INCREASED RESPONSE OF DIASTOLIC BLOOD-PRESSURE TO EXERCISE IN PATIENTS WITH CORONARY-ARTERY DISEASE - AN INDEX OF LATENT VENTRICULAR DYSFUNCTION

Objective-To determine whether an abnormal response of diastolic blood pressure during treadmill exercise stress testing correlated with the number of obstructed vessels and with left ventricular systolic funct ion in patients with coronary artery disease. Design-Diastolic blood p ressure was measured invasively during exercise stress testing and cor onary angiograms and left ventriculograms were obtained at rest in pat ients with coronary artery disease. The abnormal (greater-than-or-equa l-to 15 mm Hg) diastolic blood pressure response was compared with the number of obstructed coronary arteries and with left ventricular syst olic function. Setting-Two tertiary referral centres. Patients-50 cons ecutive patients (mean age 57 years) with coronary artery disease. Mai n outcome measures-The increase in diastolic blood pressure during exe rcise and its correlation with the appearance and disappearance of ST segment deviation, resting left ventricular systolic function, and the number of obstructed coronary arteries. Results-Group 1: 10 (20%) pat ients (three with one, four with two, and three with three vessel coro nary artery disease) (mean (SD) age 54.7(12) years) had an abnormal di astolic blood pressure response that appeared 1.2 (0.3) min before ST segment deviation and became normal 0.9 (0.3) min after the ST segment returned to normal. Group 2: 40 (80%) patients (12 with one, 16 with two, and 12 with three vessel coronary arteries disease) (aged 56.8 (8 .2) years) had a normal diastolic blood pressure response to stress te sting. The ejection fraction (46.3 (5)%) and cardiac index (2.6 (0.1) l/min/m2) in group 1 were less than in group 2 (61.6 (4.2)% and 3.8 (0 .3) l/min/m2 respectively, p less-than-or-equal-to 0.001). The end sys tolic volume was greater in group 1 than in group 2: 38.7 (0.7) ml/m2 v 28.2 (2.1) ml/m2, p less-than-or-equal-to 0.001. Conclusion-In patie nts with coronary artery disease an abnormal increase in diastolic blo od pressure during exercise stress testing correlated well with left v entricular systolic function at rest but not with the number of obstru cted coronary arteries. The abnormal response of diastolic blood press ure probably reflects deterioration of myocardial function.