Surgery for acute type A aortic dissection: Fractal analysis on the impact on heart rate variability

• Published in: The Thoracic and Cardiovascular Surgeon
• Main Authors: Immer, FF, Hess, M, Hemmig, E, Schwick, N, Saner, H, Carrel, T
• Format: Conference Proceeding
• Language: English
• Published: 01.02.2008
• ISSN: 0171-6425; 1439-1902
• DOI: 10.1055/s-2008-1038048

Objective: Aortic dissection (AADA) is associated with hypertension, abnormalities of blood pressure control and the risk of secondary dilatation of the diseased downstream aorta. We have recently shown, that significantly CAD is frequently found in patients after successful repair of AADA. We hypothesized that dissection of the aorta leads to an autonomic dysfunction. Patients and methods: We studied 36 patients after repair of AADA with remaining dissection at the level of the downstream aorta. Heart rate variability (HRV) was determined with time- and frequency-domain measures and fractal analyses have been applied. The results were compared to data obtained in a healthy population. Results: Average age was 58.5±9.1 years at the time of surgery. Mean deep hypothermic circulatory arrest came up to 22.3±9.7min in the total collective. 11 patients (30.6%) showed a HRV-index ≥20. Medication was similar in both groups. Patients with an impaired HRV showed more frequently a secondary dilatation of the diseased aortic arch and/or downstream aorta (36.4% vs. 5.6%; p<0.05), as well as a higher incidence of spiral CT-detected CAD (45.4% vs. 20%; p<0.05). Conclusions: Autonomic dysfunction is frequently found in patients after successful repair of AADA. A HRV-index ≤20 increases the risk of secondary dilatation and the development of CAD in this collective, which is probably related to the observed abnormalities of blood pressure control in this group of patients.