Measuring the effect of a study meal on portal concentrations of glucagon-like peptide 1 (GLP-1) in non diabetic and diabetic patients with liver cirrhosis: transjugular intrahepatic portosystemic stent shunt (TIPSS) as a new method for metabolic measurements.

BACKGROUND: Diabetes in liver cirrhosis is associated with a blunted insulin response, which might be explained by an impaired release of the incretin hormone glucagon-like peptide 1 (GLP-1) into the portal circulation. AIMS: To investigate basal and stimulated portal venous and peripheral GLP-1 concentrations in non-diabetic (ND) and diabetic (D) patients with liver cirrhosis undergoing transjugular intrahepatic portosystemic stent shunt (TIPSS) implantation. PATIENTS AND METHODS: After elective TIPSS portalvenous and peripheral probes were drawn from 10 ND and 10 D patients with stable liver disease during an oral metabolic test and plasma glucose, immunoreactive GLP-1, insulin and C-peptide were measured. RESULTS: The study meal led to a significant rise in portal GLP-1 levels in ND and D. Basal and stimulated portal GLP-1 concentrations were not significantly different between ND and D. Peripheral GLP-1 did not differ significantly from portal venous levels. Insulin response in ND was more pronounced in the portal blood than in the periphery and was absent in D. CONCLUSION: TIPSS allows a direct evaluation of hormonal changes in the portal circulation during an oral metabolic tolerance test. A disturbed GLP-1 secretion does not play a role in blunting the insulin response observed in patients with hepatogenous diabetes.

Reduced acute thrombus formation results in decreased neointimal proliferation after coronary angioplasty.

OBJECTIVES: We tested the hypothesis that reduced acute platelet deposition after angioplasty results in reduced late neointimal proliferation. BACKGROUND: Platelet-mediated mechanisms contribute to smooth muscle cell proliferation and migration. METHODS: Indium-111-labeled platelets were injected 16 h before coronary stent angioplasty in 10 Göttinger minipigs: group 1 (n = 5) = heparin (100-U/kg bolus) before angioplasty; group 2 (n = 5) = recombinant hirudin (CGP 39393, 1.0-mg/kg body weight bolus intravenously), followed by subcutaneous doses of 6 to 10 mg/kg every 8 h. Furthermore, stent angioplasty was performed in coronary arteries of 16 minipigs: group 3 (n = 5, nine stents) = 100 U/kg heparin only; group 4 (n = 5, 10 stents) = 1-mg/kg bolus hirudin before and 45 min after angioplasty; group 5 (n = 6, 11 stents) = hirudin (1-mg/kg intravenous bolus) before and 45 min after angioplasty, followed by 6 to 10 mg/kg subcutaneously every 8 h. RESULTS: In segments with deep arterial injury, the number of platelets/angioplasty segment in group 2 after 72 h (mean 21, range 9.7 to 39.7 x 10(6)) was significantly less than that in group 1 (mean 375, range 72 to 787 x 10(6)). Morphometric analysis after 4 weeks showed no difference between groups in degree of vessel wall injury. Mean (+/- SD) neointimal thickness was 0.70 +/- 0.06 mm in group 3 and was significantly reduced in both group 4 (0.46 +/- 0.11 mm) and group 5 (0.48 +/- 0.21 mm). CONCLUSIONS: The direct thrombin inhibitor hirudin significantly reduces platelet deposition up to 72 h after coronary stent angioplasty. A hirudin bolus alone as well as continued subcutaneous administration for 14 days substantially reduced neointimal proliferation compared with heparin 4 weeks after coronary stent angioplasty in minipigs.

Cardiac troponin I elevation in acute pulmonary embolism is associated with right ventricular dysfunction.

OBJECTIVES: The purpose of this study was to evaluate the prevalence and diagnostic utility of cardiac troponin I to identify patients with right ventricular (RV) dysfunction in pulmonary embolism. BACKGROUND: Right ventricular overload resulting from elevated pulmonary resistance is a common finding in major pulmonary embolism. However, biochemical markers to assess the degree of RV dysfunction have not been evaluated so far. METHODS: In this prospective, double-blind study we included 36 study patients diagnosed as having acute pulmonary embolism. RESULTS: Among the whole study population, 14 patients (39%) had positive troponin I tests. Ten of 16 patients (62.5%) with RV dilatation had increased serum troponin I levels, while only 4 of 14 patients (28.6%) with elevated troponin I values had a normal RV diameter as assessed by echocardiography, indicating that positive troponin I tests were significantly associated with RV dilatation (p = 0.009). Patients with positive troponin I tests had significantly more segmental defects in ventilation/perfusion lung scans than patients with normal serum troponin I (p = 0.0002). CONCLUSIONS: Our data demonstrate that more than one-third of patients clinically diagnosed as having pulmonary embolism presented with elevated serum troponin I concentrations. Troponin I tests helped to identify patients with RV dilatation who had significantly more segmental defects in lung scans. Thus, troponin I assays are useful to detect minor myocardial damage in pulmonary embolism.

A randomized trial of elective stenting after balloon recanalization of chronic total occlusions.

OBJECTIVES: The aim of this study was to assess the role of Wiktor stent implantation after recanalization of chronic total coronary occlusions with regard to the clinical and angiographic outcome after six months. BACKGROUND: Beside the common use of stents in clinical practice, the number of stent indications proven by randomized trials is still limited. METHODS: Eighty-five patients with a thrombolysis in myocardial infarction grade 0 chronic coronary occlusion were examined. After standard balloon angioplasty, the patients were randomly assigned to stent implantation, or percutaneous transluminal coronary angioplasty (PTCA) alone (no further intervention). Quantitative coronary angiography was performed at baseline and after six months. RESULTS: The minimal lumen diameter did not differ immediately after recanalization (stent group 1.61 +/- 0.30 mm vs. PTCA group 1.65 +/- 0.36 mm), and increased after stent implantation to 2.51 +/- 0.41 mm. After six months, the stent group still had a significantly greater lumen (1.57 +/- 0.59 vs. 1.06 +/- 0.90 mm; p < 0.01) and a significantly lower restenosis and reocclusion rate (32% and 3%) compared with the PTCA group (64% and 24%); restenosis analysis according to treatment was 72% (PTCA) versus 29% (stent, p < 0.01). Late loss was equal in both groups. At follow-up, the stent patients had a better angina class (p < 0.01), and fewer cardiac events (p < 0.03). A meta-analysis including this trial and three other controlled trials with the Palmaz-Schatz stent showed concordant results. CONCLUSIONS: Stent implantation after reopening of a chronic total occlusion provides a better angiographic result, corresponding to a better clinical outcome with fewer recurrence of symptoms and reinterventions after six months.

Platelet and fibrin deposition on coronary stents in minipigs: effect of hirudin versus heparin.

OBJECTIVES: The present study was designed to test the hypothesis that the direct thrombin hirudin is more efficient than heparin in reducing thrombus formation after coronary stenting. BACKGROUND: Despite aggressive anticoagulation, subacute thrombosis of coronary stents is a major complication associated with these new devices. METHODS: In 19 minipigs indium-111-labeled thrombocytes and iodine-125-labeled fibrinogen were injected 14 to 19 h before coronary implantation of tantalum balloon-expandable stents. In group 1 (n = 6, seven stents), a bolus of heparin (100 U/kg body weight) was given before stenting. Group 2 (n = 6, 11 stents) received both dextran (500 ml) and heparin (a 100-U/kg bolus followed by a continuous infusion of 50 U/kg per h). In group 3 (n = 7, 13 stents), hirudin (recombinant desulphatohirudin HV 1 [CGP 39393] [1 mg/kg]) was given before stent implantation, followed by an infusion of 1 mg/kg per h. All animals were pretreated with aspirin (250 mg intravenously). RESULTS: Activated partial thromboplastin time was prolonged to > 1.8 times control values in groups 2 and 3. Histologic examination after perfusion fixation 12 h after stenting showed a variable extent of thrombus on all stents. Medial tear was observed in three stents in group 1, six stents in group 2 and six stents in group 3. The number of platelets on all stents averaged 116.2 (range 22 to 522) x 10(6) in group 1, 64.3 (range 11 to 169) x 10(6) in group 2 and 19.7 (range 9 to 38) x 10(6) in group 3 (p < 0.05 vs. group 1 and vs. group 2). The increase in platelet deposition, associated with medial tear in all groups, was lowest in the hirudin group. Similarly, fibrin deposition was lowest on stents in hirudin-treated animals. CONCLUSIONS: Recombinant hirudin significantly reduces platelet and fibrin deposition on coronary stents compared with the reduction achieved with combined heparin, dextran and aspirin.

Laser angioplasty of restenosed coronary stents: results of a multicenter surveillance trial. The Laser Angioplasty of Restenosed Stents (LARS) Investigators.

OBJECTIVES: This study evaluated safety and efficacy of excimer laser angioplasty for treatment of restenosed or occluded coronary stents. BACKGROUND: Balloon angioplasty of in-stent restenosis is limited by a high recurrence rate. Debulking by laser angioplasty is a novel concept to treat in-stent restenosis. METHODS: A total of 440 patients with restenoses or occlusions in 527 stents were enrolled for treatment with concentric or eccentric laser catheters and adjunctive balloon angioplasty. RESULTS: Laser angioplasty success (< or =50% diameter stenosis after laser treatment or successful passage with a 2.0-mm or 1.7-mm eccentric laser catheter) was achieved in 92% of patients. Adjunctive balloon angioplasty was performed in 99%. Procedural success (laser angioplasty success followed by < or =30% stenosis with or without balloon angioplasty) was 91%. There was neither a significant difference in success with respect to lesion length, nor were there differences between small and large vessels or native vessels and vein grafts. Success was higher and residual stenosis lower using large or eccentric catheters. Serious adverse events included death (1.6%, not directly laser catheter related), Q-wave myocardial infarction (0.5%), non-Q-wave infarction (2.7%), cardiac tamponade (0.5%) and stent damage (0.5%). Perforations after laser treatment occurred in 0.9% of patients and after balloon angioplasty in 0.2%. Dissections were visible in 4.8% of patients after laser treatment and in 9.3% after balloon angioplasty. Reinterventions during hospitalization were necessary in 0.9% of patients; bypass surgery was performed in 0.2%. CONCLUSIONS: Excimer laser angioplasty with adjunctive balloon angioplasty is a safe and efficient technology to treat in-stent restenoses. These data justify a randomized comparison with balloon angioplasty.

Fasting hyperglucagonemia in patients with transjugular intrahepatic portosystemic shunts (TIPS).

BACKGROUND: Hyperglucagonemia has been described to be associated with insulin resistance in patients with liver cirrhosis. Portosystemic shunts may be involved in the etiology of hyperglucagonemia. To test this hypothesis we investigated fasting peripheral plasma glucagon levels before and after portal decompression by transjugular intrahepatic portosystemic shunting (TIPS). METHODS: Glucagon, insulin, plasma glucose, HbA1c, and C-peptide were determined in peripheral venous samples from 21 non-diabetic (ND)- and 15 diabetic patients (D; 3 treated with insulin, 3 with sulfonylurea, 9 with diet alone) with liver cirrhosis, showing comparable clinical features (gender, age, BMI, creatinine, Child-Pugh-score, complications, and etiology of liver cirrhosis) before, 3 and 9 months after elective TIPS implantation. Insulin resistance was calculated as R (HOMA) according to the homeostasis model assessment (HOMA). RESULTS: Glucagon levels before TIPS were elevated in patients with diabetes compared to patients without diabetes (D: 145.4 +/- 52.1 pg/ml vs. ND: 97.3 +/- 49.8 pg/ml; p = 0.057). 3 and 9 months after TIPS implantation glucagon levels increased significantly in ND (188.9 +/- 80.3 pg/ml and 187.2 +/- 87.6 pg/ml) but not in D (169.6 +/- 62.4 pg/ml and 171.9 +/- 58.4 pg/ml). While plasma glucose, HbA1c, and C-peptide were significantly higher in D than in ND, they did not change significantly 3 and 9 months after TIPS implantation. Insulin was increased in D before TIPS (D: 31.6 +/- 15.9 mU/l vs. ND: 14.8 +/- 7.1 mU/l; p = 0.0001). 3 and 9 months after TIPS insulin significantly increased in ND (26.6 +/- 14.7 mU/l and 23.2 +/- 10.9 mU/l vs. 14.8 +/- 7.1 mU/l before TIPS) but not in D. In ND R (HOMA) also increased from 3.5 +/- 2 mU x mmol/l(2) to 5.7 +/- 3.3 mU x mmol/l(2) after 3 and 5.4 +/- 2.6 mU x mmol/l(2) after 9 months. BMI, liver and kidney function did not change with time. CONCLUSION: In non-diabetic cirrhotic patients TIPS implantation is followed by an increase of glucagon. However, this does not result in a worsening of glycemic control, probably because of a simultaneous increase of insulin.

The single nucleotide polymorphism -1131T>C in the apolipoprotein A5 (APOA5) gene is associated with elevated triglycerides in patients with hyperlipidemia.

The -1131T>C polymorphism in the newly identified apolipoprotein A5 (APOA5) gene has been associated with elevated plasma triglycerides. We determined its incidence in 915 patients attending a lipid outpatient clinic. The frequency of the C allele was significantly higher in patients with triglycerides above the 90th percentile and patients with type III hyperlipidemia compared to those with hypercholesterolemia. The C allele was associated with increased plasma triglycerides and decreased plasma HDL cholesterol, conditions associated with an increased risk of coronary heart disease. The effects on plasma lipids were only observed in overweight (BMI>25) patients and were greater in patients who were also carriers of a least one epsilon4 allele in the APOE gene. Thus additional genetic and/or metabolic factors are required in order for the triglyceride raising and HDL lowering effect of the -1131T>C polymorphism in APOA5 to be expressed.

Expression of meta-vinculin in human coronary arteriosclerosis is related to the histological grade of plaque formation.

In the present study we demonstrate that the quantitative reduction of meta-vinculin expression parallels histological changes during the course of coronary arteriosclerosis. Immunofluorescence stainings of coronary arteries revealed that vinculin distribution resembled that of other smooth muscle-specific cytoskeletal proteins like alpha-actin, caldesmon or myosin light chain kinase in labeling smooth muscle cells brightly. Although close to arteriosclerotic plaques, the cellularity as measured by the density of nuclei was often not significantly altered. Cells of this location expressed markedly reduced amounts of vinculin, suggesting that they are smooth muscle cells of a synthetic phenotype. To determine the fractional meta-vinculin content in arteriosclerotic lesions, we performed densitometric scanning of immunoblots incubated with anti-vinculin monoclonal antibodies reacting with both meta-vinculin (150 kDa) and vinculin (130 kDa). In parallel, each tissue sample was evaluated histologically for the degree of arteriosclerotic alterations according to the morphometric atheroma score of Stratford et al. (n = 13). In type 1 lesions covering slight intimal thickening, meta-vinculin represented 36% (mean, range 35%-39%) of the total vinculin immunoreactivity. In type 2 lesions consisting of fibrous plaques of up to twice the original artery wall thickness, meta-vinculin accounted for 28% (mean, range 22%-35%) of the total vinculin content. Meta-vinculin was substantially reduced in type 3 lesions (mean 13%, range 8%-18%) which are characterized by extensive atheromatous plaques. Thus, the meta-vinculin/vinculin ratio differed significantly between early, intermediate and advanced phases of coronary arteriosclerotic plaque formation.

Accumulation of unphosphorylated calponin in the submembranous cytoskeletons of arachidonic acid-stimulated human platelets.

Calponin, a basic smooth-muscle protein capable of binding to F-actin, tropomyosin and calmodulin in vitro, was tested for its expression and subcellular localization in resting and stimulated human platelets. Using immunoblotting techniques calponin was revealed as a single protein band with a molecular weight of 34 kDa. Although calponin has been shown to be proteolytically degraded by calpain, in the presence of the calpain inhibitor E-64 and EGTA a significant hydrolysis of calponin could not be detected. Upon stimulation with 10 microM arachidonic acid calponin became increasingly incorporated into Triton X-100 insoluble cytoskeletal fractions reaching a plateau after 15 s. The accumulation of calponin in the cytoskeletons of stimulated platelets paralleled the polymerization of actin into newly formed microfilaments. Immunofluorescence microscopy revealed a submembranous co-localization of calponin and actin in aggregated platelets. Since isolated calponin is phosphorylated by protein kinase C and Ca2+/calmodulin-dependent protein kinase II thereby losing its inhibitory effect on the actomyosin MgATPase activity, we examined whether changes in cell shape due to platelet stimulation are accompanied by a phosphorylation of calponin. By performing immunoblotting analysis on either resting or stimulated platelets phosphorylation of calponin on tyrosine, serine or threonine residues could not be demonstrated. In line, [32P]radiolabeling experiments were unable to detect phosphate incorporation into calponin. These observations support the hypothesis that calponin plays a physiological role in regulating contraction and secretion of human platelets even in the absence of its phosphorylation.

On the necessity of the invasive predischarge test after implantation of a cardioverter-defibrillator.

The necessity of routine invasive implantable cardioverter-defibrillator (ICD) testing before hospital discharge was analyzed in 268 patients. In 98% of the patients, invasive ICD testing was not necessary if a preimplant electrophysiologic test was performed; most of the observed problems can be solved by noninvasive control.

Recanalization of chronic total coronary arterial occlusions by percutaneous excimer-laser and laser-assisted angioplasty.

A low primary success and high restenosis rate after recanalization of chronic total occlusions by conventional coronary angioplasty have encouraged the application of new interventional techniques like excimer-laser angioplasty. In 39 patients with a coronary occlusion for 1 to 12 months, recanalization was attempted by laser angioplasty through a multifiber-catheter coupled to a pulsed XeCl excimer laser. After successful passage of the occlusion by a standard guidewire in 27 patients (69%), the laser catheter was advanced over the central guidewire and crossed the occlusion in 25 patients (64%). In 2 patients with unsuccessful passage of the laser catheter, the subsequent attempt with a low profile balloon catheter also failed. In 19 of the 25 patients with successful laser recanalization, the residual stenosis exceeded 50% and was therefore followed by additional balloon angioplasty. The average residual stenosis after laser was 61 +/- 17% of the vessel diameter, and after balloon angioplasty 28 +/- 9% (n = 19), whereas after laser angioplasty alone it was 38 +/- 5% (n = 6). No complications associated with the laser application were observed. Angiographic control after 24 hours showed a reocclusion of 2 (8%) recanalized vessels. In this pilot study, laser angioplasty proved to be a safe and feasible method for the treatment of chronic total coronary occlusions. Because it was necessary to guide the catheter by a central wire, the primary success was limited by a successful passage of the wire of the occlusion. The rate of stand-alone laser angioplasty has to be increased by future improvements of the technique to enable a comparative evaluation of this method with conventional angioplasty.

Fragmin in unstable angina pectoris or in non-Q-wave acute myocardial infarction (the FRIC study). Fragmin in Unstable Coronary Artery Disease.

The safety and efficacy of weight-adjusted, low-molecular-weight heparin (dalteparin) was compared with that of unfractionated heparin during 6 days of treatment in 1,482 patients with unstable angina or non-Q-wave myocardial infarction. Dalteparin, at a lower dose, was compared with placebo during the following 39 days. No significant outcome difference was found between the 2 treatment regimens in the unblinded phase (days 1-6). Between days 6-45 the rates of death, myocardial infarction, and recurrence of angina were comparable between the active treatment and placebo groups. The results suggest that twice-daily administration of subcutaneous dalteparin may be an effective and safe alternative to unfractionated heparin during the acute phase of unstable coronary artery disease. Prolonged treatment with dalteparin at a lower once-daily dose did not confer any additional benefit over aspirin (75-165 mg) alone.

Recanalization of total coronary occlusions using a laser guidewire (the European TOTAL Surveillance Study).

The success rates of coronary angioplasty for the treatment of chronic total occlusions are less favorable than for coronary stenosis. Therefore, a new laser guidewire (LW) was designed to facilitate the crossing of chronic total occlusions. We report on the results of a European multicenter surveillance study, evaluating the laser guidewire performance. Between May 1994 and July 1996, 345 patients (age 59 +/- 10 years, 291 men) with chronic total occlusions were enrolled in 28 European centers. The median age of occlusion was 29 weeks (range 2 to 884), the occlusion length 19 +/- 10 mm. LW recanalization was successful in 205 patients (59%/). LW perforation occurred in 73 patients (21%), with hemodynamic consequences in 4 (1%). There were no deaths, emergency coronary artery bypass graft surgery, or Q-wave myocardial infarctions. In a multivariate regression analysis an occlusion age of <40 weeks (p = 0.001, RR = 1.34) and an occlusion length <30 mm (p = 0.01, RR = 1.59) were independent predictors of success. Results indicate that the LW is an effective and safe tool in the treatment of chronic total occlusion refractory to conventional guidewires.

The symptoms of major depression.

The 8 symptoms of Criterion B for major depressive disorder (MDE) in the third edition of the Diagnostic and Statistical Manual of Mental Disorders were studied in 107 cases and 57 noncases of MDE (all had depressed mood or pervasive anhedonia for more than 2 weeks). Sleep change, loss of energy, and appetite change were the most common symptoms, and psychomotor change and feelings of worthlessness the least common, in MDE. Loss of energy and sleep change were the best single symptoms and thoughts of death, feelings of worthlessness, and psychomotor change the worst for both diagnoses. Psychomotor change was the best and thoughts of death the worst indicator of MDE. Absence of sleep change and of loss of energy were the best and absence of thoughts of death, psychomotor change, and feelings of worthlessness the worst indicators of non-MDE. Results suggest that vegetative symptoms are more central to clinical depression than feelings of worthlessness, self-reproach, or guilt.

TIPS implantation raises leptin levels in patients with liver cirrhosis.

Increased leptin levels in patients with liver cirrhosis are postulated to result in malnutrition and increased energy expenditure. Since cirrhotic patients show improved nutritional status after a transjugular intrahepatic portosystemic stent shunt (TIPS), it was the aim of this study to evaluate plasma leptin levels and their influence on nutritional status prior to and after the TIPS procedure. We evaluated plasma leptin levels, body mass index (BMI), Child-Pugh score and pertinent biochemical parameters in 31 patients (19 men and 12 women) with severe complications of liver cirrhosis (74% ethyltoxic men, 50% ethyltoxic in women), prior to and after TIPS. Nineteen cirrhotic patients without TIPS served as controls. In women ascitic-free BMI significantly increased (from 22.8 +/- 4.6 kg/m2 to 23.9 +/- 4.9; p = 0.004 three months after TIPS), whereas in men only a tendency toward higher values (26.1 +/- 4.7 vs. 26.7 +/- 4.4; p = 0.28) was found. Analysis of peripheral venous leptin concentrations before and three months after TIPS revealed a significant increase in women (11.9 +/- 8.8 ng/ml vs. 18.6 +/- 14.9; p = 0.009) and in men (7.7 +/- 6.2 ng/ml vs. 12.2 +/- 9.0; p = 0.005). In addition, the leptin-BMI ratio increase significantly in women and men three months after TIPS implantation (women 0.49 +/- 0.29 vs. 0.73 +/- 0.52; p = 0.017; men 0.28 +/- 0.22 vs. 0.43 +/- 0.28; p = 0.002). On the other hand, patients without TIPS implantation showed no significant alterations of BMI and peripheral venous leptin concentrations. After TIPS implantation in liver cirrhotic patients, leptin levels were increased and the nutritional status improved. Therefore, our analysis suggests that in patients with predominantly ethyltoxic liver cirrhosis, elevated leptin levels are not a major reason for poorer body composition.

Sex differences in subclinical depression: administration of the Beck Depression Inventory in public and private disclosure situations.

To test the idea that the preponderance of women depressives is due to a masculine tendency to avoid negative social consequences by reporting fewer depressive symptoms, two studies were conducted in which the Beck Depression Inventory (BDI) was administered to both sexes under conditions of public and private disclosure. It was hypothesized that men would score lower on the BDI than women in the public disclosure condition but not in the private disclosure condition. Despite procedural differences in the two experiments, the results of both studies failed to support the experimental hypothesis. However, in each case, analysis of variance revealed a significant interaction between sex of subject and sex of examiner (p less than .05). These results are discussed in terms of a willingness to admit more symptoms to a same-sex person due to fear of rejection by the opposite sex and in terms of gender-specific patterns of self-disclosure in first-encounter heterosexual situations. Results of both studies also suggest BDI scores of college students can be interpreted without regard to type of administration.

Early detection of lead fracture by painless high voltage lead impedance measurement in a transvenous ICD lead system.

We report the case of a 69 year old patient, who underwent transvenous implantable cardioverter defibrillator (ICD) device change (Medtronic GEM VR 7227 Cx Active Can) because the ICD reached its replacement indicators. Preoperative chest X-ray and intraoperative defibrillation threshold tests and high voltage impedance did not show lead fracture of the five year old lead (Transvene 6936-65). At the second postoperative day the alarm of the newly implanted ICD device was activated because of high impedance in the painless lead impedance measurement (PLI) and the lead was replaced. The explanted lead showed a fracture detectable only by PLI.

Automatic atrial anti-tachy pacing for the termination of spontaneous atrial tachyarrhythmias: clinical experience with a novel dual-chamber pacemaker.

UNLABELLED: Automatic atrial anti-tachy pacing (aATP) is a novel approach to treat paroxysmal/persistent atrial tachyarrhythmias in pacemaker patients. To evaluate the efficacy of aATP in terminating spontaneous atrial flutter/tachycardia episodes (AT), a dual-chamber stimulator with extensive diagnostic capabilities and programmable aATP therapies (AT500(TM), Medtronic Inc.) was implanted in 30 patients with conventional pacing indications. During a mean follow-up time of 5.5 (1-12) months, aATP was delivered for 10494 AT. According to automatic device analysis, 8289 AT were treated with success (success-rate 79.0%). On 468 AT stored with the corresponding atrial EGM, an additional manual analysis was performed. The success-rate based on automatic analysis of these AT episodes (73.1%) was comparable to that found for all treated AT (79.0%), but manual EGM analysis revealed that only 209 of the 468 treated AT episodes (44.7%) were actually terminated by aATP. The aATP success-rate in the slower (cycle length 360-270 ms) AT detection zone was significantly higher (73.8%, 62/84 eps) than in the overlapping, faster (cycle length 270-220 ms) AT zone (38.3%, 147/384 eps, P<0.01). CONCLUSIONS: According to manual analysis, 1. aATP was safe and had a success-rate of 44.7%, 2. aATP success-rate was higher for AT in the slower than in the faster detection zone and 3. automatic analysis overestimated the efficacy of aATP.