Blog 4: Cardiac Diseases arranged by groups
In my earlier blogs, I tried to share the basic structure of the heart and its functioning. From this blog onwards I will be attempting to form groups in which pathologies fall and are discussed. I will, then, share the cardiac diseases and pathologies based on the structural position, molecular composition, tissue abnormality, hemodynamic requirements, and functional requirements. By grouping in such a manner a common man can understand the complexity of the structure and functionality of the human heart and in which of its part the pathology may have erupted rather than getting confused with the medical jargon and terminology.
1. Cardiac Structure
2. Left and Right Ventricular Function (Cardiomyopathies: Eccentric, Concentric, etc.)
3. Coronary Artery Disease (CAD)
4. Valvular heart disease (Regurgitation, Prolapse, Endocarditis, etc.)
5. Volume status (Ejection Fraction)
6. Aortic Disease (Aneurysm, etc.)
7. Cardiac Infection
8. Pleural effusion
9. Pulmonary Oedema
10. Genetic Disease (Tetralogy of Fallot, etc.)
11. Electrical disorders (Tachycardia, Bradycardia)
Let us start with the Cardiac structure by referring to the images below. These images will make one understand the directions in which the muscles of the Left Atrium (LA) and Left Ventricle (LV) movements take place during each of the diastolic and systolic phases. It can be seen the action is in all three dimensions as shown further in Fig 4.2
Fig 4.1 Macro structural appearance of the heart’s muscles
Fig 4.2 Direction of the movement of muscles of the Atrium and Ventricle
From the above Fig 4.2, the arrows indicate the heart muscles have vertical (apex to base), rotational (twisting around its axis), and horizontal movement during the diastole and systole phases. Hence, for a common person or a patient, it means that the tissues of his/her heart muscles move in three dimensions. Since muscles of the heart are formed by the joining of the tissues meaning molecules, so, broadly speaking the molecular construction of the heart muscles would be such that its tissues will have the inherent capability to perform such movement in three dimensions 24x7x365 during the entire lifetime of the patient.
Now, diastole means relaxation implies the heart muscles must return to their normal position in their respective chambers allowing the oxygenated blood from LA to move into LV while looking at the left side of the heart. For this blog, I am leaving the details about the RA and RV as their muscles movements are similar, except that those chambers' functional responsibility is different from the left side chambers, and will be dealt with separately. So, any limitation of the LV muscles’ relaxation is identified as a kind of pathology also called Diastolic Heart Failure. A complete and detailed study is carried out based on the normal and abnormal measurements taken to monitor the diastolic function of the heart to determine the severity of such pathology. We will deal with Diastolic Heart Failure in a blog later where the normal measurements and deviation from those values are interpreted by cardiologists to arrive at the health of the heart along with the treatment advised to the patient
Let me stop here. We will take up the next group of pathologies in Blog 5. It may be noted that at times a group mentioned above may require to be dealt with, in more than one blog itself.
Your comments and feedback are welcome.
Dr. Cameron Ahmad
M.Sc. (Biophysics), M. Tech (Appl Optics), Ph.D. (Eng Sc), RDCS, DMS, PMP. CTDP, CET, A Sc T, and CECC
Bibliography
1. The ESC Textbook of Intensive and Acute Cardiovascular Care (2 ed.), Oxford Medicine Online, Feb 2018 https://academic.oup.com/esc/book/38752
2. https://schaberg.faculty.ucdavis.edu/wp-content/uploads/sites/604/2021/05/Heart-Pathology.pdf by Kurt Schaburg MD
3. https://www.nature.com/articles/labinvest201417.pdf Cardiac Pathology, Annual Meetings Abstracts (356–376)
4. Understanding your heart and the causes of heart failure, by Heart and Stroke Foundation, Canada https://www.heartandstroke.ca/-/media/pdf-files/canada/lwwhd/living-well-heart-disease-risk-factores-vol2-en.ashx?la=en&hash=E4AFCECBE59E9F5D74A5FEDA9F4AD99919FC8DE3
