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The assessment of defibrillation energy requirement (DER) is a standard practice during cardioverter-defibrillator (ICD) implantation. It is recommended to assure that the energy at least 10 J below the maximal energy deliverable by the implanted device successfully converts the induced ventricular fibrillation (VF). The cardiac resynchronisation therapy with defibrillator (CRT-D) recipients are at increased risk of developing serious complications due to repeated VF induction.To define the prevalence of high DER among CRT-D recipients and to determine the factors which allow to obtain defibrillation safety margin.We examined all patients who underwent CRT-D implantation between June 2006 and June 2009 in our institution. The verification of the DER required at least one termination of the induced VF with the energy at least 10 J below the maximal energy deliverable by the implanted device.The CRT-D was implanted in 65 patients. The first defibrillation test was successful in 57 (88%) patients. In the remaining 8 patients (12%), the defibrillation test was unsuccessful. These patients required system revision: reprogramming shocking polarity (2), reversing polarity and adjusting waveform (3), lead repositioning (1) and adding a subcutaneous lead (2). The use of high output devices (maximal energy30 J) and dual-coil leads was associated with a significantly (p0.05) lower rate of high DER, although high DER occurred in one patient implanted with the high output device. There was a correlation between the probability of successful defibrillation and renal function. It was less likely to obtain successful defibrillation safety margin in patients with creatinine175 micromol/L. During the follow up, ventricular tachyarrhythmia detected in the VF detection zone occurred in 13 (20%) patients, including two patients, who required system modification during implantation. In both cases, VF was terminated by the first defibrillation with the maximal energy of the implanted devices.High DER occurred in a significant number of CRT-D recipients. There is a correlation between high DER and impaired renal function. The use of high output devices significantly decreases the number of patients who required system modification in order to obtain an adequate defibrillation safety margin.

Double counting of ventricular beats is not only one of the cause of an inappropriate detection of ventricular arrhythmias but a reason of lost of resynchronisation therapy. Sensing disturbances often creates the need for reprogramming of the device or additional pharmacotherapy and procedures. We present a case of 76-year-old man with CRT-D and inappropriate detection and intervention due to ventricular bigeminy. Fortunately, change of device program, potassium and magnesium supplementation was successful, without necessity of RF ablation of the ventricular ectopic beats.

Renal function assessment is an important element of management and therapeutic decision-making in patients with chronic heart failure (CHF).To evaluate the prognostic value of renal dysfunction in patients with CHF in 12-month follow-up.639 consecutive patients hospitalised in our department from 1 July 2002 to 31 December 2003 with diagnosis of CHF (NYHA II-IV), based on medical records, were initially enrolled in the study. Patients underwent one-year follow-up. Finally, 498 patients, aged 22-98 years (mean age 69+/-12 years) in whom creatinine concentration was measured and creatinine clearance was estimated at admission with the Cockroft-Gault quotation and with long-term follow-up results obtained, were enrolled in the study. Patients were divided into two groups according to the creatinine level: Group I without renal dysfunction (creatinine level1.4 mg/dl), and Group II--with renal dysfunction (creatinine level1.4 mg/dl).Patients with renal dysfunction were significantly older and more likely to be male and in NYHA class III-IV (p0.001). Analysis of pharmacotherapy for CHF revealed that patients with renal impairment significantly less frequently received beta-blockers (67% vs 81%, p0.005), angiotensin-converting enzyme inhibitors (68% vs 82%, p0.005) and combined treatment of beta-blocker and angiotensin-converting enzyme inhibitor (56% vs 71%, p0.05), whereas loop diuretics were more frequently prescribed in this group (80% vs 70%, p0.05). In patients with renal dysfunction, there was a significantly higher mortality rate at 30 days (32% vs 14%, p0.001) as well as at 12 months (45% vs 20%, p0.001). The incidence of re-hospitalisation for cardiovascular reasons (CHF worsening, myocardial infarction, stroke) was significantly higher in patients with renal dysfunction (70% vs 55%, p0.005). Multivariate analysis of all factors affecting one-year mortality demonstrated that renal dysfunction is a strong and independent risk factor for death in patients with CHF (RR=2.13, 95% CI: 1.31-3.45; p0.05) and it increases the risk of re-hospitalisation (RR=1.53, 95% CI: 1.01-2.14; p0.05).Renal dysfunction is an independent prognostic factor in patients with CHF, which allows identification of a high-risk group and administration of optimal therapy, which in turn can result in a reduction of mortality.