Multicentre early experience with totally subcutaneous cardioverter-defibrillators in Poland.

INTRODUCTION: Implantable cardioverter-defibrillators (ICD) have a strong position in the prevention of sudden death. Nowadays, the most commonly used high-energy cardiac devices are transvenous ICDs. A new technology of totally subcutaneous ICDs (S-ICD) was invented and recently introduced into clinical practice in order to reduce lead-related complications of conventional ICDs. The aim of this paper is to present early experience with this new technology implemented in a few centres in Poland. MATERIAL AND METHODS: Medical records of patients who had S-ICD-related interventions in Poland were retrospectively analysed. RESULTS: During the first year of S-ICD introduction into the Polish health system 18 patients underwent surgery connected with S-ICDs. Majority of them (17 patients) were implanted de novo. In one patient surgical revision of a device implanted abroad was performed. Most of patients (78%) had S-ICDs implanted for secondary prevention. Inability of transvenous system implantation due to venous access obstruction or high risk of infection related with transvenous leads accounted for 83% of indications for S-ICD. Only in three patients were S-ICDs implanted due to young age and active mode of life. The implantations of S-ICDs were performed without important early or late complications. During follow-up one patient had episodes of ventricular arrhythmia successfully terminated with high-energy shocks. One patient died due to progression of heart failure. CONCLUSIONS: S-ICD implantation procedure has been successfully and safely introduced in Polish clinical routine. Nevertheless, despite clear indications in recent ESC guidelines, this therapy is not directly reimbursed in Poland and needs individual application for refund.

Implantation of a dual-chamber pacemaker with epicardial leads in adults using a minimally invasive subxyphoid approach.

BACKGROUND: Implantation of transvenous pacemaker systems is a standard method used to treat patients with bradycardia. There are some clinical settings in which that method cannot be used despite existing indications (such as developmental defects of the cardiovascular system and limited venous access or infections). In such cases, an epicardial pacing system may be implanted with cardiac surgery techniques, at a cost of certain surgical risks. The least invasive approach is subxyphoid, but it traditionally allows to place only a ventricular lead and achieve a single-chamber VVI pacing system. AIM: The aim of our study was to determine the feasibility of subxyphoid implantation of dual-chamber pacing systems using thoracoscopic tools, as well as to and examine the short- and mid-term outcomes of such procedures. METHODS: Patients were qualified for an epicardial pacemaker system in case of absolute indications for permanent pacing therapy and coexisting contraindications for a transvenous system. DDD systems were implanted in 10 consecutive patients, in general anesthesia, in a cardiac surgery operating room, using subxyphoid access to pericardial space and a standard set of minimally invasive thoracoscopic tools. RESULTS: Implantation of a dual-chamber pacing system using the above approach was successful in all attempts. No serious complications were observed. Pacing and sensing parameters were appropriate at implantation and remained such during the follow-up of 2-27 months. CONCLUSION: Implantation of a dual-chamber pacing system using a minimally invasive subxyphoid approach is feasible. Appropriate pacing and sensing values may be obtained and they remain stable during follow-up.

Complexity of cardiovascular rhythms during head-up tilt test by entropy of patterns.

OBJECTIVE: The head-up tilt (HUT) test, which provokes transient dynamical alterations in the regulation of cardiovascular system, provides insights into complex organization of this system. Based on signals with heart period intervals (RR-intervals) and/or systolic blood pressure (SBP), differences in the cardiovascular regulation between vasovagal patients (VVS) and the healthy people group (CG) are investigated. APPROACH: Short-term relations among signal data represented symbolically by three-beat patterns allow to qualify and quantify the complexity of the cardiovascular regulation by Shannon entropy. Four types of patterns: permutation, ordinal, deterministic and dynamical, are used, and different resolutions of signal values in the the symbolization are applied in order to verify how entropy of patterns depends on a way in which values of signals are preprocessed. MAIN RESULTS: At rest, in the physiologically important signal resolution ranges, independently of the type of patterns used in estimates, the complexity of SBP signals in VVS is different from the complexity found in CG. Entropy of VVS is higher than CG what could be interpreted as substantial presence of noisy ingredients in SBP of VVS. After tilting this relation switches. Entropy of CG occurs significantly higher than VVS for SBP signals. In the case of RR-intervals and large resolutions, the complexity after the tilt becomes reduced when compared to the complexity of RR-intervals at rest for both groups. However, in the case of VVS patients this reduction is significantly stronger than in CG. SIGNIFICANCE: Our observations about opposite switches in entropy between CG and VVS might support a hypothesis that baroreflex in VVS affects stronger the heart rate because of the inefficient regulation (possibly impaired local vascular tone alternations) of the blood pressure.