The innermost layer of the heart, it forms the lining and folds back onto itself to form the four valves. It is in this layer that the conduction system is found
Muscular layer of the heart
The outermost layer of the heart. It is actually the inner layer of the pericardium
Receives deoxygenated blood returning to the heart from the body via the superior vena cav which carries blood from the upper body and the inferior vena cava which carries blood from the lower body.
Receives deoxygenated blood from the right atrium which pumps to the lungs for oxygenation through the pulmonary artery (trunk) to the right and left pulmonary arteries
Receives oxygenated blood returning from the lungs via the right and left pulmonary veins.
Receives the oxygenated blood from the left atrium and pumps it to the body through the aorta, the largest artery of the body.
The two semilunar valves
Pulmonic valves and aortic valves
Heart Sounds S1
First heart sound is due to the closure of the mitral and tricuspid valves
Heart Sounds S2
Second heart soudn is due to closure of the aortic and pulmonic valves
The arteries supplying the heart with blood
Sympathetic Nervous System
Affects both the ventricles and atrium by increasing heart rate, conduction and irritability
Parasympathetic Nervous System
Affects the atria only by decreasing heart rate, conduction and irritability
This is the ability of the cardiac cells to stimulate their own electrical impulse without being stimulated from another source
Irritability, shared by all cardiac cells and it the ability to respond to external stimulus; electrical, chemical and mechanical
This is the ability of all cardiac cellls to receive and electrical stimulus adn transmit the stimulus ot the other cardiac cells
This is the ability of the cardiac cells to shorten and cause cardiac muscle contraction in response to an electrical stimulus
Primary pacemaker of the heart, instrinisc rate of 60 -100 beats per minute
Located at the posterior septal wall of the right atrium, just above the tricuspid valve. There is a 1/10th of a second delay of electrical activity at this level to allow the blood to flow from the atria to the ventricles. Intrinsic rate of 40-60 beats per minute
Bundle of His
Found at the superior portion of the interventricular septum, it is the pathway that leads to the SA node. Intrinsic rate 40-60 beats per minute.
Located at the interventricular septum. The bundle of His divides into the right and left bundle branches. The function is to conduct the electrical impulse to the purkinje fibers.
Found within the ventricular endocardium. Instrinsic rate is 20-40 beats per minute.
Unipolar Precordial Leads
V1,V2,V3,V4,V5 and V6
The normal running speed of the EKG
1 MV will produce a deflection of
Refers to the movement away from the isoelectric line either upward (positive) deflection or downward (negative) deflection
Line between two waveforms
Waveform plus segment
Late repolarization, a prominent one could indicate hypokalemia
The interval between two Rs
PR interval measurement
QRS interval measurement
Artifact - Patient tremors or shaking the wires can produce jittery patterns on the EKG tracings.
Sweat or lotion on the patients skin or tension on the electrode wires can interfere with the signal going to the ekg apparatus causing the baseline of the tracing to move up and down on the ekg paper
60 cycle interference
Can produce deflections occuring at a rapid rate that may mimic atrial flutter. This is caused by electrical appliances or apparatus being used nearby while the tracing
The stylus goes up and down trying to find the signal. This can be caused by loose electrode or cables or by frayed or broken wires
Indications for Stress Testing
Evaluation of Chest pain in patient with normal EKG. Evaluation of patient who has recently had a myocardial infarction. Diagnosis and Treatment of arrythymias
1mv should produce a deflection of 1 cm (10mm)
Indications for Stopping Stress Test
Chest pain, Shortness of breath (SOB), dizziness, and blood pressure abnormalities
Target Heart Rate
220 minus patient age.
Heart rate for valid Stress test
85% of 220 minus patient age
Indications for pharmalogic stress test
patients with physical limitations.
Arrhythmias of sinus origin
Where electrical flow follows the usual conduction pathway but it too fast, too slow or regular.
Electrical impulses originate from somewhere else other than the sinus node
Electrical impulses go down the usual pathway but encounter blocks and delays.
The electrical impulses bypass the normal pathway and instead go down an accessory shortcut.
Occurs when there is a decrease in the amount of blood flow to a section of the heart. This is usually experienced as chest pain and discomfort and is called angina
Four elements of negligence
duty, derelict, direct cause and damage.To
A wrongful act that results in injury to one person by another.
Unprivileged touching of one person by another
Invasion of privacy
This is the release of medical records without the patient's knowledge and permission
Chain of Infection ( in order)
Agent, portal of exit, mode of transmission, portal of entry and susceptible host
the destruction of pathogenic organisms after they leave the body
The pulmonary arteries
Carry deoxygenated blood to the lungs.
The pulmonary veins
carry oxygenated blood from the lungs to the heart
carry deoxygenated blood back to the heart
carry oxygenated blood away from the heart
separates the heart into two halves
Lead I ( negative and positive)
right arm - and left arm+
Lead II (negative and positive)
right arm- and left leg +
Lead III (negative and positive)
left arm - and left leg +
Leads I, II and III
AVr, AVL and AvF
bipolar and augmented
Lead I, II and III, AVR, AVL and AVF
postive left leg
should be given to all patients with acute chest pain that may be due to cardiac ischemia. Prompt treatment of the hypoxemia may prevent cardiac arrest.
An overall increase in heart rate and myocardial contractility, but never agents have replaced in most clinical settings. It is contraindicated in routine treatment of cardiac arrest.
Reduces heart rate, blood pressure, myocardial contractility, and myocardial oxygen consumption with make them effective in the treatment of angina pectoris and hypertension. They preventing atrial fibrillation, atrial flutter, and parosysmal supra-ventricular tachycardia.
This is indicated for significant hypotension in the absence of hypovolemia. Significant hypotension is present when systolic blood pressure is less than 90mmHg with evidence of poor tissue perfusion, oliguria and changes in mental status. It should be used at the lowest dose that produces adequate perfusion of vital organs
This is the drug of choice for the suppression of ventricular ectopy, including ventricular tachycardia and ventricular flutter. Excessive doses can produce neurological changes, myocardial depression, Neurological toxicity is manifested as drowsiness, disorientation, decreased hearing ability, parethesia, and muscle twitching, and eventual seizures.
Is the treatment of paroxysmal supraventricular tachycardia (PSVT)effective in terminating more than 90% of episodes of PSVT in adults and infants.
Increases the force of cardiac contraction as well as cardiac output. Toxicity is common with an incidence of up to 20%. Patients require constant monitoring for signs and symptoms of toxicity such as: yellow vision, nausea, vomiting, and drowsiness.
This is the traditional drug of choice for pain and anxiety associated with acute myocardial infarction. In high doses may cause respiratory depression. It is a controlled substance and has a tendency for abuse and addiction.
Is a powerful smooth muscle relaxant effective in relieving angina pectoris. It is effective for both exertional and rest angina. Headache is common following the administration of this drug. Hypotension may occur and patients should be instructed to sit down or lie down while taking nitroglycerin.
This is consent given to the patient who is made aware of any procedure to be performed, its risks, expected outcomes and alternatives
4 elements of negligence
Duty- Duty of care
Derelict- Breach of duty of care
Direct Cause- Legally recognizable injury occurs as a result of the breach of duty of care
Damage- Wrongful activity must have caused the injury or harm that occured.
The basis of tort in this case is the unprivileged touching of one person by another. When a procedure is performed the patient must givve consent in full knowledge.
Invasion of privacy
This is the release of medical records with the patient's knowledge and permission
Defamation of character
This consists of injury to another person's reputation, name, or character.
Chain of Infection (Order)
Agent-Portal of Exit-Mode of Transmission_Portal of Entry-Susceptible Host
The destruction of pathogenic microorganisms after they leave the body.
Most important means of preventing the spread of infection
Also called PPE Masks, gloves, face shields, and respirator
Infection control method designed to prevent direct contact with blood and other body fluids and tissues by using barrier protection and work control practices. These include wearing gloves, wearing face shields when there is danger for splashing on mucous membranes and disposing of all needles and sharp object in puncture proof containers without recapping.
Designed to reduce the risk of transmission of microorganisms by direct or indirect contact. Involves skin to skin contact and physical transfer of microorganisms to a susceptible host from an infected or colonized person.
Designed to reduce the risk of airborne transmission of infectious agents. Special air handling and ventilation are required to prevent airborne transmission.
Designed to reduce the risk of droplet transmission of infectious agents. Droplet transmission involves contact with the mucous membranins of the nose or mouth of a susceptible person with large particle droplets generated from the source person through coughing, sneezing, or talking. Usually travel only three feet.
Located between the right atrium and right ventricle. It has three cusps.
Located between the left atrium and left ventricle. It has two cusps. Also called biscuspid valve
An emerging and important problem in the heatlh field.