Author + information
- Received December 13, 2016
- Accepted December 22, 2016
- Published online September 18, 2017.
- Ankit Maheshwari, MDa,
- Lisa Von Wald, CNPa,b,
- Balaji Krishnan, MDa,b and
- David G. Benditt, MDa,b,∗ ()
- aCardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
- bCardiac Arrhythmia and Syncope Center, Cardiovascular Division, University of Minnesota Medical Center, Minneapolis, Minnesota
- ↵∗Address for correspondence:
Dr. David G. Benditt, Department of Medicine, Cardiovascular Division, University of Minnesota, Mail Code 508, 420 Delaware Street SE, Minneapolis, Minnesota 55455.
A 65 year-old man with a history of type 1 diabetes previously treated with an auto islet cell transplant presented with acute kidney injury (creatinine 1.5 mg/dl) and asymptomatic hyperkalemia (K+, 6.8 mEq/l). The electrocardiogram revealed >2 mm coved ST-segment elevation with T-wave inversion in leads V1 and V2 (Figure 1A) characteristic of type 1 Brugada syndrome (BrS). As the K+ level normalized, serial electrocardiograms demonstrated a gradual and apparently K+ concentration-dependent resolution of the ST-segment elevation in leads V1 and V2 and the T-wave inversion in V2 (Figure 1B). The patient had no history of unexplained syncope or family history of sudden cardiac death. No pathological variants of the following genes were detected: SCN5A, GPD1L, CACNA1C, CACNB2, SCN1B, KCNE3, and SCN3B. Sodium channel blocker provocation (1) with intravenous procainamide did not unmask the BrS pattern on serial electrocardiograms. Thus, Brugada phenocopy (BrP) was suspected.
BrP has been identified in critically ill patients with inferior myocardial infarction, pulmonary embolism, hypokalemia, metabolic acidosis, hyponatremia, and hyperkalemia (2). Hyperkalemia has also been reported to unmask familial type 1 BrS (3). An apparent “dose” relationship between degree of hyperkalemia and the Brugada pattern has not previously been reported. Extracellular hyperkalemia leads to inactivation of cardiac sodium channels, which may, in part, explain hyperkalemia-induced BrP and unmasking in susceptible individuals. The prognostic significance of BrP is unknown, and further research is needed to determine whether BrP, like BrS, is a manifestation of cardiac sodium channel abnormality.
Dr. Benditt is supported in part by a grant from the Dr. Earl E. Bakken family in support of heart-brain research. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received December 13, 2016.
- Accepted December 22, 2016.
- 2017 American College of Cardiology Foundation