Armin Klesius

Prevalence, Characteristics and Clinical Implications of Regular Atrial Tachyarrhythmias in Patients With Atrial Fibrillation: Insights From a Study Using a New Implantable Device

OBJECTIVES This study prospectively analyzed atrial tachyarrhythmia (AT) organization and antitachycardia pacing (ATP) success in patients with an implanted device for AT therapy. BACKGROUND In patients with atrial fibrillation (AF), the incidence of regular, slow ATs amendable by ATP is unknown. METHODS Forty patients with previously documented AT (70% with AF) received a new pacemaker with atrial electrogram (AEG) storage and atrial ATP capabilities for standard pacing indications. The AEGs acquired during the first month (study phase 1) were classified into high (type I), intermediate (type II) and low (type III) degrees of organization. Atrial ATP was then activated, and treated AT episodes were retrieved three and six months after implantation (study phase 2). RESULTS Of 824 AEGs retrieved before ATP activation (study phase 1), 351 (43%) were classified as type 1, 47% as type II and 10% as type III. Episodes of AT starting as type I (35%) and type II or III (65%) maintained their type over 1 min in 73%. All patients with an exclusive history of AF also showed type I AEGs. In 361 subsequently treated AT episodes (study phase 2), ATP was successful in 62% of type I and 34% of type II episodes, but not in type III (p < 0.0001). CONCLUSIONS The majority of patients with a history of AF show not only disorganized but also highly organized AT episodes, which can be successfully terminated by ATP.

Correction of simple congenital heart defects in infants and children through a minithoracotomy

BACKGROUND Minimally invasive surgical techniques in pediatric cardiac surgery have evolved throughout the last 10 years. Advantages of minimally invasive procedures include excellent cosmetic results and superior postoperative outcome. However, safety of minimally invasive techniques has to be proven. METHODS In 21 female infants and children, a right anterolateral thoracotomy was performed. Mean age was 7.1 years (0.5 to 16.6 years) and mean body weight was 20.8 kg (8.3 to 56 kg). The following defects were repaired: atrial septum defect type II (n = 14); partial atrioventricular septum defect (n = 3); partial anomalous pulmonary venous connection (n = 2); ventricular septum defect (n = 2); mitral valve insufficiency (n = 1); and resection of an embolized atrial septum defect occluder (n = 1). In two cases, aortic cross-clamping was performed by using a transthoracic clamp. In 5 patients, femoral cannulation was performed. Skin incisions were limited to 4 to 7 cm. RESULTS There was no operative or late mortality. Mean operation time, bypass time, and aortic cross-clamp time were 138 (95 to 275), 72 (32 to 179), and 35 (12 to 120) minutes, respectively. Mean postoperative mechanical ventilation time, mean intensive care unit stay, and mean hospital stay were 3.9 hours (1 to 12 hours), 1.4 days (1 to 3 days), and 12 days (8 to 18 days), respectively. Postoperative complications included hemorrhage in 1 patient requiring surgical intervention. Mean follow-up period was 13.3 months (1 to 36 months). All patients were in New York Heart Association class I postoperatively. Trivial mitral insufficiency was evident in 1 patient operated for partial atrioventricular septum defect. CONCLUSIONS A small right anterolateral thoracotomy as a minimally invasive technique in pediatric cardiac surgery is a safe and suitable alternative in the operative management of simple congenital heart defects. Cosmetic results are superior, however, improved postoperative outcome has to be proven.

Extension of generator longevity by use of high impedance ventricular leads.

SCHERER, M., et al.: Extension of Generator Longevity by Use of High Impedance Ventricular Leads. The resistance of a pacing lead negatively correlates to current consumption. A prospective, randomized trial was conducted to evaluate the effect of a high impedance ventricular lead (CapSure Z) on generator longevity compared to a conventional lead (CapSure SP) eighty‐nine patients were included in the study (51 male, 37 female, age 70.0 ± 10.3 years). Forty‐six patients received a CapSure SP lead (5024 bipolar), and 43 patients received a CapSure Z lead (5034 bipolar) in a randomized fashion. Follow‐up data collected at 5 days, 3, 6, and 12 months postimplant included: lead impedance, pacing and sensing thresholds, impulse energy, and estimated time to replacement. All parameters were collected via pacemaker telemetry; the time to replacement was calculated automatically by a programmed algorithm of the pacemaker. There was no difference in the performance of the atrial lead when a dual chamber device was indicated. The CapSure Z leads displayed statistically significant higher impedance values than the CapSure SP lead in all follow‐up periods. There was no significant difference in lead related complications. No significant differences were observed between pacing and sensing thresholds in both groups. The CapSure Z leads provided a significant reduction in current drain, resulting in a reduction of mean energy consumption at the 12‐month follow‐up from 10.4 ± 5.0 μJ in the CapSure SP group to 6.6 ± 1.4 μJ in the CapSure Z group (median from 9.9 μJ to 6.9 μJ, respectively), providing an estimated increase in mean longevity of more than 1 year from 81.1 ± 23.5 months in the CapSure SP group to 94.5 ± 13.4 months in the CapSure Z group (median: 76.5 months to 95.0 months, respectively). The use of a high resistance lead for ventricular pacing appears to result in a clinically relevant extension of generator longevity.

Initial in vivo results of the new Medtronic AdvantageTM bileaflet valve in aortic position and comparison to the SJM

The present study investigated the Medtronic Advantage (MA) bileaflet valve in an animal model and compared the results to the St. Jude Medical (SJM) valve. Systolic performance and coronary artery flow in different orientations were studied.A rotation device holding either a MA or SJM aortic valve size 23 mm was implanted into eight pigs. Transvalvular pressure gradients and ventricular dimensions were investigated with the valves in different orientations. Coronary artery flow was measured at normal and high cardiac output. Orientation significantly influenced the hemodynamic performance of both valves. The best results for both valves were obtained with one orifice proximal to the right cusp. Pressure gradients and ventricular dimensions of the MA corresponded to the SJM. Coronary artery flow was higher for the MA. The systolic performance of the new MA bileaflet valve was similar to the SJM. During diastole, the MA showed significantly higher LAD coronary flow.

External stenting with a new polyester mesh reduces neointimal hyperplasia of vein grafts in a sheep model

Objective External stents placed around vein grafts have demonstrated effectiveness in reducing neointimal hyperplasia by preventing distension of the thin-walled vein grafts when exposed to arterial pressure. However, the ideal stent material has yet to be defined. The following study investigates the short- and long-term effects of an innovative polyester mesh stent designed with optimized adaptation of circumferential compliance. Methods Following in vitro definition of the ideal macro-porous polyester stent material, a total of 12 sheep underwent implantation of bilateral carotid artery vein graft bypasses. In six sheep, the short-term outcome (four weeks of implantation) was investigated by comparing the newly-designed stent to native veins, micro-porous PTFE stent grafts and metallic Biocompound® stents (BCGs). Flow volume and graft diameter were measured prior to explantation. Grafts were evaluated histologically with respect to morphometry and immunoassaying. In the long-term group (6-month implantation time), the polyester stent was compared to native veins. Results All stents effectively prevented dilatation of the graft. Perfused vessel diameters of the polyester veins were 8.3±0.6 mm. BCG as well as PTFE veins showed diameter reduction to 7.4±0.7mm (p<0.05) and 7.8±0.4 mm (p<0.05), respectively. Both in the short and long terms, the new polyester stent led to significantly higher reduction of neointimal hyperplasia and luminal encroachment compared to the native vessel. It proved superior to PTFE stenting, while the Biocompound® material failed to prove efficacy. Conclusions It was demonstrated that the new macro-porous polyester mesh stent reduced neointimal hyperplasia more effectively than other commercially available stents.

Health services research in heart failure patients treated with a remote monitoring device in Germany-a retrospective database analysis in evaluating resource use.

Abstract Objectives: Heart failure is an increasing burden for all healthcare systems with prevalence reaching over 20 million patients worldwide and direct costs of disease requiring ∼1% of healthcare budget expenditures. Beyond traditional pharmaceutical treatment, medical devices and remote monitoring tools were introduced to ensure a closely managed control of patients. In this context, a decision-maker needs to know whether the new technology provides clinical benefit towards patients and what resource use is attached to them. Methods: Health services research is a complementary approach to clinical trials providing results to the impact of the technology in real life settings. As an example this study reports of a secondary data analysis of one of the largest health insurance companies in Germany, comparing resource use of heart failure patients receiving a cardiac resynchronization therapy (CRT) device coupled with a fluid status monitoring and alert function with patients receiving conventional CRT, ICD (implantable cardioverter defibrillator), or no intervention. Results: Disease-associated expenses can be attributed to far more than 50% to heart failure. Although implementation of the CRT device with alert function was most expensive (31,794 Euros compared to 27,659 Euros in the conventional CRT group, 24,128 Euros in the ICD group, and 3735 Euros in the no intervention group) in the first year after implementation, the least costs have been caused in this group (7000 Euros compared to more than 11,000 Euros in all other groups). Conclusion: This article highlights potential health services research approaches focusing on the example of a CRT device coupled with a pulmonary diagnostic and alert function. Although this retrospective analysis holds a number of limitations (e.g., small number of patients in intervention group, cost calculations only from the payer perspective), and despite the need for randomized controlled trials, it was shown that secondary data research in this field is a valuable approach.

Bilaterale Pectoralislappenplastik nach Sternumresektion bei schwerem Poststernotomie Wundinfekt

ZusammenfassungEinführungSchwere Sternumnekrosen bedürfen einer sorgfältigen plastischen Rekonstruktion sowie adäquaten Restabilisierung des Thorax. Die Studie beleuchtet den Verlauf von Patienten, die eine bilaterale Pectoralislappenplastik erhalten haben in Bezug auf Mortalität, Infektsanierung, Thoraxstabilität, Hospitalisierung und Mobilisierung.MethodikZwölf Patienten, die sich in der Zeit von 1997–2001 einer kardiochirurgischen Operation an unserem Zentrum unterzogen haben, erlitten eine schwere Sternumnekrose, die einer plastischen Rekonstruktion bedurfte. Nach im Mittel zwei Versuchen des ausgiebigen lokalen Wunddebridements erfolgte eine komplette Sternumresektion mit anschließender plastischer Rekonstruktion durch bilaterale Pectoralislappenplastik. Studienendpunkt war die Entlassung in die Anschlussheilbehandlung.ErgebnisseDie Analyse der Risikofaktoren ergab, dass es sich mit Ausnahme eines Patienten ausnahmslos um Diabetiker handelte, zehn Patienten waren übergewichtig (Body mass Index >25). Die einseitige Verwendung der A. mammaria erfolgte bei acht Patienten, eine beidseitige Präparation erfolgte bei zwei Patienten. Postoperativ verstarben zwei Patienten im septischen Multiorganversagen, sowie ein Patient im Low-Output-Syndrom; neun Patienten konnten mit sanierten Wundverhältnissen in die Anschlussheilbehandlung verlegt werden. Die Pectoralislappenplastik erfolgte im Mittel 67,5±101,9 Tagen (median 38 Tage) nach dem Primäreingriff. Die mittlere Intensiv-Aufenthaltsdauer betrug 23,3±30,1 Tage (median 3 Tage). Die Patienten konnten nach durchschnittlich 31±24,04 Tagen (median 26 Tage) in die Anschlussheilbehandlung verlegt werden. Bei keinem der Patienten kam es zu einer erneuten Sternuminfektion. Die Stabilität des Brustkorbes war zufriedenstellend.ZusammenfassungDie komplette Sternumresektion mit Rekonstruktion durch bilaterale Pectoralislappenplastik ist eine technisch einfach durchführbare Methode zur definitiven Versorgung schwerer Sternumnekrosen nach kardiochirurgischen Eingriffen. Unter Verzicht auf ausgeprägten Gewebetransfer sind die kosmetischen Ergebnisse exzellent, der zugrunde liegende Infekt lässt sich ausheilen und es wird eine suffiziente Thoraxstabilität erzielt.SummaryObjectiveSevere sternum necrosis requires resection followed by plastic reconstruction of the resulting defect and stabilization of the chest. The following study evaluates the outcome of patients undergoing bilateral pectoralis major flaps with respect to mortality, sanitation of infection, chest stabilization, hospitalization and mobilization.MethodsTwelfe patients undergoing cardiac surgery between 1997 and 2001 suffered from a severe sternum necrosis requiring resection and plastic reconstruction of the resulting defect. After a mean of two attempts of extensive wound debridement, all 12 patients underwent a complete sternum resection with plastic reconstruction by bilateral pectoralis major flaps. Patients were followed until discharge from the hospital.ResultsRisk factors were diabetes, which was present in all patients but one, and obesity (BMI >25 in ten patients). The unilateral internal mammary artery (IMA) was used in 8 patients; both IMA were harvested in two cases. Following the operation two patients died due to septic multiorgan failure, one patient died due to low cardiac output, and 9 patients were discharged from the hospital with completed wound closure. Plastic reconstruction was performed at a mean of 67.5±101.9 days (median 38 days) after heart surgery. Mean ICU stay was 23.3±30.1 days (median 3 days). Patients could be discharged from hospital after a mean 31±24 days (median 26 days). No patient suffered a recurrent sternal infection. Chest stability was satisfactory.ConclusionsComplete sternum resection and reconstruction using bilateral pectoralis major flaps is a technically easy method for definitive treatment of severe sternum necrosis following open heart surgery. As no major tissue transfer is necessary cosmetic results are good. All local infections were cured and chest stability was satisfactory.