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.

"Pseudodisappearance" of atrial electrogram during orthodromic tachycardia: new criteria for successful ablation of concealed left-sided accessory pathways.

OBJECTIVES: This study sought to analyze two new criteria along with other known predictors of success of radiofrequency ablation. Background. Although the overall success rate of radiofrequency ablation of accessory pathways is high, the individual predictive value of each of the established criteria is low. METHODS: We prospectively studied the local electrograms obtained before the application of radiofrequency energy in 33 patients with a left-sided concealed accessory pathway successfully ablated. Two new criteria ("pseudodisappearance" during tachycardia of a bipolar atrial electrogram visible during sinus rhythm and the presence of an "atrial notch" in the ascending limb of the unipolar ventricular electrogram during tachycardia) were studied along with other known predictors. Electrograms recorded at a total of 157 sites were analyzed (33 successful applications, 124 failures). RESULTS: Electrogram characteristics that were predictive of success during ablation on the basis of univariate analyses were a pseudodisappearance criterion (p<0.001), the presence of a Kent potential (p<0.005) and the presence of an "atrial notch" (p<0.005). After adjustment for between-patient differences, logistic regression analysis showed that only the "pseudodisappearance" criterion (odds ratio [OR] 7.2, 95% confidence interval [CI] 1.2 to 42.5, p<0.03) and the presence of a Kent potential (OR 2.4, 95% CI 1.01 to 5.79, p<0.05) had independent predictive value. CONCLUSIONS: The pseudodisappearance during tachycardia or ventricular pacing of a bipolar atrial electrogram present during sinus rhythm is associated with a good outcome during radiofrequency ablation of concealed accessory pathways. These observations may help to ablate accessory pathways and to avoid missing appropriate sites for ablation when the atrial activation is not clearly visible at the local electrogram.

Evidence favoring the hypothesis that ventricular arrhythmias have prognostic significance in left ventricular hypertrophy secondary to systemic hypertension.

In the present review 6 lines of evidence will be discussed that suggest a prognostic significance for ventricular arrhythmias in patients with systemic hypertension and left ventricular hypertrophy: (1) in patients with systemic hypertension there is a statistical relation between asymptomatic ventricular arrhythmias and left ventricular hypertrophy; (2) in nonhypertensive left ventricular hypertrophy the prognostic value of ventricular arrhythmias is well known; (3) left ventricular hypertrophy is related to sudden death in patients with systemic hypertension; (4) it is generally acknowledged that ventricular arrhythmias are a frequent cause of sudden death; (5) there is experimental evidence to support the arrhythmic risk of left ventricular hypertrophy; and (6) it has been recently demonstrated that ventricular arrhythmias influence mortality in patients with left ventricular hypertrophy secondary to systemic hypertension. However, whether asymptomatic ventricular arrhythmias are specific markers for more severe sustained arrhythmias, or just markers for a more severe stage of the disease, remains to be determined.

Radiofrequency catheter ablation of ventricular tachycardia from right ventricle late after myocardial infarction.

In summary, this case illustrates how complex VT circuits may be. If the findings of this case are substantiated with additional cases, mapping and radiofrequency energy application from right ventricle would have to be considered in VT with left bundle branch blocks QRS morphology, whenever ablation from the left ventricule is ineffective.

Randomized, prospective comparison of four burst pacing algorithms for spontaneous ventricular tachycardia.

"Less aggressive" burst stimulation is more effective in terminating spontaneous monomorphic ventricular tachycardia with a lesser acceleration rate. Higher ventricular tachycardia cycle length and use of 91% coupling interval were independent predictors for pacing termination.

In patients with chronic atrial fibrillation and left ventricular systolic dysfunction, restoration of sinus rhythm confers substantial benefit.

STUDY OBJECTIVES: To evaluate the benefit of sinus rhythm (SR) restoration in patients with chronic controlled atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD). DESIGN: Prospective case-control study on the short-term outcome (6 to 9 months) of clinical and echocardiographic variables following attempted cardioversion. SETTING: Outpatient clinic of a university hospital. PATIENTS: Fifteen men and 5 women, ranging in age from 40 to 76 years, who had chronic controlled (mean [+/- SD] ventricular rate, 82 +/- 10 beats/min) AF and left ventricular fractional shortening (LVFS) of < 28% at baseline. Control was provided by retrospective paired echocardiographic examinations of six AF patients, plus the study cases with potentially unsuccessful cardioversion or early recurrence of AF. INTERVENTIONS: Attempt to restore SR with amiodarone or electrical countershock. MEASUREMENTS AND RESULTS: Conversion was attained in 17 patients, but AF recurred early in 4 patients, 3 of whom had proven ischemic LVSD. In the 13 patients with sustained SR, LVFS increased from 20 +/- 4% to 31 +/- 6% (p < 0.0001). In contrast, no changes were detected in the control group (n = 13). This improvement was paralleled by decreases in left ventricular (LV) end-diastolic dimension (from 55 +/- 7 to 51 +/- 6 mm; p = 0.014), LV mass (from 181 +/- 28 to 159 +/- 37 g; p = 0.015), and left atrial diameter (from 45 +/- 9 mm to 42 +/- 7; p = 0.003). A marked decrease in heart rate (from 82 +/- 9 to 64 +/- 5 beats/min; p < 0.0001) and a reduction in New York Heart Association functional class (from 2.3 +/- 0.9 to 1.2 +/- 0.4; p = 0.0007) also were observed in patients with sustained SR but not among subjects in the control group. CONCLUSIONS: Even when adequate control of the ventricular rate has been achieved, the LV function of patients with chronic AF greatly improves after restoration and maintenance of SR.

The value of exercise electrocardiography testing in the identification of coronary restenosis: a probability analysis.

We studied by means of probability analysis the role of exercise ECG in identifying coronary restenosis. A total of 213 patients were independently evaluated by clinical history, conventional assessment of the exercise ECG ('yes or no' statement), D score (a discriminant function derived from exercise ECG), and coronariography, 5.4 +/- 2.8 months after successful coronary angioplasty. The initial probability of restenosis (30%), that is, the prevalence of the condition, was radically changed by the result of clinical history (77% for patients with angina vs. 17% for those without angina). By contrast, ECG binary assessment, due to its low accuracy (70% vs 82% of clinical history, P < 0.005), was unable to significantly change the established probabilities after symptomatic evaluation. Finally, D score, which greatly enhanced specificity (92% vs. 76% of bivariate assessment, P < 0.0001), proved to be useful in changing the probability (from 32% to 76% or to 25%) of patients (n = 34) with a discordant result (no angina/positive exercise ECG). When this stepwise approach was tested in 46 new patients, predicted and observed probabilities were actually very similar. We conclude that exercise ECG has a very limited role in identifying coronary restenosis if positive responses are not adjusted with a weighted score which takes into account other exercise derived factors.

[Double subvalvular aortic stenosis (fixed and dynamic) diagnosed by ECHO-Doppler]. / Doble estenosis subvalvular aórtica (fija y dinámica) diagnosticada con ECO-Doppler.

Fixed subvalvular aortic stenosis is an uncommon cause of left ventricular outflow obstruction which occasionally can be found in association with dynamic muscular obstruction. In the past, the diagnosis of this association has been difficult and relied upon cardiac catheterization and angiography. To our knowledge, no case of this pathology diagnosed by echo and Doppler has previously been reported. We present a case of double subvalvular aortic stenosis in a 35 years old patient which illustrates the feasibility of detection with echo and Doppler of both types of subvalvular aortic obstruction.

[Probability analysis of the value of ergometry in the detection of restenosis after coronary angioplasty]. / Análisis probabilístico del valor de la ergometría en la detección de reestenosis tras angioplastia coronaria.

To evaluate the usefulness of treadmill exercise test in the diagnosis of coronary restenosis, we have chosen a sequential and probabilistic analysis. The rate of coronary restenosis found in the sample (n = 213) was of 30%. This initial probability of having restenosis was radically changed by the recurrence of typical angina: 77% in patients with this symptom, 17% in those without (p < 0.001). In contrast, the qualitative result of the exercise test was unable to change significantly the probabilities established after anamnesis. This was due to a lower specificity for exercise test (76%) than for angina (93%), the sensibility being the same (56%) for both. Employment of a discriminant value that integrates different ergometric variables did not enhanced sensibility, but allowed the identification of a good number of false positive results and therefore palliated the negative impact of faulty specificity. Being applied to a "discordant group" (no angina/positive exercise test, n = 34) was able to achieve a significant change in probability: from 15% to 50% or 4% (p < 0.01), according to the discriminant being lesser or greater than a preestablished value. In conclusion, prevalence of the event and evaluation of symptomatology are both important to estimate the probability of suffering coronary restenosis. On the contrary, exercise test, in the absence of a weighty method, adds more confusion than clarity to the analysis of the problem. Our results can be used to improve the follow-up of patients who have been successfully dilated by angioplasty.

[Radiofrequency ablation of a posteroseptal accessory pathway associated with coronary sinus diverticulum]. / Ablación con radiofrecuencia de una vía accesoria posteroseptal asociada a un divertículo en el seno coronario.

The case of a patient with a symptomatic Wolff-Parkinson-White syndrome undergoing attempted radiofrequency catheter ablation of a posteroseptal accessory pathway is described. Coronary sinus venography revealed the presence of a diverticulum attaching near the os. The electrogram recorded from a catheter placed in the narrow neck of the diverticulum revealed a short atrioventricular time during sinus rhythm. The pathway was easily ablated using radiofrequency energy applied in the neck of the diverticulum, after multiple failed attempts at catheter ablation from the endocardial surface of the posteroseptal space. Our report emphasizes the importance of searching for a coronary venous diverticulum in all patients with posterior accessory pathways undergoing catheter ablation.

[A mid-term clinical and hemodynamic evaluation of the Wessex and Hancock II bioprostheses]. / Valoración clínica y hemodinámica a medio plazo de las bioprótesis de Wessex y Hancock II.

The purpose of this study is to compare clinically and hemodynamically the Wessex and Hancock II porcine bioprostheses. We compared functional class and data from echo-Doppler in 34 Wessex bioprostheses (group A) with those in 42 Hancock II bioprostheses (group B). We subdivided group A into A1 and A2. A1 was made up of 23 Wessex manufactured since 1986. A2 constituted 11 Wessex made before 1986 which belonged to a series with some variations in the manufacturing process, and in which some early dysfunctions have been described. We compared data from these sub-groups between each other as well as with those of group B. The groups were homogeneous in age, sex, patients body surface and the time elapsed since the prosthetic implant. The mean mitral gradient, the mitral area, the peak aortic gradient and the regurgitation incidence were similar in groups A and B. In A2 the mean mitral gradient was significantly superior to that of group B (7.1 +/- 1.1 mmHg vs 5.4 +/- 1.4 mmHg; p less than 0.01), and the mitral area showed a tendency to be inferior, although with no statistical significance. The functional class of the patients was similar in all the groups. We conclude that the Wessex bioprosthesis presents hemodynamic data and functional class similar to those of the Hancock II, with the exception of a sub-group of Wessex manufactured before 1986 which presents mean mitral gradients superior to the others and which would warrant further studies.

[Guidelines of the Spanish Society of Cardiology on requirements and equipment in electrophysiology]. / Guías de práctica clínica de la Sociedad Española de Cardiología sobre requerimientos y equipamiento en electrofisiología.

Due to the enormous qualitative and quantitative evolution that clinical electrophysiology has experienced over the past years, specific Units dedicated to the management of patients with cardiac arrhythmias have been created. In these guidelines, the minimum technical and human needs of an Arrhythmia Unit are discussed.

[The tilt-table test in assessing syncope of unknown origin: do differences exist between children and adults?]. / El test de basculación en la evaluación del síncope de origen desconocido: existen diferencias entre niños y adultos?

BACKGROUND AND OBJECTIVES: Little is known about the differences between children and adults in the results of head-up tilt test. This study sought to investigate the potential differences concerning: a) the clinical profile and circumstances of spontaneous syncope; b) the overall diagnostic performance of the test, and c) the type of positive response obtained. MATERIAL AND METHODS: We studied 31 children and 123 adults with unexplained syncope. If baseline test (tilting at 70 degrees for 30 min) resulted negative, it was repeated under isoprenaline low-dose infusion. RESULTS: There were no differences in either clinical profile, except for severe traumatism more frequent in adults (25% vs. 3% in children; p < 0.05), or overall diagnostic performance (39% in children vs. 33% in adults; p = NS). However, the way the test rendered positive (via basal tilting in 92% of children vs. 50% in adults; p < 0.05) and the rate of cardioinhibitory response (42% in children vs 8% in adults; p < 0.01) were significantly different. CONCLUSIONS: In this study children, in contrast to adults, rarely have a positive response in tilting under isoprenaline infusion. They also present a much higher rate of cardio-inhibitory response than adults.

[Comparative study of 3 algorithms to localize the accessory pathway in Wolff-Parkinson-White syndrome]. / Estudio comparativo de tres algoritmos de localización de la vía accesoria en el síndrome de Wolff-Parkinson-White.

BACKGROUND AND OBJECTIVES: Some electrocardiographic algorithms have been developed to predict the location of the accessory pathway in the WPW syndrome. Few studies address the interobserver variability of such algorithms and the possible observer-dependent changes of accuracy. This study analyzes three algorithms to localize accessory pathways recently published, comparing the inter-observer variability, their predictive value and the most frequent problems observed during their application. METHODS: Ninety-six electrocardiograms from patients who underwent successful ablation of a single accessory pathway were reviewed. The location of each pathway was predicted by two independent observers according to three different reported electrocardiographic algorithms. The interobserver agreement, percentage of correct predictions and critical steps of each algorithm were analyzed. RESULTS: The interobserver agreement varied between 64 and 79% and the accuracy between 38 and 67%. The best results were obtained in the left lateral accessory pathways (69 to 89% correctly located). All the algorithms presented critical steps at which more than 20% of pathways were incorrectly classified. CONCLUSIONS: The analyzed algorithms present a high interobserver variability. The accuracy obtained is clearly lower than that reported by the corresponding authors. These facts should be considered when being used them in clinical settings.

[Usefulness of the angiographic examination of the left internal mammary artery in patients candidates for coronary bypass surgery]. / Utilidad del examen angiográfico de la arteria mamaria interna izquierda en pacientes candidatos a cirugía de derivación coronaria.

BACKGROUND AND OBJECTIVE: The usefulness of preoperative angiographic evaluation of the internal mammary artery (IMA) is controversial. The aim of this study is to evaluate the problem by a basic cost-benefit analysis. METHODS: One hundred and twenty-one patients whose coronary findings (left main disease and/or severe stenosis of the left anterior descending artery) made use of the IMA as a bypass graft a consideration were studied. The IMA was cannulated by the same right Judkins catheter used in the coronarography; the specific catheter was only used if the cannulation was not successful with the right Judkins. We measured the time it took for a good angiography of the IMA to be obtained; the anatomy and the size for each IMA were studied and compared with the size of the left anterior descending artery. RESULTS: An optimal angiographic picture of the IMA was obtained in 119 cases (98.3%); a specific catheter was used only in 3 patients. The mean of the time employed was 170 seconds (8-900 s) and no complications were related to IMA cannulations. Angiography findings relevant to any planned surgery were demonstrated in 15 patients (12%): large proximal branches (10); occlusion stenosis or a caliber insufficient for IMA (3); and occlusion or proximal subclavian stenosis (2). CONCLUSIONS: We have observed that the relation between the cost and the obtained information is adequate to warrant its performance, because angiographic findings relevant to planned surgery can be very important, even though they are fairly infrequent. Moreover, these findings can be achieved rapidly without additional cost.

Value of single oral loading dose of propafenone in converting recent-onset atrial fibrillation. Results of a randomized, double-blind, controlled study.

AIMS: To evaluate the efficacy and safety of a single loading oral dose of propafenone in the interruption of recent-onset atrial fibrillation. METHODS: After a complete medical history, physical examination, 12-lead ECG, chest X-ray, and routine biochemical laboratory testing, 55 consecutive patients with recent-onset atrial fibrillation were randomized double-blind in the emergency department for the administration of either a single oral dose (450 to 750 mg) of propafenone (29 cases) or a placebo (26 cases). After the 24-h observation period, comprehensive echocardiographic examination was performed. RESULTS: The groups were homogeneous as regards biological, clinical and echocardiographic characteristics. Two hours after treatment, 12 patients (41%) on propafenone but only two (8%) on placebo had converted to sinus rhythm (P = 0.005). This striking difference was maintained 6 h after treatment (65 vs 31%; P = 0.015) but lessened at 12 h (69% vs 42%; P = 0.060) and was insignificant at the end of the 24-h treatment period (79%, vs 73%; P = 0.752). Apart from hypotension, transient in three cases and sustained in one whose later echocardiographic examination demonstrated left systolic ventricular dysfunction, propafenone was well tolerated. CONCLUSION: Although there is no significant difference in the rates of conversion 24 h after treatment, propafenone works faster than placebo in achieving sinus rhythm. This rapid action of oral propafenone can be useful to solve quickly the clinical problems of a high proportion of patients arriving at the emergency department with acute atrial fibrillation.

Incidence and clinical significance of multiple consecutive, appropriate, high-energy discharges in patients with implanted cardioverter-defibrillators.

BACKGROUND: Some patients with an automatic implantable cardioverter-defibrillator (ICD) suffer multiple appropriate, consecutive, high-energy discharges (MCDs) during follow-up. Such events might represent resistant ventricular arrhythmias and might have prognostic significance. METHODS AND RESULTS: Eighty consecutive patients with an ICD were followed up for up to 82 months (mean, 21 +/- 19 months). Thirty-eight patients had survived an out-of-hospital cardiac arrest and 42 had recurrent ventricular tachycardia. During follow-up, 16 patients had MCD (group A), 26 patients had episodes of single appropriate discharges (group B), and 38 patients had no appropriate discharges (group C). Group A patients had worse functional status (P = .001), lower left ventricular ejection fractions (LVEFs) (P = .001), and lower survival rates (log rank, P = .003) than the remaining two groups of patients. Cox analysis showed LVEF (P = .001) to be an independent predictor of MCD. Independent predictors of death or heart transplant were MCD (P = .001), female sex (P = .001), age (P = .001), history of cardiac arrest (P = .003), and functional status (P = .003). The only independent predictor of total mortality was female sex (P = .002). Independent predictors of cardiac death were MCD (P = .007) and female sex (P = .018). Independent predictors of arrhythmic death were age (P = .001), female sex (P = .02), and MCD (P = .023). CONCLUSIONS: In patients with an ICD, the development of MCD is an independent predictor of cardiac and arrhythmic mortality. If this finding is confirmed in larger studies, it may help to identify patients in whom other therapeutic alternatives, ie, heart transplantation, should be considered during follow-up after ICD implantation.