Hypertension, Stroke and Congestive Heart Failure

Hypertension, Stroke and Congestive Heart Failure

Lecture 7bChapter 20 Dudek

HypertensionHypertension

• A symptom, not a disease

• Arbitrarily defined as sustained elevated blood pressure greater than or equal to 140/90 mm Hg in otherwise healthy persons (130/85 mm Hg in diabetics)

• A major risk factor for heart disease, stroke, kidney failure, congestive heart failure, and peripheral arterial disease

• One of the most common chronic conditions in the Canada

Hypertension—how does it arise?Hypertension—how does it arise?

Hypertension—(cont.)Hypertension—(cont.)

• Compared to nonblacks, blacks

– Have a higher prevalence of hypertension

– Develop hypertension earlier in life

– Have higher risks of hypertension-related complications such as

o Especially stroke

o Kidney failure

Hypertension—(cont.)Hypertension—(cont.)

• Dietary factors play a prominent role in blood pressure regulation.

• Normotensive or prehypertensive

– Dietary changes have the potential to reduce blood pressure and prevent hypertension and its complications.

Hypertension—(cont.)Hypertension—(cont.)

• Stage 1 hypertension

– Diet is the initial treatment before drug therapy is introduced and may eliminate the need for medication.

• For those who have hypertension who are treated with medication

– Diet can lower blood pressure and reduce the dose of medication needed.

Hypertension—(cont.)Hypertension—(cont.)

• The DASH Diet

– DASH = Dietary Approaches to Stop Hypertension

– Multicenter feeding study

– Eating whole “real” foods rather than individual nutrients

– Significantly lowers both systolic and diastolic blood pressures as well as cholesterol

Hypertension—(cont.) The DASH eating planHypertension—(cont.) The DASH eating plan

DASH Food Groups DASH Daily Servings (except as noted)

DASH Serving Sizes

Vegetables 4-5 250 mL (1 cup) raw leafy  vegetables125 mL (½ cup)  cooked vegetables170 ml (6 oz) juice 

Fruit 4-5 1 medium piece of fruit63 mL (¼ cup) dried fruit125 mL (½ cup) fresh, frozen or canned fruit

Grains(mainly whole grains)

7-8 1 slice bread250 mL (1 cup)  ready to eat cereal125 mL (½ cup) cooked rice, pasta or cereal

Low  Fat or No-Fat Dairy Foods

2-3 250 mL (1 cup) milk250 ml (1 cup) yogurt50 g (1½ oz) cheese

Lean meats, poultry and fish 2 or less 3 ounces cooked lean meats, skinless poultry, or fish

Nuts, seeds and dry beans 4-5 per week 1/3 cup (1.5 oz.) nuts30 mL (2 tbsp) peanut butter2 tbsp (1/2 oz.) seeds1/2 cup cooked dry beans or peas

Fats and Oils 2-3 5 ml (1 tsp) soft margarine15mL (1 tbsp) low-fat mayonnaise30 mL (2 tbsp)  light salad dressing5 ml (1 tsp) vegetable oil

    

Hypertension—(cont.) The DASH eating planHypertension—(cont.) The DASH eating plan

    

Hypertension—(cont.)Hypertension—(cont.)

• The DASH Diet—(cont.)

– DASH-sodium

o Lowering sodium lowers blood pressure.

o Greatest reduction in blood pressure occurred at 1500 mg of sodium.

o Greatest blood pressure reductions occurred in blacks; middle-aged and older people; and in people with hypertension, diabetes, or chronic kidney disease.

Hypertension—(cont.)Hypertension—(cont.)

• DASH diet is very similar to Canada’s food guide

Hypertension—(cont.)-good diet and exercise can lead to weight loss

Hypertension—(cont.)-good diet and exercise can lead to weight loss

• Weight loss

– Observational and clinical studies consistently show

o Weight is directly related to blood pressure.

o Weight loss lowers blood pressure, even if healthy weight is not attained.

– The greater the weight loss, the greater the reduction in blood pressure.

Hypertension—(cont.)Hypertension—(cont.)

• Weight loss—(cont.)

– Achieving a healthy weight (BMI <25)/waist circumference is an effective intervention to prevent and treat hypertension.

– Preventing weight gain is critical.

• Potassium-found in a good diet

– Potassium intake increases, blood pressure decreases.

– Recommended that people consume 4.7 g potassium per day-leads to drop in blood pressure

Hypertension and diet (cont.)Hypertension and diet (cont.)

• Alcohol

– Observational studies and clinical trials

o Show a direct, dose-dependent relationship between alcohol and blood pressure

o Alcohol intake should be limited to 2 drinks or less per day in men and 1 drink or less per day for women.

StrokeStroke

Stroke due to atherosclerotic process and hypertension

There are 3 types of stroke:

•Thrombotic

•Embolic

•Haemorrhagic

Dietary recommendations pre- and post-onset as in lecture 7a and 7b

Congestive Heart Failure (HF)Congestive Heart Failure (HF)

• Chapter 20

Congestive Heart Failure (CHF)Congestive Heart Failure (CHF)

• The problem-blood returning to heart cannot be pumped out as fast as it arrives so blood (and the water portion of blood) backs up

• Syndrome characterized by specific symptoms

– Shortness of breath-flooding of lungs

– Fatigue-poor gas exchange

– Oedema-water backing up

• Coronary atherosclerotic heart disease (CHD) causing heart attack (myocardial infarction), hypertension, and diabetes are prevalent causes; arrhythmias and valve disorders may also cause CHF.

Congestive Heart Failure-Pathology

 Myocardial infarction can lead to chronic or congestive heart failure

-weakened heart can not keep up with water load returning to heart and fluid backs up in

the extremities and in lungs 

-heart becomes even more weakened because it tries to pump more fluid but struggles to do

so 

-ultimately the heart is overwhelmed by the fluid load and quits

Congestive Heart Failure (CHF)Congestive Heart Failure (CHF)

Type of heart failure Description

Left-sided heart failure Fluid may back up in your lungs, causing shortness of breath.

Right-sided heart failure Fluid may back up into your abdomen, legs and feet, causing swelling.

Systolic heart failure The left ventricle can't contract vigorously, indicating a pumping problem.

Diastolic heart failure(also called heart failure with preserved ejection fraction)

The left ventricle can't relax or fill fully, indicating a filling problem.

Congestive Heart Failure (HF)-one characteristic is oedema

Congestive Heart Failure (HF)-one characteristic is oedema

Treatment of CHF 

-treatment consists of diuretics (reduce fluid load) and glycosides (strengthen cardiac intropy)

 -with this combination strong chance of

potassium deficiency (why?) and constipation 

-constipation can stress heart

CHF and Nutrition status 

-build up of fluid causes heart and lungs to work harder

 -when the heart and lungs work harder they

require more energy 

-yet that extra energy is not available because fluid build up impairs cardiac and pulmonary function

CHF and Nutrition status

- since blood flow and oxygen delivery are critical to the processes of digestion,

absorption and transport and energy release the extra energy required for the heart and lungs is

not there 

- therefore heart and lungs cannot keep up and there is heart failure and ultimately

flooding of the lungs 

-all above limits energy and protein intake

CHF and Nutrition status

-oral intake may be limited by anorexia, taste sensitivity, intolerance to food odours, physical

exhaustion, low sodium diet  

-weight loss may go unnoticed due to oedema since oedema masks weight loss

 -consequently PEM can occur – in this case

PEM is called cardiac cachexia

Congestive Heart Failure (HF)—(cont.)Congestive Heart Failure (HF)—(cont.)

• Nutrition therapy—(cont.)

– Cardiac cachexia

o Need a high-calorie, high-protein, high-nutrient diet while maintaining a low- sodium diet

o Caloric and nutrient density are important.

Congestive Heart Failure (CHF)—(cont.)Congestive Heart Failure (CHF)—(cont.)

• Nutrition therapy

– For people at risk of CHF, the goals of therapy are to control underlying risks.

– DASH-sodium diet is appropriate for people with CHD or hypertension.

– Regular exercise and smoking cessation are encouraged.

– Alcohol is discouraged.

Congestive Heart Failure (CHF)—(cont.)Congestive Heart Failure (CHF)—(cont.)• Nutrition therapy—(cont.)

– Stage C congestive heart failure is defined as structural heart disease with prior or current symptoms of CHF.

o Sodium is limited to 2 g of sodium/day or less.

o A fluid restriction of 1.5 L/day for patients with hyponatremia

o A low-calorie diet for patients who are overweight

o Small, frequent meals

o Soft, easy-to-chew foods for patients with fatigue

o Increased potassium intake for patients who are taking thiazide (potassium-wasting) diuretics or digitalis

Nutrition therapy for CHF 

-increase potassium by eating potassium rich foods if potassium deficient

  

-aim is to improve nutrition status and to reduce cardiac work (losing weight reduces cardiac

work)

Nutrition therapy for CHF

-reduce fluid and sodium intake- remember body in CHF is having trouble keeping up

with the water load 

-sodium increases the water load and ultimately the blood pressure

 

Nutrition therapy for CHF

reduce fluid and sodium intake- remember body in CHF is having trouble keeping up with the water

load

-as blood pressure increases the risk of kidney failure increases

 -if kidney failure occurs then fluid retention

will shut down the body-dialysis is an option but not nearly

as good as properly functioning kidneys

Nutrition therapy for CHF

reduce fluid and sodium intake- remember body in CHF is having trouble keeping up with the water

load

-patient gets high nutrient density foods-get energy and protein with less fluid

 -heart healthy diet described previously this week is appropriate to ensure that there is a reduced risk of heart attack or subsequent

heart attack

Nutrition therapy for CHF

-a healthier heart is critical to being able to meet the demands of increased water load

-max 2000 mg sodium per day

-if recurrent or persistent fluid retention then no more than 2 litres of fluid/day

-adequate fibre

-no alcohol

Nutrition therapy for CHF

-carbohydrate requirement is dictated by the presence of hyperglycemia-

- possible reasons for hyperglycemia

-if supplements are required then nutrient dense liquids are the first choice  

Nutrition therapy for CHF

-if patient does not want to eat then duodenal feeding can be initiated

-feedings begin slowly (30 ml/hour) and then are increased gradually

 -fluid and electrolyte status must be carefully

monitored-why?

Nutrition therapy for CHF-if patient does not want to eat then duodenal

feeding can be initiated

-overly aggressive nutritional support can worsen CHF resulting in pulmonary edema

 -2 kcal/ml and moderate to low sodium

 -continuous nasogastric feeding can result in loss of body weight (fluid) loss and lean body mass increase without compromising cardiac

status

Nutrition therapy for CHFif oral and tube feeding fail then parenteral feeding

is instituted-as with nasogastric- therapy begins slowly

 -1500 ml per day to start

-cachetic patient as low as 600 ml/day –why? 

-central venous pressure, pulse rate, arterial blood pressure and urine output are tracked

as fluid input increases

Nutrition therapy for CHF

-at the first sign of nutritional inadequacy, enteral or parenteral therapy should begin as progression of nutritional inadequacy is slow and nutritional

goals take longer to obtain

Class activity-what is the best approach to avoidingCHF?