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Updated: Feb 25, 2026

Author Spotlight: Advancing Neonatal Cardiac Diagnostics with Echocardiography-Derived Blood Speckle Imaging
Published on: December 22, 2023
QRS complex maximum deflection index in aortic cusp premature ventricular complexes
Konstantinos C Siontis1, Malini Madhavan2, Suraj Kapa2
1Department of Medicine, Mayo Clinic, Rochester, MN, United States.
Abstract:
•We reviewed 185 PVC catheter ablation cases and identified 17 in which PVCs were successfully ablated in the aortic cusps.•The MDI measured 0.53 ± 0.10 (median 0.50, IQR 0.47-0.60).•In all (100%) cases MDI was > 0.40 and in 7 (41%) cases it was > 0.55.•Pseudo-delta wave was absent in all but one PVC•PVC origin in the aortic cusps should be considered along with the epicardium when MDI is in the vicinity of 0.55.
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Electrocardiogram Fundamentals
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin...

