Original-clinicalImaging/mappingCardiac resynchronization therapy in pediatric congenital heart disease: Insights from noninvasive electrocardiographic imaging
Introduction
Cardiac resynchronization therapy (CRT) has been extensively studied in adult heart failure patients with two ventricles and a systemic left ventricle (LV). There has been less investigation of CRT in patients with congenital heart disease (CHD) who make up a substantially different population that is characterized by unusual anatomy including univentricular hearts, systemic right ventricles (RV), and other anomalies. CRT has been demonstrated to benefit certain CHD patients but significantly varies by substrate.1
Electrocardiographic imaging (ECGI) is a novel noninvasive functional imaging modality for cardiac electrophysiology (EP). It images epicardial potentials (voltage maps), electrograms, activation (isochrones), and repolarization patterns.2, 3, 4, 5, 6, 7 ECGI is based on 250-channel body surface electrocardiograms (ECGs) and an accurate heart-torso anatomy derived from ECG-gated thoracic computed tomography (CT). It has been applied to image cardiac EP in adult heart failure patients undergoing CRT.5 ECGI has been also applied successfully to guide intracardiac mapping and ablation of accessory pathways in pediatric patients with complex CHD and structurally abnormal hearts.6, 7 We hypothesize that ECGI can (1) be used to identify patients with CHD who have substantial ventricular electrical dyssynchrony (ED) in the baseline rhythm and thus may benefit from CRT; (2) help guide resynchronization lead placement by identifying both the EP substrate and the area of latest electrical activation; and (3) evaluate intraventricular ED post-CRT.
Section snippets
Methods
The study population included pediatric patients who met the following criteria: (1) age ≤21 years, (2) presence of CHD, (3) heart failure symptoms, and (4) undergoing evaluation for CRT or having a CRT device in place. Patients were chosen irrespective of their QRS duration. All patients were maximized on oral therapy before CRT.
For patients undergoing evaluation for CRT, an ECGI was performed in baseline rhythm. If the patient had a pacemaker in place and was not pacemaker dependent, ECGI was
Results
Eight pediatric patients (age 12 ± 6 years) were enrolled in the study with a total of four pre-CRT, two pre- and post-CRT, and two post-CRT studies. There was a wide variety of congenital heart lesions (Table 1) including (1) systemic LV, (2) systemic RV, or (3) univentricular heart.
Discussion
Pre-CRT echocardiographic testing used to determine dyssynchrony is fraught with limitations, mostly interobserver variability. The unusual anatomy of patients with CHD further imposes technical limitations on the utility of standard echocardiographic methods for objective evaluation. ECGI provides an objective rather than a subjective method in the assessment of dyssynchrony. The use of ECGI in selecting patients likely to benefit from CRT presupposes that mechanical dyssynchrony is preceded
Conclusions
This study reports the first experience with application of a novel noninvasive cardiac EP imaging modality for evaluation of CRT in a small group of pediatric CHD patients. It shows that ECGI can be used objectively to measure ED, which does not correlate with QRS duration. ECGI may help to correctly identify patients (with substantially large ED compared with controls) who would likely benefit from CRT. ECGI activation maps can help guide resynchronization lead placement by defining the EP
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2023, Journal of Cardiovascular Magnetic ResonanceElectrocardiographic imaging of His bundle, left bundle branch, epicardial, and endocardial left ventricular pacing to achieve cardiac resynchronization therapy
2020, HeartRhythm Case ReportsCitation Excerpt :Alternative methods of delivering cardiac resynchronization therapy (CRT), including left ventricular (LV) endocardial pacing, His bundle pacing, and left bundle branch pacing, have been developed in an effort to improve CRT. Noninvasive cardiac mapping using electrocardiographic imaging (ECGi) is a method of assessing ventricular activation and has been used in the CRT population to predict and assess response, guide LV lead placement, and optimize therapy.1–4 In this report we describe the electrical effects of these different pacing modalities using ECGi.
Cardiac electrical dyssynchrony is accurately detected by noninvasive electrocardiographic imaging
2018, Heart RhythmCitation Excerpt :Noninvasive electrocardiographic imaging (ECGi) has been developed to provide high-resolution imaging of epicardial activation.5 ECGi has been used previously to characterize conduction abnormalities in patients amenable to CRT and to optimize biventricular (BiV) pacing.4,6–11 From these studies, intraventricular electrical dyssynchrony, defined as inhomogeneous left ventricular (LV) activation, and interventricular electrical dyssynchrony, defined as activation delay between the LV and the right ventricle (RV), were considered predictors for CRT response.
Pacing and Defibrillation Use in Pediatric Patients
2016, Clinical Cardiac Pacing, Defibrillation and Resynchronization TherapyElectrocardiographic imaging of heart rhythm disorders. From bench to bedside
2015, Cardiac Electrophysiology ClinicsCitation Excerpt :The reconstruction is performed simultaneously over the entire heart and is done continuously on a beat-by-beat basis. This article provides a brief description of the ECGI procedure and selected previously published examples of its application in important clinical conditions, including heart failure (HF) and cardiac resynchronization therapy (CRT),4–6 atrial arrhythmias,7–9 and ventricular tachycardia (VT).10 All reported studies were approved by the Institutional Review Board of the participating institutions (University Hospitals of Cleveland, the Cleveland Clinic and Washington University in St Louis), and informed consent was obtained from all patients.
The first two authors contributed equally to preparation of this manuscript.
The study was supported by Merit Award no. R37-HL-033343 and grant no. R01-HL-49054 from the National Heart, Lung, and Blood Institute to Y. Rudy. Dr. Rudy is the Fred Saigh Distinguished Professor at Washington University in St. Louis.
Y. Rudy chairs the scientific advisory board and holds equity in CardioInsight Technologies (CIT). CIT does not support any research conducted by Y. Rudy, including that presented here.