Do gender differences exist in pacemaker implantation?--results of an obligatory external quality control program.

AIMS: The aim of the study was to evaluate the effects of patient gender onto primary pacemaker implantation, evaluating the database of the Institute of Quality Assurance Hessen in the federal state of Hessen, Germany. METHODS AND RESULTS: The database of the obligatory external quality control program for the years 2003-2006 was evaluated retrospectively. In 72 centres, 17 826 patients undergoing stationary primary pacemaker implantation have been registered. Male patients had more AV blocks when compared with women and less sick sinus syndrome and atrial fibrillation with bradycardia. In patients being 80 years and older, men received significantly more dual-chamber devices than women for the indications: AV block and sick sinus syndrome. In women, atrial pacing thresholds were significantly higher and P-wave amplitudes were significantly lower. Women had, independent from age or pacing system implanted, significantly more acute complications than men, with significant differences for pneumothorax and pocket haematoma. CONCLUSION: This large-scale real-life patient cohort of primary stationary pacemaker implantation showed that gender has an impact onto pacemaker implantation, with less favourable outcomes for women.

The Carotid Surgery for Ischemic Stroke trial: a prospective observational study on carotid endarterectomy in the early period after ischemic stroke.

OBJECTIVE: The purpose of this study was to examine the safety of carotid endarterectomy (CEA) within 6 weeks after a nondisabling carotid-related ischemic stroke. Endpoints were the perioperative stroke or mortality rate and the incidence rate of cerebral bleedings. METHODS: This prospective observational multicenter trial was performed in community and university centers. One hundred sixty-four hospitalized patients with nondisabling carotid-related ischemic stroke were included. The patients were identified clinically with the modified Rankin scale (initial neurologic deficit grade >/= 2, n = 160). Four patients with evidence of ischemic territorial infarction on cerebral computed tomographic (CT) scan but no persisting functional deficit were also included. CEA was performed within 6 weeks after stroke. Neurologic examinations were performed initially, before surgery, 3 days after surgery, and 6 weeks after CEA. Worsening of more than 1 grade on the Rankin scale was considered as a new stroke or stroke extension. Unenhanced CT scans of the brain were performed before and after surgery. CT scans were evaluated blind to clinical patient data. Statistical analysis included univariate and multivariate analysis. RESULTS: The combined stroke or mortality rate within 30 days after CEA was 6.7%. Ten patients had a new ipsilateral stroke or stroke extension, and one patient died after surgery of a myocardial infarction. One patient (0.6%) had parenchymatous cerebral bleeding, and in 10 patients, hemorrhagic transformation within the preexisting ischemic infarction was detected but no infarct extension was observed. In the multivariate analysis, American Society of Anesthesiology (ASA) grades III and IV and decreasing age were significant predictors for an increased perioperative risk. Patients with a higher risk profile (ASA classification grades III and IV) had a high perioperative risk when CEA was performed within the first 3 weeks (14.6% versus 4.8% beyond 3 weeks). Patients without severe concomitant diseases (ASA grades I/II) had a low perioperative risk of 3.4% if CEA was performed within the first 3 weeks. CONCLUSION: Early CEA within 6 weeks after a carotid-related ischemic stroke can be performed with a perioperative stroke or mortality rate comparable with the results reported in the European Carotid Surgery Trial and the North American Symptomatic Carotid Endarterectomy Trial. The risk of parenchymatous bleeding is low. ASA grades III and IV and decreasing age were predictive of an increased perioperative risk, especially if CEA was performed within the first 3 weeks. Patients at low risk can undergo operation safely within the first 3 weeks. Individual patient selection in an interdisciplinary approach between neurologists, anesthesiologists, and vascular surgeons remains mandatory in these patients.

[Protection of the tunica intima during preservation of venous bypass grafts from harvesting to implantation]. / Protektion der Tunica intima während der Aufbewahrung von Venenbypasses von der Entnahme bis zur Implantation.

The patency-rate of venous bypasses depends--beside other important factors--upon the integrity of the transplanted vessel, especially on the condition of the tunica intima. We investigated two different methods of venous storage and their on the intima. We examined 24 segments of healthy human saphenous vein and 65 segments of the inferior vena cava in the rat which had been harvested using a minimal touch technique. The veins were stored in the patients own arterial heparinized blood vs. Euro Collins solution at 4 degrees C, 20 degrees C and 37 degrees C over 15, 30, 60, and 90 minutes. As a reference we examined 11 segments of human saphenous vein which had been fixed immediately after harvesting. The stainings were performed with PAS, HE, Domagk-Elastica, and Toluidine-blue. We examined 1,181 slices by light-microscopy and used a damage score table for the documentation of the vein-trauma. No significant differences were found between human and animals veins. In the control-group the endothelium, the subendothelial layer, and the intern elastic membrane were intact in 57%, 78%, and 38%. At 4 degrees C the endothelium was intact in 31% having been stored in blood, and in 44% at Euro Collins solution. For the subendothelial layer the ratio was 48%/66%, and for the intern elastic membrane 26%/42%. At 20 degrees C we found a ratio of 55%/47% vs. 65%/58% vs. 37%/39%, and at 37 degrees C 56%/37% vs. 64%/51%/32%/38%. The factor time could be neglected up to 90 minutes. The results show that veins should be used immediately after harvesting.(ABSTRACT TRUNCATED AT 250 WORDS)

[Vascular problems in patients with transplants from the interdisciplinary viewpoint]. / Vaskuläre Probleme beim Transplantierten aus interdisziplinärer Sicht.

From 1979 to 12/1990 795 organ transplants have been performed at our hospital (kidney n:737, liver n:23, heart n:35). Our data reveal vascular problems in 10 percent of the transplanted patients - not concerning the vascular anastomosis. The therapeutic approach should be determined interdisciplinary. Due to the low complication rate of operative or interventionel procedures in this patients, even relative indications--to improve "quality of live"--can be accepted.

Effect of different body-exercise modes on the rate response of the temperature-controlled pacemaker Nova MR.

In order to evaluate the effect of different modes of physical exercise on the rate response of the temperature-controlled Nova MR, parameters such as temperature behaviour and correlation of work load to pacing rate were investigated using different types and protocols of stress testing. This study considered 21 patients (age: 66 +/- 12 y). The indications for the Nova MR were AV block (n: 14) and sick sinus syndrome (n: 7). The patients performed two different types of exercise (treadmill n: 13, bicycle n: 14) based on different protocols. We registered the surface ECG, pacing rate, exercise time, and (via data transmission by the RX 2000 programmer) blood temperature and pacing rate. An adequate rate response could be achieved with all the different types of exercise and protocols using more sensitive program settings. The type of stress testing used to adjust or evaluate the Nova MR seems to be secondary, although cycling as compared with treadmill exercise resulted in a slightly weakened reaction of temperature and pacing rate. Our investigations revealed a good correlation between work load and pacing rate independent of the type of stress testing. The initial DIP (48%) is not a constant phenomenon and showed inter- and intraindividual variations. Impressive psychological influences also exhibited an effect on temperature and pacing rate, sometimes preventing a DIP response. During exercise at lower work loads (under 50 watts, shorter than 3-4 min) the rate response of the Nova MR--without any detected DIP--is often delayed due either to a decrease or to a late and flat increase in temperature. An additional fast-reacting sensor could be advantageous in triggering the initial rate response in such cases.

Clinical evaluation of hypothermic ventricular fibrillation, multi-dose blood cardioplegia, and single-dose Bretschneider cardioplegia in coronary surgery.

37 patients undergoing coronary revascularization were randomly assigned to three protocols for intraoperative myocardial protection: hypothermic ventricular fibrillation (HF) (n = 13), multi-dose blood cardioplegia (BCP) (n = 12) and single-dose Bretschneider's crystalloid cardioplegia (CCP) (n = 12). As intraoperative markers of ischemic damage myocardial ultrastructure, ATP, and CP contents were determined in left ventricular biopsy specimens taken before and after cardiac arrest. Release of serum enzymes (CK, CK-MB, LDH, SGOT) was determined pre- and postoperatively. Hemodynamic data were assessed before, during, and after operation. The incidence of low cardiac output, positive inotropic support, intraaortic balloon counterpulsation, peri-operative myocardial infarction, rhythm disturbances, and the rate of spontaneous defibrillation was compared between groups. The results show a better preservation of high energy phosphates in the BCP group as compared to the HF and CCP groups. Myocardial ultrastructure showed moderate ischemic damage in the hypothermic fibrillation group; in contrast, only slightly deteriorated cells were seen after cardiac arrest, when cardioplegia was used. The incidence of rhythm disturbances was 25% for HF and 42% for CCP. In contrast, only 17% of new rhythm disturbances were seen in the BCP group. Functional recovery (i.e. CI and SWI) of hearts protected with BCP was generally greater as compared to HF and CCP. Release of MB-creatine-kinase isoenzyme was higher in the HF group as compared to cardioplegia. Clinical outcome in terms of incidence of peri-operative infarction, positive inotropic support and low cardiac output was superior in the BCP group but not significantly different between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[Susceptibility of frequency adapted cardiac pacemakers to dental treatment]. / Störanfälligkeit frequenzadaptiver Herzschrittmacher bei zahnärztlichen Behandlungsmassnahmen.

Two rate-responsive pacemakers (Activitrax and Sensolog) were tested in order to show up to which extent its function can be disturbed by dental treatment. Inhibition of the pacemaker occurred by switching the electrical dental appliance on and off, or by moving it back and forth. In most cases, inhibition was only evident when the distance between the pacemaker and the electrical appliance was less than 10 cm. The electrome proved to be the most potent source of disturbance, as the function of the pacemaker was totally inhibited when it was switched on and off with a frequency of 1 to 2 Hz and even at a distance of 2.8 meters. During dental treatment--especially osteotomies--vibrations are transferred upon the patient which can cause an increase of the pacing rate.

Studies of the tissue reaction induced by transvenous pacemaker electrodes. I. Microscopic examination of the extent of connective tissue around the electrode tip in the human right ventricle.

The purpose of this study was to investigate the extent of connective tissue of the human right ventricle induced by cardiac pacing electrodes. Between January 1984 and July 1987, 34 consecutive patients with VVI-pacing systems were autopsied in the Department of Pathology at the University of Frankfurt/M. The surrounding tissue of these 34 electrodes (17 Siemens Elema 412 S, five Medtronic 6957, one Medtronic 6959, one Medtronic 4011, three Biotronik D2K, three Biotronik K 10, two Osypka FY 62, one Biotronik N, and one Siemens Elema 588) in the right ventricle were investigated histologically. The tissue was stained with Giemsa and the thickness of the connective tissue layer was measured. Stimulation threshold data at various times were known in four of eight screw-in electrodes, in seven of 17 vitreous carbon electrodes and in two of seven smooth surface electrodes. Electrode surface area, implantation time, age of the patient and cause of death were comparable for all three electrode groups. However, a significant difference was found in the extent of connective tissue between the porous surface and screw-in electrodes (128 +/- 55 vs 397 +/- 269 micron, P less than or equal to 0.01) and porous surface and smooth surface electrodes (128 +/- 55 vs 307 +/- 117 micron, P less than or equal to 0.01). No relation (r = 0.106) was found between the duration of implantation and the extent of connective tissue for the vitreous carbon electrodes (Siemens Elema 412 S).(ABSTRACT TRUNCATED AT 250 WORDS)

Rate response during submaximal exercise: comparison of three different sensors.

Since 1983, 248 rate responsive pacemakers were implanted at our hospital. The main emphasis during clinical follow-up has to be placed on the adjustment and control of its rate adaption, to meet the requirements of the aged patient's daily life. Repeated submaximal exercise but not extreme strain, come to the fore. Kaltenbach's step test (individually by stencils defined normal ranges of the heart rate during a 6 minute submaximal exercise and a 6 minute recovery period; age and sex dependent work load relative to body surface area) is able to mimic everyday efforts in an easy and reliable way. Nineteen patients with QT-related pacemaker, 12 patients with respiratory dependent pacemaker and 45 patients with body activity directed pm Activitrax were exercised using kaltenbach's step test (mean wattage QT: 56 +/- 14, RDP: 75 +/- 29, Activitrax: 64 +/- 20). Fifty-two patients performed 3 rounds. In comparison, 42 patients with DDD-pm underwent the same test (75 +/- 28 Watt). The average curve (heart rate) with QT-pm settled in the normal range of the step test but was distorted. Only 42% of the patients reached normal range in all three rounds. The mean heart rate of the RDP-group bordered on the basis of the normal range. The average curve (heart rate) of patients with Activitrax or DDD settled exactly in the desirable range. Problems with the rate response under repeated exercise did not occur either in the RDP or in the DDD group. The rate response behavior of the QT-related pm, the RDP and the Activitrax was of different quality.(ABSTRACT TRUNCATED AT 250 WORDS)

Rate responsive pacemakers: assessment after two years.

Rate responsive pacemakers (RRPM) for patients without sufficient response of the heart rate (HR) to exercise represent an alternative to improve cardiac output (CO) and capacity for exercise via an increase of HR. From 1983 until December 1985, we implanted 30 QT-related (TX), 25 respiratory dependent (RDP), and 35 body activity directed (ACT) pacemakers. The follow-up examination consisted of Holter-ECG, treadmill and/or bicycle workload, and determination of CO (TX: thermodilution technique, n = 11; 6 months after implantation. RDP: equilibrium radionuclide ventriculography, n = 13; 1 month after implantation). The capacity for exercise of patients with ACT was studied using a climbing step. Adaptation of HR could be achieved with TX, RDP, and ACT. There was a significant increase in CO during exercise TX or RDP versus VVI-mode (TX: delta = 1.7 l/min, RDP: delta = 2.1 l/min). Although all systems exhibited weak points, RRPM are reliable devices. We abide by using these pacemakers.

Ambulatory pacemaker surgery--medical and economical advantages.

The first pacemaker implantation on an ambulatory basis was done in our hospital in 1980. Since then, approximately 1,000 pacemaker patients have been operated on as outpatients. In 1984, we performed 781 pacemaker operations including 624 ambulatory operations. 583 patients received ambulatory new implantations. 54 persons were supplied as outpatients with a dual chamber system, 31 with a rate responsive system. In order to avoid complications, we use a standardized procedure, especially because the operators change daily following a plan of rotation. Patients are observed for 3-4 h postoperatively before discharge. Complications due to ambulatory operating have not been noticed. The ambulatory implantation of single or dual chamber pacemakers has been proving true as a safe treatment in our clinic. The economical advantage is obvious. In 1984, 5,000 days of hospitalization could be avoided; complications attributable to hospital cross-infection, immobilization, etc. could be reduced.

Increase in cardiac output with rate-responsive pacemaker.

Patients with myocardial insufficiency or patients during high cardiac work loads increase cardiac output (CO) only through an increase in heart rate (HR), which is not possible with a VVI pacemaker. This clinical study tests the hypothesis that the respiratory-dependent pacemaker (RDP) is able to increase CO by an increase in HR. A multiprogrammable RDP (BIOrate RDP 2, Alpha, Köln, West Germany) was implanted in 21 patients (16 men and 5 women) for ventricular pacing. The mean age of the patients was 68.1 +/- 9.5 years (+/- standard deviation). Since the RDP can be programmed either in the RDP or VVI mode, all patients served as their own control. During follow-up examinations 4 to 6 weeks after implantation, an exercise ECG and a determination of CO during rest and exercise using equilibrium-radionuclide ventriculography were performed. One pacemaker has had to be explanted because of "end of life." No other RDP is malfunctioning. There was a significant increase in HR in all patients during exercise with the RDP versus the VVI mode (105.5 +/- 5.9 versus 84.5 +/- 7.0 bpm; p less than 0.05). CO increased during exercise to 10.6 +/- 0.8 L/min (VVI mode) and 12.7 +/- 1.5 L/min (RDP mode) (p = not significant). RDPs are reliable systems for patients in whom dual-chambered pacemakers are contraindicated (e.g., patients with bradyarrhythmias). The RDPs are able to increase CO by 26 to 35% compared with the VVI mode because of an increase in HR.

[Familial occurrence of cardiac myxomas]. / Familiäre Häufung von kardialen Myxomen.

A report is given on the occurrence of left atrial myxoma in both mother and daughter. A successful operation for a local recurrence was performed on the mother 4 years later. Sudden death of unknown cause occurred at young age in other siblings and was accompanied in one by arterial embolism, suggesting an even higher incidence. The potential accumulation of cardiac myxomas in a family was confirmed by a literature survey of 8 "myxoma families". Observation of these cases calls for the following Careful surgical excision because of the danger of a local recurrence. Echocardiographic follow-up for at least 5 years. Investigation of relatives.

Effects of various cephalosporins on the proximal tubule of the human kidney.

Cephamandol 6.0 g, cephazolin 6.0 g or cephacetrile or cephalothin 8.0 g were administered as short-term infusions on 3 consecutive days to informed volunteers, who had no history or evidence of impairment of renal function. There were 15 subjects in the cephamandol, cephacetrile and cephalothin groups and 14 subjects in the cephazolin group. Alanine-aminopeptidase, a characteristic tubule enzyme, was determined in a 24-hour urine 2 days before administration, during the 3 day administration and on the 4 subsequent days. In addition, alanine-aminopeptidase was also estimated immunologically in concentrated urine with the aid of an anti-brush border antibody. Cephamandol, cephazolin and cephalothin were completely without effect on the proximal tubule. Cephacetrile, on the other hand, showed clear reactions in 9 out of 15 subjects, in the form of elevated AAP activity in urine and in 6 of the cases membrane elimination was demonstrable immunologically. After withdrawal of the medication, the values of the responder group returned spontaneously to normal, i.e. no cumulative effect was detected. These investigations show that elimination of alanine-aminopeptidase in the urine is a very sensitive index of the action of cephalosporins on renal tubules.