Rafik Tadros1, Eline A Nannenberg2, Krystien V Lieve3, Doris Škorić-Milosavljević3, Najim Lahrouchi3, Ronald H Lekanne Deprez2, Jeroen Vendrik3, Yolan J Reckman3, Pieter G Postema3, Ahmad S Amin3, Connie R Bezzina3, Arthur A M Wilde4, Hanno L Tan5. 1. Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, the Netherlands; Cardiovascular Genetics Center, Department of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada. 2. Department of Clinical Genetics, Academic Medical Center, Amsterdam, the Netherlands. 3. Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, the Netherlands. 4. Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, the Netherlands; Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia. 5. Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, the Netherlands. Electronic address: h.l.tan@amc.nl.
Abstract
OBJECTIVES: This study evaluated the yield of ajmaline testing and assessed the occurrence of confounding responses in a large cohort of families with unexplained cardiac arrest (UCA) or sudden unexplained death (SUD). BACKGROUND: Ajmaline testing to diagnose Brugada syndrome (BrS) is routinely used in the evaluation of SUD and UCA, but its yield, limitations, and appropriate dosing have not been studied in a large cohort. METHODS: We assessed ajmaline test response and genetic testing results in 637 individuals from 482 families who underwent ajmaline testing for SUD or UCA. RESULTS: Overall, 89 individuals (14%) from 88 families (18%) had a positive ajmaline test result. SCN5A mutations were identified in 9 of 86 ajmaline-positive cases (10%). SCN5A mutation carriers had positive test results at significantly lower ajmaline doses than noncarriers (0.75 [range: 0.64 to 0.98] mg/kg vs. 1.03 [range: 0.95 to 1.14] mg/kg, respectively; p < 0.01). In 7 of 88 families (8%), it was concluded that the positive ajmaline response was a confounder, either in the presence of an alternative genetic diagnosis accounting for UCA/SUD (5 cases) or noncosegregation of positive ajmaline response and arrhythmia (2 cases). The rate of confounding responses was significantly higher in positive ajmaline responses obtained at >1 mg/kg than in those obtained at ≤1 mg/kg (7 of 48 vs. 0 of 41 individuals; Fisher's exact test: p = 0.014). CONCLUSIONS: In line with previous, smaller studies, a positive ajmaline response was observed in a large proportion of UCA/SUD families. Importantly, our data emphasize the potential for confounding possibly false-positive ajmaline responses in this population, particularly at high doses, which could possibly lead to a misdiagnosis. Clinicians should consider all alternative causes in UCA/SUD and avoid ajmaline doses >1 mg/kg.
OBJECTIVES: This study evaluated the yield of ajmaline testing and assessed the occurrence of confounding responses in a large cohort of families with unexplained cardiac arrest (UCA) or sudden unexplained death (SUD). BACKGROUND:Ajmaline testing to diagnose Brugada syndrome (BrS) is routinely used in the evaluation of SUD and UCA, but its yield, limitations, and appropriate dosing have not been studied in a large cohort. METHODS: We assessed ajmaline test response and genetic testing results in 637 individuals from 482 families who underwent ajmaline testing for SUD or UCA. RESULTS: Overall, 89 individuals (14%) from 88 families (18%) had a positive ajmaline test result. SCN5A mutations were identified in 9 of 86 ajmaline-positive cases (10%). SCN5A mutation carriers had positive test results at significantly lower ajmaline doses than noncarriers (0.75 [range: 0.64 to 0.98] mg/kg vs. 1.03 [range: 0.95 to 1.14] mg/kg, respectively; p < 0.01). In 7 of 88 families (8%), it was concluded that the positive ajmaline response was a confounder, either in the presence of an alternative genetic diagnosis accounting for UCA/SUD (5 cases) or noncosegregation of positive ajmaline response and arrhythmia (2 cases). The rate of confounding responses was significantly higher in positive ajmaline responses obtained at >1 mg/kg than in those obtained at ≤1 mg/kg (7 of 48 vs. 0 of 41 individuals; Fisher's exact test: p = 0.014). CONCLUSIONS: In line with previous, smaller studies, a positive ajmaline response was observed in a large proportion of UCA/SUD families. Importantly, our data emphasize the potential for confounding possibly false-positive ajmaline responses in this population, particularly at high doses, which could possibly lead to a misdiagnosis. Clinicians should consider all alternative causes in UCA/SUD and avoid ajmaline doses >1 mg/kg.
Authors: Arthur A M Wilde; Christopher Semsarian; Manlio F Márquez; Alireza Sepehri Shamloo; Michael J Ackerman; Euan A Ashley; Back Sternick Eduardo; Héctor Barajas-Martinez; Elijah R Behr; Connie R Bezzina; Jeroen Breckpot; Philippe Charron; Priya Chockalingam; Lia Crotti; Michael H Gollob; Steven Lubitz; Naomasa Makita; Seiko Ohno; Martín Ortiz-Genga; Luciana Sacilotto; Eric Schulze-Bahr; Wataru Shimizu; Nona Sotoodehnia; Rafik Tadros; James S Ware; David S Winlaw; Elizabeth S Kaufman; Takeshi Aiba; Andreas Bollmann; Jong-Il Choi; Aarti Dalal; Francisco Darrieux; John Giudicessi; Mariana Guerchicoff; Kui Hong; Andrew D Krahn; Ciorsti Mac Intyre; Judith A Mackall; Lluís Mont; Carlo Napolitano; Pablo Ochoa Juan; Petr Peichl; Alexandre C Pereira; Peter J Schwartz; Jon Skinner; Christoph Stellbrink; Jacob Tfelt-Hansen; Thomas Deneke Journal: J Arrhythm Date: 2022-05-31
Authors: Arthur A M Wilde; Christopher Semsarian; Manlio F Márquez; Alireza Sepehri Shamloo; Michael J Ackerman; Euan A Ashley; Eduardo Back Sternick; Héctor Barajas-Martinez; Elijah R Behr; Connie R Bezzina; Jeroen Breckpot; Philippe Charron; Priya Chockalingam; Lia Crotti; Michael H Gollob; Steven Lubitz; Naomasa Makita; Seiko Ohno; Martín Ortiz-Genga; Luciana Sacilotto; Eric Schulze-Bahr; Wataru Shimizu; Nona Sotoodehnia; Rafik Tadros; James S Ware; David S Winlaw; Elizabeth S Kaufman; Takeshi Aiba; Andreas Bollmann; Jong Il Choi; Aarti Dalal; Francisco Darrieux; John Giudicessi; Mariana Guerchicoff; Kui Hong; Andrew D Krahn; Ciorsti MacIntyre; Judith A Mackall; Lluís Mont; Carlo Napolitano; Juan Pablo Ochoa; Petr Peichl; Alexandre C Pereira; Peter J Schwartz; Jon Skinner; Christoph Stellbrink; Jacob Tfelt-Hansen; Thomas Deneke Journal: Europace Date: 2022-09-01 Impact factor: 5.486
Authors: Caroline Bruikman; Maurice W J de Ronde; Ahmed Amin; Sonja Levy; Pien Lof; Ursula de Ruijter; Kees Hovingh; Hanno L Tan; Sara-Joan Pinto-Sietsma Journal: Heart Date: 2019-08-17 Impact factor: 5.994
Authors: Rafik Tadros; Hanno L Tan; Sulayman El Mathari; Jan A Kors; Pieter G Postema; Najim Lahrouchi; Leander Beekman; Milena Radivojkov-Blagojevic; Ahmad S Amin; Thomas Meitinger; Michael W Tanck; Arthur A Wilde; Connie R Bezzina Journal: Eur Heart J Date: 2019-10-01 Impact factor: 29.983