BACKGROUND: Obstructive sleep apnea (OSA) is one of the main risk factors for cardiovascular diseases and is associated with both morbidity and mortality. OSA has also been linked to arrhythmias and sudden death.
OBJECTIVE: To assess whether OSA increases the risk of sudden death in the non-cardiac population.
METHODS: This is a systematic review of the literature. The descriptors \"sudden death\" and \"sleep apnea\" and \"tachyarrhythmias\" and \"sleep apnea\" were searched in the PubMed/Medline and SciELO databases.
RESULTS: Thirteen articles that addressed the relationship between OSA and the development of tachyarrhythmias and/or sudden death with prevalence data, electrocardiographic findings, and a relationship with other comorbidities were selected. The airway obstruction observed in OSA triggers several systemic repercussions, e.g., changes in intrathoracic pressure, intermittent hypoxia, activation of the sympathetic nervous system and chemoreceptors, and release of catecholamines. These mechanisms would be implicated in the appearance of arrhythmogenic factors, which could result in sudden death.
CONCLUSIONS: There was a cause-effect relationship between OSA and cardiac arrhythmias. In view of the pathophysiology of OSA and its arrhythmogenic role, studies have shown a higher risk of sudden death in individuals who previously had heart disease. On the other hand, there is little evidence about the occurrence of sudden death in individuals with OSA and no heart disease, and OSA is not a risk factor for sudden death in this population.

OBJECTIVE: According to current international guidelines, hypertrophic cardiomyopathy (HCM) patients should be managed in specialized units. However, there is lack of data on the impact of the creation of these units in the management of HCM patients. Our goal was to assess the impact of the creation of an Inherited Inherited Diseases Cardiac Unit (ICDU) in the current management of patients with HCM.
METHODS: We analyzed 114 consecutive patients (62.6±8 years old, 70.2% males) with HCM. Variables related to optimal management of HCM patients and their family study were recorded, as well as guidance on the risk of sudden death. We analyzed whether patients were assessed by the ICDU or at a general cardiology consultation (GCC).
RESULTS: 50 patients were assessed in the IDCU and 64 in the GCC. Familial screening was more frequent in patients assessed by the IDCU (45.3% vs. 4%; p<0.01), requesting more genetic studies of the index case (70.3% vs. 14%; p<0.01) and cardiac magnetic resonance (53.1% vs. 18%; p<0.01). Sudden death risk score was performed more frequently in patients after the creation of an IDCU (67.2% vs. 28%; p<0.01). Treatment with beta-blockers was similar in both groups (72% vs. 78.1%; p=0.24). An implantable cardiac defibrillator was indicated similarly in both groups (12.5% in ICDU and 6% in GC; p=0.24).
CONCLUSIONS: The implementation of an IDCU improved the quality of the medical care for HCM patients by performing a better study of the patients and their families.

Chagas disease is among the neglected tropical diseases recognized by the World Health Organization that have received insufficient attention from governments and health agencies. Chagas disease is endemic in 21 Latin America regions. Due to globalization and increased migration, it has crossed borders and reached other regions including North America and Europe. The clinical presentation of the disease is highly variable, from general symptoms to severe cardiac involvement that can culminate in heart failure. Chagas heart disease is multifactorial, and can include dilated cardiomyopathy, thromboembolic phenomena, and arrhythmias that may lead to sudden death. Diagnosis is by methods such as enzyme-linked immunosorbent assay (ELISA) and the degree of cardiac involvement should be investigated with complementary exams including ECG, chest radiography and electrophysiological study. There have been insufficient studies on which to base specific treatment for heart failure due to Chagas disease. Treatment should therefore be derived from guidelines for heart failure that are not specific for this disease. Heart transplantation is a viable option with satisfactory success rates that has improved survival.

Crisponi syndrome is a rare and severe heritable disorder characterised by muscle contractions, trismus, apnea, feeding troubles, and unexplained high fever spikes with multiple organ failure. Here we report perioperative care for endoscopic gastrostomy of a 17 month-old female child with Crisponi syndrome. Temperature in the surgery room was strictly monitored and maintained at 19°C. The patient was exposed to both inhaled and intravenous anesthetic agents. Surgical and perioperative periods were uneventful. Episodes of fever in Crisponi syndrome arise from CRLF1 mutation, which differs from the physiological pathway underlying malignant hyperthermia.

Young athletes are considered the healthiest group in society. Although rare, there are still reports of sudden death or cardiac arrest on the playing fields. Clinical evaluation is of paramount importance for the identification of possible pathological states that confer increased risk of these events. Interpretation of the electrocardiogram of young athletes can help identify changes associated with heart disease that might preclude the participation in sports. In this context, it is essential to recognize the electrocardiographic patterns that represent the structural and electrical remodeling resulting from continued adaptation to exercise, and which thus do not increase the risk of adverse events during exercise. The European Society of Cardiology (ESC) and the American Heart Association (AHA) have issued consensus documents summarizing which electrocardiographic abnormalities should be considered \'physiological\', resulting from adaptation to exercise (\'athlete\'s heart\'), and which should be considered pathological and thus require further study. However, the two societies have different approaches with respect to the electrocardiographic screening of athletes. This paper provides a brief review of current evidence regarding the electrocardiographic findings considered normal and abnormal in athletes, and presents the arguments of the ESC and AHA for electrocardiographic screening in this population.

Risk stratification of sudden death in patients with Brugada syndrome (BrS) is a controversial issue, and there is currently no consensus on the best method. Examination of data from the natural history of the disease is of fundamental importance and may help to identify relatives at risk. At the same time, study of the genetic mutations responsible for the disease may also contribute to risk stratification of the syndrome, enabling identification of asymptomatic relatives carrying mutations. This paper presents the case of a young man, aged 26, monitored as a pediatric cardiology outpatient from birth for a simple structural heart defect not requiring surgery. Analysis of the evolution of the patient\'s electrocardiogram revealed the appearance, at the age of 20, of a pattern compatible with type I BrS. Following an episode of syncope and induction of polymorphic ventricular tachycardia in the electrophysiological study, a cardioverter-defibrillator was implanted. One year later, a single shock terminated an episode of ventricular fibrillation. A molecular study of the SCN5A gene identified a rare mutation, c.3622G>T (p.Glu1208X), recently described and associated with more severe phenotypes in patients with BrS, as in the case presented.

BACKGROUND: Risk stratification of Brugada syndrome (BrS) remains controversial and recommendations for an implantable cardioverter-defibrillator (ICD) are not well established. The objective of this study was to assess the long-term prognosis of BrS patients with an ICD.
RESULTS: Of 55 consecutive patients with BrS assessed between April 2002 and October 2012, 36 (mean age 41.7 ± 13.8 years; 81.8% male) underwent ICD implantation. Nineteen (52.8%) were asymptomatic, 11 (30.6%) had previous history of syncope (arrhythmic cause suspected in eight) and six (16.7%) had aborted sudden cardiac death (SCD). Spontaneous type 1 electrocardiographic (ECG) pattern was present in 25 (69.4%) patients and electrophysiological study (EPS), performed in 26 (72.2%), was positive in 22 (84.6%). During a mean follow-up of 74 ± 40 months (>5 years in 72% of cases), seven (19.4%) patients had appropriate shocks (annual event rate 2.8%). These patients most frequently had aborted SCD (54.1% vs. 6.9%; p=0.008) and nonsustained ventricular tachycardia (57.1% vs. 10.3%; p=0.016) during follow-up. Spontaneous type 1 ECG pattern, syncope and positive EPS were not significantly associated with appropriate shocks. Multivariate analysis revealed that aborted SCD was an independent predictor of appropriate shocks (HR 8.07, 95% CI 1.58-41.2; p=0.012). ROC curve analysis demonstrated that aborted SCD had moderate discriminatory power to predict appropriate shocks (AUC 0.751), with sensitivity of 57% and specificity of 93%. In terms of ICD-related complications, eight (22.2%) patients had inappropriate shocks during the follow-up period, mainly due to sinus tachycardia (five patients); one patient had lead infection and another had a lead fracture.
CONCLUSIONS: In this population of BrS patients with ICD, the long-term rate of appropriate shocks was 2.8%/year. Aborted SCD was associated with a higher risk of appropriate shocks, whereas syncope and spontaneous type I ECG pattern did not predict this event.

Intense and regular physical exercise is responsible for various cardiac changes (electrical, structural and functional) that represent physiological adaptation to exercise training. This remodeling, commonly referred to as \'athlete\'s heart\', can overlap with several pathological entities, in which sudden cardiac death may be the first clinical presentation. Although pre-competitive screening can identify athletes with life-threatening cardiovascular abnormalities, there are no widely used standardized pre-participation programs and those currently implemented are controversial. Data from personal and family history, features of physical examination and changes in the 12-lead electrocardiogram can raise the suspicion of cardiac disease and lead to early detection of entities such as hypertrophic cardiomyopathy. However, interpreting the electrocardiogram is often challenging, because some changes are considered physiological in athletes. Thus, clinical decision-making in such cases can prove difficult: missing a condition associated with an increased risk of life-threatening events, or conversely, mislabeling an athlete with a disease that leads to unnecessary disqualification, are both situations to avoid. This paper provides an up-to-date review of the physiological cardiac effects of exercise training and highlights key points that should be taken into consideration in the assessment of young competitive athletes.

In 1992, Brugada and Brugada first described a new entity, which became known as Brugada syndrome, that is associated with a high risk of ventricular arrhythmias and sudden cardiac death in patients without structural heart disease. This syndrome is characterized by a distinct electrocardiographic phenotype, type 1 Brugada pattern, consisting of a coved ST-segment elevation (≥0.2 mV) followed by a negative T wave in more than one right precordial lead. This pattern is dynamic, and can be spontaneous or concealed, but is unmasked under certain circumstances, like febrile states. The authors report a case in which the diagnosis of Brugada syndrome was made in the course of etiologic investigation of recurrent syncope in a febrile state.