Safety, Utility, and Outcomes of Procainamide Challenge for the Diagnosis and Exclusion of Brugada Syndrome
Abstract
BACKGROUND: The safety, yield, and prognosis of a type 1 procainamide-induced Brugada pattern are incompletely understood and may differ from those of other sodium channel blockers with greater potencies. METHODS: The safety of procainamide infusion and yield of a type 1 Brugada pattern were assessed according to indication in consecutive patients from the Canadian Hearts in Rhythm Organization registry. Outcomes were evaluated in patients with a standard or high-lead procainamide-induced Brugada pattern (without previous cardiac arrest) and compared with those with a spontaneous type 1 pattern. RESULTS: In 947 consecutive patients undergoing procainamide infusion for the diagnosis or exclusion of Brugada syndrome, 2 patients (0.2%) experienced asymptomatic ventricular arrhythmias related to procainamide, which resolved upon discontinuation of the infusion. The yield of a type 1 pattern was 7.2% in 390 patients with unexplained cardiac arrest, 22.2% in 135 patients with a family history of Brugada syndrome, and 6.9% in 116 patients with a family history of unexplained cardiac arrest or sudden death. Test yield was 46.6% in 189 patients with a non-specific type 2 or 3 Brugada pattern and 92% in those with an intermittent spontaneous type 1 pattern (ie, implied sensitivity of 92%). Estimated specificity was very high. In 137 patients with a procainamide-induced type 1 Brugada pattern (with no previous cardiac arrest) followed for a mean of 5.9±4.5 years, no patients met the primary composite arrhythmic end point (0%). In 105 spontaneous type 1 patients, one patient (1%) met the primary end point after receiving appropriate shocks for ventricular fibrillation. Thirteen percent had a primary prevention implantable cardioverter defibrillator implanted at baseline (one appropriate shock), with an additional 7% undergoing implantable cardioverter defibrillator implantation during follow-up, predominantly for syncope with a suspected arrhythmic mechanism. No patient who underwent implantable cardioverter defibrillator implantation during follow-up subsequently received appropriate therapy. CONCLUSIONS: Procainamide infusion is extremely safe for the diagnosis and exclusion of Brugada syndrome, with yield dependent on pretest probability and indication for testing. Estimated sensitivity and specificity appear to be high. Patients with an asymptomatic procainamide-induced type 1 Brugada pattern are at very low risk of malignant ventricular arrhythmias.
Article Details
Authors (27)
Benjamin M. Moore
Department of Medicine, University of British Columbia, Vancouver, BC, Canada (B.M.M., D.C., B.D., Z.W.M.L., A.D.K.)
Douglas Chan
Brianna Davies
Zachary W.M. Laksman
Department of Medicine, University of British Columbia, Vancouver, BC, Canada (B.M.M., D.C., B.D., Z.W.M.L., A.D.K.)
Jason D. Roberts
Population Health Research Institute, Hamilton, ON, Canada (J.D.R.).
Shubhayan Sanatani
Children’s Heart Centre, BC Children’s Hospital, Vancouver, BC, Canada (S.S.)
Christian Steinberg
Institut Universitaire de Cardiologie et Pneumologie de Quebec, Laval University, Quebec City, QC, Canada (C.S.)
Rafik Tadros
Research Center (S.S., P.J., S.G., I.H.-C., A.F., N.E.I., N.B., M.A., K.D., P.G.G., P.K., L.M., B.M., A.M.P., L.R., D.R., B.T., J.-C.T., J.C.-T., A.R.-P., R.T.), Montreal Heart Institute, QC, Canada.
Julia Cadrin-Tourigny
Research Center (S.S., P.J., S.G., I.H.-C., A.F., N.E.I., N.B., M.A., K.D., P.G.G., P.K., L.M., B.M., A.M.P., L.R., D.R., B.T., J.-C.T., J.C.-T., A.R.-P., R.T.), Montreal Heart Institute, QC, Canada.
Ciorsti MacIntyre
David Lee
Joseph Atallah
Department of Pediatrics, University of Alberta, Edmonton, AB, Canada (J.A.)
Anne Fournier
Division of Pediatric Cardiology, CHU Sante-Justine, Universite de Montreal, Montreal QC, Canada (A.F.)
Martin S. Green
University of Ottawa Heart Institute, Ottawa, ON, Canada (M.S.G., S.H.)
Habib R. Khan
Department of Medicine, Western University, London, ON, Canada (H.R.K.)
Jacqueline Joza
Division of Cardiology, McGill University Health Centre, Montreal, QC, Canada (J.J.)
Bhavanesh Makanjee
Scarborough Health Network, Scarborough, ON, Canada
Erkan Ilhan
Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (E.I.)
Simon Hansom
University of Ottawa Heart Institute, Ottawa, ON, Canada (M.S.G., S.H.)
Alexio Hadjis
Division of Cardiology, Hopital du Sacre-Cœur de Montreal, Montreal, QC, Canada (A.H.)
Laura Arbour
Colette Seifer
Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada (C.S.)
Paul Angaran
St Michael’s Hospital, University of Toronto, Toronto, ON, Canada (P.A.)
Christopher S. Simpson
Department of Medicine, Queen’s University, Kingston, ON, Canada (C.S.S.)
Vijay S. Chauhan
Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.S.C.).
Jeffrey S. Healey
Population Health Research Institute, Hamilton, ON, Canada (J.D.R., J.S.H.)
Andrew D. Krahn