Search

More than 90% of sudden cardiac deaths (SCD) occur in patients with a known or previously unrecognised pre-existing coronary artery disease (CAD) or cardiomyopathy. It has become evident that SCD occurs, with sufficient frequency, in patients with an apparently normal heart, and ventricular fibrillation (VF) may represent the first clinical sign of structural heart disease that becomes manifest, only several years later, among survivors. Different causes of SCD have been documented, mainly by genetic screening and a more accurate clinical evaluation of the group of patients suffering from so-called idiopathic VF (IVF) [1–26]. Brugada syndrome [1, 5, 10, 14–16, 21–25] has been clearly shown to be one of the most frequent causes of SCD in this context, and should be differentiated from other clinical conditions or cardiac diseases [7, 13, 19, 20, 22, 26]. The purpose of the present article is: (1) to clarify the ionic alterations and electrophysiological mechanisms, underlying Brugada syndrome; (2) to verify the importance of triggering factors detected by ECG and clinical events; (3) discuss the long-term outcomes of Brugada syndrome patients and their family members.

Atrial fibrillation (AF) in both the paroxysmal and persistent atrial forms has been documented both in normal hearts without signs of demonstrable cardiac disease [1–67] and, since 1990, also in some professional and competitive athletes, by Furlanello et al. [4–17, 68–73], Maron and Mitchell [11], Fenici et al. [41] Zeppilli [42], and Naccarella and Brachetti [20, 67]. A useful classification from the diagnostic and therapeutic points of view is the following: 1. Lone vagal AF associated with severe sinus bradycardia and cardiac pauses [19,20,29,30,33–38] 2. Lone sympathetic AF induced only by strenuous physical activity or exercise test or psychological stress. [24,36–38] 3. A mixture of 1 and 2 [19,20,24] 4. AF associated with supraventricular tachycardia (RSVT) [20–27] 5. AF associated with Wolff-Parkinson-Write (WPW) syndrome or cardiac pre-excitation syndromes [21–27,32] 6. “Familial ”lone AF [29–31,43–49]

Clinical electrocardiographic evaluation and complete non-invasive assessment including nuclear magnetic resonance (NMR) are reported for 7 subjects with cardiac arrest (CA), 6 due to ventricular fibrillation (VF) and 1 to ventricular tachycardia (VT). Two more subjects, one with and one without a family history of non-resuscitated sudden death (NRSD), were included. All 9 subjects showed the typical pattern of the Brugada's syndrome (BS), characterized by incomplete right bundle branch block, ST T elevation in V1 V3. We globally evaluated 64 subjects belonging to the 9 families examined, 5 of whom were identified in Bologna, 3 in Florence and one in Parma. BS is characterized in the experience described in the present paper by a family distribution of the ECG pattern in different members. Furthermore, a family distribution of NRSD, even at a young age, was observed. Electrocardiographic features were consistent with variable degrees and aspects of the intraventricular conduction delay (ICD) and of the ST T elevation pattern. NMR has been performed so far in 23 out of 64 members examined by echo, and was normal in 17/23, with only 6 showing pathological aspects such as mild dilatation of the right ventricle, reduced thickness of the right free wall, isolated dilatation of the right ventricular infundibulum and other minor pathological aspects. Preliminary genetic screening (GS), performed on 20 members of three families, was negative for the typical genetic patterns of right ventricular dysplasia (ARVD). In six families, GS is still ongoing. Genetic screening of sodium channel pathology is in progress in the same families. In conclusion, BS has been documented in the present paper as a hereditary syndrome, both for clinical and ECG aspects, associated with CA due to VF, which required an AICD implantation, at least in symptomatic subjects. There may exist a CONGENITAL form of BS due to pathology of sodium channels, without a demonstrable structural heart disease and an ACQUIRED form of BS secondary to an initial ARVD. From the clinical point of view, a complete evaluation, including serial ECG, pharmacological testing and programmed electrical stimulation of other subjects in the families, may be important in preventing sudden death, mainly in symptomatic subjects who always require an implantable cardioverter defibrillator.