Diagnosis of type 2 Brugada pattern: insights from a pilot survey.

BACKGROUND: Differentiation of Type 2 Brugada Pattern (BP) from incomplete right bundle branch block or normal rSr' pattern can be insidious. The aim of this study was to assess interobserver and intraobserver agreement in the diagnosis of type 2 BP in a cohort of cardiologists with different skills. METHODS: We collected 14 ECGs with a positive terminal deflection of the QRS complex in lead V1 and V2 at the 4th intercostal space. We proposed these ECGs, specifying to use 2012 Consensus conference criteria for diagnosis of type 2 BP, to 42 participants: 14 arrhythmologists, 14 general cardiologists and 14 electrophysiology (EP) fellows. The same 14 ECGs, with a different order, were proposed fifteen days later to the same cohort to assess intraobserver variability. Authors analyzed all 14 ECGs in order to assess whether 2012 Consensus Conference criteria for BP were fulfilled. All patients underwent provocative test with IC antiarrhythmics drugs (flecainide) in order to exclude or confirm the diagnosis of Brugada Syndrome (BrS). RESULTS: Slight interobserver agreement (Fleiss K<0.20) in the diagnosis of type 2 BP was observed in all three categories of cardiologists. Considering five operators per class, intraobserver agreement is variable (k ranging from 0.000 to 0.857), with a slight superiority of arrhytmologists (k minimum value 0.276; k maximum value 0.857). CONCLUSIONS: This study demonstrated, for the first time, a low interobserver agreement in diagnosis of type 2 BP in categories of cardiologists with different abilities. Reproducibility of type 2 BP diagnosis (intraobserver agreement) is poor, even among experts. These findings highlight the difficulties in analysis of ECG with BrS suspicion and, therefore, underscore the key role of clinical and anamnestic data.

Functional atrial undersensing associated with device algorithm promoting AV conduction.

A 58-year-old woman received a dual chamber pacemaker (Medtronic) for sick sinus syndrome. Given intact AV conduction the Managed Ventricular Pacing mode algorithm (MVP) was programmed. The day after, she suffered from palpitations. Her ECG showed a possible loss of atrial capture accompanied by atrial undersensing. Telemetry-supported pacemaker control confirmed the loss of capture. Undersensing of atrial signal was functional, related to long atrial refractory period in MVP mode algorithm. Device algorithms could induce false suspicions. Awareness about the different pacing algorithms can be useful in order to avoid erroneous interpretations and to correct potential malfunctioning.

A Case of Brugada Pattern Migrant from Right Precordial Leads to Peripheral Leads.

Since the first report in 1992, Brugada pattern (BP) diagnosis is mainly based on analysis of the precordial leads. In cases with no clear BP evidence in the conventional right precordial leads (4th intercostal space), limb leads analysis resulted helpful in suspecting BP. Fluctuations within right precordial leads between the diagnostic ECG pattern and nondiagnostic ECGs are well known. For the first time, in the patient herewith reported, the transformation of BP phenotype involves both precordial and peripheral leads, confirming that the analysis of all the 12 leads has a key role in BP diagnosis.