[Antagonistic function of the heart muscle : Part II: Clinical implications]. / Die antagonistische Funktion des Herzmuskels : Teil II: Klinische Auswirkungen.

In the hypertrophic heart the myostructural afterload in the form of endoepicardial networks is predominant, which enhances myocardial hypertrophy. The intrinsic antagonism is derailed. Likewise, the connective tissue scaffold, i.e. the stromatogenic afterload, is enriched in the response to the derailment of antagonism in a hypertrophic heart up to regional captivation of the heart musculature. Due to the selective susceptibility of the auxotonic, contracting oblique transmural myocardial network for low dose negative inotropic medication, this promises to attenuate progress in myocardial hypertrophy. Volume reduction surgery is most effective in reducing wall stress as long as the myocardium is not critically fettered by fibrosis. The use of external mechanical circulatory support is then effective if the heart is supported in its resting mode, which means around a middle width and at minimal amplitude of motion. The takotsubo cardiomyopathy might possibly reflect an isolated, extreme stimulation of the intrinsic antagonism as a response to hormonally induced sensitization of the myocardium to catecholamine. A particular significant conclusion with respect to the diseased heart is that clinical diagnostics need new impulses with a focus on the analysis of local motion patterns and on myocardial stiffness reflecting disease-dependent antagonistic intensity. This would become a relevant diagnostic marker if corresponding (noninvasive) measurement techniques would become available.

Functional evaluation of platelet aspirin resistance after on-pump coronary bypass grafting using multiple aggregation tests.

OBJECT: The predominant mechanism of early graft failure after coronary artery bypass grafting (CABG) is associated with antiplatelet treatment using drugs such as acetylsalicylic acid (ASA). Impaired hemostasis of multiple etiologies is often present in patients undergoing on-pump cardiac surgery. We investigated the impact of intravenous ASA administration on platelet function in this setting. METHODS: Forty-two patients were enrolled in the study. Patients received 100 mg oral ASA once daily, beginning in the early postoperative period. Noncompliance was eliminated by the administration of 300 mg ASA intravenously at 6-8 days post-operation. Blood was drawn immediately before, 1 h and 24 h after ASA administration. RESULTS: A platelet function analyzer (PFA-100™) was used to evaluate closure time (CT), turbidimetric platelet aggregation (TPA) and impedance platelet aggregation (IPA) induced by arachidonic acid (AA), collagen and ADP and results were compared with the respective values from 120 healthy individuals. At 1 h and 24 h after administration, we found that intravenous ASA caused CEPI-CT to be significantly prolonged with a reduction of AA and collagen-induced IPA. Despite postoperative oral ASA administration for 6-8 days, PFA-100™ CEPI and CADP-CT were significantly shorter and ADP-TPA and IPA values induced by any agonist were significantly greater in patients than in controls. Intravenous ASA had no significant influence on CADP-CT or ADP-induced IPA (ADP-IPA). CONCLUSION: Platelet tests for diagnosing patients as aspirin responders (ASA-R) or aspirin non-responders (ASA-NR) were found to be not comparable. Patients after CABG show augmented platelet dysfunction. Intravenous ASA administration may indicate a promising approach to reduce laboratory resistance after CABG procedure. The reason for this is not clear and requires additional clinical studies.

[Transcatheter aortic valve implantation (TAVI)TAVI): A new therapeutic option for patients with severe symptomatic aortic stenosis who are not suitable or at high risk for surgical valve replacement]. / Perkutane Aortenklappenimplantation (TAVI): Neue Therapieoption für inoperable oder Hochrisikopatienten mit symptomatischer Aortenklappenstenose.

BACKGROUND: Percutaneous transcatheter aortic valve implantation (TAVI) is a new therapeutic method for patients with severe symptomatic aortic stenosis who are at very high surgical risk or in whom there are contraindications to surgical valve replacement. PATIENTS AND METHODS: Between August 2008 and December 2009, sixty such patients underwent TAVI at our hospital. RESULTS: The mean age of the patients was 82 +/- 6.1 years, 25 of them were men. The mean "European system for cardiac operative risk" (EuroSCORE) was 25.8 +/- 17.0%. A very high surgical risk was the indication for TAVI in 51 patients. The mean aortic valve orifice area was 0.6 +/- 0.1cm(2) and the mean transvalvular gradient 48.2 +/- 14.4 mm Hg before the intervention. The mean duration of the intervention was 62.6 +/- 19.9 minutes and the screening time 11.8 +/- 5.1 minutes. The procedure was technically successful in all but one patient. The post-interventional mean transvalvular gradient was 2.87.0 mm Hg. Significant residual aortic regurgitation (more than grade 3) was present in six patients but was reduced by the catheter-based "snare" technique in most cases. Mean hospital stay was 15.4 +/- 18.9 days. A permanent pacemaker was implanted in 22 of the patients. Eight patients died during the hospital stay, most of them for reasons not directly related to the intervention. CONCLUSIONS: TAVI is becoming a new therapeutic method for elderly patients with severe co-morbidities and severe symptomatic aortic stenosis. Complications of TAVI are not trivial and their management by catheter techniques is challenging. In consequence the selection of patients and of suitably experienced hospitals is crucial for the further development of this promising new technique.

INR self-management permits lower anticoagulation levels after mechanical heart valve replacement.

BACKGROUND: The Early Self Controlled Anticoagulation Trial (ESCAT I) showed that anticoagulation self-management after mechanical heart valve replacement decreased complication rates by maintaining INR levels closer to the target range than International Normalized Ratio (INR) home doctor management. The therapeutic range for the INR in that study was between 2.5 and 4.5 for all positions of prosthetic valves. ESCAT II should find out whether lowering the target range for INR self-management would further reduce complication rates. METHODS: ESCAT II is a prospective controlled randomized (valves: St. Jude Medical Standard or Medtronic Hall, treatment: conventional/low-dose) multicenter study with 3,300 patients. We present interim results of 1,818 patients. 908 were categorized as having a low-dose target range, which was INR 1.8 to 2.8 for prostheses in aortic position and 2.5 to 3.5 for prostheses in mitral position or in combined valve replacement. The control group (conventional group) with 910 patients aimed at an INR of 2.5 to 4.5 for all valve positions. RESULTS: In the conventional group, 74% of INR values measured were within the therapeutic range. In the low-dose group, 72% of the values were within that range. The linearized thromboembolism rate (% per patient year) was 0.21% for both groups. The bleeding complication rate was 0.56% in the low-dose regimen group versus 0.91% in the conventional group. CONCLUSIONS: Early onset INR self-management under oral anticoagulation after mechanical heart valve replacement enables patients to keep within a lower and smaller INR target range. The reduced anticoagulation level resulted in fewer grade III bleeding complications without increasing thromboembolic event rates.

Impact of atrio-biventricular pacing to poor left-ventricular function after CABG.

AIMS: The relation between acute postoperative management of epicardial pacing and haemodynamic status in patients with poor left-ventricular function after coronary artery bypass grafting (CABG) demonstrates the importance of synchronous ventricular activation and contraction during the vulnerable early postoperative period. METHODS: in 22 patients (mean age - 69.3 +/- 5.4 years) with poor left-ventricular function (ejection fraction 29.8 +/- 4.8), we compared the postoperative haemodynamic parameters between atrio-biventricular, atrio-monoventricular and atrial pacing 3 - 24 hours after elective coronary artery revascularisation. Temporary epicardial pacing electrodes were placed on the right atrium and the paraseptal region of the left and right ventricle. The ventricular pacing modus was confirmed by surface electrocardiogram (EGG). We used overdrive rate pacing. RESULTS: In patients with left bundle branch block, atrio-left-ventricular and atrio-biventricular pacing increased cardiac index and decreased wedge pressure. Atrial pacing and atrio-right-ventricular pacing decreased cardiac index. In contrast, atrio-right-ventricular and atrio-biventricular pacing increased cardiac index in patients with right bundle brunch block. CONCLUSION: Atrio-biventricular pacing increased cardiac index and decreased wedge pressure compared with AAI pacing. In patients with wall-motion abnormalities and impaired cardiac conduction, a site-specific pacing therapy can help to optimize postoperative haemodynamics and reduce the application of inotropic substances.

Biventricular pacing in patients with ICD: how many patients are possible candidates?

BACKGROUND: About 80 % of patients receiving an implantable cardioverter-defibrillator (ICD) due to life-threatening episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF) have structural heart disease. ICD implantation reduces the risk of sudden cardiac death to less than 2 %. However, the major obstacle in these patients is chronic heart failure (CHF). Biventricular stimulation (BIV) has shown its efficiency as an alternative therapy in drug refractory CHF. METHODS: According to the InSync registry, we predefined possible indications for BIV as follows: complete branch bundle block (> 120 ms), left-ventricular ejection fraction (EF) < 35 % and NYHA class > II. We evaluated the number of patients presenting this indication at time of implant and during follow-up (FU) at our ICD clinic. RESULTS: Between 1992 and 1998, 360 patients were provided with an ICD (mean age 64.6 +/- 5.4 yrs, mean EF 37 +/- 14 % at implant, 82 % of patients with organic heart disease). Mean FU was 34 +/- 21 months. During FU 46 patients (13 %) died, 15 of these (33 %) presenting criteria for BIV. 33 patients died of heart failure, there was 1 sudden death and 12 patients died for non-cardiac reasons. 35 % of the patients who died of heart failure had an indication for BIV. CONCLUSIONS: About 10 % of ICD patients had an indication for BIV at time of implant. Over a mean FU period of 34 months, 16% of all patients presented an indication for BIV. Patients with an indication for BIV had a higher mortality rate and more frequent atrial fibrillation compared to patients without. With this data and the good clinical results after BIV-ICD implantation, we consider the implantation of a BIV-ICD system in every patient with appropriate indications.

VAMOS--ventilator assisted model for off-pump surgery.

BACKGROUND: Introduction of innovative cardiac procedures mostly depends on extensive evaluation using laboratory animal models. Avoiding living creatures in the experimental setup where possible without loss of reliability would be progressive from a logistical as wells as an ethical perspective. METHODS: Hearts of meat-production animals (pigs) were removed without structural damage. Two tracheotomy tubes (length 35 mm, diameter 10 mm) were inserted into aortic and pulmonal positions. The atrial inflow had to be ligated. The ventilation tubes were joined to a respirator. The "ventilation" frequency was limited to a maximum of 100/min, "inspiration" volume at 100 ml and ventilation pressure at up to 60 mbar. RESULTS: "Air beats" triggered by the frequency of the respirator occurred in the ventilated heart. Insufflation and deflation generated movement that was almost the same as physiological action. CONCLUSIONS: Air-animation of the heart using a standard respirator is an easily conducted alternative to extensive and expensive laboratory experiments for development and quality control of new devices or techniques without compromising the scientific value of results and without using living animals.

Survival and quality of life after a long-term intensive care stay.

OBJECTIVE: The growing number of high-risk patients in cardiac surgery unavoidably leads to more complications, and therefore to a prolonged stay in an intensive care unit (ICU). The aim of our investigation was to elaborate on the fate of patents after long-term ICU treatment. METHODS: Out of 5055 patients, 232 had to be treated for longer than 5 days in ICU. These 232 patients were analyzed for in-hospital mortality and followed up for quality of life. The Barthel mobility index and geriatric depression scale by Sheikh and Yesavage were used to evaluate physical ability and mood disturbances. Follow-up time was 82 months, and could be completed for 99 % of the patents. RESULTS: In-hospital mortality was 34.6 %, with the majority of cases being coronary artery bypass grafting procedures (59.9 %). Average stay in ICU was 12.0 days for the survivors and 17 days for non-survivors. During follow-up time (6 - 82 months), another 56 patients (23 %) died. Survivors (n = 98) were predominantly in NYHA classes l-ll (83 %) with a Barthel index of more than 80, representing adequate mobilization during daily life in 78 % of the patients. Results according to the geriatric depression scale were normal in the vast majority of patients (91 %) with severe or life threatening depressions in only 6 patients (8 %). CONCLUSION: Long-term treatment of critically ill patients is admittedly burdened with high in-hospital and follow-up mortality. However, the excellent physical and psychological recovery of survivors unequivocally supports the employment of all technical and personnel resources within modern intensive care medicine.

Effects of solvent/detergent-treated plasma and fresh-frozen plasma on haemostasis and fibrinolysis in complex coagulopathy following open-heart surgery.

BACKGROUND AND OBJECTIVES: Solvent/detergent-treated plasma (SDP) contains markedly lower protein S (PS) and plasmin inhibitor (PI) activity than standard fresh-frozen plasma (FFP). It has also been reported that SDP contains no alpha(1)-antitrypsin. Despite the lack of clinical data, it is suspected that SDP may be less effective than FFP in the treatment of complex coagulopathies. We therefore conducted a prospective trial to study the impact of SDP and FFP on haemostasis and fibrinolysis in complex coagulopathy after open-heart surgery. MATERIALS AND METHODS: Patients received either 600 ml of SDP (n = 36) or 600 ml of FFP (n = 31) at an infusion rate of 30 ml/min. The following parameters were measured before treatment and 60 min after termination of plasma infusion: prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, factor VIII, antithrombin, protein C (PC), free PS and PS activity, prothrombin fragments F1+2 (F1+2), D-dimers (DD), fibrinogen degradation products (FDP), plasmin-plasmin inhibitor complexes (PPI), plasminogen, PI and alpha(1)-antitrypsin. RESULTS: The rise in fibrinogen, factor VIII, antithrombin, PC, free PS, alpha(1)-antitrypsin and plasminogen, and the decrease in PT and APTT, did not significantly differ between the two study arms. However, PS activity did not increase after SDP infusion but did show a significant elevation after infusion with FFP. PI declined significantly after SDP and remained uninfluenced by FFP. Neither SDP nor FFP had any significant influence on F1+2, DD or FDP. However, a significant decrease in PPI levels caused by both types of plasma indicated a reduction in hyperfibrinolysis. Clinical haemostasis evaluation revealed no significant difference between the two treatment regimens. No adverse reactions were observed. CONCLUSION: With the exception of PS and PI, SDP and FFP improved haemostasis and fibrinolysis to a similar degree. The clinical significance of these findings has to be determined in patients with severe acquired PS and PI deficiency requiring plasma transfusions.

Platelet function test HemoSTATUS 2: tool or toy for an optimized management of hemostasis?

BACKGROUND: Bleeding after open heart surgery is a common but unintended problem, which is unequivocally related to platelet function. The target of our study was to correlate platelet activation levels and postoperative blood loss as well as the predictive power of measurements focusing on postoperative hemostasis. MATERIALS AND METHODS: The prospective trial comprised 100 patients (mean age: 64.3 years, 68% male) undergoing cardiac surgery. Platelet activation was measured by the new and modified HemoSTATUS test. Blood samples were drawn pre-, intra- and postoperatively. Standard hemostasis tests, including activated clotting time (ACT), partial thromboplastin time (PTT), hemoglobin, platelet count, antithrombin III (AT III) and fibrinogen, were measured according to the clinical routine. Blood loss and consumed blood products were documented up to the 24th hour after the operation. RESULTS: Platelet activation showed a typical change, with lowest levels after the end of extracorporeal circulation and a restitution to preoperative levels after 24 h. Mean blood loss was 461 ml. Statistical analysis showed neither a correlation to the platelet activation measurements nor to low pre-, intra- or postoperative levels. CONCLUSION: The HemoSTATUS platelet function test is not suitable for a reliable monitoring of platelet pathophysiology and patient outcome after extracorporeal circulation. Furthermore, no correlation of preoperative platelet activation and blood loss could be shown.

Cell saver, ultrafiltration and direct transfusion: comparative study of three blood processing techniques.

BACKGROUND: Intraoperative blood salvage is an important part of blood conservation efforts in cardiac surgery. The purpose of this study is to examine the effects of three different circuit blood-salvaging techniques: centrifugation, ultrafiltration and direct infusion. METHODS: Sixty patients undergoing elective coronary bypass graft procedures were randomly assigned in a prospective manner to one of the three blood-salvaging methods. RESULTS: Intra- and postoperative blood samples demonstrated increased hemoglobin values in the direct infusion group and higher platelet count in the ultrafiltration group. There were no significant differences in these results. The analysis of coagulation parameters revealed a similar prolongation of partial thromboplastin time and activated clotting time in all groups. The amount of blood loss was not significantly different between the three blood conservation methods. The effect of direct infusion method does not result in either major disturbance of coagulation parameters or in increased blood loss. CONCLUSION: In a sample of adult patients undergoing coronary artery bypass grafting, direct transfusion is, in consideration of the cost-effective factor, an appropriate approach for returning cardiopulmonary bypass circuit blood.

Surface modification of extracorporeal circuits: is there really an impact on cerebral performance after cardiopulmonary bypass?

BACKGROUND: Pathophysiology of extracorporeal circulation is multifactorial, and the link between newly developed "biomaterials" and clinical outcome is not easy to illustrate. MATERIAL AND METHODS: We designed a randomized, double-blinded, prospective study in order to verify the impact of a new surface modification [SMAR(X)T] in combination with an optimized blood air interface, on the cerebral performance after cardiopulmonary bypass. 80 patients were randomly divided into two subgroups (SMAR(X)T vs. standard PVC control) and analyzed for the kinetic of cerebral ischemia markers neuronspecific enolase, protein S100 and neuropsychologically tested with the Mini-Mental-Status Test (MMST) before and after the operation. RESULTS: We could not show significant differences of protein S100 and neuron-specific enolase (NSE) levels between SMAR(X)T patients and the controls, but the incidence of neurological complications was exceptionally low. Although no statistically significant differences could be obtained for the MMST, the different pointloss between both groups trends toward a better cerebral performance in SMAR(X)T patients. CONCLUSION: The use of a biologically inert circuit in combination with an optimized perfusion management seems to be worthy of recommendation.

[Injuries of the thoracic blood vessels--diagnosis and therapy]. / Verletzungen der thorakalen Gefässe--Diagnose und Therapie.

Thoracic vascular trauma is divided into perforating and nonperforating injuries. Patients with perforating lesions with median sternotomy has to be performed if circulation is still functioning marginally. In a severe hemorrhagic shock it can be necessary to do an immediate emergency lateral thoracotomy. Trauma of the thoracic aorta occurs most frequently as a consequence of blunt injury as a result of decelerate or crushing. Fewer than 20% of patients with thoracic aortic injury survive the initial insult. Additionally the survival depends on severity of associated injuries. This means that the timing of surgical intervention in the stable, covered aortic rupture with serious associated injuries should preferably be deferred until the patients condition is stabilized. Emergency operation has to be performed in case of symptomatic transaction in the hemodynamic unstable condition including simultaneous surgery of concomitant lesions. Paraplegia remains the most deleterious problem. Endovascular stents are used increasingly to treat traumatic rupture of the aorta.

Low seroprevalence of Helicobacter pylori infection in patients with stress ulcer bleeding--a prospective evaluation of patients on a cardiosurgical intensive care unit.

OBJECTIVE: The pathogenesis of stress ulceration in seriously ill patients is uncertain and the pathogenic role of Helicobacter pylori infection is unknown. We therefore assessed the seroprevalence of patients of a cardiosurgical intensive care unit (ICU) with clinically important stress ulcer bleeding. We compared this prevalence with a control group matched for this kind of surgical intervention, missing history of peptic ulcer disease, age and gender. DESIGN: Prospective survey. SETTING: Cardiosurgical ICU in a university teaching hospital. PATIENTS AND PARTICIPANTS: Two thousand five hundred seventy cardiosurgical patients with intravenous ranitidine stress ulcer prophylaxis were screened for clinically important stress ulcer bleeding. Helicobacter pylori seropositivity was measured in all patients with a clinically important bleeding and in a control group of 245 consecutive cardiosurgical patients, matched for the kind of cardiosurgical intervention, age and gender. RESULTS: In 56 of 2,570 (2.1%) patients signs of clinically important bleeding were seen. Endoscopical examination revealed stress ulcer bleeding in 42 cases. The incidence of stress ulcer bleeding was 1.6%. The seropositivity of the group with ulcer bleeding was 45.2 % whereas 62.4 % of the patients in the control group were Helicobacter pylori positive (p = 0.08). CONCLUSIONS: Our results suggest that the Helicobacter pylori infection does not play a pathogenic role in stress ulcer bleeding. Prophylactic cure of Helicobacter pylori can not be recommended in this setting.

Electroencephalogram bispectral index predicts hemodynamic and arousal reactions during induction of anesthesia in patients undergoing cardiac surgery.

OBJECTIVE: To evaluate hemodynamic and clinical responses to induction of anesthesia and intubation at 3 different values of the electroencephalogram bispectral index (BIS). DESIGN: Prospective randomized trial. SETTING: University-affiliated hospital. PARTICIPANTS: Forty-five patients undergoing elective coronary artery bypass graft surgery. INTERVENTIONS: Patients were assigned to 3 groups (n = 15 for each group). Anesthesia was induced with midazolam, sufentanil, and pancuronium. In each group, sufentanil was titrated to a BIS value of 60, 50, or 40 before intubation. Mean arterial blood pressure, heart rate, incidence of coughing, tearing, and need for fluid replacement or injections of norepinephrine were recorded before intubation as well as immediately and 1 and 2 minutes after intubation. MEASUREMENTS AND MAIN RESULTS: Thirteen patients intubated at a BIS value of 60 coughed and 14 experienced tearing after intubation, whereas no patient of the other groups showed signs of arousal. Mean arterial blood pressure remained stable in the BIS 60 and 50 groups, whereas in the BIS 40 group it decreased significantly to lower values before and after intubation. Patients in the BIS 40 group needed significantly more fluid replacement and injections of norepinephrine compared with the other groups. No significant changes in heart rate were detected. CONCLUSIONS: Electroencephalogram BIS predicts hemodynamic and arousal reaction resulting from induction of anesthesia and endotracheal intubation. BIS value should be kept at 50 before intubation to ensure safe hemodynamic conditions during induction of anesthesia in cardiac surgical patients.

Minimally invasive saphenous vein harvesting: is there an improvement of the results with the endoscopic approach?

OBJECTIVES: In the postoperative course after conventional open removal of the greater saphenous vein, wound healing disturbances are common and often painful. Therefore the primary goal of this investigation was to prove the safety and practicability of this new less invasive technique for saphenous vein harvesting and the effect on complications and morbidity. METHODS: The study comprised 103 coronary artery bypass grafting (CABG) patients with an endoscopic approach to harvest the saphenous vein (MIVH). We used the VasoView II system developed by Origin, and compared the intraoperative procedure time and the clinical results with 105 equivalent patients in which a conventional open technique was used. RESULTS: In 101 patients endoscopic vein harvesting was successful; a conversion into open technique was necessary in two patients. On average 2.6 vein segments could be harvested in the endogroup versus 2.9 segments in the opengroup. The mean procedure time was 13.2 min per segment in the endogroup compared to 12.2 min per segment in the opengroup. Relevant hematoma were found in 29 patients (27.6%) of the opengroup, whereas only nine patients (8.7%) of the endogroup revealed severe hematoma. Infection was apparent in nine patients (8.5%) after conventional vein harvesting. Two infections were found after endoscopic intervention. CONCLUSIONS: Endoscopic saphenous vein harvesting as part of a less invasive concept in cardiac surgery is a safe and after the learning curve, fast alternative to harvest the saphenous graft. The cosmetic result is excellent and the complication rate seems to be lower. It must be noted however, that the cost effectiveness of the method has to be proved and that further histological and functional studies are needed in order to check the intimal structure of the vein.

[Lead-related complications in 340 patients with an implantable cardiverter/defibrillator]. / Komplikationen mit Sonden bei 340 Patienten mit einem implantierbaren Kardioverter/Defibrillator.

From February 1991 to May 1998, 340 patients had a cardioverter/defibrillator (ICD) implanted. Mean age was 64 +/- 9 years, 278 male and 62 female. 60% of patients had coronary artery disease and 31% dilatative cardiomyopathy. Ejection fraction was 38 +/- 14%. The indication for an implantable cardioverter/defibrillator was in 57% of patients ventricular tachycardia, in 43% ventricular fibrillation. 298 patients had a single-chamber cardioverter/defibrillator implanted, 42 patients a dual-chamber cardioverter/defibrillator. In 25 patients additional subcutaneous patch or array electrodes and in 2 patients additional epicardial patch electrodes were implanted. Implantation site was in 92 patients abdominal and in 248 pectoral. Over a period of 7 years 34 lead-related complications occurred in 33 patients (9.7%), after a median of 2 months after implantation. Diagnosis was made by routine chest x-ray in about 55% of lead-related complications, by clinical presentation (inadequate therapy, pain) in 24%, and by electrical parameters in 21%. In patients with an abdominal implantation site, lead-related complications occurred in 20%, in contrast to 6% in patients with a pectoral implantation site. Regarding patients with pectoral implantation site, lead-related complications were observed in 12% of patients with a dual-chamber ICD vs 4% with a single-chamber ICD (p = 0.05), due to dislocation of atrial electrodes with dual-chamber ICD. There were no differences in clinical parameters between patients with pectoral vs abdominal and between single vs dual-chamber ICD. There were no deaths due to lead-related complications.

Critical illness polyneuropathy following cardiac surgery.

Critical illness polyneuropathy (CIP), a neurologic complication which may occur secondary to surgery, trauma and coma, is associated with sepsis or multiple organ failure (MOF). CIP is characterized by an axonal distal degeneration of sensory and motor fibres. The patients will often become neurologically conspicuous when weaning from mechanical ventilation is unexpectedly difficult. In such cases electrophysiologic examinations must be performed. CIP following cardiac surgery is widely unrecognized. The most important aspect of CIP therapy is treatment of the underlying disease, because no specific treatment for CIP exists. We report on a 64-year old patient who developed sepsis and CIP following cardiovascular surgery. The neurological complication was initially misinterpreted as hypoxic brain damage.

Importance of preimplantation procedures in candidates for an implantable atrial defibrillator.

INTRODUCTION: Due to the limited efficacy of antiarrhythmic drugs for the treatment of atrial fibrillation, several nonpharmacologic therapeutic options have been developed. One of these options is an implantable atrial defibrillator for patients with severe symptoms and infrequent drug-refractory episodes of atrial fibrillation. The purposes of this study were: (1) to evaluate how many patients with atrial fibrillation are possible candidates for an implantable atrial defibrillator; and (2) to report the results and findings of preimplantation testing in a single center. METHODS AND RESULTS: From our atrial fibrillation outpatient clinic, we evaluated the number of possible candidates for an atrial defibrillator using the following criteria: (1) recurrent persistent atrial fibrillation; (2) long-lasting but infrequent episodes; (3) refractory to antiarrhythmic drugs; (4) capability of maintaining normal sinus rhythm; and (5) no factors increasing proarrhythmic risk. In those patients eligible for an atrial defibrillator, a separate preimplantation test was performed to evaluate atrial defibrillation limits and patient acceptance. Thirty-one of 196 patients were possible candidates for an atrial defibrillator. Fourteen of these 31 patients agreed to participate in the METRIX clinical study phase I on atrial defibrillators. Six of these patients met implantation criteria; two patients refused permanent implantation because of intolerable pain. Implantation was performed in four patients; however, one patient could not be cardioverted intraoperatively despite a successful preimplantation test. CONCLUSION: About 16% of selected patients with atrial fibrillation are possible candidates for an atrial defibrillator. However, successful preimplantation testing does not exclude implantation failure.