The purpose of the study was to analyze the factors that favor the occurrence of sustained monomorphic ventricular tachycardia in the early phase (<48 h) of acute myocardial infarction and to ...establish its prognostic implications.
Sustained monomorphic ventricular tachycardia early in the course of an acute myocardial infarction is an uncommon arrhythmia, and its significance has not been specifically studied.
The clinical characteristics and prognosis of sustained monomorphic ventricular tachycardia were studied in 21 (1.9%) of 1,120 consecutive patients admitted to the coronary care unit with a diagnosis of myocardial infarction.
Patients with sustained monomorphic ventricular tachycardia had a larger infarct on the basis of peak creatine kinase, MB fraction (CK-MB) isoenzyme activity (435 ± 253 IU/liter vs. 168 ± 145 IU/liter, p < 0.001) and higher mortality rate (43% vs. 11%, p < 0.001). By logistic regression analysis, independent predictors of sustained monomorphic ventricular tachycardia were CK-MB (odds ratio OR 11.8), Killip class (OR 4.0) and bifascicular bundle branch block (OR 3.1). Moreover, sustained monomorphic ventricular tachycardia was itself an independent predictor of mortality (OR 5.0). Compared with patients with ventricular fibrillation, those with sustained mono-morphic ventricular tachycardia had a worse Killip class (Killip class > I: 63% vs. 30%, p < 0.05), higher CK-MB activity (430 ± 260 IU/liter vs. 242 ± 176 IU/liter, p < 0.01) and higher arrhythmia recurrence rate (31% vs. 4%, p < 0.01). During the follow-up period, 5 (42%) of 12 survivors in the sustained monomorphic ventricular tachycardia group died of cardiac-related causes. Recurrence of ventricular tachycardia was seen in two patients (17%).
Sustained monomorphic ventricular tachycardia during the first 48 h of myocardial infarction is a sign of extensive myocardial damage and an independent predictor of in-hospital mortality.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Electrocardiographic Imaging (ECGI) allows computing the electrical activity in the epicardium by inverting the electrical propagation matrix, which can be solved by regularizing this ill-posed ...problem. The objective of this study is to evaluate the effects of noise on the signals in the selection of the regularization parameter (\lambda) by zero-order Tikhonov and L-curve optimization. Fourteen atrial fibrillation (AF) simulations were used for computing the ECGI with different noise levels (3, 10, 20, 30, and 40dB). Signals of real cardiac rhythms were also used to compute the ECGI(3\ AF, 2 atrial flutters, 3 atrial pacing, 3 atrial sinus rhythm and 3 ventricular tachycardia). For simulations and patients, maximum L-curve curvature and \lambda were obtained and compared. The maximum curvature of the L-curve, noise level and optimal \lambda correlated for {A}F simulations. Higher levels of noise resulted in smaller curvatures of the L-curve and the selection of higher values of\ \lambda , reducing the amplification of noise when computing ECGI. Real cardiac signals of AF presented similar results in curvature and \lambda as the higher values of noise explored in simulations (3dB, \lambda > 10^{-6} , curvature < 1 ). The noise of the signal proportionally affects to the reconstruction of ECGI. The given results show a methodology to obtain trustable ECGI maps based on the shape of the L-curve optimization.
A partial delineation of targets for ablation of ventricular tachycardia (VT) during a stable rhythm is likely responsible for a suboptimal success rate. The abnormal low-voltage near-field ...functional components may be hidden within the high-amplitude far-field signal.
The aim of this study was to evaluate the benefit and feasibility of functional substrate mapping using a full-ventricle S3 protocol and to assess its colocalization with arrhythmogenic conducting channels (CCs) on late gadolinium enhancement cardiac magnetic resonance.
An S3 mapping protocol with a drive train of S1 followed by S2 (effective refractory period + 30 ms) and S3 (effective refractory period + 50 ms) from the right ventricular apex was performed in 40 consecutive patients undergoing scar-related VT ablation. Deceleration zones (DZs) and areas of late potentials (LPs) were identified for all maps. A preprocedural noninvasive substrate assessment was done using late gadolinium enhancement cardiac magnetic resonance and postprocessing with automated CC identification.
The S3 protocol was completed in 34 of the 40 procedures (85.0%). The S3 protocol enhanced the identification of VT isthmus on the basis of DZ (89% vs 62%; P < 0.01) and LP (93% vs 78%; P = 0.04) assessment. The percentage of CCs unmasked by DZs and LPs using S3 maps was significantly higher than the ones using S2 and S1 maps (78%, 65%, and 48% P < 0.001 and 88%, 81%, and 68% P < 0.01, respectively). The functional substrate identified during S3 activation mapping was significantly more extensive than the one identified using S2 and S1, including a greater number of DZs (2.94, 2.47, and 1.82, respectively; P < 0.001) and a wider area of LPs (44.1, 38.2, and 29.4 cm
, respectively; P < 0.001). After VT ablation, 77.9% of patients have been VT free during a median follow-up period of 13.6 months.
The S3 protocol was feasible in 85% of patients, allows a better identification of targets for ablation, and might improve VT ablation results.
A partial delineation of targets for ablation of ventricular tachycardia (VT) during a stable rhythm is likely responsible for a suboptimal success rate. The abnormal low-voltage near-field ...functional components may be hidden within the high-amplitude far-field signal.
The aim of this study was to evaluate the benefit and feasibility of functional substrate mapping using a full-ventricle S3 protocol and to assess its colocalization with arrhythmogenic conducting channels (CCs) on late gadolinium enhancement cardiac magnetic resonance.
An S3 mapping protocol with a drive train of S1 followed by S2 (effective refractory period + 30 ms) and S3 (effective refractory period + 50 ms) from the right ventricular apex was performed in 40 consecutive patients undergoing scar-related VT ablation. Deceleration zones (DZs) and areas of late potentials (LPs) were identified for all maps. A preprocedural noninvasive substrate assessment was done using late gadolinium enhancement cardiac magnetic resonance and postprocessing with automated CC identification.
The S3 protocol was completed in 34 of the 40 procedures (85.0%). The S3 protocol enhanced the identification of VT isthmus on the basis of DZ (89% vs 62%; P < 0.01) and LP (93% vs 78%; P = 0.04) assessment. The percentage of CCs unmasked by DZs and LPs using S3 maps was significantly higher than the ones using S2 and S1 maps (78%, 65%, and 48% P < 0.001 and 88%, 81%, and 68% P < 0.01, respectively). The functional substrate identified during S3 activation mapping was significantly more extensive than the one identified using S2 and S1, including a greater number of DZs (2.94, 2.47, and 1.82, respectively; P < 0.001) and a wider area of LPs (44.1, 38.2, and 29.4 cm2, respectively; P < 0.001). After VT ablation, 77.9% of patients have been VT free during a median follow-up period of 13.6 months.
The S3 protocol was feasible in 85% of patients, allows a better identification of targets for ablation, and might improve VT ablation results.
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Aims To analyse whether the proportion of patients with lone atrial fibrillation engaged in chronic sport practice was higher than that observed in the general population. Methods and Results The ...records of 1160 patients, seen at the arrhythmia outpatient clinic, were reviewed. A total of 70 patients (6%) suffered lone atrial fibrillation and were younger than 65 years. Thirty two of them had been engaged in long-term sport practice. All patients in the sport group were men as compared to only 50% in the sedentary group (P<0·0001). To avoid the confounding effect of sex distribution, women were excluded. Sportsmen started their episodes of atrial fibrillation at a younger age, they had a lower incidence of mild hypertension and their episodes of atrial fibrillation were predominantly vagal in contrast to the sedentary patients. The echocardiographic parameters were similar to those observed in the sedentary patients, but when compared with 20 healthy controls, they showed greater atrial and ventricular dimensions and a higher ventricular mass. The proportion of sportsmen among patients with lone atrial fibrillation is much higher than that reported in the general population of Catalonia: 63% vs 15% (P<0·05). Conclusion Long-term vigorous exercise may predispose to atrial fibrillation.
IntroductionHypertension and structural heart disease (SHD) are the most frequent causes of Atrial Fibrillation (AF). Hemodynamic overload and inflammation are key mediators of the arrhythmogenic ...substrate, at least partly by triggering accelerated senescence. Remarkably, up to one third of AF patients have no associated SHD (lone AF), and their arrhythmogenic substrate is largely unknown. We sought to compare structural and senescence changes in AF patients with or without SHD.MethodsAtrial appendage samples from four groups of patients were analyzed; patients with no SHD (AF_lone, n=10), AF patients with SHD (AF_Card, n=14), controls with no AF but with other cardiovascular diseases (CVD) (C_CVD, n=18) and controls with no CVD (C_Healthy, n=5). The percentage of intramyocardial collagen deposition was quantified by sirius red staining and morphometric analysis, and connexin-43 was analyzed by immunohistochemistry. Tissue senescence was evaluated with telomere length quantification and mRNA levels of a family of proteins involved in cellular senescence (Sirtuin-1, -2, -3 and -6).ResultsThere were no differences in age (overall mean 60 ± 2 years) and the percentage of male gender (overall 67%) between groups of patients. AF patients had a marked increase in atrial fibrosis, with no differences between AF_lone and AF_Card (Figure A). Connexin-43 quantification and distribution was similar in AF patients with or without SHD. Nevertheless, telomeres were longer in AF_lone than in AF_Card patients (Figure B). Also, AF_lone samples had higher mRNA levels of sirtuin-2 and -3 compared to AF_Card samples with no changes in sirtuin-1 and -6.ConclusionsEven though a similar degree of structural remodelling was found, AF_Card patients presented an accelerated atrial senescence when compared to AF_lone patients. These results could have important implications in the prognosis and therapeutic options of AF_lone patients.
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