis occurred as complication of aorta aneurysm. The paper deals with the symptomatology, diagnostics, anatomic and surgical technical causes of the serious complication. Results may be improved by early recognition of complication and the consequent performance of examinations related to it.