Module 2- Cardiology and Heart Transplants Flashcards
Scale of cardiac disease
- Cardiac disease is the single largest cause of death globally, with over 610,000 people dying of heart disease
in the US each year - The chart shows the percentage of shares of deaths from heart disease
out of all the deaths by country
Cardiac disease according to economic status
There is a wide socioeconomic disparity between heart
disease treatments amongst different countries
Cardiac disease and cancer in males vs. females
Recent efforts in biotechnology have reduced death rates — but
0.3% of males and 0.15% of females still die of heart disease
Facts showing the prevalence of coronary heart disease
- Coronary heart disease (CHD) is the
most common type of heart disease, killing 370,000 people each year in the US - In other words, around 53% of all heart disease deaths are attributed to CHD
- Heart disease has been the leading cause of death in the US every year since 1900 (except in 1918 — the Spanish Flu)
Economic cost of heart disease
The United States spends the equivalent of 1.05% of its GDP on heart disease every year
Right side of heart
The human heart has four chambers
that hold blood as it enters and exits the organ
- The right atrium receives the
deoxygenated blood from the body and then it continues to the right ventricle - The right ventricle then pumps the oxygen-poor blood to the lungs
Left side of heart
- The left atrium receives oxygenated blood from the lungs and then it
continues to the left ventricle - The left ventricle then pumps the oxygen-rich blood to the body
Diagram of heart
Heart valves
The four valves regulate the flow of blood
- The tricuspid and mitral valves control
blood flow from the atria into the ventricles - The aortic and pulmonary valves
control blood flow out of the ventricles
Oxygen supply to the heart
- The heart is a muscle that needs blood and oxygen to function. But if the heart is the body’s blood pump… how does it get its own supply?
- The coronary arteries are highly branched and bifurcated, originate directly from the aorta, and total about 10% of cardiac output
Propagation of heartbeat
Specialized cardiac muscle cells (the
nodes and bundles) send electrical
signals to the rest of the cardiac muscle of the heart, inducing a muscular pulse — our heartbeat
Graphic showing different types of heart diseases
What are the two types of coronary artery disease?
Arteriosclerosis and atherosclerosis
Arteriosclerosis
Thickening of vessel walls leading to restricted blood flow — caused by aging
Atherosclerosis
Increase in plaque deposition (cholesterol, lipids, calcium) leads to restricted blood flow
Soft vs. hard plaque
- Soft plaque is more likely to break apart from the walls and enter the bloodstream — causing a blood clot, blocking flow of blood in an artery
- Hard plaque is made of calcium and causes artery walls to thicken and harden
Angiogram
Effects of atherosclerosis
This buildup of plaque can lead to:
- Coronary artery disease (heart attack and angina)
- Stroke or transient ischemic attack
- Peripheral arterial disease
- Renovascular hypertension
Overview of methods to treat clogged coronary arteries
Percutaneous coronary intervention + angioplasty
Angioplasty alone may be effective in some patients but many
patients experience restenosis and must be stented.
Overview of how stents work
70% of PCI is done with Stents
- Stents prevent restenosis (narrowing of arteries after corrective procedure)
- Improved long-term procedure
success rate of 70-80% - Stents must be flexible enough
to snake through the vasculature
Restenosis in bare metal stents
- Bare metal stents are made of stainless steel, tantalum, and/or nitinol alloy
- Restenosis is caused by arterial damage following tissue proliferation — specific damage refers to elastic recoil and neointimal hyperplasia
Drug-eluting stents
- The gold standard is drug-eluting stents
- Drug-eluting stents release drugs to inhibit restenosis
- Typically the drugs inhibit cell division
-Restenosis in control group: 36%
-Restenosis in study group: 9%
Components of first and second generation stents
Evolution of drug-eluting stents
Examples of drug-eluting stents on the market
Are stents a long-term solution?
A preliminary four year angiographic follow-up study
shows sustained and promising results
Diagram of new technologies for stents
Surgical options for when PCI is not enough
- Coronary artery bypass grafting
- Off-pump coronary artery bypass
- Minimally-invasive direct coronary bypass
Coronary artery bypass grafting
- Up to 5 arteries bypassed
- Extremely invasive
Off-pump coronary artery bypass
- Up to 4 arteries bypassed
- Moderately invasive
Minimally-invasive direct coronary artery bypass
- 1-2 arteries bypassed
- Minimally invasive
Comparison between different surgical methods
Total endoscopic coronary artery bypass (TECAB)
Less than 1% of all cardiac surgeons are technically trained to perform such a surgery
