Care of Client with Problem in Oxygenation - Cardiovascular Review

Flashcards covering anatomy, physical assessment, diagnostic lab values, ECG lead placement, dysrhythmia interpretation, pharmacotherapy, and management of acute coronary syndromes, heart failure, and inflammatory cardiac disorders.

What are the three layers of the heart wall and their defining characteristics?

The Epicardium is the outermost layer; the Myocardium is the middle layer, which is the thickest, strongest, and contracting muscular part of the heart; and the Endocardium is the innermost layer.

What are the structural layers and normal fluid volume of the pericardial sac?

The sac consists of the Parietal pericardium (tough/fibrous outermost protective layer) and the Visceral pericardium (inner layer covering the organ). Between them lies the pericardial space containing a small amount of lubricating fluid.

How does deoxygenated and oxygenated blood flow through the four heart chambers?

Deoxygenated blood enters the Right Atrium via the superior and inferior vena cava, flows into the Right Ventricle, and is pumped to the lungs via the pulmonary artery. Oxygenated blood from the lungs enters the Left Atrium, moves into the Left Ventricle, and is pumped to the body via systemic circulation.

Why is the myocardium of the left ventricle thicker and stronger than that of the right ventricle?

The left ventricle requires a thicker myocardium because it must generate enough force to pump oxygenated blood throughout the entire systemic circulation, whereas the right ventricle only pumps blood to the lungs.

How do Atrioventricular (AV) valves and Semilunar valves differ in structure and operational timing?

Atrioventricular valves (Tricuspid on the right, Bicuspid/Mitral on the left) have leaf-like structures and close at the beginning of ventricular contraction. Semilunar valves (Pulmonic and Aortic) are moon-like and open at the beginning of ventricular contraction.

What is the intrinsic impulse generation rate of the Sinoatrial (SA) node?

The SA node acts as the main/natural pacemaker of the heart and generates electrical impulses at a rate of $60\text{--}100\text{ bpm}$.

What are the intrinsic firing rates of the AV node and Purkinje fibers when higher pacemakers fail?

The Atrioventricular (AV) node fires at $40\text{--}60\text{ bpm}$ when the SA node fails. The Purkinje fibers fire at $20\text{--}40\text{ bpm}$ if both the SA and AV nodes fail.

What primary features distinguish arteries from veins?

Arteries have a pulse, higher blood pressure, deeper anatomical location, and thicker/strengthened endothelium. Veins have thinner endothelium, wider/larger lumens, and valves to prevent backflow.

What is a pulse deficit, and when does it occur?

A pulse deficit occurs when the apical pulse and peripheral pulse rates are not identical, typically during arrhythmias when some heartbeats fail to produce a pulse strong enough to detect peripherally.

When is an S3 heart sound (Ventricular Gallop) considered normal versus abnormal?

An S3 sound (caused by rapid ventricular filling) is normal in children, pregnant women, and athletes, but abnormal in older adults where it indicates Congestive Heart Failure.

What is the normal reference value for Troponin I, and what makes it the preferred biomarker for myocardial infarction?

The normal value is $<0.04\text{ ng/mL}$. It is the preferred gold-standard biomarker because it is the most sensitive and specific marker for detecting myocardial cell injury and can remain elevated for days after an MI.

How do BNP and NT-proBNP differ in terms of half-life and stability when evaluating heart failure?

BNP ($<100\text{ pg/mL}$) has a short half-life and is cleared quickly from the blood. NT-proBNP ($<125\text{ pg/mL}$) remains in the blood longer, is more stable, and is commonly used as a stable marker of cardiac wall stress.

What are the normal reference values for PT, INR, and aPTT in coagulation monitoring?

Prothrombin Time (PT) is $11\text{--}13.5\text{ seconds}$, International Normalized Ratio (INR) is $0.8\text{--}1.2$, and Activated Partial Thromboplastin Time (aPTT) is $25\text{--}35\text{ seconds}$.

How do Warfarin and Heparin differ regarding route, pathway monitoring, and specific antidotes?

Warfarin is administered orally, affects extrinsic/common pathways monitored by PT/INR, acts as a Vitamin K antagonist, and is reversed by Vitamin K. Heparin is given IV, affects intrinsic/common pathways monitored by aPTT, acts rapidly, and is reversed by Protamine Sulfate.

According to the 5-Lead Electrode Placement chart, where is each colored lead positioned?

White is placed on the upper right chest ('White on right'), Black on the upper left chest, Brown in the middle of the chest ('Chocolate near the heart'), Green on the lower right ('Snow over grass'), and Red on the lower left ('Smoke over fire').

How many physical electrodes are applied for a standard 12-lead ECG, and how many cardiac views are produced?

A 12-lead ECG uses 10 physical electrodes (4 limb electrodes: RA, LA, RL, LL, and 6 chest electrodes: V1–V6) to record electrical activity from multiple angles, producing 12 distinct lead views.

What anatomical locations correspond to chest electrodes V1 through V6?

V1: 4th intercostal space right sternal margin; V2: 4th intercostal space left sternal margin; V3: Midway between V2 and V4; V4: 5th intercostal space mid-clavicular line; V5: 5th intercostal space anterior axillary line; V6: 5th intercostal space mid-axillary line.

Based on standard ECG waveform interpretation, what do the P wave, QRS complex, and T wave represent?

The P wave represents atrial depolarization; the QRS complex represents ventricular depolarization ($<0.12\text{ seconds}$) leading to ventricular contraction; and the T wave represents ventricular repolarization/relaxation.

According to CPR guidelines in Figure 3, what are the target depth, rate, and recoil parameters for chest compressions?

Hands are placed over the lower half of the sternum, pushing at a rate of $100\text{--}120\text{ compressions/min}$ to a depth of $≥ 2\text{ inches}\text{ (5 cm)}$, allowing complete chest recoil between compressions and keeping interruptions to $≤ 10\text{ seconds}$.

What is the key mechanism that distinguishes synchronized cardioversion from defibrillation?

Cardioversion delivers an electrical shock synchronized to the R wave of the ECG to avoid delivering energy during the vulnerable repolarization period. Defibrillation delivers an immediate, unsynchronized shock at any point in the cardiac cycle.

What is the step-by-step clinical management for Supraventricular Tachycardia (SVT)?

Initial step: Vagal maneuvers (having the patient bear down/Valsalva); Second step: Adenosine rapid IV push over $1\text{--}2\text{ seconds}$ with crash cart present; Third step: Synchronized cardioversion if initial drug therapy fails or the patient is unstable.

What clinical characteristics define Pulseless Electrical Activity (PEA), and what is its proper intervention?

PEA is characterized by organized electrical activity on the ECG without a detectable pulse (rhythm present, pulse absent). Interventions include CPR and treating underlying causes (Hs and Ts); defibrillation is contraindicated.

How do Mobitz Type I (Wenckebach) and Mobitz Type II 2nd-degree AV blocks differ on an ECG?

Mobitz Type I shows progressive lengthening of the PR interval with each beat until a QRS complex is dropped. Mobitz Type II maintains a constant PR interval with random dropping of QRS complexes.

According to the Blood Pressure Ranges table, what measurements define Stage 1 and Stage 2 Hypertension?

Stage 1 Hypertension is defined as Systolic $130\text{--}139\text{ mm Hg}$ or Diastolic $80\text{--}89\text{ mm Hg}$. Stage 2 Hypertension is defined as Systolic $≥ 140\text{ mm Hg}$ or Diastolic $≥ 90\text{ mm Hg}$.

According to the blood pressure equation diagram, what factors determine Blood Pressure (BP)?

Blood Pressure is calculated as $\text{BP} = \text{Cardiac Output (CO)} \times \text{Systemic Vascular Resistance (SVR)}$, where Cardiac Output is the product of Heart Rate (HR) and Stroke Volume (SV).

How do ST-Elevation Myocardial Infarction (STEMI) and Non-ST-Elevation Myocardial Infarction (NSTEMI) differ in ECG presentation and degree of arterial blockage?

STEMI displays ST-segment elevation on ECG and is caused by complete coronary artery blockage. NSTEMI displays ST depression or T-wave inversion (no ST elevation) and involves incomplete/partial coronary blockage.

What interventions and drugs are included in the MONA regimen for acute Myocardial Infarction?

Morphine (reduces pain/anxiety and acts as a vasodilator), Oxygen ($2\text{--}4\text{ L/min}$ via nasal cannula), Nitroglycerin (causes peripheral and coronary vasodilation), and Aspirin (antiplatelet that prevents thromboxane A2 formation).

What dosing rules and blood pressure parameters apply when administering sublingual Nitroglycerin for an acute anginal attack?

Administer 1 sublingual tablet every 5 minutes up to a maximum of 3 doses. Notify the healthcare provider after the 2nd dose. Hold the medication if blood pressure is hypotensive ($<90/60\text{ mmHg}$).

How do primary clinical assessment findings differ between Left-sided Heart Failure and Right-sided Heart Failure?

Left-sided HF causes pulmonary edema manifestations (dyspnea, orthopnea, crackles, S3 heart sound, pink frothy sputum). Right-sided HF causes systemic venous congestion (peripheral edema, lower extremity weight gain, ascites, hepatomegaly, splenomegaly, JVD).

According to the Beck Triad diagram for Cardiac Tamponade, what three cardinal signs indicate severe cardiac compression?

Beck's triad consists of Hypotension, Muffled heart sounds, and Distended neck veins (JVD).

What peripheral physical signs on the skin, eyes, and nails are characteristic of Infective Endocarditis?

Findings include Roth spots (retinal hemorrhages), Osler nodes (painful red/purple nodules on fingers/toes), Janeway lesions (painless flat macules on palms/soles), petechiae, and nailbed splinter hemorrhages.