Włodzimierz Kargul

A User‐Friendly Method of Cardiac Venous System Visualization in 64‐Slice Computed Tomography

Background: Previsualization of the cardiac venous system is very important for some techniques, for example, cardiac resynchronization therapy (CRT). The aim of this study was to propose a new, user‐friendly method of cardiac venous system visualization in 64‐slice computed tomography (CT).

Totally epicardial cardiac resynchronization therapy system implantation in patients with heart failure undergoing CABG

Systolic dyssynchrony is present in a considerable number of patients with heart failure (HF) undergoing coronary artery bypass grafting (CABG). Surgical revascularization offers an optimal setting for totally epicardial cardiac resynchronization therapy (CRT) system implantation.

Rough set techniques for medical diagnosis systems

The process of discovering natural phenomena or complex system was until recently limited to finding formulas that fit empirical data. This process used with success in science and engineering has its limits when the complexity of the natural processes increases. Therefore, to analyze data in the medical domain an alternative approach was needed. Several mathematical methods including neural nets, inductive learning fuzzy sets and rough sets were proposed to model data in the form of decision tables or rules. Pawlaks rough sets theory for handling imprecision and uncertainty in data has a main advantage over the other techniques which is the possibility to analyze data without any preliminary information what favor its usage in medical decision systems. In this paper we present the results of rule generation from our implementation of the LEM2 algorithm on reduced sets of attributes calculated using the Wrapper method with different learning algorithms

Lead Interaction: Rare Cause of Oversensing During Implantation Procedure of Implantable Cardioverter‐Defibrillator System

A variety of etiologies can cause erroneous detection in patients with implantable cardioverter defibrillator (ICDs). Interaction between two endocardial leads is rare and uncommon in causing electrical noise. During a reimplantation procedure of an ICD system in a 68‐year‐old man, additional electrical signals could be detected. The interaction between two endocardial defibrillation leads was identified as the cause of sensing problems. When it is not possible to extract the nonfunctional endocardial lead during implantation of the new electrode, it should be implanted away and not in parallel from the old one to avoid interaction between them. A variety of etiologies can cause erroneous detection in patiens with ICD. Interaction between two endocardial leads is rare and uncommon to cause electrical noise.

Automated decision support and guideline verification in clinical practice

Applying international guidelines in medical, including cardiological, therapies is a guarantee of safe and modern treatment. Unfortunately, standards are often not obeyed. In this paper we present an experimental software program based on rough sets methods. The main aim of this application is to improve patient care and help the decision process using guidelines verification. We concentrate on the practical aspects using these methods. Examples and clinical tests, which were based on real-life data of our patients, show that the accuracy of results reached on a large group of patients could be acceptable in clinical practice

The presence of endocardial leads may limit applicability of coronary CT angiography.

Abstract Objectives. Some indications that MSCT is necessary may be visible in patients with implanted pacemakers, CRTs and ICDs devices. Purpose. To evaluate whether the presence of endocardial leads influences the quality of visualization of the coronary arteries in MSCT. Design. In 37 patients a 64-slice MSCT (Aquilion 64, Toshiba) was performed due to a suspicion of ischemic heart disease (33 patients) or suspicion of lead perforation (four patients). The control group consists of 35 patients. Influence of the leads was evaluated independently by two cardiologists. Results. The total number of leads that were evaluated was 63. In 26 cases (41%) significant problems with the evaluation of coronary arteries occurred: LM–1 (2%) case, LAD–3 (5%) cases, LCx–4 (6%) cases, RCA–18 (28%) cases. The presence of a right ventricular lead did not influence the quality of the imaging of the left main coronary artery (LM) and its main branches (LAD and LCx). The main concerns were related to the RCA visualization–interpretable images in 18/63 (29%) of the analyzed leads. Conclusions. The presence of implanted endocardial leads may limit the applicability of coronary CT angiography in patients with implanted anti-arrhythmic devices.

Influence of DDD rate response pacing with integrated double sensors on physical efficiency and quality of life

AIMS The aim of this study was to evaluate whether the use of a double sensor gives additional benefits for patients in improving physical efficiency as well as quality of life (QoL) as compared to the accelerometer sensor alone. METHODS AND RESULTS The presented research is a prospective, randomized, single-blind clinical trial. Double-sensor (accelerometer and minute-ventilation) pacemakers (Guidant, Pulsar Max DR) were implanted in 20 patients with sinus node dysfunction (SND) and chronotropic incompetence. After randomization, patients were placed in one of two groups: 1, only the accelerometer sensor was activated; 2, both sensors were activated. After a 3-month follow-up, an initial cardio-pulmonary exercise test was performed, after which the patients were placed in the opposite group for a further 3 months. Finally, the second tests were performed. In 75% of the patients an improvement in QoL was observed in the double-sensor group (P = 0.0242) when compared with the single-sensor group. The addition of a ventilating sensor had no influence on the duration of exercise test (A: 11 +/- 3.19 vs. B: 11 +/- 2.92 P = 1.0000). The parameters of cardio-pulmonary exercise tests recorded in situations A and B before exertion, and 6 minutes after exertion were not statistically different. CONCLUSION The use of double-sensor pacemakers does not improve physical efficiency; however, it does improve QoL.

Visualization of decision rules - from the cardiologist’s point of view

A lot of decision systems work internally using different forms of decision rules. In our experiments on large medical datasets, we found that when the number of conditions in a decision rule increases and the overall number of rules is greater than 20-50, it is really difficult to analyze and manage the stored knowledge. Our research concentrated on two methods of the visualization of decision rules: decision trees (AQDT-2 algorithm) and the so-called rule-diagrams, which present conditional parts of decision rules in a 3D matrix (2D layers are stacked in 3D cube). Experts agreed that decision trees present an attractive possibility of data visualization for small sets of rules (up to 100). They are intuitively understandable and with our own extensions, they provide a quick method for checking several what-if scenarios. For larger sets of rules (more then 100) rule-diagrams are definitely the better methods for analyzing patterns within data.

How decision system trained on a large database recognizes new cases - prelude before clinical implementation

In the research presented here, a joint team (cardiologists and software specialists) focused on the evaluation of previously created, multi-stage decision systems trained on real clinical data. The question is how a decision system trained on a large database recognizes new cases remains unanswered? Obtained results seem to confirm that decision systems trained on a large dataset works well on new data - which may confirm its usefulness in clinical practice. An acceptable level of accuracy for doctorspsila decisions was achieved. For more specialist areas (like pacemakers implantation) where strict guidelines are available, the accuracy was higher.

CRT39: TRIPLE-SITE BIVENTRICULAR STIMULATON IN PATIENT WITH CLINICALLY UNSUCCESSFUL RIGHT VENTRICULAR BIFOCAL STIMULATION–CASE REPORT

We report on a patient in whom we first implanted VVI bifocal (RVA+ RVOT) system and soon had to upgrade do biventricular (BiV) system since bifocal pacing turned to be hemodynamically insufficient. 63-yrs old male with postinfarction cardiomyopathy NYHA III, chronic atrial fibrillation, LBBB, LVEF 15%, assigned to BiV pacing was implanted with VVI pacemaker with RV bifocal stimulation because of LV lead implant failure (coronary sinus dissection, intraoperational dislodgement of lead from CS). Initially we observed certain improvement of symptoms during bifocal RV pacing, but after 3 months he returned with clinical worsening-NYHA III/IV despite optimal drug therapy, and signs of liver function impairment and BNP level 3290 fmol/l (N<250 fmol/l). Another attempt to place CS lead was successful and triple-site ventricular (TiV) pacing was applied. After3 months of follow-up significant clinical improvement is observed. Echocardiographic results are summarized in the table below View this table: Conclusion Right ventricular bifocal pacing considered as an alternative in the case of BiV system implantation failure in this case was not sufficient. Triple site biventricular stimulation provided additional benefit to BiV pacing.