Cardiac Disorders

Cardiac Output

vol of blood ejected by the heart per minute (HR x SV)

Cardiac Cycle

one complete heartbeat; systole and diastole

Systole

ventricular contraction + depolarization

Diastole

relaxation and ventricular refilling + repolarization

Preload

vol of blood in ventricles at the end of diastole (refilling)

Afterload

resistance that the ventricles must overcome to eject blood into systemic ciruclation/”out of the heart”

Lactic dehydrogenase (LDH)

found in body tissues; normally LDH2 > LDH1

LDH levels during MI?

LDH1 > LDH2; elevated within 24-72 hours and peaks in 3-4 days; returns to normal in 2 weeks

Creatine kinase (CK)

measures degree of muscle damage

CK-MB

specific isoenzyme for muscle damage; rises within 6 hour and peaks at 18 hours post-injury; returns to normal in 2-3 days

Myoglobin

degree of muscle damage in general and non-specific for cardiac muscle

Troponin

elevation before CK-MB in MI and peaks in 24 hours; highly specific for MI early and usually ordered x2 initially 1-2 hours apart for trending + preferred method for diagnosing cardiac injury

Ischemic Heart Disease

results from atherosclerosis or arteriosclerosis; plaque accumulates causing narrowing of vessels and compromising blood flow; occurs over time and causes symptoms of angina

Angina

sign of myocardial ischemia + temporary imbalance between oxygen supply and demand

Chronic Stable Angina

chest discomfort that occurs w exertion and is familiar to the patient + associates with stable atherosclerosis plaque

Unstable Angina

unpredictable chest discomfort that is new or newly occurs at rest or w minimal exertion - increases in intensity of number of episodes; medical emergency and may be a precursor to MI

Prinzmetal’s Angina

blockage of blood flow results from coronary artery spasm instead of plaque formation; may occur hours after alcohol intake and usually occurs from 12a-8a when at rest and in clusters

Anginal Pain Presentation

often radiates to L arm, back, neck, or jaw; CP, SOB, fatigue, N/V, diaphoresis, weakness

NSTEMI

partial occlusion or coronary artery; presents w ST depression

STEMI

total occlusion of coronary artery; presents w ST elevation

Acute Coronary Syndrome

broken plaque emboli lodges in artery causing a blockage in flow; inability to re-establish will cause infarction of an area of heart muscle and eventual death of the area - pump failure!!

Nonobstructive CAD

occurs due to artery spasm/dysfunction; symptoms are similar to obstructive CAD and a cardiac MRI is needed to identify underlying cause

Manifestations of MI

result of sustained ischemia (>20 minutes), causing necrosis (irreversible myocardial cell death); loss of contractile function

Nitroglycerin for Angina

dilates coronary arteries and increases blood flow; sublingual medication with three doses 5 minutes apart

Beta blockers post MI

decrease cardiac workload and oxygen demand

Calcium channel blockers

cause vasodilation, prevent coronary spasmP

PCSK9 inhibitors (Ezetimibe - Zetia)

increases absorption of cholesterol through small intestine

Fibric acids (Gemfibrozil - Lopid)

reduces cholesterol production and expedites removal of triglycerides

Niacin

decreases production of triglycerides and increases HDL

Bile acid sequestrants (Cholestryaine - Question)

converts more cholesterol into bile acids and excretes via stool to lower cholesterol

Post cardiac cath care

bedrest keep leg straight, monitor for bleeding and re-occlusion

Post CABG (coronary artery bypass graft)

post op care, bleeding, chest tube care

Heart Failure

inability of the heart to pump blood to meet the need of tissues for oxygen + nutrients; results form dysfunction of myocardial cells or chronic overloading of the heart

Left Sided HF

failure of left ventricular pumping leads to decreased CO and blood backup into left atrium + lungs; presents w pulmonary congestion, crackles, dyspnea, activity intolerance; eventually results in right sided HF

Right Sided HF

failure of right ventricular pumping leads to decreased CO to body and backup into peripheral circulation; presents w weight gain, peripheral edema, engorgement of kidneys + other organs, JVD

Class I HF

no limitation of physical activity

Class II HF

slight limitation of physical activity (palpitations, dyspnea, SOB), but comfortable at rest

Class III HF

marked limitation, less than ordinary activity causes fatigue, SOB, dyspnea, palpitations; comfortable at rest

Class IV HF

unable to carry out activity without discomfort

Aortic Stenosis

narrowing of aortic valve, obstructing LV outflow during systole

Mitral Stenosis

thickening + calcification of mitral valve; pulmonary congestion occurs, JVD, decreased CO

Aortic Regurgitation

leaflet does not close; hypertrophy occurs due to increased volume; presents w dyspnea, bounding pulse, widened pulse pressure, high pitches murmur

Echocardiogram

ultrasound to determine size + pumping function of the heart, blood vol status, valve function

Coronary angiography

gold standard for diagnosing CAD; left-sided cardiac catheterization to inspect the coronary arteries for blockage and determine the necessity of revascularization procedures such as percutaneous coronary intervention (PCI) or coronary bypass surgery (CABG)

Cardiac catheterization

invasive procedure where catheter is inserted through an artery or vein under fluoroscopy in order to evaluate cardiac filling pressures, CO, and valve function. Both right and left heart studies can be performed

Right heart catheterization

performed through a vein (subclavian, femoral, or brachial) and catheter is advanced to the right heat via superior or inferior vena cava

Left heart catheterization

performed through an artery (femoral, brachial, or radial) and catheter is advanced up through aorta into to left heart

Hemodynamic Monitoring

includes monitoring of vital signs (HR, RR, BP, O2 sats) and a single-lead EKG tracing to monitor the patient for signs of instability

PET Scan

used to determine if areas of the heart muscle is receiving sufficient blood flow, if there is any damage to the muscle, areas of infarcted tissue or scar tissue present, or a buildup of abnormal substances in the cardiac muscle

Side effects of Nitroglycerin

hypotension, headaches, flushing, tachycardia

Morphine Sulfate

used to treat chest pain not relived with nitroglycerin

Side effects of Morphine

drowsiness, constipation, respiratory depression, seizures, headache, hypotension

Anticoagulants

used to treat NTEMI and STEMI; can cause thrombocytopenia, prolonged clotting time, itching, monitor for bleeding