title: Coronary wave intensity during the Valsalva manoeuvre in humans reflects altered intramural vessel compression responsible for extravascular resistance.
abstract: Our aim was to investigate the effect of altered cardiac-coronary interaction during the Valsalva manoeuvre (VM) on coronary wave intensity and the response of coronary microvascular resistance. In 13 patients, left ventricular (P(LV)) and aortic pressure were measured during catheterization, together with intracoronary pressure and blood flow velocity (U) via a dual-sensor guide wire advanced into an angiographically normal coronary artery. Signals were analysed for the following phases of VM: baseline (B1), onset of strain (S1), sustained strain (S2), onset of release (R1), maximal response during recovery (R2), and baseline after VM. The immediate effects of VM were most evident from diastolic P(LV) (LVDP), which increased from 11.0 ± 2.3 to 36.4 ± 2.7 mmHg between B1 and S1 and fell from 28.3 ± 3.4 to 8.3 ± 1.9 mmHg between S2 and R1. Wave intensities and rate pressure product (RPP) were only minimally affected at these transient phases, but coronary wave energies decreased by about 50% and RPP by 38% from S1 to S2, together with a 30% depression of LVdP/dt. All signals were restored to baseline values during the recovery. U did not vary significantly throughout the VM. Despite the depressed cardiac performance during VM strain, microvascular resistance, calculated with LVDP as backpressure, decreased by 31% from B1 to S2, whereas an increase via metabolically induced vasoconstriction was expected. Since coronary U remained essentially constant despite the marked reduction in oxygen consumption, microvascular vasoconstriction must have been compensated by a decrease in the contraction-mediated impediment on coronary blood flow, as confirmed by the reduced coronary wave energies.
authors.affiliation: Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Rolandi
authors.forename: Froukje
authors.initials: F
authors.lastname: Nolte
authors.forename: Tim P
authors.initials: TP
authors.lastname: van de Hoef
authors.forename: Maurice
authors.initials: M
authors.lastname: Remmelink
authors.forename: Jan
authors.initials: J
authors.lastname: Baan
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Piek
authors.forename: Jos A E
authors.initials: JA
authors.lastname: Spaan
authors.forename: Maria
authors.initials: M
authors.lastname: Siebes
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D014636:Valsalva Maneuver; D014655:Vascular Resistance / Q000502:physiology*