Acute Coronary Syndrome: Pathophysiology, Diagnosis, and Treatment

This document provides an overview of Acute Coronary Syndrome, including its pathophysiology, diagnosis, and treatment. It discusses the role of ECG in diagnosis, risk factors, and the mechanism of action of drugs used in ACS. It also explores the use of aspirin and morphine in ACS.

Running Head: ACUTE CORONARY SYNDROME
ACUTE CORONARY SYNDROME

ACUTE CORONARY SYNDROME
2
INTRODUCTION
Angina pectoris is a medical condition characterised by chest pain and discomfort due
to coronary heart disease. In the following assessment, the pathophysiology of the condition
has been briefly discussed. The types of angina pectoris and rationale of carrying out an ECG
has also been discussed. Various abnormal interpretations in the ECG of the patient have also
been examined. In the assessment, various important factors which can be helpful in the
diagnosis of coronary heart syndrome have also been identified. In addition, the mechanism
of action of drugs as well as the relation between depression and chronic illnesses have also
been explained.
QUESTION 1
RATIONALE FOR ECG REQUEST:
The buddy nurse has asked Betsy for ECG even though she has no history of chest
pain. ECG is required in this case because Betsy has a past history of Coronary Heart disease,
Coronary artery bypass graft, and Chronic obstructive pulmonary disease. ECG is also
recommended for examining patients experiencing shortness of breath, dizziness, etc.
Through ECG doctor measures how long does an electric wave take to pass through the heart,
through which they analyse the activity and size of the organ? Hence ECG would be helpful
in examining the condition of Betsy's heart.
QUESTION 2
PATHOPHYSIOLOGY OF ANGINA:
Betsy is diagnosed with Angina Pectoris, which is characterised by extreme chest
pain. It is the consequence of myocardial ischemia which is mainly caused by a disturbance
in the balance between oxygen demand and myocardial blood supply. Atherosclerosis is one
of the main cause which leads to angina pectoris. It is a condition in which plaque
accumulates inside arteries that restrict the flow of oxygen-rich blood to cardiac muscles.

ACUTE CORONARY SYNDROME
3
Plaque is mainly made up of cholesterol, fat and other substances found in the blood. To
compensate for the loss of oxygen-rich blood, heart muscles start working rigorously by
pumping blood to the muscles with more force, which results in the development of angina
pectoris. In order to compensate for oxygen loss, heart muscles start transitioning from
aerobic to anaerobic metabolism. According to Prisby, Adenosine is the key factor which
regulates the progression of Angina pectoris (Angina Pectoris, n.d.). It has been reported that
in order to dilate arteries to increase blood supply, adenosine triphosphate degrades during
low blood supply and diffuse in extracellular space. Which results in extreme chest pain.
There are many types of angina pectoris, some of which are as follows:
Stable Angina: Stable angina is characterised by pain in the chest or severe discomfort that
most commonly results from stress, anxiety or depression. It is caused by the restriction of
blood flow through the vessels to the heart.
Unstable Angina: Unstable angina is a type of angina pectoris which develops
spontaneously and unpredictably. Unlike other types, it is not triggered by any activity or
stressful condition.
NSTEMI Angina (Non-ST segment Elevated Myocardial Infarction): It is a type of
angina pectoris in which no ST-segment elevates in 12-lead ECG.
STEMI Angina (ST Segment Elevated Myocardial Infarction): It is a type of angina in
which manifestation of symptoms of angina occur as a consequence of cardiac necrosis. In
this type, ST-segment elevates in 12-lead ECG.
RISK FACTORS
The two main risk factors that are crucial in this case are; hypertension and type II
diabetes mellitus. According to researchers, these conditions are some of the major risk
factors for the development of acute coronary syndrome.
QUESTION 3

ACUTE CORONARY SYNDROME
4
INTERPRETATION OF ECG:
The ECG report of the patient shows the following characteristics,
Heart Rate: The heart rate of the patient is 100 beats per minute.
P Waves: These waves are present as well as regular.
ST segment: ST segment is elevated more the 0.1mv.
Sinus Rhythm: With a heart rate of 100 beats per minute, ECG is showing the condition of
Tachycardia.
The ECG of the patients shows that the patient is suffering from the complications of Inferior
wall MI with reciprocal changes.
QUESTION 4
DIAGNOSIS OF ACUTE CORONARY SYNDROME:
The disease is suspected when specific clinical criteria are met. Three of the most
crucial findings that confirm the diagnosis of the disease are as follows:
ST-Segment Elevation: According to National (2013), the ST segment is supposed to be
elevated when the blood supply to heart muscles got impaired due to thrombus formation in
the arteries. The prolonged elevation of ST segment leads to chronic complication of
Myocardial Infarction.
Sinus Tachycardia: It has been suggested that tachycardia is one of the manifestations of
acute coronary syndrome and can be resulted from dysfunction of the sinus node, withdrawal
of beta blockers, or super ventricular tachycardia ablation.
Increased Heart Rate: It has been reported that increased heart rate is also one of the clinical
manifestations of coronary heart disease. The heart rate is increased due to pumping blood
forcefully by cardiac muscles to compensate for the loss of blood and oxygen supply in the
cardiac muscles.
QUESTION 5

ACUTE CORONARY SYNDROME
5
ACTION MECHANISM OF DRUGS:
GENERIC NAME GTN DILTIAZEM PRAVASTATIN
DRUG GROUP Nitrates/
Vasodilators
A calcium channel
blocker that used to
treat angina,
hypertension and
certain heart
diseases.
Statin used to
prevent
cardiovascular
diseases in patients
at high risk.
MECHANISM OF
ACTION
This drug contains
nitroglycerin which
converts into nitric
oxide and activates
guanylate cyclase
enzyme. This, as a
result, stimulates the
synthesis of cGMP
and in the cells
present in smooth
muscles, activates
protein kinase-
dependent
phosphorylation
series and also the
dephosphorylation
of the light chain of
myosin smooth
muscle fibres. This
process, as a result,
release calcium ions
which leads to
vasodilation.
Diltiazem deforms
the channels and
alters the ion-control
gating mechanism
and block calcium
release from the
sarcoplasmic
reticulum. This drug
inhibits the influx of
extracellular calcium
across cells of
myocardial cells and
vascular smooth
muscles. This leads
to inhibition in the
contraction of
myocardial smooth
muscle cells. This
process leads to the
dilation of coronary
and systemic arteries
and increases
oxygen delivery to
myocardial tissues
(DrugBank2019b).
This drug has
lipoprotein
inhibiting effect
through two
different ways:
1- The one way
through which it
inhibits lipoprotein
is that it inhibits
HMG-CoA
reductase activity
and helps in
reducing
intracellular pools
of cholesterol.
Which as a
consequence
increase the
number of LDL
receptors on the
cell surfaces and
induce the
receptor-mediated
catabolic process.
This whole process

ACUTE CORONARY SYNDROME
6
leads to the
clearance of LDL,
which is present in
the blood
circulation.
(DrugBank,2019c)
2- This drug reduces
the production of
LDL by restricting
the synthesis of
VLDL, which are
the precursors of
LDL, in the hepatic
cells.
COMPLICATIONS/
SIDE EFFECTS
Bradycardia and
Hypotension are
some of the crucial
side effects of this
drug.
Palpitations and
Tachycardia are
some of the side
effects of this drug.
Muscular disorders
and Liver
dysfunction.
NURSING
CONSIDERATIONS
1- Monitoring of blood
pressure and heart
rate of the patient
continuously.
2- Maintaining
systemic blood
pressure and
coronary perfusion
pressure.
1- Periodically monitor
concentration of
serum calcium.
2- Monitor serum
potassium
concentration.
3- Monitor renal and
hepatic function.
1- Panel for
monitoring lipid
levels periodically.
2- To check any
anomaly, liver
function tests
should be done.
QUESTION 6
USE OF ASPIRIN AND MECHANISM OF ACTION:

ACUTE CORONARY SYNDROME
7
Aspirin is a non-steroidal anti-inflammatory drug that is used as an analgesic and anti-
pyretic to relieve pain (Nordqvist, 2017). In high doses, it is also used to prevent
cardiovascular diseases, treatment of arterial fibrillation, strokes, and ischemic attacks. The
mechanism of action of the drug for treating cardiovascular issues includes inhibition of
platelet activation and aggregation. Aspirin inhibits a platelet-dependent Cyclooxygenase
enzyme, which leads to the restriction in the synthesis of prostaglandins. There are two iso-
enzymes of COX named by COX-1 and COX-2. According to researchers, COX-1 produce
thromboxane A2, which leads to the accumulation of platelets. Aspirin leads to the
irreversible inactivation of COX-1 and restricts the formation of thromboxane A2. Which
shows the antiplatelet effects of the drug. Aspirin also reduces the formation of COX-
dependent vasoconstriction, which leads to endothelial dysfunction. The whole process
results in vasodilation and thrombotic reduction among cardiac patients (Nordqvist, 2017).
Ticagrelor is used for the prevention of the atherothrombotic events in patients having
acute coronary syndromes like non-STEMI, unstable angina, and STEMI. The drug acts by
reducing P2Y12 platelet which binds reversibly to the receptors of P2Y12 adenosine
diphosphate. Ticagrelor helps in reducing signal transduction and platelet activation. This
drug doesn’t require activation for the prevention of P2Y12 bonding to P2Y12 ADP
receptors. Hence, it helps in the prevention and treatment of acute coronary syndrome.
These both drugs, i.e. aspirin and ticagrelor have been given in combination to
improve the outcome of Betsy. It has been reported that these drugs in combination provide
better antiplatelet activity and improve the health outcomes of the patient. The reason behind
it is that ticagrelor reduce ADP-mediated platelet activity and aspirin block further platelet
aggregation.
QUESTION 7
USE OF MORPHINE IN ACUTE CORONARY SYNDROME:

ACUTE CORONARY SYNDROME
8
According to de Alencar Neto (2018), morphine is one of the most potential
analgesics, which has been used to treat Acute coronary syndrome. It helps in reducing the
pain that occurs due to injury of ischemic tissues. Morphine is also used as an anxiolytic
agent, required for the condition of patients suffering from myocardial infarction. The drug
also helps in facilitating vasodilation and reduction of heart rate and blood pressure
effectively. Which, as a result, inhibits myocardial oxygen demand.
There are many controversies associated, in the treatment of Acute Coronary
Syndrome, with the use of morphine. According to researchers, it is μ-receptor’s agonist, the
receptors which are present in the central nervous system and smooth muscles (Nitrostat,
n.d.). The drug is beneficial for the management of severe pain associated with coronary
complications. Morphine also helps in facilitating opioid receptors activation, which is
present in myenteric plexus and reduces the mobility of gut. This drug also inhibits the
activation of P2Y12 inhibitors by reducing their absorption and bioavailability.
QUESTION 8
CORONARY HEART DISEASE AND DEPRESSION:
According to Dhar and Barton (2016), depression is one of the most common medical
conditions that has been characterised by negative cognition, anergia, loss of appetite, low
mood, and anhedonia (Nordqvist, 2018). It is a condition that holds the psychological and
emotional well-being of the affected person. Researchers suggest that depression is often
associated with an illness like coronary heart diseases. According to Sanchis-Gomar et al.,
(2012), permanent depression can be experienced by patients suffering from coronary heart
disease. According to Duarte et al., (2019), depression is highly prevalent among patients
suffering from chronic illnesses like diabetes, cancer, stroke and heart diseases. It has been
reported that these type of illnesses lead to sleep disturbance, lack of physical activity,
smoking and substance abuse among patients that leads them to depression. The fear of loss

ACUTE CORONARY SYNDROME
9
of life and reduce the quality of life imparts depression in patients. This thing can affect the
lifestyle, mobility, freedom, professional, personal and social relations, leading these patients
to depression (Dhar & Barton, 2016; Lu et al., 2019).
CONCLUSION:
In the above-mentioned assessment, the rationale of doing ECG in the patients having
the previous history of cardiac diseases has been discussed. It has been found that ECG is
helpful in the prediction of future complications related to heart even in patients experiencing
no pain. Along with it, the pathophysiology of angina pectoris has also been discussed along
with the anomalies in the patient’s ECG. Also, there is a discussion about the factors crucial
for the confirmation of coronary syndromes. The mechanism of action has also been
discussed of various drugs. The role of various chronic illnesses in depression has also been
discussed.

ACUTE CORONARY SYNDROME
10
REFERENCES:
Acute coronary syndrome. (2019, April 11). Retrieved from
https://www.mayoclinic.org/diseases-conditions/acute-coronary-syndrome/diagnosis-
treatment/drc-20352140
Angina Pectoris (Stable Angina). (n.d.). Retrieved from https://www.heart.org/en/health-
topics/heart-attack/angina-chest-pain/angina-pectoris-stable-angina
de Alencar Neto, J. N. (2018). Morphine, oxygen, nitrates, and mortality reducing
pharmacological treatment for acute coronary syndrome: An evidence-based
review. Cureus, 10(1).
Duarte, G. S., Nunes-Ferreira, A., Rodrigues, F. B., Pinto, F. J., Ferreira, J. J., Costa, J., &
Caldeira, D. (2019, March 01). Morphine in acute coronary syndrome: Systematic
review and meta-analysis. Retrieved from
https://bmjopen.bmj.com/content/9/3/e025232
Lu, L., Rao, X., Cong, R., Zhang, C., Wang, Z., Xu, J., ... & Xie, W. (2019). Design,
Synthesis and Biological Evaluation of Nitrate Derivatives of Sauropunol A and B as
Potent Vasodilatory Agents. Molecules, 24(3), 583.
Nitrostat (Nitroglycerin): Side Effects, Interactions, Warning, Dosage & Uses. (n.d.).
Retrieved from https://www.rxlist.com/nitrostat-drug.htm#clinpharm
Nordqvist, C. (2017, December 18). Aspirin: Health benefits, uses, and risks. Retrieved from
https://www.medicalnewstoday.com/articles/161255.php
Nordqvist, C. (2018, January 19). Coronary heart disease: Causes, symptoms, and treatment.
Retrieved from https://www.medicalnewstoday.com/articles/184130.php
Pravastatin. (n.d.). Retrieved from https://www.drugbank.ca/drugs/DB00175

ACUTE CORONARY SYNDROME
11
Sanchis-Gomar, F., Perez-Quilis, C., Leischik, R., & Lucia, A. (2016). Epidemiology of
coronary heart disease and acute coronary syndrome. Annals of translational
medicine, 4(13).