Energy supply to the heart

1. Energy Supply to heart muscles
Dr. Marwa Matboli
Dr. Walaa Ibrahim
Dr. Heba Morsi
Assistant professor of Medical biochemistry& Molecular Biology

2. Concept map of cardiovascular module
Energy supply to heart
Triglycerides
Metabolism
Cholesterol
Metabolism
Lipoprotein metabolism
Hyperlipoproteinemia and atherosclerosis

3. • Intended Learning Outcome
• By the end of this lecture, students should be able to:
➢ Know about nutritional cardiomyopathy and most important
nutrients deficiency causing it.
➢ Understand the underlying mechanism of cardiac BeriBeri
➢ Identify different sources of energy supply to the heart under
normal and abnormal conditions

4. Clinical Case Scenario
A 72-year-old female presented at the
emergency department with extreme fatigue
that started 1 week ago, progressive
dyspnea, and generalized edema.
She denied smoking or using addictive drugs,
but confessed excessive alcohol consumption
and a dietary pattern restricted to intake of
only carbohydrates; specifically, eating only
cookies without any intake of essential
nutrients.
On admission, she appeared to be chronically
ill-looking, but alert with mild hyperventilation.
Cardiac imaging revealed dilated
cardiomyopathy.

5. • Based on the patient's history of excessive alcohol consumption in
combination with nutritional insufficiency, as well as cardiac imaging
findings suggestive of dilated cardiomyopathy.
• Intravenous thiamine administration was initiated for the next seven
days, which was subsequently switched to oral vitamin B complex.
• With thiamine supplementation, the patient's condition steadily and
gradually improved, and she was given permission to leave hospital
two weeks after admission.

6. What are the chief presenting complaints in this case?
Extreme
fatigue
Dyspnea,
generalized
edema

7. Deficiency in some
important
nutrients, most
common of which
is thiamine
deficiency.
Nutritional
cardiomyopathy
Clinical case analysis

8. Alcohol consumption
decreasing the transport of thiamine
across the intestinal mucosa
decreasing the transport of thiamine across
the intestinal mucosa
impairing the phosphorylation of thiamine to the more
biological active thiamine diphosphate.
thiamine deficiency
Why is chronic alcoholism usually associated with thiamine
deficiency?

9. Why is chronic alcoholism usually associated with thiamine
deficiency?
Chronic exposure
to alcohol, further
decreases the
amount of thiamine
diphosphate.

10. Why is chronic alcoholism usually associated with thiamine
deficiency?
decrease the contractility of the heart
energy produced from carbohydrates
will decrease
when the active form of thiamine
decreases
Thiamine diphosphate, is the co-enzyme several
enzymes that are important in carbohydrate
metabolism and in production of energy.

11. Energy supply to the heart
The heart is one
of the most active
tissue in the body.
The heart
requires a high
rate of energy
expenditure to
fuel the constant
power output of
the ventricles.

12. The main
energy
currency in
the cell is
called ATP
ATP
ADP + Pi
Contractile
work of
systole
Calcium uptake into
the sarcoplasmic
reticulum that
allows for
relaxation during
diastole

13. The concentration of ATP in the heart remains constant,
even when the heart is stressed by exercise.
ATP CONSUMPTION ATP Resynthesis

14. Energy sources under basal aerobic conditions:
• from free fatty acids and triglycerides
• (oxidation of fatty acids is strictly aerobic)
60%- 80%of
energy
• from carbohydrates
• oxidation of carbohydrates can occur aerobically or
anerobically
10%-30%
• by lactate uptake.
10-30%
• (beta-hydroxybutyrate and acetoacetate)
can also readily be oxidized by the heart only under certain
conditions.
Ketone bodies

15. Energy sources to the heart muscle
Energy source to
heart
Aerobic condition
Fatty acid 60-80% Glucose 10-30%
Ischemic
Glucose and fatty
acid are equally
used(50%) for
each one

16. The rates of glucose and
fatty acid oxidation
The rate of
contractile work
Contractile
work of
the heart
Supply of
oxygen
Rate of
oxidation of
nutrients

17. During starvation or poorly controlled diabetes
Ketone bodies
Glucose oxidation
Fatty acid
oxidation
_ _

18. Randle Cycle
Randle observed that the main effects
of fatty acid and ketone bodies are to
inhibit the oxidation of glucose.
Sparing glucose for the brain.

19. Other nutrients related to the health of the
heart
1.Vitamin D
2.Carnitine
3.Selenium

20. 1-Vitamin D
Other nutrients related to the health of the
heart
Studies have shown that vitamin D plays an important role in the health of the cardiovascular system.
Effects on the
myocardium
Antihypertrophic effects
Modulation of calcium flux
and contractility
Renin suppression
Modulation of extracellular
matrix turnover
Effects on the
vessels
anti atherosclerotic
effects
Inhibition of vascular
calcification
Improvement of
endothelial functions
Effects on
cardiovascular risk
factors
Renoprotective effects
Antihypertensive
effects
Antidiabetic effects
PTH suppression
Antinflammatory effects
Antioxidative effects

21. 2-Carnitine
Carnitine is the main
constituent of carnitine
shuttle
Allows for the entry of
fatty acids into the
mitochondria
to be oxidized and
produce energy.
Energy
production
(ATP)

22. Carnitine
deficiency
impaired energy
production in
the heart
•Fatty acids are the main source of
energy to the heart under physiological
conditions.
2-Carnitine

23. 3-Selenium
Selenium is
one of the
most
important
antioxidants
Protects the
mitochondri
a from
oxidative
stress.

24. Since energy supply to the heart is mainly
through mitochondrial oxidative
phosphorylation,
Selenium deficiency will lead to impaired
cardiac mitochondrial function
impaired energy supply and
cardiomyopathy.
3-Selenium