The Patient
The Cardiac Cycle
Cardiovascular Disease Reduction
• Steady decline since 80’s
• Correlates with progress of treatment and prevention
How was it reduced?
• Biggest impact (50%) was smoking
• 2nd was diet
• No. of drugs prevent death by:
o Controlling hypertension
o Preventing blood clots
o Controlling blood cholesterol
Cardiovascular Drug Use
• No. of prescriptions increased steadily over the last 20 years. Plateaued at 350 million
Pharmacists and CVD
• Roles:
o Disease prevention: by promoting healthy living and supporting early
detection
o Supporting patients with established disease: by optimising drug treatment in
primary care and hospitals
Anatomy of CV system
• Left atrium→ Left ventricle→ Arteries→ Peripheral tissues (Aorta on left side)
• Right atrium→ Right ventricle→ Pulmonary arteries→ Lungs
• Pulmonary vein back to left atrium
• Volume of blood is controlled by the kidney
Heartbeat
• Beat starts at SAN. Banana shaped region at the top of the heart
• Spontaneously emit an electrical impulse that spreads to the rest of the heart making
the chambers contract (depolarisation)
• SAN connected to neighbouring cells through gap junctions. So signal quickly spreads
to the upper chambers then moves to the AVN
• Travels along Bundle of His→ Purkinje Fibres→ Ventricular muscle
• Each time the SAN fires there is a short delay before AVN fires
,The Patient
Cardiac Cycle
• Period from end of heartbeat to the next. Comprises of 2 major events:
1) Systole- Period when ventricular muscles contract and pumps blood out of
the heart
2) Diastole- Period between systoles when ventricular muscle is relaxed
• Mitral valve (left) and Tricuspid valve (right) are AV valves between the atria
• Aortic valve (left) and pulmonary valve (right) are closed during diastole to allow
ventricles to fill
• Volume of blood that reaches maximum point in cardiac cycle is the End-diastolic
volume
• AV valves shut when ventricular pressure rises to prevent backflow
Characteristics of diastole
• Chamber contains minimum blood
• Pressure in ventricles fall to zero- Helps blood flow in on next cardiac cycle
• AV valves closed- Helps maintain pressure in arteries to propel blood
Blood flow during diastole
• Low pressure in ventricles allows AV valves to open and blood to flow from atrium to
ventricle
• As ventricles fill their walls become stretched, opposes filling so volume reaches a
plateau while pressure is low
Heart and systemic blood pressure
• Systemic blood pressure= Diastolic pressure/Systolic pressure
• Diastolic pressure: The minimum pressure in arterial system
,The Patient
• Systolic pressure: Maximum pressure in arterial system
, The Patient
Excitable Cells
Cell membrane potential
• Membranes are electrically polarised. Voltage difference between the interior and
exterior of the cell, is known s membrane potential.
• Changing potential provides means for cell signalling
• Resting membrane potential
o Potential when cell is at rest
• Action potential
o Large, rapid, and reversible depolarisation of the membrane
o Always the same. “All-or-Nothing”
• Graded potential
o Change in membrane potential that is of varying amplitude and may or may
not result in an action potential
• Factors that determine membrane potential:
1) Gradients of ions across the membrane
2) Selectively permeable ion channels in the membrane
Transmembrane Ion Gradients
• K+ high in cell, Na+ high outside
• Cross membranes via ATPase or ion pumps
• Primary active transporters that use ATP to move ions against concentration gradient.
E.g. Na+, H+, Ca2+.
• Ion gradients can be created because the lipid bilayer is impermeable to ions. If the
barrier is disrupted; however, ions will move passively down their concentration
gradient
Ion Channels control membrane ion permeability
• Voltage-Gated:
o Usually activated by depolarisation. When membrane potential becomes more
positive than the resting potential
o One channel is activated by hyperpolarisation, when the membrane becomes
more negative than the resting potential
• Ligand-Gated:
o Open in response to the binding of a receptor agonist e.g. Nicotinic acetyl
receptor, glutamate, and GABA receptors
• Ion channels can be selective for either cations or anions, can also be specific for a
particular ion
The Cardiac Cycle
Cardiovascular Disease Reduction
• Steady decline since 80’s
• Correlates with progress of treatment and prevention
How was it reduced?
• Biggest impact (50%) was smoking
• 2nd was diet
• No. of drugs prevent death by:
o Controlling hypertension
o Preventing blood clots
o Controlling blood cholesterol
Cardiovascular Drug Use
• No. of prescriptions increased steadily over the last 20 years. Plateaued at 350 million
Pharmacists and CVD
• Roles:
o Disease prevention: by promoting healthy living and supporting early
detection
o Supporting patients with established disease: by optimising drug treatment in
primary care and hospitals
Anatomy of CV system
• Left atrium→ Left ventricle→ Arteries→ Peripheral tissues (Aorta on left side)
• Right atrium→ Right ventricle→ Pulmonary arteries→ Lungs
• Pulmonary vein back to left atrium
• Volume of blood is controlled by the kidney
Heartbeat
• Beat starts at SAN. Banana shaped region at the top of the heart
• Spontaneously emit an electrical impulse that spreads to the rest of the heart making
the chambers contract (depolarisation)
• SAN connected to neighbouring cells through gap junctions. So signal quickly spreads
to the upper chambers then moves to the AVN
• Travels along Bundle of His→ Purkinje Fibres→ Ventricular muscle
• Each time the SAN fires there is a short delay before AVN fires
,The Patient
Cardiac Cycle
• Period from end of heartbeat to the next. Comprises of 2 major events:
1) Systole- Period when ventricular muscles contract and pumps blood out of
the heart
2) Diastole- Period between systoles when ventricular muscle is relaxed
• Mitral valve (left) and Tricuspid valve (right) are AV valves between the atria
• Aortic valve (left) and pulmonary valve (right) are closed during diastole to allow
ventricles to fill
• Volume of blood that reaches maximum point in cardiac cycle is the End-diastolic
volume
• AV valves shut when ventricular pressure rises to prevent backflow
Characteristics of diastole
• Chamber contains minimum blood
• Pressure in ventricles fall to zero- Helps blood flow in on next cardiac cycle
• AV valves closed- Helps maintain pressure in arteries to propel blood
Blood flow during diastole
• Low pressure in ventricles allows AV valves to open and blood to flow from atrium to
ventricle
• As ventricles fill their walls become stretched, opposes filling so volume reaches a
plateau while pressure is low
Heart and systemic blood pressure
• Systemic blood pressure= Diastolic pressure/Systolic pressure
• Diastolic pressure: The minimum pressure in arterial system
,The Patient
• Systolic pressure: Maximum pressure in arterial system
, The Patient
Excitable Cells
Cell membrane potential
• Membranes are electrically polarised. Voltage difference between the interior and
exterior of the cell, is known s membrane potential.
• Changing potential provides means for cell signalling
• Resting membrane potential
o Potential when cell is at rest
• Action potential
o Large, rapid, and reversible depolarisation of the membrane
o Always the same. “All-or-Nothing”
• Graded potential
o Change in membrane potential that is of varying amplitude and may or may
not result in an action potential
• Factors that determine membrane potential:
1) Gradients of ions across the membrane
2) Selectively permeable ion channels in the membrane
Transmembrane Ion Gradients
• K+ high in cell, Na+ high outside
• Cross membranes via ATPase or ion pumps
• Primary active transporters that use ATP to move ions against concentration gradient.
E.g. Na+, H+, Ca2+.
• Ion gradients can be created because the lipid bilayer is impermeable to ions. If the
barrier is disrupted; however, ions will move passively down their concentration
gradient
Ion Channels control membrane ion permeability
• Voltage-Gated:
o Usually activated by depolarisation. When membrane potential becomes more
positive than the resting potential
o One channel is activated by hyperpolarisation, when the membrane becomes
more negative than the resting potential
• Ligand-Gated:
o Open in response to the binding of a receptor agonist e.g. Nicotinic acetyl
receptor, glutamate, and GABA receptors
• Ion channels can be selective for either cations or anions, can also be specific for a
particular ion
