MA- all About the Heart

atrium

Each of the two upper chambers of the heart that receives blood that comes into the heart

Ventricles

the two lower chambers of the heart, and they pump blood out to the lungs and body.

heart valves

structures within the heart that open and close with the heartbeat to regulate the one-way flow of blood

septum

Divides the right and left chambers of the heart

epicardium

outer layer of the heart

Myocardium

Thick middle muscle layer of the heart

endocardium

inner lining of the heart, smooth and glass like

Depolarization

Contraction. Heart at work.

Repolarization

Resting phase. Heart at rest

Conduction

Property of being able to transport electrical charge through physical space

sinoatrial (SA) node

the pacemaker; highly specialized, neurological tissue impeded in the wall of the right atrium. All electrical activity starts here. 60-100 bpm

Bundle of His

neurological fibers extending from the AV node to the right and left bundle branches that fire the impulse from the AV node to the Purkinje fibers

bundle branches

conduct the impulses through the interventricular septum

atrioventricular (AV) node

2nd pacemaker, if SA node fails. Intristic rate of 40-60 bpm

Purkinje fibers

fibers in the ventricles that transmit impulses to the right and left ventricles, causing them to contract

Ischemia

an inadequate blood supply to an organ or part of the body, especially the heart muscles.

EKG

electrocardiogram

superior vena cava

A vein that is the second largest vein in the human body and returns blood to the right atrium of the heart from the upper half of the body.

Atherosclerosis

hardening of the arteries

pulmonary veins

Deliver oxygen rich blood from the lungs to the left atrium

pulmonary artery

Carries deoxygentated blood from the heart to the lungs

tricuspid valve

valve between the right atrium and the right ventricle

bicuspid valve

Aka mitral valave, an atrioventriculat valve

Semi-lunar valves

Valves in either side of the heart that controls exit from the ventricles.

P wave

depolarization of the atria

PR segment

the isoelectric line from the end of the P wave to the beginning of the QRS complex, when the electrical impulse is traveling through the AV node, where it is delayed

QRS complex

ventricular depolarization and atrial repolarization

Q wave

Depolarization of septum

R wave

Depolarization of apex

ST segment

time during which ventricles are contracting and emptying

T wave

repolarization of ventricles

Atrial Flutter

Rhythm presents as a "saw toothed" P wave formation on EKG

apex

Thickest region of the myocardium

Holter monitor

portable ECG monitor worn by patient for period of few hours to few days to assess heart and pulse activity as person goes through activities of daily living; used to assess patient who experiences chest pain and unusual heart activity during exercise and normal activities

Bradycardia

slow heart rate

Tachycardia

fast heart rate

arrhythmia

irregular heartbeat

Atrial Flutter

irregular beating of the atria; often described as "a-flutter with 2 to 1 block or 3 to 1 block"

Supraventricular tachycardia

rate varies btwn 160-250 bpm, regular rhythm, originates from a location above AV node, will start and stop w/o cause. common causes: mitral valve prolapse, cor pulmonale, digitalis toxicity, and rheumatic heart disease

Premature Atrial Contraction

A contraction originating from an ectopic focus in the atrium, in a location other than the SA node.

PR wave in the heart normal range and meaning:

-0.12-0.20 seconds

-SA node to AV node, Bundle and Purkinje

QRS wave in the heart normal range and meaning:

-0.06 to 0.1 seconds (no more than 0.12)

-Conduction thru ventricles

T wave represents

ventricular repolarization

telemetry/EKG monitoring

3-5 leads to be worn continuously for cardiac patients

Junctional Rhythm

40-60 Regular!

-impulse from AV node w/ retro/antegrade transmission

- P wave often inverted/buried/follow QRS

- slow rate

- narrow QRS (not wide like ventricular)

Junctional Bradycardia

A rhythm that begins in the AV bundle with a rate of less than 40 beats/min.

Accelerated Junctional Rhythm

regular rhythm, rate 60-100, p waves inverted or occur before during or after QRS, PRI measured if p before QRS

Idioventricular Rhythm

•**Heart is dying, slowly stopping, periodic QRS wave**

•ECG Appearance:

-Slow wide QRS complexes

•Hemodynamic Effects & Nursing Implications:

-Faint pulse or none

•Treatment:

-Check DNR status

-Check pt: Call code

-CPR

-Epi / vasopressin

-Do not shock!

ventricular tachycardia

a very rapid heartbeat that begins within the ventricles

Polymorphic Ventircular Tachycardia

Amplitude of each wide QRS complex, varies from one contraction to another.

Premature Ventricular Complex

Is typically greater then 0.12 seconds, because the ventricular depolarization is abnormal or aberrant. A pause then a PVC appears.

Ventricular Asystole

no rhythm

Ventricular fibrillation (V-fib)

abnormal heart rhythm which results in quivering of ventricles

Ventricular Pacemaker

spike before QRS

AV sequential pacemaker

implanted pace maker that stimulates the atrium to contract as well as the ventricles to contract mimicking the normal action of the heart and preserving the atrial kick

EKG artifact

abnormal waveform on an EKG tracing; additional electrical activity; somatic tremor, alternating current (AC), wandering baseline(poor lead connections), interupted baseline (broken lead wire or disconnection), patient movement (interferance); must be identified and then corrected and another tracing must be run; unwanted errors that appear on the tracing

heart block

interference with normal conduction of electrical impulses that control activity of the heart muscle

precordium

area of the chest wall overlying the heart and great vessels

Somatic tremor

Voluntary or involuntary muscle movement; also known as body tremor.

left pulmonary artery

carries poor oxygenated blood from the right ventricle to the left lung.

right pulmonary artery

takes blood from the right ventricle to the right lung

pulmonary veins

Deliver oxygen rich blood from the lungs to the left atrium

aortic valve

heart valve between the left ventricle and the aorta

interventricular septum

separates ventricles

inferior vena cava

receives blood from lower limbs and abdominal organs

pulmonic valve

Heart valve between the RV and pulmonary artery

Function of the heart

to act as a pump to send blood throughout the body.

cardiac output

heart rate x stroke volume

Systole

Contraction of the heart

disatole

Relaxation of the heart

systemic circulation

The branch of the circulatory system that supplies all body organs and then returns oxygen-poor blood to the right atrium via the veins.

chordae tendineae

heart strings

QRS complex

ventricular depolarization

P wave

atrial depolarization

T wave

ventricular repolarization

ST segment

time during which ventricles are contracting and emptying

Ics

intercostal space

PR segment

AV nodal delay