Chapter 16

The coronary arteries supply the blood to the heart and atherosclerosis and arteriosclerosis cause obstructions in the coronary arteries and block the blood flow to the heart and cause

acute coronary syndrome or myocardial ischemia

If myocardial ischemia is prolonged it can lead to

myocardial infarction

Most common type of heart disease

coronary artery disease

The three layers of the heart (inside to out)

endocardium, myocardium, epicardium

Cardiac muscle stores very little calcium and relies on an

influx of extracellular calcium ions for contraction

Very thin, three layered membrane that lines the interior of the heart and covers the valves

endocardium

Moves blood from the pulmonary artery into the lungs and allows oxygenation and gas exchange at the capillary bed to the pulmonary vein that empties into the left atria where the artery carries deoxygenated blood and a vein carries oxygenated blood

pulmonary system

Begins at the aorta, where blood from the left ventricle s moved into the tissue for oxygenation and the cells absorb O2 and deoxygenated blood is carried back to the heart via the veins and drain into IVC

systemic circulation

Functions as a low pressure system that allows the blood to move through the lungs slowly that improves adequate gas exchange

pulmonary circulatory system

High pressure system where its pulsations reflect the contraction of the left ventricle that must work against gravity to move blood into the body's tissues

systemic circulation

Pushes blood through the pulmonary circulation

right ventricle

Pushes the blood through the aorta to all the body's peripheral tissues

left ventricle

Time where the ventricles contract and the left ventricle ejects 70% of the blood into the aorta

systole

When the left ventricle ejects 70% of blood into the aorta is called

stroke volume or left ventricular ejection fraction

Also during systole the right ventricle

ejects blood into the pulmonary artery

Time when the ventricles relaxed and the ventricles accept blood from atrial contraction

diastole

During diastole, in the left ventricle the blood that is accepted by ventricles from the atria is known as

LV end diastolic volume

Where is the SA node located

right atrium

Where is the AV node located

centrally in the heart between the atria and the ventricles and the bundle of His

Impulse of heart begins where

in the SA node within the right atrium

Also known as the hearts pacemaker

SA node

Provides a one-way conduction of the impulse down into the ventricles and the bundle of His

AV node

The bundle of His activates the Purkinje fibers and the fibers

excite the left and right ventricles

Nerve impulse that occurs in cardiac tissues

action potential

In the five-phase action potential the action potential rises in voltage in the stage

depolarization or phase 0

Action potential reaches its max point and then slightly decreases in voltage

phase 1

Long plateau phase

phase 2

Rapid depolarization

phase 3

Returns to baseline

phase 4

Disorders of cardiac rhythm

dysrhythmias or arrhythmias

Two types of cardiac dysrhythmias

supraventricular or ventricular

Dysrhythmias in the SA node, atria, and AV node

supraventricular

Dysrhythmias in the conduction system (bundle of His, Purkinje fibers, and ventricular muscle

ventricular

Dysrhythmias that are potentially fatal

ventricular

Excitable area outside the normal conduction pathway

ectopic pacemaker

Occurs when ectopic pacemaker initiates a contraction

premature ventricular contraction (PVC)

When several PVCs in a row can lead to

ventricular tachycardia

Happens when the ventricle is beating independently without waiting for a completion of each action potential

ventricular tachycardia

Ventricular tachycardia can lead to

ventricular fibrillation

Occurs when heart is beating so rapidly that the ventricle is actually quivering and not ejecting blood

ventricular fibrillation

Recording of electrical activity of the heart that can eb measured

electrocardiogram

P wave

SA node and atrial depolarization

ORS waves

ventricular depolarization

T wave

ventricular repolarization

Disorder caused by the deprivation of blood to the myocardium of the heart

ischemic heart disease

Can be temporary and blood flow can be reestablished

myocardial ischemia

Acute coronary syndrome is also called

chronic stable angina

Acute coronary syndrome can present in two types

unstable angina and MI

squeezing pain in the chest that occurs when there is lack of blood flow to the myocardium

angina pectoris

Angina can be

stable or unstable

Chronic chest pain that the patient has experienced in the past and feels similar to past episodes

stable angina

Cardiac chest pain that is occurring for the first time in a patient

unstable angina

Is an emergency situation that requires immediate medical attention

unstable angina

Angina is more common in

women at 62

Signs of myocardial ischemia that differ from the classic chest pain such of dyspnea, sweating, feeling faint, dizziness, extreme fatigue or heartburn

anginal equivalents

When a patient clenches a fist over the sternum when experiencing angina pain is known as

positive Levine's sign

Is common in people with MI or angina pectoris

positive Levine's sign

Coronary vasospasm can lead to

Prinzmetal's or variant angina

If a patient with angina takes 3 NTG tablets in a 10 minute period without the relief of chest pain always assume

MI

NTG and other nitrate preparations can cause

severe hypotension

Should not be administered with sildenafil due to the severe risk of hypotension

NTG

Considered the preferred biomarker for diagnosing MI

cTnI

Cardiac specific contractile protein that is not normally found in serum and is released only when myocardial cell death has occurred

cTnI

Indicates that the infarction is completely through the heart wall

Stemi

Indicates that the MI is subendocardial and not completely through the heart wall

NSTEMI

Echocardiogram cannot diagnose an

MI or dx an acute MI

Main tx of an acute MI

-reestablish blood flow to affected areas-chewing non-coated ASA-O2 if sat is less than 95%-sublingual NTG

Who should not take NTG

males taking drugs to EDPt with aortic stenosis and hypertrophic cardiomyopathy

The murmur of pericarditis

pericardial friction rub

Pericardial friction rub sound

rough, scratchy sound

Inflammation of the membrane that surrounds the heart

pericarditis

When does pericarditis occur?

2-3 days after MI

What does pericarditis feel like

sharp, stabbing pain that is aggravated with deep inspiration and positional changes

Pericarditis is a component of

Dressler's syndrome

Hypersensitivity reaction to tissue necrosis of MI that includes pericarditis, pleuritis, pneumonitis and tx with anti-inflammatory agents

Dressler's syndrome

Weakening of the ventricles and is a common complication of MI

heart failure

Heart's blood pumping action becomes impaired, blood accumulates in chambers, and pressure builds up backwards in cardiovascular system

heart failure

Left sided heart failure

pulmonary edema

S/S of left sided heart failure

dyspnea, cough, crackles, peripheral edema

right sided heart failure

causes swelling in extremities

S/S of right sided heart failure

Enlarged organs, edema, weight gain, distended neck veins, ascites

Chronic coronary artery disease

stable angina

Characterized by recurring chest pain caused by transient myocardial ischemia

chronic coronary artery disease

Chest pain with stable angina occurs during

exertion or other conditions that increase the hearts work demands

Inflammation of the pericardium and epicardium

Pericarditis

When pericardium undergoes inflammation, additional fluid accumulates in pericardial space

pericardial effusion

If pericardial effusion exceeds 200mL or greater the heart becomes compressed and the heart chambers are restricted and they are unable to stretch and fill with blood

cardiac tamponade

Cardiac tamponade presents

-sudden sharp pain that worsens with deep breathing, swallowing, and coughing -pain radiates to the neck, jaw, ABD, or back-pericardial friction rub

S/s of cardiac tamponade are called

Beck triad

Beck triad of cardiac tamponade

Distant heart sounds, distended neck veins, hypotension

prinzmental (variant) angina is caused by

vasospasm of coronary arteries

Myocarditis is caused by

viral infection

Major reason for cardiac transplant rejection

myocarditis

Manifestation of ineffective endocarditis is a

heart murmur, petechiae, splinter hemorrhages, Janeway lesions, Osler's nodes, Roth spots

Janeway lesions

nontender hemorrhagic lesions - fingers, toes, nose, earlobes - associated with endocarditis

Osler's nodes

painful nodules on finger and toe pads....seen in endocarditis caused by strep viridans

Roth spots

Round white spots on retina surrounded by hemorrhage

Leading cause for IE

aureus bacteremia