PR interval adaptation in the denervated transplanted heart
| Autor: | Christoph Kratochwill, Guenther Laufer, Jeanette Koller-Strametz, Slobodan Gasic, Gottfried Heinz, N Gemeiner, Martin Grabenwöger, Richard Pacher |
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| Rok vydání: | 1997 |
| Předmět: |
Adult
Male medicine.medical_specialty medicine.medical_treatment Transplanted heart Treadmill exercise Electrocardiography Heart Rate Internal medicine Heart rate medicine Humans PR interval Peak exercise Aged Heart transplantation medicine.diagnostic_test business.industry Age Factors Heart General Medicine Middle Aged Adaptation Physiological Surgery Transplantation Cardiology Exercise Test Heart Transplantation Female Cardiology and Cardiovascular Medicine business |
| Zdroj: | Pacing and clinical electrophysiology : PACE. 20(5 Pt 1) |
| ISSN: | 0147-8389 |
| Popis: | In the present study, the dynamic PR response upon standardized treadmill exercise was investigated in 21 transplant recipients (recipient age 48 +/- 17 years, donor age 31 +/- 12 years, > 1 year after transplantation). HR and PR interval were measured at rest and at the end of each 25-W increase in workload till peak exercise. In 17 cases norepinephrine (NE) was assessed at rest, and at the end of each workload the HR increased from 99.3 +/- 14 to 143.4 +/- 25 beats/min at individual peak exercise, and NE increased from 1,307 +/- 1,163 to 3,688 +/- 2,036 pg/mL, while the PR interval shortened from 149.2 +/- 13 to 119.3 +/- 20 ms. On average, PR decreased by 3.4 ms for a 10-beat increase in HR, and the HR-PR interval relationship was described by a linear regression (y = 176.8-0.3469x, P = 0.0001). One patient who was unable to increase his NE levels upon exercise showed virtually no decrease in the PR interval and no HR increase. Both recipient age and donor age were moderately and significantly related to the minimum PR interval achieved at peak exercise (r = 0.6, P = 0.008 and r = 0.51. P = 0.049, respectively). These data show the following: (1) adaptation of the PH interval upon exercise does occur in the denervated transplanted heart; (2) the HR-PR relation is similar to that reported in the innervated heart; (3) the overall decline in PR interval is blunted, since denervated patients start at shorter resting PR intervals and achieve relatively longer PR intervals at peak exercise when compared to their innervated counterparts; (4) these exercise induced changes of the PR interval may be explained by circulating NE; and (5) NE levels achieved at peak exercise and the sensitivity of the AV node to NE seem to be age related. |
| Databáze: | OpenAIRE |
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