Haemodynamic and catecholamine response to simulated ventricular tachycardia in man: effect of baseline left ventricular function.
OBJECTIVE
To examine the effects of baseline left ventricular function on the haemodynamic and catecholamine responses to ventricular tachycardia.


METHODS
Experimental cohort study.


METHODS
Cardiac catheterisation laboratory in tertiary referral centre.


METHODS
24 patients (19 male, 5 female; mean (SD) age, 59 (10) years) without coronary artery disease, divided into two groups with normal or impaired left ventricular function: group A, ejection fraction > 65% (n = 10); group B, ejection fraction < 45% (n = 14). Other medical and demographic factors were similar in the two groups.


METHODS
Ventricular tachycardia was simulated with rapid pacing at 150 beats/min for 10 minutes.


METHODS
Arterial blood pressure; venous plasma catecholamine concentrations.


RESULTS
During rapid pacing, blood pressure was lower in group B (with impaired left ventricular function) than in group A: systolic blood pressure, 102 (11) v 115 (9) mm Hg (p = 0.005); mean blood pressure, 79 (6) v 85 (6) mm Hg (p = 0.02). The ejection fraction correlated with the lowest systolic blood pressure (r = 0.64, p = 0.0006). Although the rise in adrenaline was comparable between the two groups, the rise in noradrenaline was more pronounced (p < 0.05) in patients in group B.


CONCLUSIONS
At low rates and in selected patients, the underlying state of left ventricular function affects haemodynamic tolerance of ventricular tachycardia. Patients with impaired left ventricular function have a lower blood pressure during ventricular tachycardia, despite an exaggerated noradrenaline release.
Kolettis
T M
TM
Department of Cardiology, University of Ioannina, Ioannina, Greece. thkolet@cc.uoi.gr
Psarros
E
E
Kyriakides
Z S
ZS
Katsouras
C S
CS
Michalis
L K
LK
Sideris
D A
DA
D001794:Blood Pressure / Q000502:physiology*; D002304:Cardiac Pacing, Artificial; D002395:Catecholamines / Q000097:blood*; D015331:Cohort Studies; D004837:Epinephrine / Q000097:blood; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D013318:Stroke Volume / Q000502:physiology*; D017180:Tachycardia, Ventricular / Q000097:blood / Q000503:physiopathology*; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology*
D002395:Catecholamines; D009638:Norepinephrine; D004837:Epinephrine