Investigating Electrocardiographic Abnormalities in Patients with Coronary Microvascular Dysfunction
Authors: Merdler Ilan , Hill Andrew P. , Ozturk Sevket Tolga , Cellamare Matteo , Zhang Cheng , Banerjee Avantika , Chitturi Kalyan R. , Lupu Lior , Sawant Vaishnavi , Ben-Dor Itsik , Waksman Ron , Hashim Hayder D. , Case Brian C. 
Published: April 2024

AbstractBACKGROUNDCoronary microvascular dysfunction (CMD) is a frequently overlooked and underdiagnosed mechanism of cardiac ischemia despite its heightened risk of major adverse cardiovascular events. The potential impact of CMD on the conduction system and occurrence of arrhythmias has received limited attention. This study aimed to examine the link between CMD and surface electrocardiography (ECG).METHODSWe harnessed the Coronary Microvascular Disease registry (CMDR), utilizing the CoroVentis CoroFlow System (Abbott) to invasively assess patients presenting with symptomatic chest pain. All patients underwent microvascular assessment of the left anterior descending artery territory. Our cohort was stratified into two groups, CMD-positive and CMD-negative, with an analysis of the most recent ECG performed prior to the invasive evaluation for each patient.RESULTSOur cohort comprised 230 patients, of which 60 were classified as CMD-positive and 170 as CMD-negative. T-wave inversion was observed in 30.5% of CMD-positive patients compared to 20% in the CMD-negative group (P=0.09), and ST depression was identified in 6.7% of CMD-positive patients compared to 2.4% of CMD-negative patients (P=0.12). There were no differences in conduction disorders, such as left bundle branch block (LBBB), left anterior hemiblock (LAHB), left posterior hemiblock (LPHB), right bundle branch block (RBBB), incomplete right bundle branch block (ICRBBB), and bifascicular block, between the two groups. There were no discernible distinctions in the ECG intervals, including the PR, QRS, and QT. There was a trend of increased left ventricular hypertrophy (LVH) according to the ECG criteria in patients with CMD (11.7% vs. 5.3%;P=0.09).CONCLUSIONOur study revealed a tendency toward ischemic and hypertrophic ECG changes among CMD-positive patients, but no differences in the occurrence of conduction disorders in patients with and without CMD.REGISTRATIONURL:https://clinicaltrials.gov; Unique Identifier:NCT05960474GRAPHIC ABSTRACTA graphic abstract is available for this article.Graphic Abstract.Clinical pathway for patients with chest pain undergoing ECG and coronary microvascular assessment, highlighting key findings, and insights.Clinical PerspectivesWHAT IS KNOWN?Limited research has explored the impact of coronary microvascular dysfunction (CMD) on surface electrocardiogram (ECG) changes.The bolus thermodilution method has demonstrated efficacy for the invasive assessment of the coronary microvasculature in patients with symptomatic chest pain. These tools can aid in early detection and diagnosis of CMD.WHAT THE STUDY ADDSIn this study from the Coronary Microvascular Disease Registry (CMDR), higher rates of T-wave inversion and ST depression were observed in CMD-positive patients, providing valuable clinical insights. These ECG changes were similar to those observed in patients with stable angina.No difference in conduction disorders or ECG intervals was observed, although a greater tendency for left ventricular hypertrophy in CMD-positive patients suggests the importance of monitoring for cardiac structural changes and their potential association with CMD.