Abstract
Objective Ventriculoseptal defect;VSD and atrial septal defect;ASD exhibit increased pulmonary blood flow through the left-to-right shunt. In patients with these pathological states arising from volume and/or pressure overload in the right heart can result in sympathovagal imbalance. We investigated the correlation between the HRV and respiratory frequency, and shunt ratio (Qp/Qs) measured by the Doppler echocardiography.Subjective and methodsWe enrolled 66 patients. Diagnoses were: VSD (n=21) and ASD (n=45). Mean age was 5.6 ± 3.3 years. ECG and respiratory waves were recorded during the Doppler UCG test. We performed HRV analysis to calculate LF, HF, TF, respiratory frequency (RF), LF/HF, RF/TF, and LF/RF. Qp/Qs was also calculated and quantified by multivariate analysis with HRV parameters. Results1) Qp/Qs and LF/HF exhibited correlation in both ASD and VSD groups. 2) The ASD group showed a positive correlation between Qp/Qs and LF/RF. However, in the VSD group the correlation was negative. 3) Qp/Qs correlated negatively with RF/TF in the ASD group, however, the correlation was positive in the VSD group.ConclusionsASD and VSD showed different effects of respiratory vagal activity on HRV. We believe that a reason is that volume and low pressure overload to the right atrium in ASD inhibits respiratory vagal innervation of the sinus node. [J Physiol Sci. 2006;56 Suppl:S135]
