PREvention of recurrent arrhythmias with Mediterranean diet (PREDIMAR) study in patients with atrial fibrillation: Rationale, design and methods.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia. Catheter ablation aims to restore sinus rhythm. However, relapses occur in up to 30% of patients. A Mediterranean diet (MedDiet) enriched with extra-virgin olive oil (EVOO) substantially reduced the incidence of AF in the PREDIMED trial. The PREDIMAR will test a similar intervention in secondary prevention. Methods: PREDIMAR is a multicenter, randomized, single-blind trial testing the effect of a MedDiet enriched with EVOO to reduce tachyarrhythmia relapses after AF ablation. The primary outcome is the recurrence of any sustained atrial tachyarrhythmia after ablation (excluding those occurring only during the first 3 months after ablation). The target final sample size is 720 patients (360 per group) recruited from 4 Spanish hospitals. A remote intervention, maintained for 2 years, is delivered to the active intervention group including periodic phone calls by a dietitian and free provision of EVOO. The control group will receive delayed intervention after trial completion. Routine electrocardiogram (ECG) and Holter ECG are performed, and a portable cardiac rhythm monitoring device is provided to be worn by participants during 15 months. Results: Recruitment started in March 2017. Up to July 2019, 609 patients were randomized (average inclusion rate: 5.3 patients/wk). Retention rates after 18 months are >94%. Conclusions: If our hypothesis is confirmed, the utility of the MedDiet enriched with EVOO in slowing the progression of AF will be proven, preventing recurrences and potentially reducing complications.

Anatomic characteristics of the left atrium in subjects undergoing radiofrequency ablation for atrial fibrillation.

OBJECTIVE: To analyze the anatomic characteristics of the left atrium and pulmonary veins in individuals undergoing ablation for atrial fibrillation and to identify possible anatomic factors related with recurrence. MATERIAL AND METHODS: We retrospectively reviewed the CT angiography studies done to plan radiofrequency ablation for atrial fibrillation in 95 patients (57 men; mean age, 65 ±â€¯10 y). We reviewed the anatomy of the pulmonary veins and recorded the diameters of their ostia as well as the diameter and volume of the left atrium. We analyzed these parameters according to the type of arrhythmia and the response to treatment. RESULTS: In 71 (74.7%) patients, the anatomy of the pulmonary veins was normal (i.e., two right pulmonary veins and two left pulmonary veins). Compared to patients with paroxysmal atrial fibrillation, patients with persistent atrial fibrillation had slightly larger diameter of the left pulmonary veins (left superior pulmonary vein 17.9 ±â€¯2.6 mm vs. 16.7 ±â€¯2.2 mm, p = 0.04; left inferior pulmonary vein 15.3 ± 2 mm vs. 13.8 ±â€¯2.2 mm, p = 0.009) and larger left atrial volume (91.9 ±â€¯24.9 cm3 vs. 70.7 ±â€¯20.3 mm3, p = 0.001). After 22.1 ±â€¯12.1 months' mean follow-up, 41 patients had sinus rhythm. Compared to patients in whom the sinus rhythm was restored, patients with recurrence had greater left atrial volume (81.4 ±â€¯23.0 mm3 vs. 71.1 ±â€¯23.2 mm3, p = 0.03). No significant differences in pulmonary vein diameters or clinical parameters were observed between patients with recurrence and those without. CONCLUSION: The volume of the left atrium is greater in patients with persistent atrial fibrillation and in those who do not respond to ablation.

Role of sCD40L in the prediction of super-response to cardiac resynchronization therapy.

BACKGROUND: The aim of this paper is to analyze the role of the biomarkers Interleukin 6, Tumoral Necrosis Factor a, sCD40L, high sensitive Troponin T, high sensitive C-Reactive Protein and Galectin-3 in predicting super response (SR) to Cardiac Resynchronization Therapy (CRT), as they have not been studied in this field before. METHODS: Clinical, electrocardiographic and echocardiographic data was obtained preimplant and after one year. SR was defined as reduction in LVESV = 30% at one year follow-up. Blood samples were extracted preimplant. Multivariate logistic regression and ROC curves were performed. RESULTS: 50 patients were included, 23 (46%) were SR. Characteristics related to SR were: female (35 vs. 11%, p?=?0.04), suffering from less ischemic cardiomyopathy (13 vs. 63%, p?

[Progress in diagnostic and management of cardiac arrhythmias]. / Avances en el diagnóstico y tratamiento de las arritmias cardíacas.

The era of catheter ablation for the treatment of arrhythmias began in 1981 when Dr Scheinman performed the first atrioventricular junction ablation using direct current shocks in a patient with drug refractory atrial fibrillation and an uncontrolled ventricular rate. With the progress of radiofrequency catheter ablation, the range of arrhythmias amenable to catheter ablation and the number of patients that could be treated safely by this procedure expanded enormously. Lastly, although still in an evolutionary phase, catheter ablation to eliminate atrial fibrillation has been demostrated in the past years to be feasible and clinically useful. On the other hand, innovations in technology and pharmacology, and better preventive and diagnostic tools, have provided our patients with an important improvement in their prognosis. The new developments in molecular genetics and biology are likely to change the way we approach a cardiac patient in the future. The diseases are now being deciphered at the most basic level, and the information obtained opens new possibilities not only for better therapeutic and diagnostic measures but also for prevention of the disease.

Meglumine antimoniate, amiodarone and torsades de pointes: a case report.

Pentavalent antimonial drugs used for the treatment of leishmaniasis have been associated with sudden deaths, probably due to the development of ventricular tachyarrhythmias. Prolongation of the QT interval and ventricular tachyarrhymias have been described in patients on amiodarone therapy. We report a case of recurrent torsades de pointes following treatment with pentavalent antimonial drugs and amiodarone.

Implantation of 500 consecutive cardiac pacemakers in the electrophysiology laboratory.

OBJECTIVE: The purpose of this study was to examine the practice of cardiac bradycardia pacing in an electrophysiology laboratory and to evaluate the safety and efficacy of pacemaker implantation by cardiologists in this setting. METHODS AND RESULTS: We evaluated a consecutive series of the first 500 permanent pacemakers (mean age of patients: 74 +/- 14 years) implanted entirely in the electrophysiology laboratory at our institution. All procedures were performed by two cardiologists. Three-hundred and four patients (60.8%) received a dual-chamber device. After 3 months of follow-up, procedure-related complications occurred in 19 patients (3.8%). The most frequent complication was lead dislodgement (1.4%). There were 2 postoperative infections (0.4%). The mean time to hospital discharge after the implant was 2.9 +/- 1.6 days. CONCLUSIONS: These results show that permanent pacemaker implantation may be successfully carried out by cardiologists in the electrophysiology laboratory with a low complication rate. Atrial lead dislodgement seems to be the most frequent complication in centres with a high proportion of dual-chamber pacemaker implantations.

Magnetic resonance imaging in a patient with a dual-chamber pacemaker.

The presence of an implanted cardiac pacemaker has been considered an absolute contraindication for magnetic resonance imaging due to the interactions between the pulse generators and the magnetic and radiofrequency fields generated by the magnetic resonance unit. We describe the case of a patient with a dual-chamber pacemaker who underwent two magnetic resonance imaging examinations of the head without any sequelae. Both procedures were performed with a 1 Tesla unit, with the pacemaker programmed to the AOO mode. The only interference observed was activation of the reed switch -probably due to the static magnetic field- resulting in asynchronous atrial pacing at the magnet rate. Although the general policy of never exposing a patient with a pacemaker to magnetic resonance imaging should not be revised, we think that if the testing is considered essential, it could be safely used in certain carefully selected patients.

[Radiofrequency ablation of occult left accessory pathways without catheterization of the coronary sinus]. / Ablación mediante radiofrecuencia de vías accesorias ocultas izquierdas sin cateterismo del seno coronario.

BACKGROUND: Radiofrequency catheter ablation of concealed left-sided accessory pathways conventionally implies the introduction of several catheters for the assessment of electrophysiological properties as well as for the localization of the accessory pathways. PATIENTS AND METHODS: Feasibility of radiofrequency ablation using a simplified two-catheter technique without coronary sinus catheterization was prospectively studied in 95 consecutive patients with a single concealed left free-wall accessory pathway. A 6F quadripolar catheter was introduced into the right atrium/right ventricle and tachycardia was induced by electrical stimulation. The presence of a concealed left-sided accessory pathway was suggested electrocardiographically (negative P wave in I and/or aVL during orthodromic tachycardia) or by earlier atrial activation in the pulmonary artery compared to the right atrium. Mapping of the mitral annulus and ablation were performed during orthodromic tachycardia or ventricular pacing using a 7F steerable catheter. Radiofrequency energy was applied at sites with the shortest VA interval. The procedure was considered effective if tachycardia could not be induced and if VA dissociation or exclusive nodal VA conduction were observed. RESULTS: The procedure was initially successful in 93 out of 95 patients (98%). Mean number of applications were 3.2 +/- 2. Mean fluoroscopy time and total procedure duration were 14 +/- 9 and 108 +/- 33 minutes respectively. At a mean follow-up of 21 +/- 13 months, 2 patients required a second session because of tachycardia recurrence. CONCLUSIONS: Radiofrequency catheter ablation of concealed left-sided accessory pathways can be safely, effectively and rapidly performed using a two-catheter technique without coronary sinus catheterization.

[Quantification of myocardial tomography with thallium in coronary disease. Evaluation of the Cedars-Sinai technique]. / Cuantificación de la tomografía miocárdica con talio en la enfermedad coronaria. Valoración del método Cedars-Sinai.

OBJECTIVE: The aim of this study is to evaluate the contribution of the Cedars-Sinai quantification tomographic method (CS) in the diagnosis and localization of ischemic areas in coronary artery disease (CAD) and to optimize the threshold values proposed by CS. PATIENTS AND METHODS: Fifty patients with clinical suspicion of CAD performed a maximal stress test by cycloergometer; thallium myocardial tomographic images were obtained; applying the CS program afterwards. The sensitivity and specificity variations obtained by changing the criteria for extent of myocardial hypoperfusion (range 1% to 100%) were used to calculate the new thresholds (CS-I), using the results of coronariographic studies as a reference. The data determined by qualitative analysis were compared with that obtained by quantitative analysis by means of CS and CS-I using coronary angiography as the standard of reference. RESULTS: The coronary angiography showed coronary disease in 37 patients. The sensitivity for the diagnosis of CAD was superior using CS (97%) at the expense of low specificity (15%) which nevertheless improved with CS-I (54%). For the location of CAD, the visual analysis was statistically significant (p < 0.05) in the left anterior descending and right coronary arteries, CS being superior in the diagnosis of 3 vessel disease. CONCLUSIONS: The quantification of tomographic studies with thallium by means of CS needs a readjustment of the thresholds. The tested values (CS-I) improved the CS results, although they require prospective validation. Quantitative study permits the confirmation of visual findings, being a complementary method that can be rapidly and easily interpreted, although it is not recommended as a single technique for the diagnosis of coronary disease.

[Growth factors and mitogenic activity in experimental hypercholesterolemia]. / Factores de crecimiento y actividad mitogénica en la hipercolesterolemia experimental.

INTRODUCTION: Hypercholesterolemia is associated with increased platelet reactivity and changes in megakaryopoiesis, which might influence the synthesis of growth factors in the megakaryocyte. MATERIAL AND METHODS: 20 miniature pigs were randomly assigned to received 18 weeks of either regular pig chow feed (control group, n = 10) or a high cholesterol diet (cholesterol group, n = 10). Platelet count, mean platelet volume, platelet distribution width and bleeding time were determined in both groups. Intraplatelet and serum mitogenic activity was quantified by Swiss 3T3 and vascular smooth muscle cells proliferation assays. Insulin-like growth factor I and platelet-derived growth factor (BB isoform) levels were quantified in platelet lysates and in serum in both groups. RESULTS: Hypercholesterolemia was associated to a significant decrease in mean platelet volume and bleeding time, but it did not affect the proliferative effect of serum and platelet lysates nor its growth factor content. CONCLUSIONS: Taken together, our results suggest that although hypercholesterolemia affects platelet reactivity, its atherosclerosis-promoting effects cannot be explained by a direct effect on vascular smooth muscle cell proliferation or by changes in serum or intraplatelet growth factor content.

[Contraceptives and ischemic cardiopathy]. / Contraceptivos y cardiopatía isquémica.

The incidence of myocardial infarction is higher in women that use oral contraceptives. The most important pathophysiologic mechanisms are: a) modification of coronary risk factors: the pill produces an elevation of both serum cholesterol and trygliceride levels, increase of blood pressure and decompensation of diabetes mellitus; b) blood coagulation disorders: oral contraceptives increase platelet aggregation and fibrinogen blood levels, therefore they have a considerable thrombogenic capacity. At this moment there are several update publications concerning this matter; however most of the mechanisms involved in the increase of coronary heart disease in this specific group still remain unclear.

[Supraventricular arrhythmia. Potential applications of esmolol]. / Arritmias supraventriculares. Posibles aplicaciones del esmolol.

Atrial fibrillation, atrial flutter, paroxistical supraventricular tachycardias and atrial tachycardias are the main supraventricular arrhythmias. Atrial fibrillation is the most common. In this review we comment their physiopathology, clinical manifestations, and treatments, paying special attention to the possible esmolol applications.

[Radiofrequency ablation of supraventricular tachycardias]. / Ablación con radiofrecuencia de taquicardias supraventriculares.

Radiofrequency catheter ablation has been established as a non-surgical curative treatment modality for the management of patients with paroxismal supraventricular tachycardia. Success rates for atrioventricular node reentrant tachycardia and accessory pathway-mediated macroreentrant tachycardia exceed 95%. Results in patients with atrial flutter and atrial tachycardia are encouraging, with success rates exceeding 75%.

[Practical approximation to the diagnosis of tachyarrhythmias]. / Aproximación práctica al diagnóstico de las taquiarritmias.

Even though the 12-lead electrocardiogram is the most helpful tool in the diagnosis of tachycardia, a careful history and physical examination can be useful in both differentiating between ventricular and supraventricular tachycardia and elucidating the electrophysiological mechanism of supraventricular tachycardia. This article will focus on the most relevant clinical aspects of tachyarrhythmias as well as on the electrocardiographic differential diagnosis of regular broad complex tachycardia.

[Oxygen-derived free radicals. Their role in cardiology]. / Radicales libres derivados de oxígeno. Su papel en Cardiología.

Oxygen-derived free radicals are highly reactive molecules characterized by the presence of an unpaired electron in one of its outer orbitals. They have been found responsible for some pathologic phenomenons which in the field of cardiology, occurs during tissue reperfusion of a previously ischemic area. Ischemia predisposes an outburst in the production of these molecules upon the reintroduction of oxygen during reperfusion. Animal experimental models have been designed to reduce the damages induced by free radicals using various pharmacologic agents. It is probable that these agents may form a part of the conventional treatment of certain cardiac pathologies in the future.

[Applications of nuclear magnetic resonance in the diagnosis of cardiopathies]. / Aplicaciones de la resonancia magnética nuclear en el diagnóstico de las cardiopatías.

Applications of nuclear magnetic resonance imaging in cardiovascular diagnosis. The role of magnetic resonance imaging in the evaluation of cardiovascular system is still evolving. Nevertheless, this technique is of great promise for cardiac patient management in the near future. Magnetic resonance imaging provides a high contrast between the blood pool and myocardial function that has been shown to be effective for the evaluation of a wide variety of anatomic abnormalities as well as to assess cardiac contractile function or myocardial perfusion. Moreover, magnetic resonance spectroscopy has provided a new research tool for the evaluation of myocardial metabolism. Such performances indicate the potential of magnetic resonance techniques to establish the link between myocardial function and metabolism. In this presentation we will review the current status of magnetic resonance imaging for the diagnosis and evaluation of a wide variety of cardiovascular diseases and discuss its future potential.

Late fatal right ventricular perforation as complication of permanent pacing leads.

Perforation of the right ventricle during placement of pacing electrodes is a well-documented complication. Most of these perforations occur intraoperatively and rarely cause symptoms. This case report describes a fatal cardiac perforation that occurred 10 days after implantation of a permanent cardiac pacemaker. This complication should be considered as one of the potential mechanisms responsible for the high rate of sudden death observed in paced patients during the first year after pacemaker implantation.

Effect of hypercholesterolaemia on platelet growth factors.

Evidence from several sources suggests that important interactions occur between platelets and low-density lipoproteins. This study was undertaken to find out if diet-induced hypercholesterolaemia affects the growth factor content in circulating platelets. Minipigs were fed either normal diet supplemented with 2% cholesterol (n = 12) or normal diet alone (n = 12). After 4 months, mean platelet volume was significantly lower (P < 0.05) and monocyte count was significantly higher (P < 0.05) in the cholesterol group. Serum and intraplatelet levels of platelet-derived growth factor (BB homodimer) and transforming growth factor beta 1 were statistically unchanged after diet. Hypercholesterolaemia did not affect the proliferative effect of either serum or platelet lysates on porcine vascular smooth muscle cells and Swiss-3T3 cells in culture. A significant positive correlation between Swiss-3T3 and smooth muscle cell proliferation was present in both groups. These results suggest that the atherosclerosis-promoting effect of hypercholesterolaemia cannot be explained by its direct effect on smooth muscle cell proliferation or by changes in serum or intraplatelet concentrations of growth factors.