Chemoreflexsensitivity among patients with paroxysmal atrial fibrillation

Atrial fibrillation is the most common cardiac arrhythmia with typical complications of thromboembolisms. The autonomic nervous system is an important factor for the initiation of arrhythmias. A vagally or adrenergically hyperfunction could cause the initiation of paroxysmal atrial fibrillation (PAF). METHOD: We measured the chemoreflexsensitivity (CHRS) among 110 patients to determine a disturbed autonomic function as risk factor for PAF. We examined 45 patients with PAF (group A), 45 patients with sinus rhythm (group B) and 20 young volunteers (group C). The ratio between the difference of RR intervals in ECG and venous pO(2) was measured for the determination of CHRS. The margin of the CHRS was 3 ms/mmHg. RESULTS: Patients of group A had a significantly lower CHRS compared to group B (1.56+/-1.46 vs 6.29+/-3.71 ms/mmHg, p<0.0008) or group C (1.56+/-1.46 vs 6.35+/-4.29 ms/ mmHg, p<0.0003). A significant difference between group B and C could not be observed (6.29+/-3.71 vs. 6.35+/-4.29 ms/mmHg, p = n.s.). A specificity of 74% and a sensitivity of 71% was achieved for identifying patients with PAF by using a margin of 3 ms/mmHg for the CHRS. CONCLUSIONS: An analysis of CHRS seems to be an appropriate method to demonstrate a neurovegetative imbalance which might be one possible trigger mechanism of PAF. The predictive power has to be examined by prospective investigations of a larger patient population.