Having understood the basic structure and function of the heart we can now categorize the CVD into three main groups:
- Plumbing problems: These diseases primarily affect the vascular system. This could be the blood vessels of the heart—coronary arteries—which could get thickening, narrowing and obstruction—Atherosclerosis -- “hardening of the arteries” leading to angina (chest pain from the heart due to lack of oxygen) or heart attacks (damage to the heart muscle due to blocked blood supply) or sudden death (unanticipated death in someone thought to be healthy or in stable condition occurring quickly). (Fig 1)
The plumbing problems (atherosclerosis) could involve the arteries to other organs such as the brain leading to Stroke
(paralysis or death),
(Fig2), dementia, bleeding in or around the brain, etc.
Involvement and obstruction of the arteries in the legs (Fig 3) could lead to Claudication (pain in the leg or hip muscles due to lack of oxygen) or even gangrene
and could require amputation.
The whole vascular system could be involved leading to Hypertension
(high blood pressure) (Fig 4).
So the vascular disease could be the same in all parts of the body (such as atherosclerosis), but the clinical manifestations in any given patient would depend which organ develops the vascular blockage—coronary artery blockage—heart attack, brain artery blockage—stroke, leg artery blockage—gangrene, etc.
- Electrical problems: These diseases affect the specialized natural pacemaker of the heart (SA Node), the electrical junction box in the middle of the heart (AV Node) or the specialized fibers, the conduction system (“electrical wires”). (Fig 5)
This can lead to the heart beating very slow or even stopping from time to time (often the patient passes out transiently) requiring the insertion of an artificial pacemaker
to treat the problem and stabilize the patient.(Fig 6)
The opposite could happen as well. There could be episodes of very rapid heart rates or irregular heart rates (“palpitations”)
(Fig 7) suddenly making the heart function inefficiently and significantly dropping the blood supply to the heart muscle itself or the brain, leading to angina (chest pain from the heart), lightheadedness, unconsciousness, fatigue, etc. The blood could stagnate in the heart leading to formation of clots, which could then fly out into the circulation and causing blockages in the organs where they land—such as strokes in the brain (Fig 8). This could require treatment with medications (anti arrhythmic agents and / or anti coagulants—blood thinners).
Some patients may need specialized artificial pacemakers, cardiac procedures to ablate
(“burn out or laser or freeze) the culprit electrical malfunctioning “sparking” or “short circuit” spot in the heart, or may require other specialized cardiac surgery.
- Pump problems: These are conditions which lead to heart muscle damage or intrinsic muscular disorders affecting the heart specifically or as part of other systemic, genetic or metabolic diseases in the body. Disorders of the heart valves (narrowing –stenosis or leaking –regurgitation) lead to pump malfunction as well.
All these diverse diseases essentially lead to the heart unable to pump the blood efficiently
around the body, there is lack of required nutrient delivery to the body for its energy demands, blood backs up in the heart, lungs, abdomen and extremities. This is “fluid retention” (Edema). This then is the overall condition of “Heart failure”
, which can be slowly, chronically, progressive or present acutely initially or during exacerbations of chronic heart failure. This leads to considerable disability, repeat hospitalizations and death.
There is often overlap in these three areas of malfunction, one leading to the other or one aggravating the other, although the primary initiating disorder is usually in one of these three categories.So being a cardiologist, is all about knowing the Plumbing, Electrical and the Pump malfunctions of the Heart and how to treat them.