DKA-induced Brugada phenocopy mimicking STEMI

Genetic Causality between Type 1 Diabetes and Arrhythmia Identified by a Two-sample Mendelian Randomization Study

BACKGROUND

Clinical studies have shown that cardiovascular diseases in patients with type 1 diabetes (T1D) are often atypical or asymptomatic. The link between T1D and arrhythmia remains unclear. To infer causality between T1D and arrhythmia at the genetic level, we conducted a Mendelian randomization study through the genetic tools of T1D.

METHODS

In this study, we used genetic variables and summary statistics from genome-wide association studies of T1D and arrhythmia. Single nucleotide polymorphisms were selected based on the assumptions of instrumental variables. The inverse variance-weighted method was used as the primary analysis to summarize the causal effects between exposure and outcome. The weighted median and weighted mode methods were used as secondary methods. We tested for horizontal pleiotropy using the MR-Egger method and detected heterogeneity using the Q-test. A leave-one-out sensitivity analysis was performed. Scatter plots, forest plots, and funnel plots were used to visualize the results of the MR analysis.

RESULTS

In this study, we selected 28 T1D-related SNPs as instrumental variables. The IVW [odds ratio (OR) = 0.98, 95 % confidence interval (CI) = 0.97-1.00, P = 0.008], weighted median (OR = 0.98, 95 % CI = 0.96 - 0.99, P = 0.009), and weighted mode (OR = 0.98, 95 % CI = 0.96-0.99, P = 0.018) analysis methods suggested a causal effect of T1D on arrhythmia. The MR-Egger method indicated no horizontal pleiotropy (P = 0.649), and the Q-test showed no heterogeneity (IVW, P = 0.653).

CONCLUSIONS

Our MR analysis revealed a causal association between T1D and the development of arrhythmia, indicating that patients with T1D had a higher risk of arrhythmia.

Brugada Pattern in Diabetic Ketoacidosis: A Case Report and Scoping Study

Brugada syndrome is a rare cardiac arrhythmia which is associated with right bundle branch block pattern (RBBB) and ST-segment elevation in right precordial leads. SCNA5 mutation is the most common genetic abnormality associated with Brugada syndrome. Brugada pattern not related to genetic mutations has been previously reported in the setting of fever, metabolic conditions, lithium use, marijuana and cocaine abuse, ischemia and pulmonary embolism, myocardial and pericardial diseases. Multiple isolated cases of Brugada pattern associated with diabetic ketoacidosis (DKA) have been previously reported. We here present a case of type 1 Brugada pattern in a 23 year-old-male who presented with DKA. Brugada pattern in DKA is attributed to acidosis and multiple electrolyte abnormalities including hyperkalemia which alter ion channel expression in the heart thus leading to Brugada pattern which subsequently resolved with treatment of DKA. In such patients, Brugada pattern is not reproducible on procainamide induction cardiac electrophysiology study (EPS). Our scoping study demonstrates male predominance 20/22 cases of (DELETE this highlighted area) Brugada pattern in DKA, a finding that is consistent with prevalence of this disease among males.