Is there an isolated arrhythmogenic right atrial myocarditis?

Two cases with drug refractory ectopic atrial tachycardia are described. A map-guided partial resection of the right atrium (RA) was done after preoperative endocardial catheter mapping hadshown well-defined areas of fractionated RA potentials. Intraoperatively, there were no aneurysmal formations present as described by other authors. Histopathologic examination of the resected tissue showed atrial myocarditis in both patients. Postoperative right ventricular myocardial biopsies revealed no inflammatory tissue. A minor elevation of antibodies against echoviruses was found in one case. Postoperative electrophysiologic studies were negative. We conclude: focal RA myocarditis without concomitant ventricular myocarditis may represent one cause of drug-resistant ectopic atrial tachycardia. Map-guided surgical intervention may cure the diseas

Conversion of supraventricular arrhythmias to sinus rhythm using flecainide

We evaluated the efficacy of flecainide acetate (given intravenously to a maximal dose of2 mg kg−1 and then orally in a dose of 100 mg b.d. or 100 mg t.d.s.) in the conversion to sinus rhythm of 50 patients exhibiting supraventricular arrhythmias (39 with atrial fibrillation, 6 with atrial flutter, 4 with supraventricu tachycardia and onewith supraventricular tachycardia in association with the Wolff—Parkinson—White syndrome). Conversion was achieved in 36 patients (72%) (29 cases with atrial fibrillation, 4 cases with supraventricular tachycardia, 2 cases with atrial flutter and one case with Wolff—Parkinson-White syndrome), over a mean period of 7.4 ± 9 h. The patients in which conversion was achieved had arrhythmias which had been in existence for a shorter time (5.3 ± 9.8 days) than those in which conversion was not achieved (16.7 ± 26.2 days) (P<0.01). The mean dosage of flecainide used to achieve conversion was 2.5 ± 2.36 mg kg−1. Flecainide appears to be an effective agent for the conversion to sinus rhythm of atrial fibrillation and supraventricular tachycardias. Its efficacy in cases of atrial flutter has not yet been demonstrate

Paleo and historical seismicity in Mallorca (Baleares, Spain): a preliminary approach

The island of Mallorca is subject to low seismic activity. The instrumental record shows that current seismicity is surficial (&lt;10 km depth) and low in magnitude (mb&lt;4). Both historical and geological records display the occurrence of strong events, e.g. the 1851 Palma earthquake (VIII, MSK intensity). Data on this destruct ive event indicate that this was a seven month long seismic sequence, with two strong events, causing severe damage and collapse of buildings along Palma bay in addition to moderate ground collapses in the macroseismal zone. The earthquake epicenter was situated between Sa Cabaneta and Sta. Eugènia. This earthquake can be correlated with the trace of the Sencelles fault, the main extensional structure of the island on the surface. The geological and geophysical analyses of recent surface faulting features at the Portol doline (reverse surface faulting) and on the Sta. Eugènia segment of the Sencelles fault (bedrock fault scarp ) suggest recurrent large prehistoric events. Preliminary data show minimum vertical offsets of 2.56 m at the Portol doline and offsets of 3.50m at the Sta. Eugènia bedrock fault scarp. These offsets were accumulated in recent times (Holocene?). Displacements per event can be initially estimated as mean values of 0.88 to 0.40 m in both places, but larger offsets of a maximum of 1.68 m can also be inferred. Specific dendrochronologic, lichenometric, and weathering analyses to assess true single-event slip values, and their time-bracketing will be necessary. The interpretation of these displacement events in terms of earthquake magnitude is not straightforward because of the apparent subordinate nature of the ground rupture at the Po rtol doline and the possible influence of salt tectonics in both places. To address these issues, a fault-trench was planned along the Sencelles fault within the framework of a new research project. The Spanish seismic code (NCS94) assigns an expected maximum ground acceleration of 0.04 g for a 500 year return period to the area. In the light of our data these values are underestimated. The historical and geological records indicate the occurrence of historical VII to VIII MSK, and stronger prehistoric events. Peak ground horizontal accelerations of up to 0.10 g could be expected during modern earthquakes

Alloimmunity and nonimmunologic risk factors in cardiac allograft vasculopathy

Graft vasculopathy is an accelerated form of coronary artery disease that occurs in transplanted hearts. Despite major advances in immunosuppression, the prevalence of the disease has remained substantially unchanged during the last two decades. According to the ‘response to injury' paradigm, graft vasculopathy is the result of a continuous inflammatory response to tissue injury initiated by both alloantigen-dependent and independent stress responses. Experimental evidence suggests that these responses may become self-sustaining, as allograft re-transplantation into the donor strain at a later stage fails to prevent disease progression. Histological evidence of endothelitis and arteritis, in association with intima fibrosis and atherosclerosis, reflects the central role of alloimmunity and inflammation in the development of arterial lesions. Experimental results in gene-targeted mouse models indicate that cellular and humoral immune responses are both involved in the pathogenesis of graft vasculopathy. Circulating antibodies against donor endothelium are found in a significant number of patients, but their pathogenic role is still controversial. Alloantigen-independent factors include donor-transmitted coronary artery disease, surgical trauma, ischaemia-reperfusion injury, viral infections, hyperlipidaemia, hypertension, and glucose intolerance. Recent therapeutic advances include the use of novel immunosuppressive agents such as sirolimus (rapamycin), HMG-CoA reductase inhibitors, calcium channel blockers, and angiotensin converting enzyme inhibitors. Optimal treatment of cardiovascular risk factors remains of paramount importanc

Un modelo de mapa neotectónico en la región Nor-oriental de la provincia de Valencia (España)

We are presenting here a neotectonic map model of the northeastern area of Valencia (Spain). This region has been submited to a distensive tectonic in which it is possible to distinguish several phases from the lower-middle Miocene up to now (Simon, 1984). After the studies done in the area, the last important fracturation phase took place in the early Pleistocene, and was particulary strong in the Náquera, Casinos and Chelva areas. The neotectonic map shown here has been based a two maps: the geological one, in which the Plio-Quaternary, and Quaternary deposits are particularly well detailed, and the geomorphological one. The use of the geomorphological units sequence, together with their geometrical distribution (encasement and/or superposition), as well as the representation of the geomorphological features indicating neotectonics such as anomalous slopes (in excess or defect), talweg rectification, anomalous sediment thickness, etc.; can by the only available way to put the recent movements in a temporal scale, especially in areas in which the materials are azoic and the nature of the lithology is similar. Thanks to the possibility to use colours or alphabetical and/or numerical characters to indicate the last movements of the accidents, this map can be used for sismotectonical hazards.Se realiza un modelo de mapa neotectónico en el área Nor-oriental de la provincia de Valencia. Dicha zona está sometida a una tectónica distensiva desde el Mioceno inferior-medio a la actualidad, dentro de la cual pueden ser distinguidas varias fases (Simon, 1984). Después de los estudios realizados en el área, la última fase de fracturación importante sucede en el Pleistoceno inferior, y ésta es particularmente intensa en el área de Náquera, Casinos y Chelva. El mapa neotectónico que aquí se elabora parte de dos mapas base, por un lado el geológico, en el que están particularmente detallados los depósitos correspondientes al Plio-Cuaternario y Cuaternario, y el geomorfológico. La utilización de las secuencias de unidades geomorfológicas, el dispositivo geométrico de las mismas (encajamiento y/o superposición) y la representación de los rasgos geomorfológicos indicadores de neotectónica tales como: pendientes anómalas por exceso o defecto, contrapendientes, rectificación del talweg, potencias anómalas de sedimentos, etc., puede ser el único medio utilizable para inscribir los movimientos recientes dentro de una escala temporal, sobre todo en áreas donde los materiales son azoicos y las litologías semejantes. Quizás la mayor aplicación de este mapa, sobre todo en riesgos sismotectónicos, se deba a la posibilidad de utilización del color o en su defecto caracteres alfabéticos y numéricos para indicar el último movimiento de los accidentes

Oscilaciones eustáticas e implicaciones climáticas en el tránsito Neógeno-Cuaternario en la isla de Sal (archipiélago de Cabo Verde)

Solution pipes interpreted as a cryptokarst separate large-scale cross-bedded megaforms of shallowmarine calcarenites deposited at the Neogene-Quatemary transition in Cape Verde Islands. This implies that depositional phases were followed by subaerial exposure of the cemented calcarenites during subsequent falls of sea level, and accumulation of unconsolidated eolianites which supported a vegetal cover that promoted the cryptokarst. The process was repeated several times. A widespread, more recent karstification with red silty clay filling of voids may represent the aridification of climate at the beginning oi the Quaternary and the increased supply of Saharan dust by Trade Winds

Prevention of coronary restenosis by stenting

Balloon angioplasty fails to provide acceptable long-term results for a significant proportion of patients. An intravascular mechanical support, developed with the aim of preventing restenosis and acute closure of diseased arteries after transluminal angioplasty, was implanted in 44 patients (39 male and five female), aged from 35 to 70 years (mean 56 years) with documented restenosis of native coronary artery (41 stents) and bypass grafts (12 stents). In the group of bypass graft patients there was no local restenosis and no major complication. In patients in whom stents were placed in native coronary arteries, the complication rate was higher (two patients died after coronary bypass surgery). One patient died suddenly at home. Except for one patient, in whom a new lesion developed proximally with extension into the stent, no case of restenosis could be observed. Despite the still relatively high complication rate, we feel that stenting may present a rational approach to the unresolved problem of restenosis after coronary angioplast

Time on a Rotating Platform

Traditional clock synchronisation on a rotating platform is shown to be incompatible with the experimentally established transformation of time. The latter transformation leads directly to solve this problem through noninvariant one-way speed of light. The conventionality of some features of relativity theory allows full compatibility with existing experimental evidence.Comment: 12 pages, Latex, no figure. Copies available at [email protected] accepted for publication in Found. Phys. Let

Three-Body Halos in Two Dimensions

A method to study weakly bound three-body quantum systems in two dimensions is formulated in coordinate space for short-range potentials. Occurrences of spatially extended structures (halos) are investigated. Borromean systems are shown to exist in two dimensions for a certain class of potentials. An extensive numerical investigation shows that a weakly bound two-body state gives rise to two weakly bound three-body states, a reminiscence of the Efimov effect in three dimensions. The properties of these two states in the weak binding limit turn out to be universal. PACS number(s): 03.65.Ge, 21.45.+v, 31.15.Ja, 02.60NmComment: 9 pages, 2 postscript figures, LaTeX, epsf.st