Method specificity of the auscultatory estimates of the inodilatory reduction of diastolic blood pressure based on Korotkoff IV and V criteria.

Non-invasive measurements of blood pressure (BP) are method-specific estimates of actual blood pressure. The agreement of the auscultatory Korokoff V ('disappearance' of sound, kv) and Korokoff IV ('sound muffling' kiv) cut-off points in measuring diastolic blood pressure (DBP) was evaluated in healthy subjects in the presence of various controlled inodilatory interventions. 2. Eating (n = 8), 10 min i.v. infusion of 1 microgram min-1 isoprenaline and adrenaline (n = 12), p.o. administration of 40 mg of the PDE-III inhibitors isomazole and meribendan (n = 18) and p.o. administration of 1200 mg celiprolol (n = 15) caused evident chrono-inodilatory responses: average HR increases of 7, 19, 10, 17, 17 and 8 beats min-1, estimated CO increases of 1.6, 4.5, 2.3, 1.9, 2.6 and 1.8 1 min-1 and average shortening of QS2c of 18, 41, 8, 37, 42 and 9 ms for food, isoprenaline, adrenaline, isomazole, meribendan and celiprolol, respectively. 3. In general, there was good agreement between DBPkV and DBPkIV measurements before the administration of the inodilatory treatments (bias DBPkV-DBPkIV: 1-2 mm Hg) but the extent of inodilatory DBP reduction (-8, -6, -10, -2, -7 and -8 mm Hg according to DBPkIV for food, isoprenaline, adrenaline, isomazole, meribendan and celiprolol, respectively) was substantially overestimated when based on Korotkoff-V rather than -IV (bias DBPkV-DBPkIV in estimating the inodilatory effect on DBP: -8, -12, 1, -13, -12 and -7 mm Hg for food, isoprenaline, adrenaline, isomazole, meribendan and celiprolol, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)