How likely is this to be a heart problem, asthma, or panic attack?

Denise’s case is very likely to be a heart attack or what is medically known as the acute myocardial infarction (MI). Asthma was eliminated in the diagnosis because there was no prior indication that Denise had been exposed to allergens, sensitizer, irritants or any form of air pollution.  Asthma is associated with chronic inflammation of the lower respiratory tract and requires a triggering factor like one of those mentioned above (Fauci, et al., 2008).

 Cardiac ischemia was also considered but was eliminated because of the absence of its hallmark symptom of angina pectoris.  An asymptomatic cardiac ischemia was also not considered because Denise presents some symptoms like breathlessness or dyspnea, anxiety, irregular beating of the heart and cold sweating.  These symptoms, however, are present in painless acute myocardial infarction.

It had also been indicated in several studies that cigarette smoking also increases the risk of MI (Fauci, et al., 2008).  Although Denise had not been smoking, she is in close association with someone who had been a chronic cigarette smoker, her husband.  It could be inferred that Denise had suffered from second hand smoking and is, therefore, at risk of having a heart disease, too.
2. Why do you say this? What are the symptoms that are consistent with your preliminary diagnosis? Is there anything unusual?
Myocardial infarction usually presents with pain as the chief complaint of the patient. The pain felt was usually described as heavy, squeezing, and crushing.  In rare cases, the pain is also described as stabbing or burning.  It is very similar to the pain experience in cases of angina pectoris or chest pain.  However, pain of MI usually occurs at rest, more severe, and lasts longer.
 In our case, however, no pain was felt.  Nevertheless, this is not to be used as a basis in eliminating the possibility of MI.  The clinical presentation of Denise’s case is termed as the painless myocardial infarction. The proportion of painless MI is greater in elderly patients and is and usually presents with breathlessness, appearance of an arrhythmia, and a sensation of profound weakness (Bayer, Chadha, Farag, & Pathy, 1986).
An arrhythmia is the medical term referring to irregular beating of the heart.  Denise’s case is a type of arrhythmia called tachycardia or the abnormal increase in heart rate, i.e. heart is beating very fast (Guyton, 2006).  MI, in general, is also accompanied by sweating, anxiety, and a sense of impending doom (Fauci, et al., 2008).  All these clinical presentations had been experienced by Denise.
The oxygen-poor blood from the (1) right atrium empties to the (2) right ventricle, which then pumps blood to the (3) pulmonary artery.  The blood then enters the pulmonary circulation through the (4) pulmonary arterioles and pulmonary capillaries where exchange of gases takes place.
The oxygen-rich blood the goes back to the heart via the (5) pulmonary vein and empties to the (6) left atrium and then passes to the (7) left ventricle.  The left ventricle then pumps the oxygen-rich blood to the (8) aorta, the largest artery, and flows through the large (9) systemic arteries to reach the organs they supply.
The blood then flows through (10) arterioles and (11) capillaries of the organs to deliver oxygen and nutrients.  Cellular waste products and carbon dioxide are exchanged for nutrients and oxygen at the level of the capillaries.
The blood then passes through the (12) venules and then to the (13) larger veins.  Blood from the upper part of the body, e.g. head and upper extremities, drains into the (14) superior vena cava.   Blood from the lower part of the body, e.g. stomach, intestines, and lower extremities, drains into the (15) inferior vena cava.  Both the superior and inferior vena cava drains into the right atrium (Guyton, 2006).
3. What are the characteristics of Denise’s lifestyle that might lead to a heart problem?
Denise’s genetic make-up predisposes her to hypercholesterolemia.  However, her diet aggravates her situation and causes her blood cholesterol level to be higher than normal.  It has been shown that hypercholesterolemia induces the formation of atherosclerosis (Prassad & Kalra, 1993).
The disruption of atherosclerotic plaques attracts platelets and promotes the formation of thrombus or blood clot leading to obstruction of blood supply to the heart. Hence, patients with hypercholesterolemia are at very high risk of having myocardial infarction.
 From the case, it could also be gathered that Denise is closely associated with a man who had been a chronic cigarette smoker and that she has been exposed to second hand smoking.  Smoking had been found in many studies to be associated with the increased risk of myocardial infarction.  Tobacco contains nicotine that promotes vascular constriction and aggravates the narrowing of vessels caused by of atherosclerosis (Wilhelmsson, Vedin, Elmfeldt, Tibblin, & Wilhemsen, 1975; Rosenber, Plamer, & Shapiro, 1990).
Denise had also been undergoing a lot of emotional and physical stress, which had been found to trigger acute MI (Gelernt & Hochman, 1993).  Also there are several facts that point to Denise’s predisposition to MI such as aging and being in early menopausal stage (Rosenberg, Hennekens, Rosner, Belanger, & Speizer, 1981).
4. Has Denise suffered a heart attack?
Indeed, Denise had suffered from heart attack or acute myocardial infarction (MI).  However, her case might, in the early part of the case, have only been a painless and mild MI.  The infarct located on her left ventricle.  This is due to the obstruction on her left anterior descending artery, the major blood supply of the left ventricle.
The left ventricle is a high pressure chamber and, therefore, demands a very high blood supply.  Her case may have developed over the years such that angiogenesis, i.e. formation of new blood vessels, or the opening of collateral vessels had provided her with heart enough blood that the infracted portion is not very great (Fauci, et al., 2008).  She also presents the symptoms typical of older women presenting painless MI with dyspnea or what is commonly known as breathlessness, anxiety, tachycardia, and sweating.
5. Define the following terms: cholesterol, hypercholesterolemia, cardiac ischemia, collateral vessels, angina pectoris, and plaque.
Cholesterol is the best know steroid probably because of its association with atherosclerosis and other various heart disease.  Biochemically, it is also of great importance because it is the precursor of equally important steroids that include the adrenocortical hormones, sex hormones, vitamin D, and bile acids.  It occurs in animals but not in plants or bacteria.  Figure 4 shows the chemical structure of cholesterol (Murray, Granner, & Rodwell, 2006).