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.

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.

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.

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.

Efficacy of balloon valvuloplasty in patients with critical aortic stenosis and cardiogenic shock--the role of shock duration.

BACKGROUND: Because of limited long-term success, aortic balloon valvuloplasty is considered to be a palliative procedure, including patients at excessive risk for standard therapy-aortic valve replacement-that is, those in cardiogenic shock. HYPOTHESIS: The study was undertaken to evaluate the outcome of balloon valvuloplasty for critical aortic stenosis complicated by cardiogenic shock. METHODS: Over a 10-year-period, we followed 14 patients (age 74+/-11 years, range 50-91) presenting in cardiogenic shock and critical aortic stenosis, who underwent valvuloplasty, together with 19 patients with critical aortic stenosis requiring urgent major noncardiac surgery. RESULTS: In patients in shock, calculated aortic valve area could be increased successfully by at least 0.3 cm2, from 0.38+/-0.09 to 0.81+/-0.12 cm2, with an insignificant increase in cardiac index from 1.89+/-0.33 to 2.01+/-0.41 l/min * m2. In-hospital mortality was 71% (10 patients). Two patients underwent valve replacement within 16 days and survived after 1 year, as did two patients refusing surgery. By multivariate logistic regression analysis, only an interval between onset of shock symptoms and valvuloplasty of > 48 h was significantly associated with fatal outcome (p < 0.01). In those patients requiring noncardiac surgery, this was possible after valvuloplasty in 95% who survived 1 year after hospital discharge. One patient in this group died of pulmonary embolism the day after the procedure. CONCLUSION: These data support the concept of causal treatment in patients with cardiogenic shock, as well as in the setting of cardiogenic shock and critical aortic stenosis, at the earliest possible convenience.

Cutting balloon coronary angioplasty--initial clinical experience.

The success of percutaneous transluminal coronary angioplasty is limited by acute occlusion and late restenosis. In 25 patients (20 men, 5 women, age range 36-81 years) coronary angioplasty was performed using a new cutting balloon into which 3-4 longitudinally orientated blades are incorporated so as to reduce the rate of severe dissections. In 12 patients stenoses were reduced from 83.9 +/- 7.8% to 28.4 +/- 10.7% (mean +/- SD) by the cutting balloon alone, using predilatation with a small conventional balloon in two cases. Thirteen other patients were additionally dilated with a conventional balloon because of a residual stenosis > 50% after cutting balloon angioplasty. Here the stenoses could be reduced from 78.1 +/- 8.7% to 29.1 +/- 11.3%. Six months follow-up angiography in 14 patients showed > 50% restenosis in two of seven patients dilated with a conventional balloon in addition to the cutting balloon, and in one of seven patients dilated with the cutting balloon alone but predilated with a small conventional balloon. These results show that coronary angioplasty by the new cutting balloon results in a stenosis reduction comparable with conventional balloons at a low complication rate. Available 6 months follow-up data show three restenoses in patients either pre- or postdilated by a conventional balloon and none in stand-alone cutting balloon cases.

[The renin-angiotensin system in cardiovascular diseases]. / Das Renin-Angiotensin-System bei kardiovaskulären Erkrankungen.

BACKGROUND: The renin-angiotensin system is mainly involved in several cardiovascular diseases and in the pathophysiology of heart failure. It exists as a circulating and a local system which can be differently regulated. Interventions in this system by angiotensin-converting enzyme (ACE) antagonists or angiotensin-receptor antagonists slow the progression of heart failure and result in prolongation of life expectancy and improvement of hemodynamics. MECHANISMS OF ACTION: The main underlying mechanisms are: 1. Heart failure results in activation of the renin-angiotensin system as a compensatory mechanism with elevation of circulating angiotensin II, norepinephrine and vasopressin. Antagonists of this compensatory mechanisms acutely result in improvement of the hemodynamic situation. 2. Elevated circulating and local renin-angiotensin systems cause chronic structural myocardial and vascular effects. Angiotensin-converting enzyme antagonists and angiotensin-receptor blockers modulate and partly antagonize these structural changes such as myocardial hypertrophy, myocardial fibrosis and vascular proliferative responses. Gene and receptor regulation of the system are currently not fully understood and are subject of intensive research. 3. The renin-angiotensin system is closely related to the bradykinin system and thus indirectly to nitric oxide and endothelial function. Bradykinin has multiple other effects on the hemostatic system as a well as on the myocardium and vascular system. CONCLUSION: These complex interactions require further evaluation. Research with specific bradykinin antagonists will give new insights into this system.

[20-year old woman with diarrhea of unknown etiology]. / Unklare persistierende Diarrhö bei einer 20-jährigen Patientin : Protrahierte infektiöse Duodenitis als sehr seltene Differenzialdiagnose.

We report on a 20-year old woman who suffered from watery diarrhea. The results of the histology and the serology as well as clinical symptoms lead us to the diagnosis of sprue. Under specific gluten-free diet the diarrhea frequency was reduced. After a few weeks the patient returned to hospital again because of watery diarrhea. Histological examination of duodenal biopsy specimen showed a protracted infectious duodenitis and a secondary villous flattening of the small bowel. This diagnosis was a life-threatening illness that needed antibiotic treatment. These patients receive parenteral nutrition as long as the villous have not been recovered from the flattening. Additionally octreotid can be given to reduce the frequency of the diarrhea.

Oxygen free radical damage of isolated cardiomyocytes: comparative protective effect of radical scavengers and calcium antagonists.

Oxygen free radicals have been shown to play a major role in the development of perfusion abnormalities, contractile dysfunction, and irreversible injury in ischemic-reperfused myocardium. The aim of this study was to assess the direct protective effects of radical scavengers, calcium antagonists, and combination of these substances against free radical induced myocyte damage. Viability (% of rod-shaped cells) and adenine nucleotide content (AdN, high-pressure liquid chromatography) of isolated adult rat cardiomyocytes were measured after exposure to hypoxanthine (2 mM) and xanthine oxidase (25 mU/ml). After 90 min, viability of myocytes decreased to 4.2 +/- 3.4% (mean +/- SEM) of pre-exposure control, and AdN decreased from 28.2 +/- 1.8 to 8.09 +/- 1.1 nmol/mg protein. Addition of catalase (1500 U/ml) resulted in the preservation of viability (77 +/- 6% of pre-exposure control, n = 6, mean +/- SEM), and AdN 84 +/- 6%, p less than 0.001. These values are not significantly different from those measured in myocytes not exposed to free radicals (88 +/- 9% and 79 +/- 6%, respectively). Superoxide dismutase (2400 U/ml), dimethylthiourea (10 mM), and desferrioxamine (1 mM) did not preserve either viability or AdN. The calcium antagonist verapamil (10 microM) also preserved myocyte viability significantly (23 +/- 9.7%, p less than 0.05 vs unprotected cells), but failed to prevent the loss of AdN (13.2 +/- 4%, not significant as compared to unprotected cells). Viability and AdN in myocytes treated with nifedipine (10 microM) or diltiazem (10 microM) were not higher than in unprotected cells. All combined treatment forms which included catalase resulted in the preservation of myocyte viability as well as AdN. These data show that only the hydrogen peroxide scavenger catalase protects isolated cardiomyocytes against free radicals generated in the purine catabolic pathway.

[Successful lysis of iliofemoral and inferior vena cava thrombi in heparin-induced type-II thrombocytopenia]. / Erfolgreiche Lysetherapie einer Vena-cava-inferior- und iliofemoral-Venenthrombose bei Heparin-induzierter Thrombozytopenie Typ II.

HISTORY AND CLINICAL FINDINGS: After 10 days of intravenous heparin treatment of a 25-year-old woman with recurrent pulmonary emboli, thrombocytopenia occurred with a platelet drop from 1.52 x 10(5)/microliter to 3.6 x 10(4)/microliter. Heparin-induced platelet activation assays confirmed the diagnosis of heparin-induced thrombocytopenia (HIT). The detected heparin-dependent antibodies exhibited in vitro cross-reactivity with low-molecular-weight heparins, but not with danaparoid. TREATMENT AND COURSE: After heparin was stopped and platelet counts were normal, a massive thrombosis of the iliofemoral veins and the inferior vena cava occurred. Under protection of a temporary vena cava filter, systemic anticoagulation with danaparoid (anti-factor Xa-activity 0.4-0.8 U/ml) and transcatheter thrombolysis with urokinase (70,000 U/h) was initiated. Within 8 days of treatment a complete recanalisation of the occluded iliofemoral and caval veins was achieved. Oral anticoagulation with phenprocoumon was started and the patient has since then been free of symptoms. CONCLUSION: The case demonstrates successful treatment of massive iliofemoral and caval thrombosis in the HIT syndrome achieved by combined transcatheter administration of urokinase and systemic infusion of danaparoid.

[Optimized programming of sustained rate duration in patients with implantable cardioverter-defibrillators and diagnosed atrial fibrillation]. / Programmierungsoptimierung der sustained rate duration bei Patienten mit implantierbarem Cardioverter-Defibrillator und bekanntem Vorhofflimmern.

The discrimination of supraventricular versus ventricular tachycardias by an implantable cardioverter-defibrillator (ICD) is still a remaining clinical problem. The false positive detection of supraventricular as ventricular tachycardias causes inadequate electrical therapies of the ICD. To improve the increase of specificity criterias like "Onset" or "Stability" are offered. If these criterias during tachycardia are not fulfilled, the "sustained rate duration" (SRD) is offered as a security criterion. The SRD reasons the delivery of the therapy during tachycardia after a programmable time. Aim of the study was to evaluate, if SRD in patients with known arrhythmia absoluta (AA) in atrial fibrillation and programmed "Onset"/"Stability" increases the sensitivity without loss of specificity in the treatment of hemodynamically tolerated ventricular tachycardias and which programming should be chosen. Our patient collective included 274 patients (pts) with new implanted ICD of the third generation. In 39 (14%) pts AA was known in the medical history. From these 39 (100%) pts, 18 (46%) pts had known tachyarrhythmic episodes (group I) in the area of the ventricular tachycardia-zone > or = 160 beats per minute, whereas in 21 (54%) pts a tachyarrhythmia absoluta (TAA) was unknown (group II). During follow-up of 12 +/- 8 (2-26) months, 151 tachycardias occurred and could be classified as supraventricular tachycardias by stored electrograms. In 9/18 pts of group I, a TAA occurred during follow-up. The initial programmed SRD during first TAA was 62 +/- 39 (35-90) s and was prolonged to 135 +/- 64 (90-180) s. After this prolongation, no inadequate therapy was delivered. In group II, 19/21 (90%) were inadequately treated during TAA. The initial SRD-programming was 45 +/- 28 (0-90) s and was prolonged to 201 +/- 150 (60-480) s during follow-up. After prolongation of the SRD, no more inadequate therapies due to AA were delivered. In pts with new implanted ICD and known TAA, which is hemodynamically tolerated, the SRD should be programmed beside all other available detection parameters for improving the increase of specificity at least 135 s to avoid inadequate therapies of the ICD. In pts with unknown TAA, SRD should be prolonged to 135 s at least the second tachyarrhythmic episode, which is hemodynamically well tolerated.

Long-term clinical experience with the EGM width detection criterion for differentiation of supraventricular and ventricular tachycardia in patients with implantable cardioverter defibrillators.

Inappropriate therapy by ICDs due to SVTs is an important problem. A third generation ICD with a new detection criterion ("EGM width criterion") for differentiation of SVTs and VTs by measuring the width of the intracardiac EGM was studied in 47 patients. A wide EGM was defined as the longest measured EGM plus 4-12 ms (programmed as EGM width threshold). EGM width detection function was programmed to the "Passive" mode so that no therapy was withheld. During a follow-up of 29.9 +/- 8.3 (12-45) months, 489 spontaneous episodes were analyzed. SVTs occurred in ten patients with 305 episodes; 301 were correctly classified by use of the new detection criterion. In four patients four episodes were incorrectly detected as wide QRS tachycardias. Thus specificity for SVT was 98.7% (on a per episode basis) and 60% on a per patient basis. Of 184 VTs in 23 patients, 118 episodes were correctly classified (19 patients), however, in 4 patients 66 VTs were falsely detected as SVTs, 62 (94%) of which occurred in 1 patient with complete left BBB and continuously increasing QRS width in 12-lead surface ECGs. Overall sensitivity (on a per episode basis) for VT detection was 64.1% and 96.7% in patients with stable width of the QRS complex in a 12-lead surface ECG. These data show that this criterion is not superior to data on rate dependent detection criteria and furthermore not applicable in patients with complete BBB.

[Coronary angioplasty with controlled longitudinal dissection. Initial clinical results using a new cutting balloon]. / Koronarangioplastie mit kontrollierter Längsdissektion. Erste klinische Ergebnisse mit einem neuen Schneideballon.

A recently developed cutting balloon was used for coronary angioplasty in 21 patients (4 women, 17 men; mean age 57.6 [36-81] years) with coronary heart disease (angioplasty of the right coronary artery in 4, of the circumflex branch in 4, and of the anterior interventricular branch in 13 patients). The balloon contains 3-4 longitudinally arranged metal cutters to prevent uncontrolled vessel tears. An average stenosis reduction from 84 +/- 8.6% to 30 +/- 10.6% was achieved in ten patients. In the eleven others a second dilatation with a conventional balloon was necessary because of a residual stenosis of over 50% after the first dilatation with the cutting balloon. This reduced the original stenosis from 78.6 +/- 9.4% to 30.4 +/- 9.9%. Complete occlusion at the place of previous dilatation occurred in one patient 14 hours after the procedure, due to a dissection which required a stent implantation. These preliminary results suggest that the cutting balloon can achieve a stenosis reduction similar to that with a conventional balloon.