1. Graduate Program in Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, RS, Brazil
2. School of Nursing, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre 90620-110, RS, Brazil
3. Cardiology Department, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre 90035-903, RS, Brazil
4. Nursing Department, Faculdades Integradas de Taquara (FACCAT), Taquara 95612-150, RS, Brazil
5. Department of Medicine, University of Colorado, Denver, CO 80045, USA