Introduction:
Periodic repolarization dynamics (PRD) reflects sympathetic modulation of ventricular repolarization and has been associated with adverse cardiovascular outcomes. Deceleration capacity (DC) represents vagal innervation of the heart. After heart transplantation, autonomic reinnervation remains incomplete, and the long-term electrophysiological consequences are not fully understood. Therefore, we investigated PRD and DC in heart transplant recipients several years after transplantation and compared these parameters with those of an age-matched control cohort.
Methods:
We included 19 patients two to five years after orthotopic heart transplantation who underwent standardized electrocardiographic assessment. PRD and DC were derived from high-resolution ECG recordings using established methods. An age-matched control group without a history of heart transplantation was analyzed for comparison. Clinical characteristics, cardiovascular risk factors, and medication were recorded. Continuous variables are presented as median and interquartile range (IQR) and categorical variables as counts and percentages. Group comparisons were performed using the Wilcoxon- test and Fisher’s exact test, as appropriate.
Results:
Heart transplant recipients had a mean age of 59.0 ± 9.6 years and 7 (36.8 %) were female compared with mean age of 61.5 ± 7.8 years in the control group (p = 0.802), of whom 9 (64.3 %) were females. There was no significant difference between transplant recipients and controls regarding BMI, cardiovascular risk factors and comorbidities, except for the prevalence of arterial hypertension which was higher in the transplant recipient cohort (16 (84.2%) vs 6 (42.9 %) p = 0,033). PRD was significantly higher in heart transplant recipients compared with controls (4.88 [IQR 6.86] vs 1.67 [IQR 2.03] deg²; p = 0.007). In contrast, DC did not differ significantly between groups (1.45 [IQR 0.85] vs 1.43 [ IQR 1.12] ms; p = 0.743).
Conclusion:
PRD is significantly increased in patients several years after heart transplantation, whereas DC remains comparable to age-matched controls. These findings suggest persistent alterations in sympathetic cardiac regulation long after transplantation and may have implications for further risk stratification in this population.
