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The short- and long-term efficacy of oral encainide was studied in 14 patients with chronic high-frequency ventricular arrhythmias and in 14 patients with chronic frequent episodes of non-sustained ventricular tachycardia (NSVT). Encainide efficacy was assessed during a dose–titration perios and in a 36-month follow-up alos studying the drug effects on routine haematologic data and left ventricular function (LVF). During does–litration, encainide caused a 78.3% decrease in the average hourly frequency of isolated PVC and a 96.1% reduction in NSVT episodes in the two groups pf patients. On follow-up (11 patients in each group) the mean percentage redutions were 95.1% in isolated PVC and 99.7% in NSVT episodes. Encainide did not impair LVF as showed by the comparision of echocardiographic fractional shortening before and after 12 months of treatment. Minor adverse effects of encainide were dose-related visual disturbances in two patients. A major adverse effect was the apperance of sustained VT in one NYHA class IV patient. Oral encainide effectively reduces the frequency of PVC and NSVT, it does not impair left ventricular function and it is associated with infrequent minor side effects. Uncommon, but severe, side effects may appear in patients with marked impairment of left ventricular function. [ABSTRACT FROM PUBLISHER]

Background: Riata (RT) and Sprint Fidelis (SF) leads were recalled by the United States Food and Drug Administration because of an increased rate of failure mainly due to conductor fracture or insulation abrasion. According to lead design and type of failure, extraction complexity may be different, potentially affecting procedural outcomes and indications., Objective: The purpose of this study was to assess the extraction profile of RT leads with and without cable externalization in comparison to SF leads., Methods: From January 1997 to April 2014, all consecutive RT and SF leads extracted transvenously were analyzed. Among 661 consecutive patients with 705 ventricular implantable cardioverter-defibrillator (ICD) leads extracted, 194 patients with 134 RT leads (RT group) and 61 SF leads (SF group) were identified. Removal indications often were infective (64%), and extracted leads had a prevalence of dual-coil design (89%). Baseline patients and lead characteristics were comparable between groups., Results: Success rate was high in both groups (97.8% RT vs 100% SF) without major complications. Mechanical dilation was comparable between groups, but RT leads often required larger sheaths (11.7 ± 1.4 vs 11.3 ± 1.4), a more frequent crossover to the internal transjugular approach (14% vs 3%), and a longer procedural time (23 ± 33 minutes vs 12 ± 16 minutes). Implantation time (odds ratio 4.84, 95% confidence interval 1.05-22.2, P = .042) and RT leads (odds ratio 1.04, 95% confidence interval 1.02-1.06, P <.001) were independent predictors of the internal transjugular approach., Conclusion: Extraction of RT leads is feasible and effective. However, extraction of RT leads is more complex than that of SF leads. Lack of coil backfilling and cable externalization in RT group may account for these differences., (Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

The implantable cardioverter defibrillator is today an indisputable evidence-based treatment for cardiac sudden death both in primary and secondary prevention. However, trans-venous cardioverter defibrillator implantation still carries a not negligible risk of complications both acutely and during follow-up. Trans-venous endocardial lead is the weak link of implantable cardioverter defibrillator (ICD) technology being the source of most mechanical complications on vessels and heart structures and exposed to infection, malfunction and recalls. A totally subcutaneous defibrillation lead has recently been introduced in clinical practice. With the subcutaneous pulse generator forms a defibrillation system that leaves the vessels and the heart completely "untouched." Subcutaneous ICD has proven to be safe and effective in many clinical trials. Patients without pacing indications and at higher risk of complications from trans-venous lead implantation represent the perfect candidates to S-ICD technology. However, with technical improvement, it is reasonable to expect a further expansion of indications.

Background: Intravascular ultrasound imaging provides information on vascular lumen and arterial wall structure and it has potential application in arterial wall dynamic study. The aim of this study was to develop a computer assisted system for analysing digitised cross sectional ultrasound images of coronaries to easily display and quantify coronary dynamic and its relationship with arterial wall morphology., Methods and Results: To extract the anatomical regions of interest from the digitised sonograms, automatic image segmentation and interactive procedures for manual correction were implemented. This step included the recognition of the lumen edge and an analysis of gray level intensity of the wall. Subsequently, a virtual 3D reconstruction of lumen and vessel wall was done in a Cartesian system where the XY plane was parallel to each cross-sectional sonogram, while the Z axis corresponded to the acquisition time. The baricentre of vascular lumen was used as a reference for alignment. We obtained a cylinder-like solid representing the behavior of the arterial cross-sectional sonogram in time, with the possibility to look either at the wall or at the lumen. In this virtual solid it was possible to measure the variation of lumen area and of 16 hemidiameters; in addition, the derivatives of these values, allowing an estimate of the velocity of events, can be obtained., Conclusions: The described computerised system for the analysis of intravascular ultrasound images could become a very useful tool for 3D representation and quantitative monitoring of coronary compliance and their relationship with segmental arterial wall morphology.

One of the most important problems in rate responsive (RR) pacing is the clinical experimental evaluation of the reliability of various sensors. In particular, it is difficult to test their sensitivity and specificity during daily activity of the patients. Atrial rate, when present and normal, is the most physiological marker of metabolic requirements, but sometimes it is impossible to analyze the P wave in ventricular paced rhythm during routinely performed tests (e.g., ergometric test and 24-hour Holter monitoring). During various physical activities, we monitored atrial electrograms on an esophageal lead on the first channel of a standard Holter tape recorder; on the second channel a surface ECG lead was recorded. We selected 10 patients with high grade heart block and normal sinus node function paced in RR-VVI mode. RR pacing was obtained using various sensors (body activity, blood temperature, spike-T interval, minute ventilation). The good quality of recording allowed an easy evaluation of atrial and ventricular rates. In four cases an appropriate increase in heart rate was documented; sensitivity threshold and/or rate response slope were reprogrammed when indicated. The pacing rate of one patient did not parallel the atrial rate during walking only. In three cases, we observed a delay in the ventricular rate increase, with ventricular rate decreasing at peak exercise despite further atrial rate increase. In the last two patients, we observed inappropriate pacing response; pacing rate increased later and to a lower level than the atrial one. This new method is applied easily and appears reliable to evaluate the response of RR pacemakers to individual metabolic needs.(ABSTRACT TRUNCATED AT 250 WORDS)

The development of a reliable system for analysis of ambulatory ECG recordings, for evaluation of arrhythmias and ST-T segment changes is a great challenge for technology and cardiovascular medicine. Signal superimposition or AVSEP system, conceived by Norman J. Holter, has been widely used and is employed even in recent sophisticated devices for analysis of ambulatory ECG recordings. As an alternative way we have chosen contourography, known since 1966, enhanced by a dynamic and perspective effect (Fig. 1). Figure 2 shows the display mechanism of the ECG signal. Cardiac cycles are continuously sampled, triggered and positioned along the running time axis. The QRS complexes undergo progressive amplitude decrease while "sliding" toward a viewpoint adjustable by the operator (Fig. 3). As memory contains a fixed number of cycles, the latest cycle enters the screen while the oldest falls out. Instead of being superimposed as in AVSEP system, cardiac cycles are displayed separately. In this way it is possible to make comparisons between one cycle and another or among different areas of the ECG tracing. At any instant, the tracing can be stopped, and an intensified area of interest can be recorded on a paper strip in a standard fashion (Fig. 4). A clinical comparison has been performed between this device and two different commercial systems; 25 tapes, 24 hours each, have been separately analyzed by two cardiologists with the Avionics system and 25 with the Pathfinder, and then with the new system. Each operator was not aware of the results of the other one.(ABSTRACT TRUNCATED AT 250 WORDS)