1. Internal Medicine Department, Cardiology Division, Federal University of Pernambuco, Recife 50670-901, Brazil
2. Cardiology Emergency Room of Pernambuco, University of Pernambuco, Recife 52010-010, Brazil
3. Internal Medicine Department, Maurício de Nassau University, Recife 51021-140, Brazil
4. Internal Medicine Department, Faculty of Medicine of Sertão, Arcoverde 56512-670, Brazil
5. Mestre Vitalino Hospital, Caruaru 55015-901, Brazil
6. Galeão Air Force Hospital, Rio de Janeiro 21941-353, Brazil