Pathophysiology of Coronary Ischemic Heart Disease

Discuss about the Paramedicine for European Heart Journal.

The essay discusses the hospital management of the patient named Amit Singh, 58 year old presented with the chest pain and vomiting. In response to the case study the essay discusses the pathophysiology of the presenting condition of the patient along with brief highlight on the epidemiology and the risk factors.  The essay further presents the hospital management of the patient’s condition. The essay discusses in details about the general management of the condition as well as the national and international guidelines used in this process. The evidence is supported with literature and the factors such as hospital, geographical, or regional factors that may affect the patient management are also discussed.

In the given case study the patient was NBN installer and was travelling for work. While working in the remote area the person had onset of nausea and vomiting with pain in his chest, left arm and jaw thirty minutes ago. It was described by the bystander that the Mr Singh quickly becoming pale and sweaty before vomiting. The past medical history of the patient reveals of the Hypertension, hypercholesterolaemia and type two diabetes mellitus. There is the family history of heart attack (in case of father) and stents (in case of brother). The patient’s social history reveals him to have a sedentary lifestyle with poor diet pattern. The patient consumes fat rich food and high sugar containing diet. It is because the patient is traveler and mostly eats outside home. On examination it was fund that the patient had central chest pain that is described by the patient as heavy like sitting on chest and rated severity is 7/10. The patient feels tightening numbness in left arm and jaw. The pain is persistent and non changing with the associated symtoms like Nausea, vomiting, pallor and diaphoresis. On observation the patient showed up with respiratory rate 18, SpO2: 97% on air, regular heart rate- 104bpm, and Blood pressure: 142/87. Based on physical examination, presenting symptoms, and ECG the patient can be interpreted to have ischemia that is coronary ischemic heart disease (1).

Heavy chest pain is related to heart attack. According to (2) coronary ischemia is the condition caused by the insufficient blood through the coronary arteries. It is linked with heart attack and heart diseases. The typical symptoms of the coronary ischemic heart disease are the chest pain that is heavy as someone sitting in chest. This pain does not persist after rest but occurs during strenuous activity such as exercise. It is accompanied with other symptoms such as sweaty palms or diaphoresis, nausea or vomiting (3).  The other typical symptoms of the coronary heart disease are the radiating chest pain towards left arm (4) which are all presented by the patient.  The underlying cause of the diseases is the blockage of the walls of the coronary arteries by fatty substances. It is known as atheroma of the coronary arteries causing occlusion.  It leads to narrowing of the arteries and the constricted blood flow.  This process is also called as the Arthrosclerosis which is the common cause of coronary ischemia.  It is characterized by the narrowing of the arteries due to building up of plaque made of cholesterol. It decreases the blood flow to the heart increasing the risk of the myocardial infarction that is the damage to the heart muscle. The patient feels nausea due to vagus nerve arising in the brain, through esophagus gives the nerve fibers to the heart. It then continues to the abdomen giving nerves to stomach. It is due to this stomach-heart-brain connection that the patient feels nausea and vomiting (4).  

Risk Factors and Epidemiology

The pathophysiology is justified considering the symptoms of the cardiac ischemia in patients along with the risk factors.  It includes high blood pressure, diabetes, high blood cholesterol level and lack of physical activity, pain for  more ten minutes (4,5, 6). High blood pressure accelerates the arthrosclerosis, resulting in damage of the coronary heart disease. High cholesterol or bad cholesterol mainly causes the deposition and narrowing of arteries   (low density lipoprotein in blood). It is attributed to hereditary and dietary conditions (diet high in saturated fats and cholesterol). Further, physical activity like exercise lowers the risk of high blood pressure (4,5).   Age and sex are the other risk factors of the ischemic heart disease. Men die from this disease at the rate twice as that of women and the sex bias is consistent over time.  In case of woman the proportion of death due to this disease increases with age. Death rate increases among women above 85 years of age. This proportion is much higher at younger age for man.  More than 1 in 10 deaths is noted in males above 45 years and above (5).  

As per (5) cardiac ischemia and acute myocardial infarction as a subsequent outcome, is present in approximately 6% of all hospital admissions for heavy chest pain. Cardiac ischemia is the common cause of death in western affluent countries. In Australia, the ischemic heart disease is the leading cause of the death, with 12.4% of the 159,052 deaths (7).  People with diabetes have 10-20% risk of silent ischemia when compared to rate of 1% to 4% in nondiabetics. In developed countries the coronary ischemia heart disease is the major cause of the death and disability in people above 35 years.  However, past four decades of records show decline in the deaths due to the Coronary heart disease. The growth of the population and the increase in aged people led to higher global burden of the ischemic heart disease since 2010 (8).

 In order to manage the patient care it is necessary to interpret the ECG that determines the risks and care needed by the patient. Optimal use of the ECG helps in diagnosis, prognosis and appropriate treatment.  In the given case study the use of ECG is important to get the information on the localisation and time course of ischemia (1).   In the normal heart the regular sinus rhythm 82 beats per minute. The P wave is observed to be upright in leads I, aVF and V3 – V6 and the polarity is positive in the leads I, II, aVF and V4 – V6. The PR interval is between the 0.12 and 0.20 seconds. The QRS complex shows a small Q wave in I, aVL, V5 and V6 that may have same amplitude as the R wave.  A large upright R is detected with the large deep S and when proceeding with the V1 to V6, S waves get small and R get taller. These waves are equal at the transitional zone. In the normal ECG ST Segment is slanting upwards to the T wave. This segment marks the ventricular depolarisation and repolarisation.  In the T wave the deflection would be same as that of the QRS complex in atleast 5-6 leads (9).  On the contrary to this, the ECG of Amit Singh is quite different.  In QRS complex, there is no positive deflection seen with large upright R in V4 – V6 there is no negative deflection with large deep S in the V1 and V2. ST elevation was observed in 3-4 chest leads which is the block pattern that is ST-T changes (1,10). According to (10) ischemia is characterised by the ST elevation. In the patient’s ECG T wave can be called as T wave inversion (negative wave). With increasing amplitude there is flattening of T waves. The ST changes are strong indication for chest discomfort. It is also the risk factor for subsequent myocardial infarction.

General Management of the Condition

 This is an emergency situation as the ECG reveals the possibility of the heart attack in the patient and it would take long time before the patient is taken to the hospital with good cardiac facility.  The patient is at risk of death as the preliminary diagnosis. The patient may be provided with the oxygen to relive pain. The patient may be given morphine through a vein. Alternately the patient may be administered with glyceryl trinitrate (GTN) that the patient can keep it under tongue (2013 ACCF/AHA Guideline) (11, 12). By chewing it will make the thin blood. This process is known as the early treatment that can save life. It will prevent the damage to heart muscle by clot dissolving medicine.  The commonly administered agents are the tissue plasminogen activator alteplase, streptokinase, urokinase, and anistreplase. These can be administered with single injection. These are simple to use in the out of the hospital management. The medication can be given irrespective of the body weight (13).  This early treatment is based on the (British Heart Foundation – heart attack leaflet 2014) (14).  These measures are effective as time is the risk factor in this case may decrease the time for treatment and reduce the mortality rate.

According to (15) Canada Stoke care guidelines, a paramedic can accurately identify patient with the likeliness to benefit from the thrombolytic therapy. Morrver, based on UK studies, there is no difference in the Paramedic and the cardiologist in identifying the ST elevation. Therefore, the paramedics may not wait for interpretation by the cardiologist in hospital. Studies based on Scotland also showed positive outcome of initiating the thrombolytic therapy out of the hospital to reduce the treatment delays.  This is also in congruent with the “European Society of Cardiology and the European resuscitation council” that recommends thrombolysis outside hospital if it may take more than 30 minutes to reach. Thrombolysis is considered to be effective for reperfusion of ischemic myocardium (16). Hence this is applicable in case of Amit Singh whom may take more than 3 hours to reach intervention centre. The European Society of Cardiology also recommends the mode of transportation of the patient considering it as the stretcher case with% elevation of the head. At the outset the peripheral intravenous access.   However, the speed of transportation should not be discomforting to patient or create an anxiety levels. It also recommends that the paramedics should use the defriblitairs   as the emergency equipment (manual or AED) and mandatorily  monitor the cardiac rhythm and use pulse oximetry.   The ambulance must have the automatic delivery system (16).

National and International Guidelines

According to clinical guidelines by Queensland on cardiac/Acute Coronary Syndrome, if there is an ST elevation this is the STEMI case and mandates the CCP or ACP₂ involvement where available. The paramedic may facilitate the early reperfusion therapy (17,18).  The paramedic may consider the pPCI referral. It may be Ticagrelor or another one if recommended by the interventional cardiologist as well as go for heparin. The prehospital fibrinolysis administration may include clopidogrel, Enoxaparin, Tenecteaplase. The patient may be transported to hospital in 3  hours and 50 minutes, so the paramedic may prenotify the hospital.  The paramedic may forward the appropriate pPCI referral checklist, STEMI capture form, eARF, and 12 lead ECG  to the manager of the cardiac outcome program (18).

In the hospital on arrival emergency evaluation of the symptoms is conducted.  The complete assessment of the airway, breathing, and circulation shall be conducted. Acute management includes the “coagulation studies, complete blood count, emergent head CT (HCT), and electrocardiogram” (19,20). A CT angiogram may help with the eligibility with the intervention. Since the patient is having hypertension blood pressure management will be initiated with Acute IV medications like labetalol,  or nicardipine. It may be followed with neurogenic examination to prevent intracerebral hemorrhage.  The common complications in patient may include fever, hyperthermia, or external cooling and infections. For fever acetaminophen may be administered. The patient may decrease level of consciousness and high risk of pneumonia in first week.  The patient may be given IV fluid, vasopressor therapy followed by intervbentions for hypo or hyperglycemia. Standard therapy for the patient may be IV rtPA along with consent to treatment (fibrinolytic therapy and hen intra-arterial reperfusion). Endovascular techniques may be used for the large vessel occlusions (19, 20).  For secondary stroke prevention the patient may have the antiplatlet agents in combination with aspirin. The patient may be transitioned to warfarin therapy. The patient may receive the multiple interventions such as initiation of secondary prevention measures. The physician may prevent the complications of the stroke with fever control, blood pressure, seizure control, cerebra edema control, neuroprotective measures, dual antiplatelet therapy for secondary prevention (18,19,20).  Eventually the patient may be assessed for rehabilitation needs, occupational therapy, and typical physical therapy interventions (19).

 Overall the essay had discussed the emergency care for the patient with the chest pain. The condition was interpreted to be the cardiac ischemia and its pathophysiology was be discussed which is mainly due to Arthrosclerosis caused by high cholesterol. As per epidemiology study this disease was found to be the brining problem across the world.  The risk factors are mainly hypertension, diabetes, and sedentary lifestyle.  The paramedical care in this case comprise of national and international guidelines.  It mainly comprise of thrombolysis and administration of blood thinning factor. The  in hospital care comprise of the in-depth evaluation and treatment.  

Reference 

1. Authors/Task Force Members, Hamm CW, Bassand JP, Agewall S, Bax J, Boersma E, Bueno H, Caso P, Dudek D, Gielen S, Huber K. ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: The Task Force for the management of acute coronary syndromes (ACS) in patients presenting without persistent ST-segment elevation of the European Society of Cardiology (ESC). European heart journal. 2014 Aug 26;32(23):2999-3054.
2. Sheikh U, Swabrick D, Ripley DP, Gosling OE, Kotecha A, Ludman AJ, Strain WD, Shore AC, Kannoly S, Bellenger NG, Sanghvi M. ISCHEMIC HEART DISEASE. European Heart Journal-Cardiovascular Imaging. 2017 May 1;18(suppl_2):ii7-11.
3. Hall JE. Guyton and Hall textbook of medical physiology e-Book. Elsevier Health Sciences; 2015 May 31.
4. Ambrose JA, Singh M. Pathophysiology of coronary artery disease leading to acute coronary syndromes. F1000prime reports. 2015;7.
5. Moran AE, Forouzanfar MH, Roth G, Mensah GA, Ezzati M, Flaxman A, Murray CJ, Naghavi M. The global burden of ischemic heart disease in 1990 and 2010: the Global Burden of Disease 2010 study. Circulation. 2014 Feb 26:CIRCULATIONAHA-113.
6. Varbo A, Benn M, Tybjærg-Hansen A, Jørgensen AB, Frikke-Schmidt R, Nordestgaard BG. Remnant cholesterol as a causal risk factor for ischemic heart disease. Journal of the American College of Cardiology. 2013 Jan 29;61(4):427-36.
7. Australian Bureau of Statistics. 3303.0 – Causes of Death, Australia, 2015 [Internet]. Abs.gov.au. 2018 [cited 28 April 2018]. Available from: https://www.abs.gov.au/ausstats/[email protected]/Lookup/by%20Subject/3303.0~2015~Main%20Features~Ischaemic%20Heart%20Disease~10001
8. Leon BM, Maddox TM. Diabetes and cardiovascular disease: Epidemiology, biological mechanisms, treatment recommendations and future research. World journal of diabetes. 2015 Oct 10;6(13):1246.
9. Russo AM, Stainback RF, Bailey SR, Epstein AE, Heidenreich PA, Jessup M, Kapa S, Kremers MS, Lindsay BD, Stevenson LW. Accf/hrs/aha/ase/hfsa/scai/scct/scmr 2013 appropriate use criteria for implantable cardioverter-defibrillators and cardiac resynchronization therapy: A report of the american college of cardiology foundation appropriate use criteria task force, heart rhythm society, american heart association, american society of echocardiography, heart failure society of america, society for cardiovascular angiography and interventions, society of cardiovascular computed tomography, and society for cardiovascular …. Heart Rhythm. 2013 Apr 1;10(4):e11-58.
10. Gorgels AP. ST-elevation and non-ST-elevation acute coronary syndromes: should the guidelines be changed?. Journal of electrocardiology. 2013 Jul 1;46(4):318-23.
11. Gupta A, Ghimire G, Hage FG. Guidelines in review: 2013 ACCF/AHA Guideline for the Management of Heart Failure. Journal of Nuclear Cardiology. 2014 Apr 1;21(2):397-9.
12. Sivaraman V, Yellon DM. Pharmacologic therapy that simulates conditioning for cardiac ischemic/reperfusion injury. Journal of cardiovascular pharmacology and therapeutics. 2014 Jan;19(1):83-96.
13. Woo JS, Kim W, Ha SJ, Kim JB, Kim SJ, Kim WS, Seon HJ, Kim KS. Cardioprotective Effects of Exenatide in Patients With ST-Segment–Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary InterventionSignificance: Results of Exenatide Myocardial Protection in Revascularization Study. Arteriosclerosis, thrombosis, and vascular biology. 2013 Sep 1;33(9):2252-60.
14. Layland J, Oldroyd KG, Curzen N, Sood A, Balachandran K, Das R, Junejo S, Ahmed N, Lee MM, Shaukat A, O’donnell A. Fractional flow reserve vs. angiography in guiding management to optimize outcomes in non-ST-segment elevation myocardial infarction: the British Heart Foundation FAMOUS–NSTEMI randomized trial. European heart journal. 2014 Sep 1;36(2):100-11.
15. Casaubon LK, Boulanger JM, Blacquiere D, Boucher S, Brown K, Goddard T, Gordon J, Horton M, Lalonde J, LaRivière C, Lavoie P. Canadian stroke best practice recommendations: hyperacute stroke care guidelines, update 2015. International Journal of Stroke. 2015 Aug;10(6):924-40.
16. Task Force Report. The pre-hospital management of acute heart attacks- Recommendations of a Task Force of the The European Society of Cardiology and The European Resuscitation Council [Internet]. besancon. 2018 [cited 28 April 2018]. Available from: https://www.besancon-cardio.org/recommandations/infphesc.pdf
17. Hausenloy DJ, Yellon DM. Myocardial ischemia-reperfusion injury: a neglected therapeutic target. The Journal of clinical investigation. 2013 Jan 2;123(1):92-100.
18. Deapartment of Haelth (Queensland Ambulance Service)). Clinical Practical Guildeines- Cardiac/Acute Coronary Syndrome [Internet]. Ambulance.qld.gov.au. 2018 [cited 28 April 2018]. Available from: https://www.ambulance.qld.gov.au/docs/clinical/cpg/CPG_Acute%20coronary%20syndrome.pdf
19. Meisel KM, Thabet AM, Josephson SA. Acute care of ischemic stroke patients in the hospital. 2015, 629-637
20. Verpillat P, Guilhaume-Goulant C, Dorey J, Dabbous F, Brunet J, Aballéa S. A chart review of management of ischemic stroke patients in Germany. Journal of market access & health policy. 2015 Jan 1;3(1):24223.