Summary, Pathophysiology of the heart and vascular system
Introduction lecture
Relevance
• The Netherlands
-1.7 million people with chronic heart disease of heart or circulation
• Daily
-103 cardiovascular deaths
-Women (52); men (51)
-25 patients <75 years
-644 patients are hospitalized because of cardiovascular disease
• Examples
-Stroke (95 daily), cardiomyopathies, cardiac arrhythmias, vascular disease, diabetes
-Covid-19 &cardiovascular disease
,Keynote: The increase of cardiac output in evolution
Abstract:
The structurally complex and incredibly hardworking organ we call ‘the heart’ has more than
half a billion years of evolutionary history. Genes that are necessary for the pulsating vessel
of fruit flies can, if mutated in human, lead to congenital malformations. But not all hearts
are alike. Our heart has to do the double job of driving blood through both the body and the
lungs, whereas in fish and fruit flies, which do not have lungs, the heart is a single circuit
pump only. Ultimately, however, the heart is a service organ that supports the metabolism
by driving the circulation of the nutritious blood that takes away waste. A central concept is
therefore ‘cardiac output’ which is the volume of blood pumped by the heart per minute.
Because the heart cannot pump more blood than it receives, heart function is intimately
related to the function of the venous system – experiments on alligators and human elite
cyclists show this. The output of any pump is the product of the number of pumps per time
(heart rate) and the volume per pump (stroke volume) and in animals heart rate is the most
important factor of the two - experiments on whales and shrews, ostriches and
hummingbirds, show this. This lecture will make a synthesis of the insights from a
menagerie of different animals to show how venous function, blood pressure, stroke
volume, and heart rate have changed in evolution to sustain the great metabolisms that
characterize warm-blooded animals including human.
,Lecture 1, Cardiac Energetics
Understand
- The significance of the arrangement of the cardiovascular system
- Energetics in the healthy heart
- How myocardial inefficiency contributes to heart failure
- How to study myocardial energetics
Why do we have this sophisticated (geavanceerd) system?
• Transport of oxygen
• Removal of waste products
Arrangement of the cardiovascular system
1. Oxygen pressure (mmHg); high where we inhale the air and it decreases when
oxygen is taken
-Pressure at right ventricle is 40mmHg or 15mmHg in exercise because then more
oxygen is extracted by the circulation
2. Systolic and diastolic pressures (mmHg)
-left ventricle: systolic 120, diastolic 80
-Right ventricle: systolic 25, diastolic 40
Thus, the mean arterial pressure in the systemic circulation is higher than in
pulmonary circulation
, Arrangement
• In series: 2 pumps (left and right side of the heart)
- Output of both sides of the heart do closely match
• In parallel: most major organs (except the liver)
- Enables adaptations to specific needs in blood flow,
without affecting blood flow in other organs
Adaptations across species
Mammals and birds have a 4-chamber heart.
Crocodiles can lower their metabolic rate when they dive into the water. Due to the lower
metabolic rate the heartbeats lower and the only use blood with low oxygen content
How many chambers has the alligator heart? > 4
What is the heart frequency of an alligator while below water/at rest? > lower (2 to 3 beats
per minute
Flow of oxygen
1. Taking up of oxygen in our lungs
2. Pulmonary circulation
3. Oxygen flows into the heart via the left
atrium
4. Systemic circulation
5. Oxygen reaches muscles (sarcomeres→
smallest contractile unit int the muscles)
where it can be consumed
6. Mitochondria
7. ATP
Introduction lecture
Relevance
• The Netherlands
-1.7 million people with chronic heart disease of heart or circulation
• Daily
-103 cardiovascular deaths
-Women (52); men (51)
-25 patients <75 years
-644 patients are hospitalized because of cardiovascular disease
• Examples
-Stroke (95 daily), cardiomyopathies, cardiac arrhythmias, vascular disease, diabetes
-Covid-19 &cardiovascular disease
,Keynote: The increase of cardiac output in evolution
Abstract:
The structurally complex and incredibly hardworking organ we call ‘the heart’ has more than
half a billion years of evolutionary history. Genes that are necessary for the pulsating vessel
of fruit flies can, if mutated in human, lead to congenital malformations. But not all hearts
are alike. Our heart has to do the double job of driving blood through both the body and the
lungs, whereas in fish and fruit flies, which do not have lungs, the heart is a single circuit
pump only. Ultimately, however, the heart is a service organ that supports the metabolism
by driving the circulation of the nutritious blood that takes away waste. A central concept is
therefore ‘cardiac output’ which is the volume of blood pumped by the heart per minute.
Because the heart cannot pump more blood than it receives, heart function is intimately
related to the function of the venous system – experiments on alligators and human elite
cyclists show this. The output of any pump is the product of the number of pumps per time
(heart rate) and the volume per pump (stroke volume) and in animals heart rate is the most
important factor of the two - experiments on whales and shrews, ostriches and
hummingbirds, show this. This lecture will make a synthesis of the insights from a
menagerie of different animals to show how venous function, blood pressure, stroke
volume, and heart rate have changed in evolution to sustain the great metabolisms that
characterize warm-blooded animals including human.
,Lecture 1, Cardiac Energetics
Understand
- The significance of the arrangement of the cardiovascular system
- Energetics in the healthy heart
- How myocardial inefficiency contributes to heart failure
- How to study myocardial energetics
Why do we have this sophisticated (geavanceerd) system?
• Transport of oxygen
• Removal of waste products
Arrangement of the cardiovascular system
1. Oxygen pressure (mmHg); high where we inhale the air and it decreases when
oxygen is taken
-Pressure at right ventricle is 40mmHg or 15mmHg in exercise because then more
oxygen is extracted by the circulation
2. Systolic and diastolic pressures (mmHg)
-left ventricle: systolic 120, diastolic 80
-Right ventricle: systolic 25, diastolic 40
Thus, the mean arterial pressure in the systemic circulation is higher than in
pulmonary circulation
, Arrangement
• In series: 2 pumps (left and right side of the heart)
- Output of both sides of the heart do closely match
• In parallel: most major organs (except the liver)
- Enables adaptations to specific needs in blood flow,
without affecting blood flow in other organs
Adaptations across species
Mammals and birds have a 4-chamber heart.
Crocodiles can lower their metabolic rate when they dive into the water. Due to the lower
metabolic rate the heartbeats lower and the only use blood with low oxygen content
How many chambers has the alligator heart? > 4
What is the heart frequency of an alligator while below water/at rest? > lower (2 to 3 beats
per minute
Flow of oxygen
1. Taking up of oxygen in our lungs
2. Pulmonary circulation
3. Oxygen flows into the heart via the left
atrium
4. Systemic circulation
5. Oxygen reaches muscles (sarcomeres→
smallest contractile unit int the muscles)
where it can be consumed
6. Mitochondria
7. ATP
