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Evaluation of 3D Curvature and Lead Stress of Transvenous Right Ventricular Leads: The Human Use Conditions Study (HUCS)



Jonathan Piccini, Tim Quinn, Lucas Koepke, James Dawson, Nicki Mara, Jason Santelli, Diane Muff, Jordan Savela, Alex Felber, Michael Friedrich, Jens Rump, Felix Tschentscher, Jake Benzing, Charles Swerdlow


Transvenous leads of cardiac implanted electronic device (CIED) systems are meant to last the life of the patient, but they are at risk for conductor fatigue fracture from applied alternating stress. This stress depends on lead design and use conditions (implant technique, anatomy, patient motion). Present engineering standards for preclinical testing do not relate test conditions to use conditions because stresses during clinical use are not well known. Stress is proportional to lead curvature (C, inverse radius of curvature). HUCS is the first large study to measure C in humans. It was powered to examine the correlation between lead stiffness and the maximum alternating C (CA max). HUCS was a prospective, observational, multicenter clinical study. Four leads of widely varying stiffness (2 tachycardia and 2 bradycardia) were chosen with a target enrollment of 20 patients per lead. Biplane cinefluoroscopic imaged the extravenous and connector regions (EVR, CNR) during arm motion. The intracardiac region (ICR) was imaged for multiple cardiac cycles. Lead contours were traced on images (Fig C). After 3-D reconstruction of images, CA max was determined for each section and includes the altering curvature at the transition points of every lead. A linear model was fitted, treating log (C) as the outcome and stiffness as the predictor: log (C) = alpha*stiffness + beta + normally distributed error. The 90% upper confidence limit of alpha was compared to 0 for significance. Across all 117 enrolled subjects, CA max was greatest in the EVR (p<2e-16); the maximum CA max occurred in the EVR for 65.3% of subjects, in the CNR 19.4%, and in the ICR 15.3%. CA max is correlated to stiffness (alpha=-0.067, CI (-Inf,-0.046]) with data taken across the ICR and CNR regions, in all sections, and transition points, but just taking the overall maximum for each patient in each region and its corresponding stiffness, the data were not correlated. HUCS is the first large study to measure stresses applied to transvenous leads in clinical use. The greatest stress occurs in the extravenous region during arm motion. Lead stiffness affects the alternating curvature, but the patient anatomy and implantation technique may have a more important role. The quantitative results of this study will be used to develop a new standard for preclinical testing of conductor fatigue-fracture based on human use conditions.
Proceedings Title
Proceedings of Heart Rhythm 2023
Conference Dates
May 19-21, 2023
Conference Location
New Orleans, LA, US
Conference Title
Heart Rhythm 2023


Cardiac device lead, lead stress, fatigue failure, in vivo curvature, clinical study


Piccini, J. , Quinn, T. , Koepke, L. , Dawson, J. , Mara, N. , Santelli, J. , Muff, D. , Savela, J. , Felber, A. , Friedrich, M. , Rump, J. , Tschentscher, F. , Benzing, J. and Swerdlow, C. (2023), Evaluation of 3D Curvature and Lead Stress of Transvenous Right Ventricular Leads: The Human Use Conditions Study (HUCS), Proceedings of Heart Rhythm 2023, New Orleans, LA, US, [online],, (Accessed June 19, 2024)


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Created September 9, 2023, Updated October 2, 2023