European survey on efficacy and safety of duty-cycled radiofrequency ablation for atrial fibrillation.

AIMS: Duty-cycled radiofrequency ablation (RFA) has been used for atrial fibrillation (AF) for around 5 years, but large-scale data are scarce. The purpose of this survey was to report the outcome of the technique. METHODS AND RESULTS: A survey was conducted among 20 centres from seven European countries including 2748 patients (2128 with paroxysmal and 620 with persistent AF). In paroxysmal AF an overall success rate of 82% [median 80%, interquartile range (IQR) 74-90%], a first procedure success rate of 72% [median 74% (IQR 59-83%)], and a success of antiarrhythmic medication of 59% [median 60% (IQR 39-72%)] was reported. In persistent AF, success rates were significantly lower with 70% [median 74% (IQR 60-92%)]; P = 0.05) as well as the first procedure success rate of 58% [median 55% (IQR 47-81%)]; P = 0.001). The overall success rate was similar among higher and lower volume centres and were not dependent on the duration of experience with duty-cycled RFA (r = -0.08, P = 0.72). Complications were observed in 108 (3.9%) patients, including 31 (1.1%) with symptomatic transient ischaemic attack or stroke, which had the same incidence in paroxysmal and persistent AF (1.1 vs. 1.1%) and was unrelated to the case load (r = 0.24, P = 0.15), bridging anticoagulation to low molecular heparin, routine administration of heparin over the long sheath, whether a transoesophageal echocardiogram was performed in every patient or not and average procedure times. CONCLUSION: Duty-cycled RFA has a self-reported success and complication rate similar to conventional RFA. After technical modifications a prospective registry with controlled data monitoring should be conducted to assess outcome.

The left bundle branch block revised with novel imaging modalities.

Left bundle branch block (LBBB) is related to abnormal cardiac conduction and mechanical asynchrony and is associated with hypertension and coronary artery disease. Improved evaluation of left ventricular (LV) mechanical asynchrony is needed, because of the increasing number of patients with LBBB and heart failure. In this paper, we describe tissue Doppler imaging (TDI), strain (rate) imaging and tissue tracking in LBBB patients. A variety of patterns of mechanical activation can be observed in LBBB patients. A recent development, referred to as tissue synchronisation imaging, colour codes TDI time-to-peak systolic velocities of segments and displays mechanical asynchrony. Furthermore, real-time 3D echocardiography provides new regional information about mechanical asynchrony. Contained in an LV model and projected on a bull's eye plot, this modality helps to display the spatial distribution of mechanical asynchrony. Finally, segmental time-to-peak circumferential strain curves, produced by cardiac magnetic resonance imaging, provide additional quantification of LV mechanical asynchrony. Effects of LBBB on regional and global cardiac function are impressive, myocardial involvement seems to play a role and with the help of these novel imaging modalities, new insights continue to develop.

Distribution of renal lesions in idiopathic systemic vasculitis: A three-dimensional analysis of 87 glomeruli.

Extracapillary proliferation and fibrinoid necrosis are the main diagnostic glomerular lesions in renal biopsy specimens of patients with idiopathic systemic vasculitis. Neither the incidence nor the correlation between extracapillary proliferation and fibrinoid necrosis in renal biopsy specimens from patients with systemic vasculitis has been systematically evaluated. By means of a three-dimensional analysis, we made a topographic reconstruction of the distribution of extracapillary proliferation and fibrinoid necrosis in affected glomeruli and tested different biopsy-processing protocols to optimize histopathologic analysis in clinical practice. Paraffin blocks of renal biopsy specimens from six patients diagnosed with systemic vasculitis were completely and serially sectioned in 2-microm thick sections and stained with the Gomori trichrome method. Glomeruli were scored per section for the presence of fibrinoid necrosis and extracapillary proliferation. Subsequently, a three-dimensional reconstruction was obtained for 87 glomeruli. In only one glomerulus did fibrinoid necrosis occur without extracapillary proliferation; in 51%, a combination of the two lesions was found; in 22%, extracapillary proliferation occurred in the absence of fibrinoid necrosis; and 26% did not show either lesion. Using the standard protocol from our department (ie, evaluation of 20 consecutive sections in various stainings), the chance of finding extracapillary proliferation was 100% and that of finding fibrinoid necrosis was 73%. If 5 sections stained with the Gomori trichrome were added, the latter percentage increased to 86%. Using skip-serial sections, even better results (87% to 92%) were obtained, with four skips as the best option (92%). In conclusion, our finding that fibrinoid necrosis rarely occurs in the absence of extracapillary proliferation may imply that both lesions are etiologically related. In addition, our observations indicate that the incidence of fibrinoid necrosis may be underestimated in clinical practice, depending on the number of sections evaluated.