Clinical guide for the diagnosis and follow-up of myotonic dystrophy type 1, MD1 or Steinert's disease. / Guía clínica para el diagnóstico y seguimiento de la distrofia miotónica tipo 1, DM1 o enfermedad de Steinert.

BACKGROUND AND OBJECTIVES: Steinert's disease or myotonic dystrophy type 1 (MD1), (OMIM 160900), is the most prevalent myopathy in adults. It is a multisystemic disorder with dysfunction of virtually all organs and tissues and a great phenotypical variability, which implies that it has to be addressed by different specialities with experience in the disease. The knowledge of the disease and its management has changed dramatically in recent years. This guide tries to establish recommendations for the diagnosis, prognosis, follow-up and treatment of the complications of MD1. MATERIAL AND METHODS: Consensus guide developed through a multidisciplinary approach with a systematic literature review. Neurologists, pulmonologists, cardiologists, endocrinologists, neuropaediatricians and geneticists have participated in the guide. RECOMMENDATIONS: The genetic diagnosis should quantify the number of CTG repetitions. MD1 patients need cardiac and respiratory lifetime follow-up. Before any surgery under general anaesthesia, a respiratory evaluation must be done. Dysphagia must be screened periodically. Genetic counselling must be offered to patients and relatives. CONCLUSION: MD1 is a multisystemic disease that requires specialised multidisciplinary follow-up.

[Radiofrequency catheter ablation of ventricular tachycardias in patients with postinfarction scars]. / Ablación con catéter mediante radiofrecuencia de taquicardias ventriculares en pacientes con cicatriz postinfarto.

Radiofrequency catheter ablation has recently emerged as a therapeutic option for ventricular tachycardia in postinfarction patients. However, the indications for its use and the mapping procedure remain controversial. The most common arrhythmogenic circuit found fits an "8" shape model. This model incorporates a slow conducting central area, separated from the surrounding myocardium by conduction blocking areas and with entrance and exit sites. This circuit has classically been confined in the left ventricle. However, recently successful radiofrequency catheter ablation of ventricular tachycardia has been reported from the right ventricle. Several markers for adequate positioning of the ablation catheter have been reported: local presystolic activity, isolated mid diastolic potential, transient entrainment with concealed fusion, match between electrogram-QRS and stimulus-QRS intervals, match between first postpacing interval and tachycardia cycle length and tachycardia electrocardiographic reproduction by pace-mapping. Procedure related complications are rare and the success rate is around 70%. Nevertheless, currently this technique should be limited to postinfarction patients with ventricular tachycardia meeting certain requisites.

[Focal auricular fibrillation: catheter ablation with radiofrequency]. / Fibrilación auricular focal: ablación con catéter mediante radiofrecuencia.

Although atrial fibrillation is usually caused by multiple circulating reentrant wavelets, a focal origin has recently been reported. This focal source could be successfully treated by discrete radiofrequency catheter ablation. We report a patient without structural heart disease, but with multiple episodes of palpitations related to atrial premature beats, irregular atrial tachycardia and atrial fibrillation. The electrophysiological study demonstrated that all the atrial arrhythmias were due to the same focus firing irregularly and exhibiting a unique and centrifugal pattern of activation. Successful radiofrequency catheter ablation of the focus was performed, without complications. After three months follow-up the patient is asymptomatic and she has not presented arrhythmia recurrences.

[Ventricular fibrillation secondary to radiofrequency application in ventricular tachycardia ablation]. / Fibrilación ventricular secundaria a la aplicación de radiofrecuencia en la ablación de una taquicardia ventricular.

Radiofrequency catheter ablation has become a first line therapy for several types of tachycardias because of its high efficacy and low complication rate. The development of proarrhythmic complications due to a direct effect of radiofrequency is very unusual. We describe a patient with previous myocardial infarction and well tolerated sustained monomorphic ventricular tachycardia who underwent catheter ablation of the tachycardia substrate. During two of the radiofrequency applications, ventricular fibrillation developed and external defibrillation was required.

[Proarrhythmic effect following radiofrequency catheter ablation of repetitive monomorphic ventricular arrhythmia]. / Efecto proarrítmico tras la ablación con radiofrecuencia de una arritmia ventricular monomórfica repetitiva.

Radiofrequency catheter ablation is a first line therapy for many supraventricular and some ventricular tachycardias due to a high success rate and a low probability of complications. Although the majority of them are related to the catheterization technique, some are due to a direct effect of radiofrequency application. We report a patient with a nonsustained, repetitive, monomorphic ventricular arrhythmia that presented, after a successful radiofrequency ablation, an incessant sustained monomorphic ventricular tachycardia requiring a new ablation procedure.

[Demonstration of accelerated growth of heart sarcoma using imaging techniques]. / Demostración del crecimiento acelerado de un sarcoma cardíaco mediante técnicas de imagen.

We report the case of a patient presenting a sarcoma of interatrial septum with an accelerated growth and a fulminate clinical course documented by non-invasive image diagnostic techniques, habitual in the cardiologic practice. The natural history of some cardiac malignant tumours, as aggressive as in this case, explains the diagnostic delay, the difficulty to establish a curative treatment such as surgery and/or chemotherapy/radiotherapy and the awful short-term prognosis.

[Uncommon atrial flutter related to cicatrix from atriotomy surgery: radiofrequency catheter ablation]. / Aleteo auricular no común relacionado con cicatriz de atriotomía quirúrgica: ablación con catéter mediante radiofrecuencia.

A patient with a complex congenital abnormality required the implantation of an interatrial septum patch through a right lateral atriotomy. Nine years later he developed two different morphologies of an incessant uncommon atrial flutter refractory to antiarrhythmic drug treatment. The electrophysiological study localized a site on the right atrium lateral wall where local activation time was 75 ms earlier than the onset of the P wave, transient entrainment with concealed fusion was obtained, the first postpacing interval after transient entrainment was 5 ms longer than tachycardia cycle length and the stimulus to P wave interval was 50 ms. At this site, radiofrequency delivery terminated the atrial flutter in less than 1 second. No further induction or recurrences of any morphology of the atrial flutter were observed after a four month follow up. These findings suggest the existence of a narrow conduction isthmus amenable to interruption by focal delivery of radiofrequency. The isthmus was most probably located between the atriotomy and the crista terminalis, posterior to the former and anterior to the latter.

[Radiofrequency catheter ablation for atrial tachycardia]. / Ablación con catéter mediante radiofrecuencia de taquicardias auriculares.

INTRODUCTION: Radiofrequency catheter ablation of atrial tachycardia guided by bipolar activation mapping has been reported in the last years. This article reports the use of radiofrequency catheter ablation for the treatment of atrial tachycardia using simultaneous bipolar and unipolar activation mapping at our institution. METHODS: Nine patients (7 male and 2 female, mean age 37.2 +/- 24.1 years), were selected for radiofrequency catheter ablation of drug refractory atrial tachycardia. Mapping procedure included an investigation of the local earliest bipolar and unipolar activity and unipolar morphology analysis. RESULTS: Atrial tachycardia was successfully ablated in 7 patients (78%) with an average number of 6.8 +/- 3.1 RF pulses. Procedure related complications and tachycardia follow-up recurrences were not observed in any patient. Bipolar local activation time was significantly shorter at successful than at unsuccessful ablation sites (-30 +/- 21.1 ms vs -18.3 +/- 20.6 ms; p = 0.01). No difference was observed in unipolar local activation time between successful and unsuccessful sites (-22.5 +/- 26.2 ms vs -19.8 +/- 21.5 ms; p = 0.56). Accurate localization of the successful ablation site by unipolar electrogram analysis was not feasible because a "QS" pattern was found at both 21 unsuccessful and 2 successful ablation sites. Finally, a fast slope of the negative deflection of the unipolar electrogram was found at 2 out of 45 unsuccessful and 3 out of 6 successful ablation sites. CONCLUSIONS: Radiofrequency catheter ablation of atrial tachycardia is feasible without complications in most patients. Bipolar activation mapping accurately localizes the successful ablation site. A "QS" pattern is not predictive of successful radiofrequency application.

[Radiofrequency catheter ablation of ventricular tachycardia in patients without apparent structural cardiopathy]. / Ablación con catéter mediante radiofrecuencia de taquicardias ventriculares en pacientes sin cardiopatía estructural aparente.

BACKGROUND AND PURPOSE: It has been suggested that the efficacy of radiofrequency ablation of idiopathic ventricular tachycardia (VT) is dependent on the site of VT origin, with the efficacy being greater for VTs originating from right ventricle. The electrophysiologic characteristic and the results of radiofrequency catheter ablation of ventricular tachycardia in patients without structural heart disease are reported. Special emphasis was focused to the differences observed in the pace and activating mapping between VTs originating in the right ventricle and those originating from the left ventricle and its possible implications for radiofrequency efficacy. METHODS AND RESULTS: 14 consecutive patients with idiopathic VT (7 women and 7 men, mean age 35 +/- 16 years), 8 originating in the right ventricle (RV) and 6 in the left ventricle (LTV), underwent catheter ablation using radiofrequency energy. The observation of entrainment with fusion in all LV VT suggested that the electrophysiologic mechanism was a reentry, meanwhile the RV VT were due to focal non-reentrant mechanisms. Sites for radiofrequency energy delivery were selected on the basis of pace and activation mapping in all patients less in two patients with incessant VT in whom only activation mapping was performed. 14 VT were mapped. The activation mapping demonstrated isolated presystolic electrograms in the point of origin in all VT arising from the LV. However in RV tachycardias there was continuous activity between presystolic and systolic electrograms, although the prematurity of these electrograms was similar (31 +/- 16 ms vs 33 +/- 9 ms; p = 0.77). Radiofrequency was successful in eliminating 93% of TV (100% RV TV vs 83% LV TV; p = 0.23). No complications were observed. CONCLUSIONS: The results of this study suggest that radiofrequency ablation is highly successful either in right and left ventricles idiopathic tachycardias when pace and activation mapping are used complementary.