Claus J. Preusse

Tissue resident C reactive protein in degenerative aortic valves: correlation with serum C reactive protein concentrations and modification by statins

Objective: To assess aortic valve probes for valvar C reactive protein (CRP) presence, the relation between valvar and serum CRP, and a possible modification of CRP by statin medication. Setting: Tertiary referral centre. Patients and design: End stage, degenerative valve tissue was taken from 81 patients, 57 with non-rheumatic aortic valve stenosis (AS) and 24 with degenerative aortic valve bioprosthesis (BP). Five non-stenosed valves served as controls. Tissue from four non-implanted bioprostheses was also examined. The presence and location of CRP was analysed by use of immunostaining and morphometry. Serum CRP concentrations were measured preoperatively. Results: The majority of AS and BP valves exhibited CRP labelled cells, predominantly localised to the valvar fibrosa. The expression of CRP was much higher in BP than in AS (by a factor of 3.7, p  =  0.03). Notably, non-stenosed aortic valves and non-implanted bioprostheses did not have CRP signalling. Serum CRP was also increased with BP (by a factor of 2.5, p  =  0.02) and was significantly correlated with valvar CRP expression (r  =  0.54, p < 0.001). The main finding in patients with (n  =  26) and without statin treatment (n  =  55) was that both valvar CRP expression (p  =  0.02) and serum CRP concentrations (p  =  0.04) were lower in the statin treated group. Conclusions: CRP was found in a large series of degenerative aortic valves, more often in bioprostheses than in native cusps. Serum CRP concentrations may reflect inflammatory processes within the aortic valve. The association of statin treatment with decreases in both valvar and serum CRP concentrations may explain known pleiotropic effects of statins in patients with aortic stenosis.

Transit time flow measurement in on-pump and off-pump coronary artery surgery

OBJECTIVE Transit time flow measurement is frequently used during coronary artery bypass with and without cardiopulmonary bypass to detect graft dysfunction resulting from technical errors. METHODS Intraoperative transit time flow measurement measurements of 896 patients requiring surgery for double- or triple-vessel disease were reviewed retrospectively. Six-hundred and ninety-five patients were operated on-pump (Group A: coronary artery bypass with cardiopulmonary bypass), and 201 patients off-pump (Group B: coronary artery bypass without cardiopulmonary bypass). Transit time flow measurement measurements were analyzed for mean flow (mL/min). In total, measurements of 2247 grafts were analyzed. RESULTS Transit time flow measurement flows were lower in coronary artery bypass without cardiopulmonary bypass patients (left internal thoracic artery to left anterior descending artery: Group A, 37 [31, 40] mL/min vs Group B, 24 [20, 26] mL/min; saphenous vein graft to left anterior descending artery: Group A, 46.5 [40, 56] mL/min vs Group B, 21 [14, 57] mL/min. Troponin I release was reduced in the coronary artery bypass without cardiopulmonary bypass patients, with median values of 7.8 [7.0, 8.3] microg/L in Group A and 1.2 [0.9, 2.3] microg/L in Group B. CONCLUSION Evaluation of transit time flow measurement is valuable in determining coronary graft patency after coronary artery bypass with cardiopulmonary bypass and coronary artery bypass without cardiopulmonary bypass. Decreased troponin I release suggests a myocardial benefit of coronary artery bypass without cardiopulmonary bypass compared to coronary artery bypass with cardiopulmonary bypass, although the intraoperative transit time flow measurement flow measurements are markedly lower.

Detection of (Reversible) Myocardial Ischemic Injury by Means of Electrical Bioimpedance

The scope of this paper was to determine whether ischemic and reperfusion damage in cardiac surgery can be detected by measurement of electrical bioimpedance (EBI). Conventional pacing wires were replaced by pacing wires with sputtered iridium coating in order to reduce polarization associated with two-electrode impedance measurements. A custom-built bioimpedance analyzer (Osypka Medical GmbH, Berlin, Germany) measured the real part of impedance Re( Z) and the phase (φ) at three frequencies (1, 10, and 1000 kHz) and determined an extracellular space index (EZRI) as the quotient of Re( Z) at 1000 kHz and Re(Z) at 1 kHz. Our study included six patients (conventional coronary artery bypass graft, age 68.1 ± 8.3 years) subject to routine cardioplegic ischemia and reperfusion. Preischemic bioimpedance measurements were not impaired by interference of the beating heart. Intraischemically, bioimpedance at 1 kHz and phase at 10 kHz increased until opening of a bypass graft, which is probably induced by closure of gap junctions and cell swelling processes. After cross clamping, EZRI slowly decreased as an effect of mild cell swelling. After ischemia, values returned almost to baseline measurements, indicating sufficient reperfusion processes. Measurement of EBI correlates with myocardial ischemic injury and is applicable in a two-electrode setup providing low-polarization pacing wires.

An Unusual Case of Pacemaker Failure: Complete Disconnection of Connector Block and Battery of a Subpectorally Implanted Dual Chamber Pacemaker

MELLERT, F., et al.: An Unusual Case of Pacemaker Failure: Complete Disconnection of Connector Block and Battery of a Subpectorally Implanted Dual Chamber Pacemaker. Local trauma to patients with implanted pacemaker devices may result in lead fracture or breakage of the lead socket with leakage of fluid into the connector system. This report describes an unusual case of complete entrance and exit block in a subpectorally implanted dual chamber pacemaker due to total disconnection and dislodgement of header block and battery part. Damage may be caused by an interaction of machine fatigue/manufacturing defective and fixation of the header with unusual movability of the battery, leading to breakage with intermittent malfunction and consecutive bradycardia and syncope.

Radiofrequency Catheter Ablation of an Incessant Ventricular Tachycardia Following Valve Surgery

LEWALTER, T., et al.: Radiofrequency Catheter Ablation of an Incessant Ventricular Tachycardia Following Valve Surgery. Sustained monomorphic ventricular tachycardia (VT) after valve surgery represents a clinical entity with different tachycardia mechanisms. This case report describes an incessant VT after tricuspid and aortic valve replacement that did not respond to antiarrhythmic drug treatment. The tachycardia exhibited VA block and a right bundle branch block pattern with left‐axis deviation, suggesting ventricular excitation via the left posterior fascicle. The electrophysiological study was limited by the prosthetic tricuspid and aortic valve replacement, therefore a transseptal approach was necessary to obtain access to the ventricular myocardium. Radiofrequency catheter ablation was performed in the proximal left bundle or distal His region with termination of the incessant VT followed by complete AV block. After pacemaker implantation using a transvenous right atrial and an epicardial ventricular lead, no VT reoccurrence could be documented.

Therapeutic optimization of atrioventricular delay in cardiosurgical ICU patients by noninvasive cardiac output measurements versus pulse contour analysis.

BACKGROUND Optimizing atrioventricular (AV) delay improves cardiac output and postoperative outcome. Impedance cardiography (ICG) is a non-invasive method for CO measurement. This study evaluates the ability of two ICG methods to determine the optimal AV delay (OAVD) and to compare ICG with invasive PICCO measurements. METHODS In 14 cardiosurgical ICU patients (age 70.4 +/- 12.0 yrs) with temporary pacing wires, OAVD was determined by pulse contour analysis (PICCO) and ICG (conventional ICG [CI] and electrical velocimetry [EV] ICG monitors). Cardiac output (CO) and stroke volume (SV) were measured during DDD pacing with AVD varying from 70 to 270 ms in 20-ms increments. RESULTS Measured OAV showed a linear correlation between PICCO and ICG: CI (r = 0.82, P < 0.0002) and EV (r = 0.84, P < 0.0002). The mean OAVD deviation between PICCO and ICG was 15.7 +/- 21.0 ms (CI) and 17.1 +/- 20.5 ms (EV). Hemodynamic parameters (SV increase OAVD against worst case) improved significantly (+ 11.7 +/- 7.2 %, P < 0.0001). CONCLUSION Inappropriate selection of AVD can compromise the hemodynamic situation of cardiosurgical patients. As it is totally noninvasive, ICG is a reliable and effective tool for tailoring AVD. Both systems (CI and EV) offer valid OAV determination.

Implantation of Left Ventricular Epicardial Leads in Cardiosurgical Patients with Impaired Cardiac Function–A Worthwhile Procedure in Concomitant Surgical Interventions?

BACKGROUND Cardiac resynchronization therapy (CRT) by means of multisite biventricular pacing is an effective therapeutic option for the treatment of severe heart failure. The present study estimates how many open heart-surgery patients could benefit from the implantation of permanent left ventricular (LV) pacing leads. After routine preoperative screening, epicardial electrodes were implanted in selected patients. Lead performance and outcomes were investigated. METHODS Primarily, 1059 patients were retrospectively investigated with regard to LV function, left bundle branch block and QRS duration. Afterwards, suitable patients were identified and epicardial electrodes [Medtronic 5071 (ME) or Enpath (EP)] were implanted during concomitant procedures. Mean follow-up time was 6.3 ± 5.5 months. RESULTS The retrospective study showed that 24 patients (2.3%) could potentially profit from CRT. After routine preoperative screening for CRT-responders, 22 patients (1.6%) were identified who finally received epicardial leads. No complications occurred. Acute capture threshold was 0.9 ± 0.4 V (ME, n = 17) and 0.5 ± 0.2 V (EP, n = 5). While leads in 18 patients were implanted as an upgrade to an existing pacemaker or implantable cardioverter-defibrillator (ICD) technologies (Group B), 4 patients underwent prophylactic implantation with no device attached (Group A). CRT-ICDs were implanted at follow-up in 3 Group A patients (75%). In Group B patients, the QRS duration decreased (from 189 ± 35 ms to 152 ± 16 ms, p < 0.02) and their postoperative mean NYHA functional class improved significantly (2.2 ± 0.5 versus 2.8 ± 0.6). CONCLUSION A small group of cardiac surgery patients may benefit from LV-lead implantation during concomitant procedures. A protocol for responder identification is useful. Existing devices should be upgraded to CRT systems. As CRT-ICD implantation is frequent, the additional costs and time are justified.

Evaluation of Fractal‐Coated Temporary Pacing Leads in the Early Postoperative Course

Background: The performance of temporary pacing wires is still limited by capture and sensing problems. Fractal coating can enhance electrical properties and reliability. We therefore investigated fractal‐laminated wires in comparison with conventional wires.

A Rare Case of Skin Cancer above a Subcutaneously Implanted Pacemaker: Implications for Future Implants

BACKGROUND The occurrence of a skin neoplasm close to the position of an implanted pacemaker or cardioverter-defibrillator device is not very common. CASE REPORT We report on an 82-year-old patient who developed a basal cell carcinoma in the skin directly above a subcutaneously implanted pacemaker generator. The patient presented with a history of recurrent basalioma at various locations. The pacemaker (Kappa KDR 731; Medtronic) was implanted 17 months before and represented a series that was recalled because of problems occurring after submuscular implantation. CONCLUSION Primary submuscular implantation of pacemaker devices should be carefully considered in elderly patients with a history of previous skin tumors.

The imbalance between proliferation and apoptosis contributes to degeneration of aortic valves and bioprostheses

BACKGROUND The pathomechanisms underlying aortic valve degeneration are incompletely understood. Therefore, the aim of our work was to assess the quantitative changes of proliferation and apoptosis accompanied by cellular phenotype alternations and matrix secretionin aortic sclerotic and stenotic valves and degenerative bioprostheses, as well as to detect the expression pattern of the rapamycin receptor FKBP12 across these three valve types. METHODS Mild-to-moderate sclerotic and stenotic valves and degenerative bioprostheses from 30 patients (n = 10 per group) were collected at autopsy or by surgery. Ki67+, FKBP12+, alpha-actin+, HSP47+ and TUNEL+ apoptotic cells were analyzed by immunohistochemistry. RESULTS The main finding was the reduced proliferation and increased apoptosis in stenotic valves (ST) compared to the sclerotic ones (SC) (proliferation: ST: 20.8 ± 2.0% vs. SC: 30.1 ±2.2%, apoptosis: ST: 40.7 ± 5.0% vs. SC: 28.0 ± 5.1%, p < 0.05, respectively). Analogical alternations were found in degenerative bioprostheses (BP) (proliferation: 4.8 ± 2.3%; apoptosis: 13.1 ± 6.8%). Corresponding changes were observed in the valve cellularity (ST: 893 ± 168, SC: 1034 ± 284, BP: 385 ± 179 cells/mm2, p < 0.05, respectively). The FKBP12 signaling was reduced in diseased valves and bioprostheses (ST: 28.1 ± 3.6%, SC: 42.2 ± 3.8%, BP: 5.8 ± 1.9%, p < 0.05, respectively). Further, the augmented alpha-actin expressionwas observed as the degenerative process progressed (ST: 30.3 ± 5.0%, SC: 22.6 ± 2.7%, BP:8.7 ± 4.0%, p < 0.05, respectively), followed by the upregulation of HSP47 (ST: 22.6 ± 2.8%,SC: 15.4 ± 2.1%, BP: 3.4 ± 1.0%, p < 0.05, respectively) and consecutive matrix accumulation. CONCLUSIONS The imbalance between proliferation and apoptosis with cellular phenotypical shift and subsequent matrix secretion may contribute to aortic valve stenosis and bioprosthesis degeneration. The identification of FKBP12 expression may implicate potential therapeutic strategies.