Prognosis of programmed ventricular stimulation in adult patients with syncope of unexplained origin: A historical cohort.

Background: Programmed ventricular stimulation (PVS) during electrophysiological study (EPS), is a globally accepted tool for risk stratification of sudden cardiac death (SCD) in some specific clinical situations. The aim of this study was to evaluate the prognosis of ventricular arrhythmia induction in a cohort of patients with syncope of undetermined origin (SUO). Methods: This is a historical cohort study in a population of patients with SUO referred for EPS between the years 2008-2021. In this interval, 575 patients underwent the procedure. Results: Patients with induced ventricular arrhythmias had a higher occurrence of structural heart disease (36.7% vs. 76.5%), ischemic heart disease (28.2 vs. 57.1%), heart failure (15.5% vs. 34.4%), and lower left ventricular ejection fraction (59.16% vs. 47.51%), when compared to the outcome with a negative study. PVS triggered ventricular arrhythmias in 98 patients, 62 monomorphic and 36 polymorphic. During a median follow-up of 37.6 months, 100 deaths occurred. Only the induction of sustained ventricular arrhythmias showed a significant association with the primary outcome (all-cause mortality) with a p value <.001. After the performance of EPS, 142 patients underwent cardioverter-defibrillator (ICD) implantation. At study follow-up, 30 patients had therapies by the device. Only the induction of sustained monomorphic ventricular arrhythmia showed statistically significant association with appropriate therapies by the device (p = .012). Conclusion: In patients with SUO, the induction of sustained monomorphic ventricular arrhythmia after programmed ventricular pacing is related to a worse prognosis, with a higher incidence of mortality and appropriate therapies by the ICD.

[Left atrium remodeling after catheter ablation of atrial fibrillation]. / Remodelado reverso de aurícula izquierda posablación de fibrilación auricular.

Atrial fibrillation (AF) is the most common cardiac arrhythmia. It has a high association with cardiovascular embolic events and heart failure. Structural and functional changes are a fundamental part of the pathophysiological process, leading to left atrial myopathy and progressive left ventricular dysfunction that modifies the prognosis of patients. We present the case of a 75-year-old patient with symptomatic paroxysmal AF with good functional class who was referred for pulmonary vein ablation after antiarrhythmic therapy failure. The initial echocardiogram showed preserved biventricular systolic function, mild diastolic dysfunction, and normal left atrium (LA) volumes. However, functional LA impairment was observed with decreased reservoir phase strain. Pulmonary vein isolation was successfully performed without evidence of new arrhythmic events, in addition to improvement in LA reservoir strain, left ventricular (LV) global longitudinal strain, and myocardial work index at three months follow-up. The patient has remained asymptomatic and is under clinical follow-up. LA and LV strain as new advanced echocardiography techniques is useful in the assessment of reverse remodeling of atrial myopathy and LV structural assessment.

Electrophysiological study as a predictor of mortality in unexplained syncope.

Background: Electrophysiological study can help in the diagnosis of arrhythmic syncope. According to the electrophysiological study finding, the prognosis of patients with syncope is still a matter of study. Objective: The aim of this study was to assess the survival of patients undergoing electrophysiological study according to their findings and to identify clinical and electrophysiological independent predictors of all-cause mortality. Methods: A retrospective cohort study included patients with syncope who underwent electrophysiological study from 2009 to 2018. A Cox logistic regression analysis was performed to identify independent prognostic factors for all-cause mortality. Results: We included 383 patients in our study. During a mean follow-up of 59 months, 84 (21.9%) patients died. The split His group had the worst survival compared with the control group, followed by sustained ventricular tachycardia and HV interval ≥ 70 ms, respectively (p = .001; p < .001; p = .03). The supraventricular tachycardia group showed no differences compared with the control group (p = .87). In the multivariate analysis, independent predictors of all-cause mortality were Age (OR 1.06; 1.03-1.07; p < .001); congestive heart failure (OR 1.82; 1.05-3.15; p = .033); split His (OR 3.7; 1.27-10.80; p = .016); and sustained ventricular tachycardia (OR 1.84; 1.02-3.32; p = .04). Conclusion: Split His, sustained ventricular tachycardia, and HV interval ≥ 70 ms groups had worse survivals when compared to the control group. Age, congestive heart failure, split His, and sustained ventricular tachycardia were independent predictors for all-cause mortality.

Brugada pattern as part of the electrocardiographic abnormalities in hyperkalemia.

A 78-year-old man presented to the emergency department with a 10-day history of diarrhea and presyncope. His electrocardiogram showed a type-1 Brugada pattern but also a first-degree atrioventricular block, right bundle branch block, and peaked and symmetrical hyperacute T waves. A blood test revealed a potassium level of 9.3 mEq/L. After hemodialysis with normalization of serum potassium, the electrocardiographic abnormalities disappeared. An ajmaline challenge excluded the possibility of Brugada syndrome.

Brugada syndrome unmasked by left ventricle posteromedial papillary muscle ventricular tachycardia: Coincidence or consequence.

A 46-year-old man presented with left ventricle posteromedial papillary muscle ventricular tachycardia, presyncope, and a type-1 Brugada pattern on the post-electrical cardioversion electrocardiogram. There was a probability of a Brugada syndrome with the expression of its disease in the left ventricle; or a left monomorphic ventricular tachycardia as a part of Brugada phenocopy; or a Brugada syndrome with left monomorphic ventricular tachycardia as an epiphenomenon. Cardiac magnetic resonance, electrophysiological study, and ajmaline test were the key diagnostic tools employed.