|Year : 2021 | Volume
| Issue : 2 | Page : 105-107
A lesson on ‘Cardiac tamponade’ from the cadaver
Doris George Yohannan1, Thomas Varghese Attumalil2, Komalavallyamma Chandrakumari3
1 Assistant Professor, Department of Anatomy, Government Medical College, Thiruvananthapuram, Kerala, India
2 Assistant Professor, Department of Cardiology, Government Medical College, Thiruvananthapuram, Kerala, India
3 Former Professor, Department of Anatomy, Sree Gokulam Medical College, Venjaramoodu, Kerala, India
|Date of Submission||09-Jan-2021|
|Date of Decision||13-Feb-2021|
|Date of Acceptance||07-Mar-2021|
|Date of Web Publication||09-Apr-2021|
Doris George Yohannan
Department of Anatomy, Government Medical College, Thiruvananthapuram, Kerala
Source of Support: None, Conflict of Interest: None
While dissecting the thorax, when the pericardium was opened, massive clots were seen, concealing the heart. The experience was used to teach about pericardial pericardial tamponade, which most probably caused the death of the “patient.” The concept of how the intrapericardial pressure builds up to compromise cardiac hemodynamics, how it can be clinically suspected, rapidly investigated, and managed as a medical emergency, was taught. This incident was an eye-opener that the time-tested cadaveric dissection should never be entirely replaced by alternatives though they may be wisely and effectively used to complement dissection.
Keywords: Cadaver, cardiac tamponade, educational techniques, teaching
|How to cite this article:|
Yohannan DG, Attumalil TV, Chandrakumari K. A lesson on ‘Cardiac tamponade’ from the cadaver. Natl J Clin Anat 2021;10:105-7
Dissection of the human cadaver is an enlightening experience. Still, many medical schools have phased out cadaveric dissection or are in the process of doing so considering economical and ethical factors., Fortunately, most medical schools in India still have access to cadavers although the rising number of medical colleges in India have created an insufficient supply which is an emerging concern. Though there are many debates on the role of the cadaver's role in teaching anatomy especially with the advent of technology-aided alternatives, some experiences, like the one described here, can be a memorable teaching and learning experience.
On dissecting a male cadaver of around 60 years of age, there were massive blood clots within the pericardium, concealing the heart. An anterior view [Figure 1]a and a left anterior oblique view [Figure 1]b show the dimensions of the heart in situ and clots. On partial removal of clots, the apical myocardium and epicardial fat with coronaries were seen. The depth of blood clot near the left heart border was about 3.5 cm and near the right heart, border was about 2.5 cm [double arrowed lines in [Figure 1]]. Clinical history or examination details were unfortunately not available. With limited knowledge about the “patient,” the only comment that can be made is that this massive pericardial tamponade should have been the most probable cause of death.
|Figure 1: Photographs of the heart within the pericardium with clots partially removed around it. The left and right hemidiaphragms and part of pericardium that was not removed are visible. (a) Anterior view (b) Left anterior oblique view. LAD: Left anterior descending artery|
Click here to view
Pericardial tamponade, the case described here, is a medical emergency. Although its removal has no obvious negative consequences, pericardium does have functions. The best-characterized mechanical function of the pericardium is its restraining effect on cardiac volume. At low stresses, the tissue is very elastic. With further stretch, it abruptly becomes stiff and resistant to even more stretch. The point on the stress-strain relation where this transition occurs is near the upper range of physiologic cardiac volumes. Thus, the sac has a relatively small reserve volume. When exceeded, the pressure within the sac operating on the surface of the heart increases rapidly and is transmitted into the cardiac chambers. Thus, the mechanical consequences of high pressure acting on the surface of the heart mainly result from compression and collapse of the right heart and caval vessels. Underfilling of the left heart then ensues from reduced right heart output. The most critical point occurs when an effusion reduces the diastolic volume of the cardiac chambers such that cardiac output declines. As fluid accumulates, left- and right-sided atrial and ventricular diastolic pressures rise, and in severe tamponade, they equalize at a pressure similar to that in the pericardial sac, typically 20–25 mm Hg.
Bleeding into the pericardial sac occurs after blunt and penetrating trauma, post Myocardial Infarction (MI) rupture of the left ventricular free wall, and increasingly, as a complication of cardiac procedures. Retrograde bleeding is a major cause of death due to aortic dissection. The most likely cause of death for this gentleman would have been that he must have sustained a large acute MI which could have caused a mechanical complication such as free wall rupture which ensued into a lethal cardiac tamponade.
The image of this cadaver – “the silent teacher,” speaks louder than words on the anatomical concept of intra pericardial pressure precluding the normal diastolic filling of cardiac chambers, thus compromising the hemodynamics of the heart, obscuring the apex beat; causing the clinical triad-muffled heart sounds, decreasing arterial pressure and dilated neck veins, the classic Beck's triad. The image conveys the idea of how the electrocardiogram of electrical alternans is generated when the heart mechanically wobbles in a “bag of blood;” the echocardiographic picture and the need for rapid diagnosis and pericardiocentesis. It is to be noted that the diagnosis of pericardial tamponade is missed frequently and failure to recognize it or delay in initiating treatment may mean imminent death for the patient. Hearing back from the students, the experience of dissecting this case was very well received and helped them to link the basic subject anatomy to clinical significance – An objective of the present competency-based medical education curriculum in India.
The role of dissection is often debated by many anatomists and educationalists. Virtual dissectors, prosections, three-dimensional projection, body painting are all wonderful innovations and should be used whenever apt, as an adjunct, but never should we succumb to the temptation to make any of these as a surrogate to the cadaver. Dissection will impart basic anatomical and surgical skills as simple as eye-hand co-ordination, expectation of normal anatomical variations, the three dimensionality of the human body and countless subtle qualities, attitude, emotional maturity, teamwork mentality, leadership qualities and knowledge needed for a physician/clinician. Voiced in a more poetic way – A cadaver can teach you “more than anatomy.”
The central role of the cadaver in anatomy can be seen as analogous to the role of the patient in clinical training. Replacing cadavers with virtual dissectors may be as perilous as replacing patients from wards with case descriptions. The case described here is just one of the many possibilities of “clinical” material that anatomists may encounter in the anatomy lab. The authors recall seeing a cerebellar hematoma extending to the ventricular system causing hydrocephalus, an extradural hemorrhage, a massive renal stone, a case of situs inversus, a stony hard axillary lymph node, a massive splenomegaly, an abdominal aortic aneurysm and dozens of anatomical variants in cadaveric dissection. Experiences like these make anatomy learning interesting and immediately pertinent to students as they proceed to clinical training. These experiences aid them to build the link between the sub-disciplines-anatomy, pathophysiology, clinical features, and diagnostic medicine and principles of management; a skill which they have to develop and master throughout their academic and professional medical career.
The authors feel that this virtue of anatomy can only be sustained if cadaveric dissection is made a routine in medical training and can be wisely assisted by the medically trained anatomy teachers who can guide them how to integrate concepts, and derive differentials. Such cadaveric dissection experiences will be forever etched in the minds of the students. After all, a cadaver is just a patient at a different point of time, beyond his or her death!
The authors wish to thank the unknown donors and their relatives for donating their bodies for the advancement of anatomy. The authors also thank the 1st year MBBS students (2016 admission batch) of Sree Gokulam Medical College, Venjarammoodu, Kerala, India for involving in the dissection and for sharing their feedback.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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