The Ventriculophasic Response: Relationship to Sinus Arrhythmia and the Duration of Interposed QRS Complexes. Issue 4 (20th January 2013)

• Record Type: Journal Article
• Authors: Dadu, Razvan T.; McPherson, Craig A.
• Is Part Of: Annals of noninvasive electrocardiology. Volume 18:Issue 4(2013:Jul.)
• Page Start: 336
• Page End: 343
• Publication Date: 2013-01-20
• Subjects: Electrocardiography -- Periodicals; Arrhythmia -- Periodicals; 616.1207547
• DOI: 10.1111/anec.12038
• Languages: English
• ISSNs: 1082-720X

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="anec12038-sec-0010" sec-type="section"> <title>Background</title> <p>The ventriculophasic response (VR) refers to shortening of sinus cycle length during heart block when a QRS complex is interposed between 2 P waves. Our purpose was to analyze its relationship to respiratory sinus arrhythmia (SA) and to compare VR in relation to paced versus intrinsic QRS complexes.</p> </sec> <sec id="anec12038-sec-0020" sec-type="section"> <title>Methods</title> <p>Patients with advanced heart block had their pacer devices temporarily programmed to ventricular inhibited mode at 30 ppm. In 35 subjects, we analyzed VR and SA before, during and after 3 cycles of deep breathing. In 16 other patients we compared VR in the presence of paced versus narrower intrinsic QRS complexes.</p> </sec> <sec id="anec12038-sec-0030" sec-type="section"> <title>Results</title> <p>The magnitude of P‐P interval shortening surrounding QRS complexes during inspiration correlated with SA (r = 0.36, P = 0.03). The prevalence of VR increased from 37% at baseline to 77% of subjects during deep breathing (P = 0.02). The mean P–P interval shortening was greater surrounding intrinsic QRS complexes than paced QRS complexes (3.6 ± 3.6% vs. 1.4 ± 1.1%, P = 0.02). The prevalence of VR increased from 25% during paced rhythm to 56% when intrinsic complexes were present.</p> </sec> <sec id="anec12038-sec-0040" sec-type="section"> <title>Conclusion</title> <p>VR, like SA, increases with deep breathing and likely reflects intact parasympathetic nervous system function. Its increase in the presence of narrower beats suggests it may reflect ventricular synchrony.</p> </sec> </abstract>