Myocardial infarction (MI), commonly known as acute myocardial infarction (AMI), occurs when blood circulation occlude to a part of the heart causing destruction to the heart muscle and ischemia. As a result, angina (chest pain) may develop that may radiate towards left shoulder, back and jaw (Johari, Shah & Yick 2014). According to Dicker et al. (2016), the most common risk factors of this chest pain can be obesity, smoking and age. This crushing pain can be detected through ST elevation in ECG that is called STEMI. A STEMI is the combination of symptoms related to insufficient oxygenation of the heart with elevation of the ST segments on the electrocardiogram followed by an increase in proteins in the blood related to heart muscle’s death (Kytö, Sipilä & Rautava 2015). Similarly, in case 2 scenario, a 52 years old man, Mr Ben O'Brien has complaint of acute chest pain during washing the car one hour ago. His pain become worse during movement and radiate from chest to left arm. Finally, he is diagnosed with a myocardial infraction after doing secondary assessments according to following observations:

Central Nervous System (CNS): The temperature of Mr Ben is 36.5 which is normal because he has no previous history of any infection and heart disease. Moreover, his GCS (Glasgow Coma Scale) is 15 that means he is fully conscious and awake. Numerous questions such as patient's name, age and his residential address are asked from the patient and he responds coherently and appropriately to all questions which represents he is well oriented.  His pupils are equally reactive to light and 6 in size. He has no problem while performing adduction, pronation, flexion and plantar flexion of all extremities except left arm because of numbness which may occur due to devastating pain and ischemic muscles. He has no symptom of dizziness, however, his pain become worse while movement of left arm which is most commonly happen in MI. Furthermore, patient states pain in chest and arm is 4 out of 10 on pain scale. It means he is suffering from moderate pain as a result of lack of blood supply to heart muscles as well.

Cardiovascular system (CVS):  According to Kiani et al. (2016), lack of blood supply to heart muscle can develop tachycardia, cardiac arrhythmia and dyspnoea because insufficient blood and oxygen supply to heart muscles can stimulate heart to fulfil the need of deprived oxygen and blood as well. The ECG represents ST elevation more than 2mm that means less ventricular depolarisation (contraction). Additionally, his blood pressure is 130/90 which is higher than normal can be a result of obesity, age and smoking because his smoking capacity is 10 cigarette per day. The excessive smoking is responsible for formation of plaque (hardening of blood vessels) that can cause obstruction of normal blood flow as well. Neurovascular observations such as CWMS can be less especially in the left arm as a result of weakness due to insufficient blood supply. He is pale, diaphoretic due to sympathetic nervous stimulation and cold on touch. The elevation in troponin level also be identified after blood tests because its level may increase in the blood due to destruction of actin and myosin muscles of heart (Esmaeilzadeh, Parsaee & Maleki 2013). His pulse rate is 90 and irregular. He has developed peripheral oedema because of delayed capillary refill could be less or more than 2.

Respiration assessment (Resp): Respiration rate is 20/min. He has developed shortness of breath that can lead to cyanosis because of lack of oxygen in the blood. As a result, to overcome this critical situation, 2L oxygen can be given through nasal prongs according to the condition and situation of the patient. The respiration is mainly assessed by following methods:

• Inspection: The chest may not be fully expanded due to damage of accessory muscles of lungs. This means there is no symmetry between rise and fall of chest. He has history of smoking so he may develop the productive cough with sputum as well. Patient may develop Beck's Triad due to lack of oxygen that is characterised by distended neck veins. 
• Palpation: He has developed pain during palpation especially on the left side due to blockage of coronary artery. 
• Percussion: It can be used to evaluate the respiratory flexibility of the thorax. It can be dull because of less expansion of diaphragm and pulmonary congestion as well. 
• Auscultation: The crackle sound could be listened during auscultation because of fluid and sputum in the chest that can lead to blockage of normal inspirations and expirations. This may also indicate pulmonary oedema that can lead to secondary cardiac decomposition.

Abdominal assessment (GIT): Abdominal assessment can be also assessed by four methods:

• Inspection: As he has no any medical and surgical history so he has no problem with digestion. However, he can progress nausea and vomiting due to pain. Therefore, he can tolerate only small and frequent diet. No sign of abdominal distention but he is 20kg overweight. No bowel obstruction has seen in this patient.
• Palpation: There is no rigidity and mass found in the abdomen. Likewise, muscle contraction is normal. BSL is checked and is 12.9mmol. Thus, actrapid can be given as per sliding scale. 
• Percussion: There is no sign of splenomegaly and hepatomegaly found during percussion. No abnormal sound on tapping as well.
• Auscultation: Bowel sounds are present. Absence of these sounds may be caused by peritonitis.

 Renal assessment (Renal): Additionally, renal hypo perfusion and sympathetic activation stimulate renin release, which leads to increased plasma levels of angiotensin II and aldosterone that enhance renal retention of sodium and water. This can result in peripheral oedema in heart failure patients. U+E's and urinalysis are monitored to check the progression of kidney failure which is a major cause of MI progression.

Integumentary assessment: There is no sign of bleeding, bruising on the skin. Skin is intact and no sign of bleeding and pressure injury. 

After this secondary assessment, the medical diagnose for Mr Ben O'Brien is Myocardial Infraction.

Acute nursing Care: The nursing care interventions can be divided into three basic categories such as pain management, maintenance of oxygen saturation and educational motivation as following:

Pain Management intervention:  As Abbas (2015) point out the following effective pain management to control the pain in case of Mr Ben:

• An inclusive assessment of pain may include (PQRST) provoke, location, characteristics, onset, duration, frequency, quality, intensity or severity, and triggering factors of pain (Blanchard & Murnaghan 2010). This assessment could be monitored and documented through verbal, nonverbal and checking vitals such as blood pressure, pulse rate and heart rate because respirations may be altered as a result of pain and associated anxiety due to release of stress-induced catechol amines increases heart rate and BP (Abbas 2015). 
• It is essential to provide noiseless atmosphere, calm activities, and comfort measures. Approach patient peacefully and positively because increased external stimuli and movement may aggravate anxiety and cardiac strain. Therefore, Patient may limit activities and take rest properly. 
• Analgesic glyceryl trinitrate (GTN) can be given to the patient to treat angina pectoris. However, it can be repeated after 5 min. if pain could not manage. Nitrates are beneficial for angina because it has vasodilation effects, which can enhance the coronary blood flow and perfusion of myocardium as well. This vasodilation effects may diminish the preloading of blood. As a result, myocardial workload may decrease (NPS MedicineWise 2014). Moreover, the essential management for MI with ECG indication of ST elevation (STEMI) could comprise thrombolysis and percutaneous coronary intervention (Kunadian et al. 2013). Thrombolysis includes the administration of medication that triggers the enzymes that can be helpful for dissolution of blood clots. These agents include streptokinase and reteplase which can be given within 6 hours of the onset of symptoms. However, these agents cannot be given if patient has bleeding problems.
• Pain can be controlled by administering morphine 2.5 to 5mg. However, this analgesic can depress the respiratory rate and lead to hypotension. That is why vital signs are carefully monitored especially blood pressure before and after administration of this medicine.    

Administration of oxygen and tissue perfusion: 

• Supplementary oxygen could be provided through nasal prongs or face mask according to patient comfort, as indicated to maintain saturation. As higher amount of oxygen can overcome myocardial workload and thereby may relieve anxiety allied with tissue ischemia.
• Maintain comfortable position especially semi-sitting position (Fowler's position) during breathing difficulty because this position facilitate oxygenation and reduce respiratory distress (Blanchard & Murnaghan 2010). 
• Inspection of pallor, cyanosis, cool, clammy skin, strength of peripheral pulses and respiration rate can reduce the risk of cardiac pump failure.
• Encourage the patient about active or passive leg exercises and prevention of isometric exercises because these exercises may undesirably affect cardiac output by increasing myocardial workload and oxygen consumption. 
• It is essential to maintain intake-output chart because reduced intake or obstinate nausea may result in reduced circulating volume, which may undesirably affects perfusion and organ function. It is essential to maintain total fluid intake at 2000 mL/24 hours to fulfil normal body requirements. Reflection of hydration status and renal function can be measured through Specific gravity as well. Furthermore, decreased cardiac output may result in impaired kidney perfusion, sodium and water retention, and reduced urine output (Johari, Shah & Yick 2014).
• Assessment of GI function such as nausea, vomiting, absent bowel sounds, anorexia, abdominal distension and constipation can be helpful to detect reduced blood flow to mesentery because these problems could be aggravated by use of analgesics, decreased activity, and dietary changes.
• Carefully inspect the level of consciousness because cerebral perfusion may directly associated with cardiac output and may also influenced by electrolyte, hypoxia, and systemic embolism.
• Educate the patient to take low sodium and high potassium diet because sodium may enhance fluid retention that lead to oedema or swelling. In this case, diuretic such as furosemide can be helpful to reduce fluid overload. On the other hand, hypokalaemia can limit effectiveness of therapy (Aish & Isenberg 1996).
• Regular weight check-up might be effective as sudden changes in weight reveal variations in fluid balance.

Education and motivation: According to Wu et al. (2016), the following nursing care plans for Mr Ben O'Brien symptoms and his associated anxiety has been developed:

• Observation of verbal and nonverbal responses can be effective to detect the condition of the patient because sometimes patient cannot express their problems directly. At this time, patient can be identified through words and actions like distress and aggression.
• Cessation of smoking might be a better way to decrease the risk of cardiovascular disease because smoking also is a key risk factor for peripheral artery disease. It is a condition in which plaque accumulate in the arteries that transport blood to the brain and limbs. Dicker et al. (2016) states that there is 30% reduction in MI mortality rate because of education and limiting smoking.
• Encourage the patient to take more rest and sleep well to conserve energy and enhance coping abilities to overcome distress and anxiety.
• Encourage patient to eat nutritional diet such as protein, calcium, minerals and vitamins and restrict unhealthy fatty junk food and deep fried foods because they are full of cholesterol which can enhance the risk of heart attack (Aish & Isenberg 1996).
• Carefully identify and acknowledge patient's perception of threat and situation because the fear of death in the patient make the patient hopeless and anxious as well.
• Encourage independence, self-care, and decision making within accepted treatment plan. These kinds of things can increase individuality from staff promotes self-confidence and reduces feelings of rejection.
• Encourage the patient about regular check-up and follow-up at regular interval in order to diagnose further complications in early stage. The regular tests such as ECG, chest X-ray and blood test repeat after few months to review further complications (Esmaeilzadeh, Parsaee & Maleki 2013).

Introduction 

Non-ST Segment Myocardial Infarction, along with T-segment elevation myocardial infarction (STEMI) and unstable angina, is a type of acute coronary syndrome (ACS). This type of ACS occurs post a blockage in the minor coronary artery and can cause damage to the heart owing to plaque formation. Predominantly the condition is associated through a partial and dynamic non-occlusive thrombus to the coronary arteries (Ambrose and Singh, 2015). This contributes to an abnormal cardiac rhythm which was characteristic in the case of Mr. Paul.

Pathophysiology 

Predominantly the condition is associated with a patient history of smoking, sedentary life, high blood pressure, diabetes, obesity and a family history of heart disease (Overbaugh, 2009). Typically the symptoms include shortness of breath, chest discomfort, pain in the jaw, neck, back or stomach, dizziness, nausea, and sweating. Mr. Paul is an overweight patient, at 88 kg, who came to the ER with these signs, where he showed a Heart rate at 88 and RR at 18. Clinically, he presented with a typical heart attack (STEMI); however, his ECG representation showed signs of NSTEMI where he exhibits depressed ST wave and lack of progression to Q wave, thus depicting arrhythmia was noted (Overbaugh, 2009).

(Some parts of the solution has been blurred due to privacy protection policy)