The incidence of cardiac perforation related to pacing and defibrillation leads is low. The use of active fixation leads is associated with an increased risk of cardiac perforation. We did not find any correlation between the perforation rate and any particular model of the implanted lead.

ICD therapy is effective in SCD prevention in patients with HCM, although the complication rate is significant. Nonsustained ventricular tachycardia seems to be the most predictive RF for appropriate device discharges. Number of RF did not impact the incidence of appropriate ICD interventions.

Background-Slowed or delayed myocardial activation and dispersed refractoriness predispose to reentrant excitation that may lead to ventricular fibrillation (VF). Increased ventricular electrogram duration (⌬ED) in response to extrastimuli and increased S1S2 coupling intervals at which electrogram duration starts to increase (S1S2 delay ) are seen both in hypertrophic cardiomyopathy (HCM) in those at risk of VF and in patients with idiopathic VF (IVF). Methods and Results-⌬ED and S1S2 delay have been measured using paced electrogram fractionation analysis in 266 patients with noncoronary heart disease. Of these, one group of 61 patients had a history of VF and included 21 HCM, 17 IVF, 13 long-QT syndrome (LQTS), 5 dilated cardiomyopathy (DCM), and 5 others. These were compared with 205 patients with similar diseases with no VF history (non-VF group) and a control group (nϭ12) without heart disease.Results from HCM VF patients (⌬ED, 19Ϯ3.3 ms; S1S2 delay , 350Ϯ9.7 ms) differed sharply from observations in HCM non-VF patients (⌬ED, 7.3Ϯ1.35 ms; S1S2 delay , 312Ϯ6.7 ms; PϽ0.001). DCM VF patients had longer delays (⌬ED, 14.3Ϯ5.9; S1S2 delay , 344Ϯ11.2) than DCM non-VF patients (⌬ED, 5.8Ϯ1.87 ms; S1S2 delay , 311Ϯ5.7 ms; PϽ0.001), with major differences also seen comparing LQTS VF (⌬ED, 12.4Ϯ5.3 ms; S1S2 delay , 343Ϯ13.8 ms) and LQTS non-VF patients (⌬ED, 11.0Ϯ2.7 ms; S1S2 delay , 320Ϯ5.4 ms; PϽ0.001). IVF patients had both severely abnormal and normal areas of myocardium. Conclusions-Slowed or delayed myocardial activation is a common feature in patients with noncoronary heart disease with a history of VF, and its assessment may allow the prospective prediction of VF risk in these patients. Key Words: death, sudden Ⅲ electrophysiology Ⅲ cardiomyopathy Ⅲ long-QT syndrome N oncoronary heart disease altering myocardial structure or function predisposes to ventricular fibrillation (VF) and sudden cardiac death (SCD). 1-3 SCD can be prevented by prophylactic implantable cardioverter-defibrillators (ICDs), 4 and consequently the identification of patients at high risk of SCD is an important goal of clinical cardiology. 5,6 Methods for the precise identification of patients at risk of SCD, which might provide a basis for electrophysiological indicators of risk, do not yet exist, 1,2 a situation that partly arises from our poor understanding of the mechanisms that predispose to VF. 7 The initiation of reentrant tachyarrhythmias, such as macroreentrant ventricular tachycardia in patients with coronary artery disease, is known to require one or more areas of slowed conduction and activation block. 8,9 Such anatomical substrates can be demonstrated by following the activation sequence during sustained tachycardia or deduced by observing the pattern of responses to the delivery of extrastimuli. 8 -10 VF is also thought to be a reentrant tachyarrhythmia 7 ; however, it has no specific anatomical basis and so investigations directed to the identification of a functional substrate and the prediction of the risk of VF are likely ...

Intravenous antazoline was effective and safe in the rapid conversion of non-valvular paroxysmal atrial fibrillation to sinus rhythm in patients without heart failure. Clinical Trial Registration number: NCT01527279.

Comparison of PAF and non-AF patient groups showed that intra-atrial conduction delay start in the PAF group earlier (with longer S1S2 intervals) and they are significantly longer in the PAF group. This suggests that atria in patients with PAF are diffusely diseased and that the measured activation delays form one component of an arrhythmogenic substrate.

No abstract

No abstract

PEFA identifies HCM patients at risk of SCD with greater accuracy than non-invasive techniques and may have an important role in determining indications for ICD prescription.