title: Effect of short atrioventricular delay on cardiac output.
abstract: Short atrioventricular (AV) delay modifies late diastolic filling dynamics. The effect of this change on cardiac output (CO) was studied in closed chest, AV blocked canine preparations (N:10), during AV sequential pacing (80 bpm). CO (thermodilution technique) and transmitral flow velocity (TMFV, pulsed-wave Doppler) were measured and compared (paired t-test) on the basis of TMFV pattern, when atrial contraction (A wave) started just after early diastolic transmitral flow deceleration (PR: 219 +/- 25 ms, mean +/- SD) and when A wave occurred at the end of late diastole and shortened due to the next ventricular contraction (PR: 56 +/- 11 ms). The short AV delay resulted in 12.0 +/- 5.9% decrease of CO, reflecting the interrupted late diastolic atrial transport. Properly timed atrial contraction is necessary for optimal AV sequential pacing.
authors.affiliation: Department of Cardiology, University Hospital Gasthuisberg, Leuven, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Ronaszeki
authors.forename: H
authors.initials: H
authors.lastname: Ector
authors.forename: B
authors.initials: B
authors.lastname: Denef
authors.forename: A E
authors.initials: AE
authors.lastname: Aubert
authors.forename: V
authors.initials: V
authors.lastname: de Werf
authors.forename: H
authors.initials: H
authors.lastname: de Geest
mesh_terms: D000818:Animals; D001283:Atrioventricular Node / Q000503:physiopathology*; D001783:Blood Flow Velocity; D002302:Cardiac Output / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D004285:Dogs; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000503:physiopathology*; D008297:Male; D013599:Systole / Q000502:physiology; D013815:Thermodilution; D013997:Time Factors