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Updated: Jun 26, 2026

Viral Transgene Expression in Rodent Hearts and the Assessment of Cardiac Arrhythmia Risk
Published on: July 27, 2022
Ventricular premature depolarizations triggered by incremental dose isoproterenol infusion: common
Nuria Rivas1, Sandhya Dhruvakumar, Sumeet K Mainigi
1Cardiovascular Division, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
Purpose:
To identify the prevalence of adrenergically mediated ventricular premature depolarizations (VPDs) and characterize their electrocardiographic (ECG) features and specific anatomically determined sites of origin within the ventricles.
Methods:
VPDs occurring during incremental isoproterenol infusion (3 to 20 mug/min) in 108 patients (30 women, mean age 58 +/- 10 years) with normal ventricular function and no previous ventricular tachycardia (VT) were identified. VPDs were grouped to a probable anatomic region of origin based on 12-lead ECG.
Results:
The 235 VPD morphologies (median 2 per patient, range 1-13) were observed in 85/108 (79%) patients. The most frequent regions of origin were: peri-mitral annulus 17%, left-Purkinje network 14%, right ventricle (RV) outflow tract 14%, apical RV free wall 11% and peri-tricuspid annulus 10%. Only 39 (17%) VPDs were not easily classified.
Conclusion:
Adrenergically mediated VPDs are frequent in patients without structural heart disease or VT and tend to originate from a few anatomic sites.
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