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Updated: May 29, 2026

Implantation of Left Ventricular Assist Device (LVAD) in Juvenile Landrace Swine: A LVAD Implantation Model of Pediatric Heart Failure
Published on: January 16, 2026
Chronotropic incompetence and abnormal heart rate recovery early after left ventricular assist device implantation
Stavros Dimopoulos1, Nikolaos Diakos, Eleni Tseliou
11st Critical Care Medicine Department, Cardiopulmonary Exercise Testing and Rehabilitation Laboratory, National and Kapodestrian University of Athens, Athens, Greece. a-icu@med.uoa.gr
Background:
Chronotropic response to exercise and heart rate recovery immediately after exercise (HRR(1) ) are valid prognostic markers in patients with chronic heart failure (CHF). The aim of this study was to evaluate heart rate profile during and after exercise in CHF patients early after left ventricular assist device (LVAD) implantation.
Methods:
We enrolled seven stable consecutive CHF patients (five males, mean age: 45 ± 16 years) after 1 month of LVAD (HeartMate II; Thoratec Corp, Pleasanton, CA, USA) implantation, seven healthy subjects, and 14 patients with advanced HF (HF control group) who performed an incremental symptom-limited cardiopulmonary exercise testing (CPET). CHF patients performed CPET at 1 and 3 months after LVAD. HRR(1) was defined as the HR difference from peak to 1 minute after exercise and chronotropic response to exercise as the chronotropic reserve ([CR, %]=[peak HR-resting HR/220-age-resting HR]× 100).
Results:
LVAD patients 3 months after implantation had a significantly different HR profile during exercise compared to healthy controls, with significantly lower CR (57 ± 31 vs 90 ± 14, %, P < 0.001) and HRR(1) (14 ± 6 vs 28 ± 8, bpm, P < 0.01). HR profile during exercise did not significantly change 1 and 3 months after LVAD implantation. There was no statistical difference compared to HF control group and LVAD group regarding cardiopulmonary parameters.
Conclusions:
LVAD patients present an impaired CR and an abnormal HRR(1) after implantation, indicating significant cardiac autonomic abnormalities. These alterations seem to remain unaltered 3 months after LVAD implantation.
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