CONDUCTING AN AUTOPSY OF THE CARDIOVASCULAR SYSTEM

The heart is a vital organ and the cardiovascular system is an important part of any autopsy.   Statistically, the heart is the most common cause of sudden and unexpected death. Heart disease is also the leading overall cause of death in the United States.

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What is included in an autopsy of the cardiovascular system?

The cardiovascular system technically includes the heart and all of the blood vessels in the body.   Typically, at autopsy the heart and major blood vessels (aorta and vena cava) are examined as part of a standard autopsy.   It is impossible to examine fully the miles of blood vessels that course through the body.   But it is important to keep in mind that heart disease may be a contributing factor in other diseases that occur throughout the body (e.g., hypertension is a contributing factor in kidney disease).

Examination of the heart includes removing the chest plate then taking the heart out of the pericardial sac (the protective sac around the heart).   The outside surfaces are examined first and the blood vessels (coronary arteries) are dissected.   The heart is opened to reveal the internal surfaces and structures, including the valves and heart muscle (myocardium).     The muscle is then cut to reveal the surface color, textures and other features.   Finally, tissue sections are prepared to examine under the microscope.

What should I look for when conducting an autopsy of the cardiovascular system? The simplest answer is EVERYTHING.   Since heart failure is the most common cause of sudden death it is important to be aware of any abnormalities.   There are a few heart-related problems that are more common than others when determining cause of death.   The blood vessels can have changes of atherosclerosis (hardening and narrowing) that restrict blood flow and cause a heart attack.   Structural problems with the heart valves (such as congenital bicuspid aortic valve, where the aortic valve is formed by two leaflets rather than the normal three) can lead to back up of blood flow and heart failure.   Structural heart valve problems usually can be seen when the heart valve doesn't form normally (2 instead of 3 leaflets in aortic valve), or the valve is abnormally thickened, such as in mitral valve prolapse.   Heart valve leaflets should normally be thin and semi-transparent.

Abnormalities in the heart wall, such as thickening from hypertension and hypertrophic cardiomyopathy, can lead to abnormal electrical impulses and sudden death.   Infections in the heart such as myocarditis can lead to heart failure.   Chronic drug abuse can lead to many alterations in the heart muscle and valves.   While there are many other kinds of heart abnormalities, medical examiners try to confirm or disconfirm the most likely and/or common explanations when determining cause of death.

As part of a typical autopsy, it is important to examine all areas of the heart for abnormalities in the surfaces, the internal structures such as heart valves and arteries, and changes in the coloration of structure of the heart wall.   And remember that the heart is the center of the cardiovascular system (which includes all of the blood vessels, so anytime there is bleeding in the body, it may be related to the heart in some way.

Gross Images

Photograph of a normal heart (front)

Photograph of a normal heart (back)

Photograph 1 of a healthy aortic valve in a normal heart.

Photograph 2 of a healthy aortic valve

Photograph 1 of a healthy tricuspid valve in a normal heart.

Photograph 2 of a healthy tricuspid valve.

Photograph of cross-sections of a normal heart

Photograph of a healthy pulmonic valve in a normal heart.

Photograph of a healthy mitral valve in a normal heart.

Microscopic Images

Image of normal heart tissue (2x magnification)

Image of normal heart tissue (4x magnification)

Image of normal heart tissue (10x magnification)

Image of normal heart tissue (20x magnification)

What should I look for when trying to dis/confirm heart arrhythmia? It can be difficult to detect a cardiac arrhythmia, or an abnormal electrical impulse conduction, at the autopsy stage, because it is only possible to "see" a heart arrhythmia while a person is alive and the heart is beating.   Detecting arrhythmias at autopsy depends on identifying structural or developmental changes in the heart that can lead to an arrhythmia.       Such abnormalities can include things like heart muscle thickening (due to hypertension or hypertrophic cardiomyopathy) or abnormal thickening or formation of heart valves.

Microscopic examination of tissue slides is an important part of the autopsy examination when looking for arrhythmias.   It is important to examine the cellular structure of the tissue under the microscope, looking for things such as thickening of heart muscle due to hypertension and hypertrophic cardiomyopathy, two common causes of cardiac arrhythmia.

Even if your autopsy examination of the heart is normal, that still doesn’t entirely exclude an arrhythmia as a possibility, since the arrhythmic changes occur at the cellular, electrical and chemical level (areas that can’t be seen at autopsy).   Even if there is no physical evidence of an arrhythmia at the cellular level, arrhythmia may stay in the list of potential diagnoses until it can be ruled out by process of elimination (e.g., another cause can be confirmed).

What should I look for when trying to dis/confirm heart attack due to atherosclerosis? Death to atherosclerosis is one of the easier things to diagnose at autopsy because the symptoms are usually quite evident.   The coronary arteries (vessels that supply blood to the heart muscle) are typically hardened and narrowed, making it difficult for blood to course through them and supply the heart muscle with oxygen.   At autopsy you would see the cross sections of the arteries have yellow to yellow-white material building up on the inside of the vessel, narrowing the lumen.   This material is made of cholesterol, fat and inflammatory cells.   Calcium will often be present making the arteries hard and inflexible.

In the heart muscle you would look for anything from slight softening and light red pale discoloration, to a full-blown "heart attack" with areas of heart muscle death and scarring (white firm discoloration and hardening of the heart muscle wall).  

Under the microscope you would look for narrowing of the blood vessels with fat and cholesterol tissue in the blood vessel wall.   Sometimes calcium will also be present in the microscopic sections. If there are no signs of atherosclerosis when initially examining the heart (with the naked eye), then there is no need to pursue the microscopic exam.

Gross Images

Photograph 1 of coronary arteries with atherosclerosis

Photograph 2 of coronary arteries with atherosclerosis

Photograph 3 of coronary arteries with atherosclerosis

Photograph 4 of coronary arteries with atherosclerosis

Photograph of cross-sections of a coronary artery with atherosclerosis

Photograph of normal coronary arteries

What should I look for when trying to dis/confirm congenital heart disease? Congenital heart disease is a broad topic, but in general terms it involves the development of the heart.   So at autopsy you would look for any abnormal development or placement of the normal heart components (valves, muscle, arteries, etc).   An example might be abnormal formation of the aortic valve so it only has two cusps (bicuspid aortic valve); the aortic valve normally has three cusps.   Abnormal thickening of the heart muscle can also be considered a congenital heart disease as in hypertrophic cardiomyopathy (see below).

Microscopic examination of the heart is not as important in congenital heart disease since most of these abnormalities can be seen grossly (with the naked eye) as abnormal structure development.

Gross Images

Photograph of a healthy aortic valve.

Photograph of a healthy tricuspid valve.

Photograph of cross-sections of a normal heart

Photograph of a healthy pulmonic valve in a normal heart.

Photograph of a healthy mitral valve in a normal heart


What should I look for when trying to dis/confirm hypertrophic cardiomyopathy?

In hypertrophic cardiomyopathy the heart is enlarged and thickened, often up to 2 or 3 times the normal heart size.   This disease is primarily a problem with over-development of the heart muscle cells, where they become enlarged and "swollen" to many times the normal size.   When examining the heart with the naked eye, you would see an enlarged and thickened heart with abnormal muscle tissue that often looks pale and scarred (because the blood vessels cannot keep up with the oxygen demands of the enlarged cells).   The rest of the heart structures are typically normal.

Under the microscope you would see abnormally large muscle fibers without any inflammation or other defects.   The fibers are many times the normal size.   Also you may see fibrosis (scarring) of the heart muscle wall, again due to the increased oxygen demand of the enlarged heart.

Gross Images

  Photograph of a heart with hypertrophic cardiomyopathy

Photograph of a heart with hypertrophic cardiomyopathy compared with a normal heart

Photograph of cross-sections of a heart with hypertrophic cardiomyopathy

Microscopic Images

Image of HCM heart tissue (2x magnification)

Image of HCM heart tissue (4x magnification)

Image of HCM heart tissue (10x magnification)

Image of HCM heart tissue (20x magnification)

What should I look for when trying to dis/confirm myocarditis? Myocarditis (inflammation of the heart) is typically due to a viral infection, such as that from Coxsackie B virus.   At gross examination (examining the heart without the aid of a microscope), the heart can range from being totally normal, to having a diffuse tan pale discoloration and softening. A yellowy film (like an egg yolk) may coat the surface of the heart.  The other heart structures are typically normal.

Microscopically the hallmark of viral myocarditis is individual heart muscle fiber death (myocyte necrosis) with associated inflammation (usually due to lymphocytes).  

Gross Images

Photograph of cross sections of a heart with myocarditis

Photograph of exterior of a heart with myocarditis

Microscopic Images

Image of heart tissue with myocarditis (2x magnification)

Image of heart tissue with myocarditis (4x magnification)

Image of heart tissue with myocarditis (10x magnification)

Image of heart tissue with myocarditis (20x magnification)

What should I look for when trying to dis/confirm drug use?

Complications of drug use seen in the heart typically center on two areas.  The first is infections of the heart valves (endocarditis) where bacteria from the blood stream get stuck on the valve surfaces as red-tan growths that can eat away the valve.  This type of heart disease is only seen in chronic intravenous drug users (heroin, cocaine).

The other type of heart change is seen in chronic use of stimulant medications or drugs.  This is typically associated with “hard” drugs like methamphetamine or cocaine, but can also be seen in chronic use of other stimulants like caffeine or ephedrine (found in a lot of “herbal” teas, sports drinks or “stay awake” pills).  With these heart changes you will see thickening and enlargement of the heart like that seen in hypertrophic cardiomyopathy.  The heart may be 1 ½ to 2 times the normal size with thickened walls. 

Microscopically you will see changes similar to hypertrophic cardiomyopathy with thickened heart muscle cells.  The changes in chronic drug use are often similar but less severe than those seen in hypertrophic cardiomyopathy, but not always.

When writing an autopsy report, what should I include in a thorough description of the cardiovascular system?

When writing an autopsy report of the heart it is important to examine and record the following areas:

  • Overall appearance, coloration and size of the heart (including weight) is important.
  • The presence or absence of abnormal structures visible on the outside of the heart.
  • The cut sections of the coronary arteries must be examined for atherosclerosis (narrowing) noting the approximate percentage and areas.  Typically the narrowing can be described as 25%, 50%, 75%, 90% or occluded (100%).
  • Slicing of the heart is done to describe the color and consistency of the muscle walls, looking for areas of scarring or other discoloration.  You should also note the thickness of the left ventricle in cases of heart enlargement.  The left ventricle thickness is measured on the "septum" and on the "free wall".  It is a measurement taken of the muscle wall thickness on of the cross sections of the heart examination.  The measurement should not include the muscle bulges on the inside of the heart chamber (papillary muscles), but only the wall muscle itself.
  • Opening of the heart reveals the heart valves and inside surfaces of the great vessels.  You should note the appearance of the heart valves (normally thin and pliable), the number of valve leaflets and any other abnormalities seen.