Role of Provocable Brugada ECG Pattern in The Correct Risk Stratification for Major Arrhythmic Events

The so-called Brugada syndrome (BS), first called precordial early repolarization syndrome (PERS), is characterized by the association of a fascinating electrocardiographic pattern, namely an aspect resembling right bundle branch block with a coved and sometime upsloping ST segment elevation in the precordial leads, and major ventricular arrhythmic events that could rarely lead to sudden death. Its electrogenesis has been related to a conduction delay mostly, but not only, located on the right ventricular outflow tract (RVOT), probably due to a progressive fibrosis of the conduction system. Many tests have been proposed to identify people at risk of sudden death and, among all, ajmaline challenge, thanks to its ability to enhance latent conduction defects, became so popular, even if its role is still controversial as it is neither specific nor sensitive enough to guide further invasive investigations and managements. Interestingly, a type 1 pattern has also been induced in many other cardiac diseases or systemic diseases with a cardiac involvement, such as long QT syndrome (LQTS), arrhythmogenic right ventricular cardiomyopathy (ARVC), hypertrophic cardiomyopathy (HCM) and myotonic dystrophy, without any clear arrhythmic risk profile. Evidence-based studies clearly showed that a positive ajmaline test does not provide any additional information on the risk stratification for major ventricular arrhythmic events on asymptomatic individuals with a non-diagnostic Brugada ECG pattern.

Intraoperative defibrillation threshold testing during implantable cardioverter-defibrillator insertion: do we really need it?

BACKGROUND

The assessment of defibrillation efficacy using a safety margin of 10 J has long been the standard of care for insertion of implantable cardioverter-defibrillator (ICD), but physicians are concerned about complications related to induction test. Therefore, the need for testing has been recently questioned. The aim of our study was to assess the impact of defibrillation threshold (DFT) testing of ICD on the efficacy of ICD therapy.

METHODS

We analyzed data obtained from follow-up visits of 122 consecutive patients who underwent ICD implantation at our institute from April 1996 to June 2008, with (n = 42) or without (n = 80) DFT testing. Patients in the DFT group were less likely to be men (83.3% vs 96.3%, P < .031) than those in the non-DFT group. Conversely, the 2 groups were similar in age, left ventricular ejection fraction at baseline, functional class, and underlying cardiovascular disease. Results during a 12-month follow-up, 13 (31.0%) and 30 (37.5%) ventricular tachyarrhythmic episodes were recorded in the DFT and non-DFT groups, respectively (P = .472). Antitachycardia pacing (ATP) terminated most of episodes, reducing the need of defibrillation at 7.7% in the DFT group and 3.3% in the non-DFT group (P = .533). Similar percentages of inappropriate ATP interventions (7.1% vs 3.8%, P = .413) and shock deliveries (2.4% vs 5.0%, P = .659) were recorded between DFT and non-DFT groups.

CONCLUSIONS

At 1-year follow-up, the performance of DFT testing does not seem to add any significant efficacy advantage in patients undergoing ICD implantation. Prospective randomized trials and long-term follow-up are warranted to clarify whether routine DFT testing may be safely abandoned leading to a revision of current guidelines.

Recurrent respiratory infections in childhood: experience with a bacterial extract plus bacterial ribosomes (Immucytal)

A total of 60 children (mean age +/- SD 7.6 +/- 3.5 years, range 2 - 14.2 years) with recurrent respiratory infections were treated with bacterial wall extract plus bacterial ribosomes (Immucytal) or placebo sprayed into the nostrils and oropharynx three times a day for 1 or 2-week periods over 3.5 months. The treatment was completed by 58 subjects; two patients in the placebo-treated group were withdrawn, one for poor compliance and the other because of headaches. Respiratory symptoms improved from the first month in the Immucytal treated children, but not in the placebo group, with a reduction in the incidence of infections in the upper and lower airways. No changes were noted in respiratory function parameters. Treatment with Immucytal significantly increased serum immunoglobulin A (P less than 0.02) and immunoglobulin M (P less than 0.01) and enhanced skin response to the in vivo lymphocyte blastization test, but there was no significant change in the circulating lymphocyte subpopulations. Both physicians and the patients' parents judged the bacterial extract to be clinically better than the placebo. Immucytal, therefore, may provide a useful alternative therapy for recurrent respiratory infections in infancy.

Domiodol treatment for bronchopulmonary diseases in the paediatric age group: a double-blind controlled clinical trial versus placebo

Thirty children (25 males, five females), mean age 9.33 +/- 2.57 years, with acute infectious pulmonary diseases or acute flare-ups of chronic bronchitis, were randomly treated with either domiodol or placebo. The study was conducted between November 1986 and February 1987. Domiodol was administered orally for 14 days in doses of 0.5 mg/kg three times daily. Subjective symptoms (cough, sputum viscosity, difficulty in raising sputum and sputum characteristics) were assessed semi-quantitatively. They were all reduced significantly in the group treated with domiodol compared to those given placebo. Spirometric measures of vital capacity and peak expiratory flow rate were also improved in patients given domiodol compared with placebo. Conversely, no differences were noted in forced expiratory volume in 1 s, Tiffenau index, or mid-expiratory flow. There were no clinical side-effects and no changes in any other parameters measured; in particular, levels of thyroid hormone and thyroid stimulating hormone were unchanged. Thus, domiodol proved effective in reducing the symptoms of infection of the lower respiratory tract and in improving the consistency of mucus in children.