Hypertension

Question 1

What is blood pressure (BP)?

Answer 1

Blood Pressure (BP) is a product of the increase and decrease with cardiac cycle (CO) and pressure in arterial system (TPR)/ BP= CO x TPR.

Systolic (SBP)= LV empties into aorta.
Diastolic (DBP)= Ventricular filling/ Normal reading:120/80 mmHg

Question 2

What are the determinants of BP?

Answer 2

1. Cardiac output (CO)
2. Peripheral Resistance (TPR)- Vasconstriction/Vasodilation.
3. Kidneys- Blood volume regulator

Question 3

What are the major mechanisms that regulate blood pressure?

Answer 3

1. Volume of blood pumped into the arterial tree is determined by= volume of blood within the heart, vigor of the hearts contraction and kidneys
2. Stiffness of arteries (Pipes)= Vascular Smooth muscle cell contractile tone, endothelial cell function, Matrix (scaffold) that embeds the vascular smooth cells.

Question 4

What is the definition of Hypertension (HTN)?

Answer 4

Hypertension is the definition of elevated high BP following consecutive measurements.

Systolic (SBP)- >140mmHg
Diastolic (DBP)- >90mmHg

Question 5

What is low blood pressure?

Answer 5

A low blood pressure reading a level that is 90/60mmHg or lower.

Question 6

What is resistant hypertension?

Answer 6

BP of at least 140/90mmHg or at least 130/80mmHg in patients with diabetes or renal disease or renal disease despite adherence to treatment with full doses of at least 3 antihypertensive medications, including a diuretic.

Question 7

What risk factors increase BP?

Answer 7

1. Excess weight
2. Alcohol intake
3. Sodium (Na) intake
4. Smoking
5. Accumulation of intra-abdominal fat and hyperinsulinemia play a role in pathogenesis of hypertension
6. Low potassium intake, physical inactivity, psychosocial stress
7. Genetic predisposition

Question 8

What are the risk factors of Hypertension?

Answer 8

The risk factors of Hypertension include stroke, blood vessel damage (arteriosclerosis), heart attack or heart failure and kidney failure and left ventricular hypertrophy.

Question 9

What is an AAA, how is it identified, what is the symptoms and what are the risk associated?

Answer 9

Abdominal Aortic Aneurysm (AAA) which is widening/bulge of abdominal aorta and exceeding normal size by >50%.
Identified: CT angiogram and Ultrasound (routine screening)
Symptoms: Usually asymptomatic/Pain in abdomen, back and legs
Risk of AAA: can lead to rupture/High mortality rate (Hypotension/Tachycardia)

Question 10

What are the risk factors of AAA?

Answer 10

Smoking, Hypertension, Obesity, Gender 3:1 (males), Atherosclerosis, High Cholesterol and Genetic.

Question 11

What is the AAA exercise precautions?

Answer 11

Patients with AAA usually have other comorbidities i.e. CAD, Diabetes, Heart disease.
Medications: Cholesterol and Blood Pressure
Exercise end points: Should monitor BP, ECG and SPO2 throughout exercise and observe

Question 12

Exercise for AAA?

Answer 12

1. Weight lifting/heavy physical activity as it can lead to aortic dissection/death
2. Exercise involving significant isometric muscle action and or the Valsalva manoeuvre as extreme elevations in blood pressure can cause AAA rupture
3. However, resistance exercise without breath-holding at 40-60% might be okay since intra-arterial blood pressure responses of cardiac patients have been shown to be clinically acceptable in this range

Question 13

What are the barriers to exercise for AAA?

Answer 13

1. Patients are not able to drive once their AAA reaches >5.5cm
2. Patients often lead a sedentary lifestyle
3. Other existing comorbidities
4. Contraindications to exercise (uncontrolled BP)
5. Anxiety around AAA rupture

Question 14

What is the effects of exercise on BP?

Answer 14

With aerobic exercise there is volume overload, but a potential pressure overload (pressor response due to systemic vascular resistance, i.e. no concomitant vasodilation) with isotonic or isometric resistance training. There is also a higher risk of Valsalva manoeuvre in resistance training (particularly with heavy loads).

Question 15

What is the Blood Pressure response to exercise in hypertension?

Answer 15

At all levels of dynamic and isometric exercise, SBP and DBP is higher in patients with HTN.

The relative increase in BP from resting values is similar to those with normal BP.

BP is rest and maintained at higher levels throughout the spectrum of activity from rest to peak exercise in those who suffer HTN.

Question 16

What is the blood pressure response to static or isometric exercise?

Answer 16

The normal response to isometric exercise is a rise in both SBP and DBP is commonly referred to as pressor response.

For people suffering with HTN the increase in BP during isometric exercise may or may not be mediated by an increase in CO but rather the pressor response is mainly associated with an increase in systemic vascular resistance (SVR) (This has been attributed to inability to increase CO because of LV hypertrophy or a blunted beta-adrenergic reactivity & predominance of alpha-adrenergic reactivity).

Static exercise= may put a greater strain on the vascular system than dynamic exercise (increases MVO2 – due to increased afterload).

Question 17

What is the BP response following exercise for endurance exercise (acute)?

Answer 17

The acute response include 5-7mmHg decrease post-exercise, post exercise hypotension for up to 22 hours
The chronic response is BP lowering effect.
The proposed mechanisms for the BP lowering effects of exercise include: neurohumoral, vascular & structural adaptations.

Question 18

What is the BP response to Resistance exercise?

Answer 18

Resistance training leads to a SBP decrease of 3mmHg and DBP decrease of 4mmHg and can increase arterial wall stiffness

Question 19

What pre exercise evaluation takes place for Hypotension?

Answer 19

The need for pre-training depends on 1) intensity of anticipation 2) Patients symptoms, signs, CVD risk & clinical CVD

Peak or symptom limited medically supervised ECG stress test required when:
Men over 45 & women over 55 planning vigorous exercise (see ACSM Risk Stratification).
Engaging in hard / v.hard exercise ( 60% VO2R).
Symptomatic of CVD (e.g. exertional dyspnoea, palpitations, etc.).
Contraindicated if resting SBP  180 or DBP ≥ 100 mm Hg (BACR, 2006); SBP > 200 mmHg & / or DBP > 110 mmHg at rest (relative contraindication, ACSM, 2014) .

Question 20

What is the exercise prescription for hypertension?

Answer 20

Mode: rhythmical large muscle group activity (endurance training) + resistance training
Frequency: Most days/week
Duration: 40-70 VO2 max (moderate)/ (=60-80% HRmax)/12-13 RPE

Question 21

Exercise progression for HTN?

Answer 21

Start with aerobic activity:
40% VO2max for elderly (increasing to 50% VO2max)
50% VO2max for more capable individuals (increasing to 70% VO2max or 85% VO2max for younger population).
Keep it below an RPE of 13.
10 – 15 mins. (increase by < 10% per week).
3 – 7 sessions per week.

Resistance training added a few weeks name:
For those with SBP > 160 mmHg or DBP > 100 mmHg should undergo pharmacological treatment to stabilise BP.

Question 22

What are the Anti-HTN medications?

Answer 22

1. Beta blockers (decrease CO by reducing RHR and inhibiting its rise with stress or exercise.
2. Diuretics: increases urination to reduce plasma & extracellular volumes thus reducing SV & CO.
3. Ca2+ channel blockers: also decrease CO by blocking the rise in contraction force of the ventricles. Lower BP response during exercise.
4. Vasodilators (Alpha-Blockers & Angiotensin Receptor Antagonists): used to reduce systemic vascular resistance.
5. ACE inhibitors: these will not alter HR response, yet blood pressure response to exercise will be reduced.

Question 23

What are the implications for Anti-HTN medication?

Answer 23

1. Beta-blockers & calcium channel blockers blunt HR response, so use RPE to monitor intensity.
2. Vasodilators = danger of hypotension, so avoid sudden postural changes & longer cool down required.
3. Beta-blockers may impair thermoregulation.
4. Diuretics may cause dehydration or hypokaelemia (low K+).

Question 24

Lifestyle interventions for HTN?

Answer 24

Losing weight (if overweight).
Reducing salt intake in the diet (< 6g / day sodium chloride).
Increase consumption of fruit & vegetables (ideally 7 – 9 portions / day).
Restricting alcohol intake.
Reduce saturated fat & cholesterol intake.
Stop smoking.
Taking regular exercise.
Reduce consumption of caffeinated drinks
Reducing or managing stress effectively (relaxation therapies).
Lifestyle modification leads to same reduction in BP as one drug (SBP 10 , DBP 6 mmHg) – medications may need to be taken to achieve BP target (< 140 / 90).

Question 25

What are the safety considerations for HTN?

Answer 25

1. Avoid isometric contractions- even gripping too tight.
2. Extended cool-down for those on antihypersensitive medication (to prevent post-exercise hypotension and venous pooling)
3. Physician evaluation for those with severe or uncontrolled hypertension (> 160 mmHg SBP & > 100 mmHg DBP).
4. Relative contraindication SBP > 200mmHg &/or DBP > 110mmHg @ rest.
5. Avoid floor-based exercise due to increased venous return & increased cardiac work (Woolf-May, 2006 p91).
6. Postural hypotension, post-exercise hypotension and/or exertional hypotension for those on anti-hypertensive medication