The ECG Characteristics of Patients With Isolated Hypomagnesemia.

Yiheng Yang,Lianjun Gao,Xiaolei Yang,Simei Hui,Yingxue Dong,Cheng Chen,Suman Thapaliya,Ruopeng Tan,Richard Sutton,Xiaomeng Yin,Penghong Duan,Rongfeng Zhang,Yue Wang,Yunlong Xia

doi:10.3389/fphys.2020.617374

Abstract

BackgroundElectrocardiographic (ECG) characteristics of patients with isolated hypomagnesemia are not well defined. We aimed to investigate these ECG characteristics in order to define clearly the features of isolated hypomagnesemia.HypothesisLower serum magnesium could affect ECG parameters after excluding potential confounders.MethodsThis retrospective study was of patients with low serum magnesium <0.65 mmol/L compared with the same patients after restoration to normal serum magnesium. Patients with hypokalemia, hypocalcemia and other electrolyte disturbances were excluded. ECG parameters manually determined and analyzed were P wave dispersion, PR interval, QRS duration, ST-T changes, T wave amplitude, T peak-to-end interval (Tpe), corrected Tpe (Tpec), QT, corrected QT (QTc), QT peak corrected (QTpc) and Tpe dispersion, Tpe/QT ratio.ResultsTwo-hundred-and-fourteen patients with isolated hypomagnesemia were identified with 50 of them (56.9 ± 13.6 years; 25 males) being eligible for final analysis from 270,997 patients presenting April 2011–October 2017. In the period of isolated hypomagnesemia, P wave duration was found prolonged (p ≤ 0.02); as was QTc (439 ± 27 vs. 433 ± 22, p = 0.01). Tpec (122 ± 24vs. 111 ± 22, p = 0.000) and Tpe/QT ratio (0.29 ± 0.05 vs. 0.27 ± 0.05, p = 0.000) were increased. QTpc decreased during hypomagnesemia (334 ± 28 vs. 342 ± 21, p = 0.02). However, no significant differences were found in PR interval, QRS duration (85 ± 12 ms vs. 86 ± 12 ms, p = 0.122) and ST-T segments between the patients and their own controls.ConclusionsIn patients with isolated hypomagnesemia, P wave duration, QTc, Tpec, and Tpe/QT ratio suggesting atrial depolarization and ventricular repolarization dispersion were significantly increased compared with normal magnesium levels in the same patients after restoration to normal levels.

Highlights

Sudden cardiac death (SCD) has been widely studied because of its important public health implications (Ackerman et al, 2016); electrolyte disturbances have been thought to be related to its etiology
Seven-hundred-and-sixtyseven patients with intermittent low serum magnesium levels were selected from 270,997 patients from electronic medical records; The inclusion criteria were as follows: (1) Patients with isolated hypomagnesemia without other electrolyte disturbance according to laboratory criteria in The First Affiliated Hospital of Dalian Medical University
We found that patients with isolated hypomagnesemia presented significantly higher T peak-to-end interval (Tpe)/QT ratio

Summary

Introduction

Sudden cardiac death (SCD) has been widely studied because of its important public health implications (Ackerman et al, 2016); electrolyte disturbances have been thought to be related to its etiology. The possible mechanisms are thought to involve QT prolongation (Kieboom et al, 2016) These studies have, generally, not excluded hypokalemia, hypocalcemia and other electrolyte disturbances, or were based only on animal data. The electrocardiographic (ECG) characteristics of isolated hypomagnesemia remain not clearly defined. We performed this study to investigate the specific changes in various ECG parameters among patients with isolated hypomagnesemia. Electrocardiographic (ECG) characteristics of patients with isolated hypomagnesemia are not well defined. We aimed to investigate these ECG characteristics in order to define clearly the features of isolated hypomagnesemia.

Objectives

Methods

Results