Mean Blood Pressure Assessment during Post-Exercise: Result from Two Different Methods of Calculation.
At rest the proportion between systolic and diastolic periods of the cardiac cycle is about 1/3 and 2/3 respectively. Therefore, mean blood pressure (MBP) is usually calculated with a standard formula (SF) as follows: MBP = diastolic blood pressure (DBP) + 1/3 [systolic blood pressure (SBP) - DBP]. However, during exercise this proportion is lost because of tachycardia, which shortens diastole more than systole. We analysed the difference in MBP calculation between the SF and a corrected formula (CF) which takes into account changes in the diastolic and systolic periods caused by exercise-induced tachycardia. Our hypothesis was that the SF potentially induce a systematic error in MBP assessment during recovery after exercise. Ten healthy males underwent two exercise-recovery tests on a cycle-ergometer at mild-moderate and moderate-heavy workloads. Hemodynamics and MBP were monitored for 30 minutes after exercise bouts. The main result was that the SF on average underestimated MBP by -4.1 mmHg with respect to the CF. Moreover, in the period immediately after exercise, when sustained tachycardia occurred, the difference between SF and CF was large (in the order of -20-30 mmHg). Likewise, a systematic error in systemic vascular resistance assessment was present. It was concluded that the SF introduces a substantial error in MBP estimation in the period immediately following effort. This equation should not be used in this situation.
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Gianmarco
G
Sainas
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Raffaele
R
Milia
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Girolamo
G
Palazzolo
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Gianfranco
G
Ibba
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Elisabetta
E
Marongiu
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Silvana
S
Roberto
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Virginia
V
Pinna
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Giovanna
G
Ghiani
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Filippo
F
Tocco
Department of Medical Sciences, Sports Physiology Lab., University of Cagliari , Italy.
Antonio
A
Crisafulli
cardiac output; contractility; exercise; recovery; stroke volume