Effetti Acuti Cardiovascolari ed Esercizio Fisico Risposta Cardiovascolare all’Esercizio Acuto 1. Fase preparatoria iniziale Stimolazione adrenergica Vasocostrizione distrettuale 2. Fase intermedia metabolica Fattori locali Stimolazione adrenergica Risposta Cardiovascolare all’Esercizio Acuto • Fase preparatoria iniziale • Stimolazione adrenergica (cuore) vasocostrizione distrettuale • Risposta Cardiovascolare all’Esercizio Acuto Fase preparatoria iniziale Stimolazione adrenergica (cuore) Resting, anticipatory, and maximum exercise heart rate in competitive runners and untrained subjects during all-out running Event 60 yards 220 yards 440 yards 880 yards 1 mile 2 mile T = Trained UT = Untrained REST T UT 67 69 67 67 63 63 62 70 58 64 59 74 ANTICIP T UT 148 124 130 115 129 118 122 129 118 128 108 109 EXERCISE T UT 177 162 191 186 187 189 186 194 195 198 206 199 McArdle W.D. Telemetred cardiac response to selected running events J. Appl. Physiol. 23:566,1967 Integreted chemical,neural and hormonal adjustaments prior to and during exercise Activator Preexercise “anticipatory” response Activation of motor cortex and higer areas of brain causes increase in sympathetic outflow and reciprocal inhibition of parasympathetic activity Response Acceleration of heart rate; increased myocardial contractility; vasodilatation in skeletal and heart muscle (cholinergic fibres); vasoconstriction in other areas, especially in skin,gut,spleen, liver and kidneys (adrenergic fibres); increase in arterial blood pressure. Integreted chemical,neural and hormonal adjustaments prior to and during exercise Condition EXERCISE Activator Continued sympathetic cholinergig outflow; alterations in local metabolic conditions due to hypoxia, pH, CO2, ADP, Mg++, Ca++, temperature. Continued sympathetic adrenergic outflow in conjunction with epineprhine and norepineprhine from the adrenal medulla Response Further dilatation of muscle vasculature Concomitant constriction of vasculature in inactive tissues to maintain adeguate perfusion pressure throu ghout arterial system. Venous vessels stiffen to reduce their capacity. This venoconstrinction facilitates venous return and maintainsthe central blood volume Distribution of Flow at Rest and during Acute Exercise Distribution of Flow at rest and during Acute Exercise 20% 22% 4% 6% Muscle Heart Skin Brain Other Liver Kidneys 14% 27% 4% 5% 4% 1% Muscle 84% 7% Rest 3-5 Lmin Exercise CRMS 25-30 Lmin Heart Rate in Response to Exercise HR Watts Cardiovascular Response to Acute Exercise ( Stroke Volume) Cardiovascular Response to Acute Exercise (Cardiac Output) Cardiovascular Response to Acute Exercise Cardiovascular Response to Exercise in Men and Women Age and End Diastolic Volume during Acute Exercise Change of Left Ventricular Ejection Fraction from Rest to Exercise Blood Pressure = CO x Peripheral Resistance In normal subjects exercise increases Cardiac Output and/or decreases Peripheral Resistance Exercise and Blood Pressure in normal subjects 200 180 160 P.A. 140 120 100 80 60 0 100 150 Watts 250 Exercise and Blood Pressure normal subjects Exercise and Blood Pressure normal subjects Men < 20 Systolic Diastolic Men > 20 Systolic Diastolic Coronary Flow and Heart Rate Cor.Flow HR Cardiovascular Response to Exercise Watts Myocardial O2 Cosumption cc/min/100gr Effetti della Vasocostrizione sul Flusso Coronarico Exercise,Vasoconstriction and Coronary Flow 25% Radius 63% Area Vasoconstriction (Acute Exercise) 17% Radius 96% Area Effetti della Vasocostrizione sul Flusso Coronarico Cardiovascular Response to Acute Exercise in trained subjects H.R. b/min Cycloergometer Recovery Cardiovascular Response to Acute Exercise in trained subjects