Computed tomography with positron emission tomography is more useful in local than systemic infectious process related to cardiac implanted electrotherapy device: a prospective controlled multicenter diagnostic intervention PET-Guidance Trial.

Assess the diagnostic value of 18-F FDG PET/CT in cardiac implantable electronic devices (CIED) infections in facilitating diagnostic process and optimizing decision-making process.Study group (n = 21) patients with initial suspected diagnosis of CIED-related infection or fever of unknown origin and patients referred for device removal due to infection. Control group (n = 13) patients with implanted CIED, who underwent PET/CT due to other non-infectious indications and had no data for infectious process in follow-up.PET/CT scan showed pocket infection in 12 patients (including 1 in whom infection was not finally diagnosed-the examination was performed early after the implantation procedure-1.5 months), increased tracer uptake in intravascular lead part in 3 patients, and increased uptake in intracardiac part in 5 patients.We found that sensitivity, specificity, positive predictive value, and negative predictive value of the diagnosis made by PET/CT in generator pocket infection was 91.7%, 70%, 78.6%, 87.5% and in lead-dependent intracardiac infection 100%, 47.1%, 35.7%, 100% respectively. PET/CT scan enabled reclassification of diagnosis from possible to definite CIED-related infection in 6 out of 9 patients, and to excluded in 3 out of 9.Establishing diagnosis of device related infections may be challenging due to non-specific symptoms. Incorporation of PET/CT scan in the diagnostic schema can improve accuracy and timing of the diagnosis and help to assess the extent of infection. PET/CT is more useful in local than systemic infectious process related to cardiac implanted electrotherapy device.Trial registration Consent of the bioethics committee nr IK-NP.-0021-85/1465/14. Registration in the www.clinicaltrials.gov database: NCT02196753.

Spiral wave breakup in excitable media with an inhomogeneity of conduction anisotropy.

Many conditions remodel the heart muscle such that it results in a perturbation of cells coupling. The effect of this perturbation on the stability of the spiral waves of electrochemical activity is not clear. We used the FitzHugh-Nagumo model of an excitable medium to model the conduction of the activation waves in a two-dimensional system with inhomogeneous anisotropy level. Inhomogeneity of the anisotropy level was modeled by adding Gaussian noise to diffusion coefficients corresponding with lateral coupling of the cells. Low noise levels resulted in a stable propagation of the spiral wave. For large noise level conduction was not possible due to insufficient coupling in direction perpendicular to fibers. For intermediate noise intensities, the initial wave broke up into several independent spiral waves or waves circulating around conduction obstacles. At an optimal noise intensity, the number of wavelets was maximized-a form of anti-coherent resonance was obtained. Our results suggest that the inhomogeneity of conduction anisotropy may promote wave breakup and hence play an important role in the initiation and perpetuation of the cardiac arrhythmias.

Bleeding complications after pacemaker or cardioverter-defibrillator implantation in patients receiving dual antiplatelet therapy: Results of a prospective, two-centre registry.

Introduction. The aim of the study was to define the prevalence of bleeding events in patients treated with dual antiplatelet therapy (DAT) in comparison with patients receiving only acetylsalicylic acid (ASA).Methods. Prospective two-centre registry of all first implantations of pacemakers, cardioverter-defibrillators and cardiac resynchronisation therapy units in patients receiving ASA (n=194) or DAT (n=53).Results. Bleeding complications were detected in 27 (16.2%) patients in the ASA group and in 13 (24.5%) in the DAT group. There was no significant difference in the overall number of complications between the patients receiving ASA or DAT, although there was a trend towards a higher incidence of overall complication rates in the DAT group (p=0.0637). The incidence of major complications (requiring blood transfusion or surgical intervention or prolonging hospital stay) was low (3.6%), and similar in both groups (3.6 and 3.8% respectively, ns). The rate of minor complications (subcutaneous haematomas) was greater in the DAT group (p=0.015).Conclusions. Treatment with DAT does not increase the risk of major bleeding complications as a result of device implantation; however, minor complications are significantly more frequent. Our results suggest that DAT could be continued in patients undergoing device implantation with a moderate risk of bleeding complications. (Neth Heart J 2010;18:230-5.).

Integration of the data from electroanatomical mapping system and CT imaging modality.

Heart mapping systems allow approximate reconstruction of the heart chamber geometry which is used as a base for the representation of the spatial distribution of electrophysiological parameters. Main limitation lies in the difficulty of the reconstruction of the geometry of more complicated areas of the heart. Here, we propose a new method of representation of the spatial distribution of the electrophysiological parameters-an integration of the data points collected by a classical mapping system with the geometry reconstructed from a computed tomography (CT) image. CARTO maps of activation and bipolar viability of seven patients undergoing atrial fibrillation ablation were integrated with the geometry of the left atria reconstructed from the CT image. In all cases, integration was successful with the registration error measured as the distance between objects equal to 2.52 +/- 0.25 mm. Bipolar viability and activation maps were reconstructed on the CT geometry. Our method allowed us to create maps of electrophysiological parameters of anatomically complex structures without the need for their detailed mapping.

The reconstruction, from a set of points, and analysis of the interior surface of the heart chamber.

Adequate description of heart muscle electrical activity is essential for the proper treatment of cardiac arrhythmias. Contemporary mapping and ablating systems allow a physician to introduce an electrode (catheter) into the human heart, to measure the position of the electrode in space and, simultaneously, the electrical activity timing and the bipolar and unipolar signal amplitudes--which correspond to the electrical viability of the heart muscle. If enough data points are collected, an approximate reconstruction of the heart chamber geometry (anatomy) is possible using also surface data such as the viability and local activity isochrones. Myocardial viability in patients after myocardial infarction is crucial for understanding and treating life threatening arrhythmias. Although there are commercial tools for heart chamber reconstruction, they lack the ability to quantitatively analyse the reconstructed data. Here, we show a method of reconstruction of the left ventricle of the heart from a measured set of data points and perform an interpolation of the measured voltages over the reconstructed surface. Next, we detect regions with voltage in a specified range and compute their areas and circumferences. Our methods allowed us to quantitatively describe the 'normal' muscle, the damaged or scar areas and the border zones between healthy muscle and the scars. In particular, we are able to find geometries of the damaged muscle areas that may be dangerous, e.g. when two such areas lie close to each other creating an isthmus--a macroreentry arrhythmia substrate. This work was inspired by a clinical hypothesis that the size of the border zone corresponds to the rate of occurrence of ventricular arrhythmia in patients after myocardial infarction.

[Surgical treatment of aortic valve disease in patients with severe left ventricular failure]. / Leczenie operacyjne wady lewego ujscia tetniczego u chorych z zaawansowana niewydolnoscia lewej komory.

Two patients with aortic stenosis and severe left ventricle failure who underwent aortic valve replacement with satisfactory outcome were presented. Case report.