Chapter 16 Alterations in Blood Pressure I Blood Pressure a Aorta needs more pressure i Vasodilation Parasympathetic 1 Decreases speed increase blood lower BP ii Vasoconstriction Sympathetic 1 Increase BP decrease blood increase speed increase tension b Definition i Arterial Blood Pressure 1 Pressure difference between the left and right side of the heart 2 Gradient allows systemic movement of blood 3 Produced by the force of the left ventricular contraction needed to overcome the resistance of the aortic valve resulting in valve opening c Regulation i Neural humoral and renal factors 1 Normal Blood Pressure Function a During the day due to physiological changes associated with the circadian rhythm suprachiasmatic nuclei i Nuclei in brain that controls circadian rhythm and blood pressure ii Higher in the morning to afternoon iii Lower from the afternoon to the evening iv Lowest while sleeping 2 Neural and Hormonal a Nervous system short term regulation i Sympathetic epinephrine and ii Parasympathetic acetylcholine lowers norepinephrine BP antagonistic 3 Lifestyle a Diet and Exercise ii Short term regulation 1 Mediated through the stimulation of the sympathetic nervous system a Release epinephrine and norepinephrine neurotransmitters 2 Vasomotor Center located in brain stem indirectly activated via baroreceptors sense pressure on blood vessels a Alpha receptors in smooth muscle of arterioles b Beta 1 receptors of the heart c Adrenergic Sympathetic iii Long term regulation 1 Changes in extracellular fluid volume 2 Increased serum sodium solute increased osmolality increased ADH which maintains fluid volume a ADH Antidiuretic Hormone allows you to retain more water rather than urinating it out b More H20 higher blood volume more blood coming back to the heart 3 Renin Angiotension Aldosterone System RAAS d RAAS sodium 1 ii Renin i Neurohormonal regulatory mechanism for body water and Increases water volume and Na reabsorption 1 Proteolytic enzyme secreted by the kidney 2 Converts angiotensinogen to angiotensin I in the liver iii Angiotensin I converts to angiotensin II in the lung and kidney II Hypertension a Most common primary diagnosis in the US i Responsible for 7 million deaths worldwide ii The no 1 killer in the US Heart Disease can be caused by Hypertension b Increased morbidity and mortality associated with heart and kidney disease peripheral vascular disease and stroke i Morbidity complications ii Mortality death c Classification i Primary Secondary ii Normal Prehypertension initiate intervention early enough to prevent or deter disease progression Stage1 Stage2 iii Categories 1 Normal Systolic 120 mmHg Diastolic 80 mmHg 2 Prehypertension Systolic 120 139 mmHg Diastolic 80 89 mmHg mmHg 3 Stage 1 Systolic 140 159 mmHg Diastolic 90 99 4 Stage 2 Systolic greater or equal to 160 mmHg Diastolic greater then or equal to 100 mmHg d Primary Idiopathic i Most common form of hypertension ii iii Rare in children under 10 years old iv Subtypes 1 Isolated systolic HT 140 70 changes more regularly 2 Isolated Systolic HT 120 100 clinically what we look for because it changes more slowly 3 Combined systolic and diastolic HT v Risk Factors 1 Non modifiable a Family History b Age c Being Male d European African American Hispanic 2 Modifiable a Diet b Sedentary Lifestyle c Obesity d Metabolic Syndrome e Diabetes f Low HDL High LDL vi Outcomes End Organ Damage Increased myocardial work results in heart failure 1 2 Glomerular damage results in kidney failure 3 4 Impaired ocular microcirculation Increased cerebral vascular pressure results in hemorrhage 5 Aneurysm high pressure which causes vessel to dilate then weaken and pop bleed out Ischemia angina 6 vii Treatment 1 Lifestyle modifications a First line most important prevention and management strategy b Lower BMI to somewhere between 19 24 2 Drug Therapy a Affects heart rate and stroke volume viii Drugs Used to Treat Hypertension 1 ARBs reduce stroke volume 2 Beta Blockers decrease heart rate 3 ACE Inhibitor reduce systemic vascular resistance e Secondary to another disease i Most Common form in children under 10 years condition ii Possible Etiological Factors iii III Hypotension a Possible etiological factors Impaired vasomotor baroreceptor response i ii Adverse effects of drugs iii Arterial stiffness volume depletion b Orthostatic Postural Hypotension getting out of bed too quickly and feeling like you re going to faint Postural changes causing drops in BP i Fainting Syncope ii Decrease in systolic blood pressure less than or equal to 10 mmHg within 3 minutes when changing from a supine to an upright position c Can be associated with a 20 30 bpm increase in heart rate d Management i Etiological 1 Drug history 2 Slow positional changes 3 Avoid hot environments 4 Avoid large carb rich meals 1 Squatting bending forward 2 Crossing legs ii Symptomatic