Cardiovascular Emergencies - PDF

Cardiovascular Emergencies Acute MI & Heart Failure Sandy George 1  Cardiovascular System Purpose – delivery of oxygen, nutrients, hormones, and other protective components to the body cells Pulmonary circulation is low...

Cardiovascular Emergencies Acute MI & Heart Failure Sandy George 1  Cardiovascular System Purpose – delivery of oxygen, nutrients, hormones, and other protective components to the body cells Pulmonary circulation is low pressure to allow slow movement through the lungs and improved gas exchange Systemic circulation is high pressure where you feel pulsations and works against gravity to allow for blood return to the heart from the body tissues Right Atrium: Deoxygenated blood returns to the heart from the body through two large veins, the superior vena cava and inferior vena cava. This deoxygenated blood enters the right atrium. Tricuspid Valve: From the right atrium, the blood flows through the tricuspid valve into the right ventricle. Right Ventricle: The right ventricle contracts, pumping the deoxygenated blood through the pulmonary valve into the pulmonary artery. Pulmonary Artery: The pulmonary artery carries deoxygenated blood to the lungs. Lungs: In the lungs, carbon dioxide is exchanged for oxygen. Oxygenated blood 2 returns to the heart through the pulmonary veins. Left Atrium: The oxygenated blood enters the left atrium. Mitral Valve (Bicuspid Valve): The mitral valve allows blood to flow from the left atrium to the left ventricle. Left Ventricle: The left ventricle contracts, pumping oxygenated blood through the aortic valve into the aorta. Aorta: The aorta is the main artery that carries oxygenated blood away from the heart and distributes it to the rest of the body. Systemic Circulation: Oxygenated blood is delivered to various organs and tissues through a network of arteries and arterioles. Capillaries: Within the tissues, oxygen and nutrients are exchanged for waste products in tiny blood vessels called capillaries. Venules and Veins: Deoxygenated blood, along with waste products, is collected by venules and veins and returns to the heart. Superior and Inferior Vena Cava: Deoxygenated blood from the upper body returns to the right atrium through the superior vena cava, while deoxygenated blood from the lower body returns through the inferior vena cava. 2  The Heart Layers Circulation Chambers & Valves Blood Flow Electrical Nodes Layers Pericardium – outside sack with pericardial fluid which is a lubricant to minimize friction with heart movement (contraction/relaxation) Epicardium – outer layer of the heart that covers all the vessels and folds to form the pericardium Myocardium – muscle layer that contracts Endocardium – inner most layer, lines the interior heart and valves Systolic – ventricular contraction (Cardiac Output = Stroke Volume X Heart Rate) 70% of blood volume from heart goes into the aorta known as stroke volume (SV). Also known as ejection fraction. Diastolic – ventricular relaxation Ventricles accept blood from the atria which is contracting 3  The Heart: Chambers & Valves Chambers & Valves Right Atrium (A – on top) – thin layered chamber on top of the heart, received blood from the superior and inferior Tricuspid Valve – 3 leaflets open with atrial contraction and close with ventricular contraction, chordae tendineae, allows flow one direction Right Ventricle (V – on bottom) - Strong-walled chamber on the bottom of the heart, contracts to push blood through the pulmonic valve into the pulmonary artery to the lungs for gas exchange and back into the left atrium Pulmonic Valve – semilunar, opens with ventricular contraction and closes with ventricular relaxation, flow in one direction Left Atrium – thin layered chamber on top of the heart, received blood from the lungs and contracts to move blood through the mitral valve into the left ventricle Mitral Valve – 2 leaflets open with atrial contraction and closes with ventricular contraction, chordae tendineae connects to muscle, allows flow in one direction Left Ventricle – Strong-walled chamber on the bottom of the heart, contracts to push blood through the aortic valve into the aortic arch Aortic Valve – semilunar, opens with ventricular contraction and closes with ventricular relaxation, flow in one direction 4  The Heart: Blood Flow Right Coronary Artery Posterior Artery Left Coronary Artery Circumflex Artery Left Anterior Descending Artery Coronary Arteries: The heart has its own network of blood vessels called coronary arteries. The main coronary arteries are the left coronary artery and the right coronary artery. Left Coronary Artery (LCA): The left coronary artery branches into the left anterior descending (LAD) artery and the left circumflex artery. The LAD artery supplies blood to the anterior part of the left ventricle and a portion of the interventricular septum. The LAD artery is a branch of the left coronary artery and supplies a large portion of the left ventricle of the heart. The term "widow-maker" is often colloquially used to refer to a specific and particularly dangerous blockage or occlusion in the coronary arteries, specifically the left anterior descending (LAD) artery. Right Coronary Artery (RCA): The right coronary artery supplies blood to the right atrium, right ventricle, and the inferior part of the left ventricle. Posterior artery. Coronary Perfusion Process: During diastole (the resting phase of the cardiac cycle), the coronary arteries receive blood flow. As the heart relaxes, the aortic valve closes, and the coronary arteries fill with blood. Oxygenated blood, which is rich in nutrients, is delivered to the myocardium through small branches of the coronary arteries. 5  Coronary perfusion ensures that the heart muscle receives the oxygen and nutrients it needs to sustain its metabolic activities and maintain contractility. Myocardial Oxygen Demand: The demand for oxygen by the myocardium increases during periods of increased activity or stress, such as during physical exertion. The coronary arteries respond by dilating to allow more blood flow, ensuring an adequate supply of oxygen to meet the increased demand. Coronary Artery Disease (CAD): Coronary perfusion can be compromised in conditions such as coronary artery disease (CAD), where the coronary arteries may become narrowed or blocked by atherosclerotic plaques. Reduced blood flow to the heart muscle can lead to ischemia (lack of oxygen) and may result in chest pain (angina) or, in severe cases, a myocardial infarction (heart attack). 5  Cardiovascular System Nursing Assessment What do you want to assess? Normal Inspection – no pallor or cyanosis, PMI not visible unless cachectic or very young, no JVD when 45 degree angle lying down Palpation – Skin is warm, capillary refill 10mmHg drop in systolic BP during inspiration), tachycardia, muffled heart sounds, jugular vein distention Nursing actions – administer fluids for hypotension, prepare for pericardiocentesis Image: https://www.myamericannurse.com/acute-cardiac-tamponade/ 8  Cardiac BioMarkers Troponin CK-MB BNP Cardiac ischemia: Troponin is a contractile protein (cardiac enzyme) that is released from the cardiac muscle when it has a mismatch between oxygen demand and oxygen supply. If there is an ischemic event for some reason. We must evaluate a baseline and serial troponins over time to see if the level is changing (in the case an ischemic event is developing). Troponin I