Download Cardiac Review - Morris Hospital EMS

Cardiovascular Emergencies
January 2016 Continuing Education
Cardiovascular Emergency Objectives
• Review the anatomy of heart structures, vessels and function.
• Review of the Cardiac Cycle
• Blood Flow through the Heart
• Electrical Conduction System of the Heart
• Case Study
• Formulate a field impression from a case study assessment
and implement a treatment plan.
• Skill Drills (pt. assessment, cardiac monitoring, cardioversion)
• SMO Review
Epidemiology
• In 2007, heart disease
contributed to about 34% of all
US deaths.
• Heart disease is the number
one killer.
• Kills 600,000 Americans each year
• About half in ED or before reaching
a hospital
• During first minutes or hours
• Prevention strategies include
education and early recognition.
Anatomy
Coronary Arteries
• Coronary arteries
• Left coronary artery
supplies:
• Left ventricle
• Interventricular septum
• Part of right ventricle
• Coronary arteries (cont’d)
• Right coronary artery
supplies:
• Right atrium
• Right ventricle
• Part of the left ventricle
Valves
• Atria are separated
from ventricles by
atrioventricular (AV)
valves:
• Tricuspid valve
• Mitral valve
• Semilunar valves
• Pulmonary semilunar
valve
• Aortic semilunar valve
The Cardiac Cycle
• Represents complete depolarization and repolarization of the
atria and ventricles
• Diastole: atria or ventricles are resting
• Systole: atria or ventricles contracting
• Relaxation phase: left atrium fills with blood under venous
pressure
• Atrial contraction: blood in each atrium is squeezed into
respective ventricle
• Atrial kick: contribution made by contraction
The Cardiac Cycle
• As ventricular contraction begins:
• Ventricles contract.
• Semilunar valves are forced
open.
• Blood from the right ventricle is
squeezed into the pulmonary
arteries.
• Left ventricle blood is pushed
into the aorta.
Blood Flow Through the Heart
• The heart acts as two pumps,
separated
by an interventricular septum.
• Right side: low-pressure pump
• Superior vena cava collects
blood from upper body
• Inferior vena cava collects blood
from lower body
• Left side: high-pressure pump
• Pulmonary veins collect blood
from the lungs.
Blood
Flow
Through
the
Heart
Blood Flow Through the Heart
• Preload: initial stretching of cardiac myocytes prior to left-sided
contraction
• Afterload: blood is driven out of the heart against systemic
arteries
• Two circulations:
• Systemic circulation
• All blood vessels between left ventricle and right atrium
• Pulmonary circulation
• All blood vessels between right ventricle and left atrium
Blood Flow Through the Heart
The Electrical Conduction System of
the Heart
• Cardiac cells have four properties:
•
•
•
•
Excitability: allows response to electrical impulse
Conductivity: ability to pass on electrical impulses
Automaticity: can generate own electrical impulses
Contractility: ability to contract
• Specialized conduction tissue propagates electrical impulses to
the muscular tissue.
• Pacemaker: area where electrical activity arises
• Sets rate for cardiac contraction
The Electrical Conduction System of
the Heart
• Sinoatrial node
• Located in right atrium
• Receives blood from the RCA
• Fastest pacemaker
• Impulses are spread through
intermodal pathways, causing
depolarization.
• Electrical impulses move from
SA node to the atrioventricular
(AV) node
• Impulse conduction is delayed so
the atria will empty into the
ventricles.
Adapted from 12-Lead ECG: The Art of Interpretation, courtesy of Tomas B. Garcia, MD.
The Electrical Conduction System of
the Heart
• Sinoatrial node (cont’d):
• If atrial rate becomes rapid,
not all impulses go through
AV junction
• Normally pass:
• Into bundle of His
• Into right and left bundle
branches
• Into Purkinje fibers
The Electrical Conduction System of
the Heart
• Secondary pacemakers
• Any conduction system component can act as a secondary pacemaker
if the SA node is damaged.
• The farther removed from the SA node, the slower the intrinsic rate of firing.
The Electrical Conduction System of
the Heart
• Measuring the
heart’s electrical
conduction activity
• Show as a series of
waves and
complexes on ECG
Adapted from 12-Lead ECG: The Art of Interpretation, courtesy of Tomas B. Garcia, MD.
The Electrical Conduction System of
the Heart
ECG Monitoring and Dysrhythmia
Recognition
Integral to interpreting the ECG rhythm is understanding the
components of the normal ECG.
You should become familiar with the following electrical
events:
P wave
• QRS complex
• T wave
• PR interval
•
ECG Monitoring and Dysrhythmia
Recognition
Each wave represents specific electrical events:
•P
wave = Atrial depolarization
• QRS complex = Ventricular depolarization
• T wave = Ventricular repolarization
• P-R interval = Conduction from atria to ventricles
• Atrial repolarization is buried in the QRS complex
ECG Monitoring and Dysrhythmia
Recognition
The electrocardiogram
(ECG).
ECG Monitoring and Dysrhythmia
Recognition
The relationship of the
ECG (the heart’s electrical
activity) to the anatomical
sequence of the heart’s
mechanical actions.
ECG Monitoring and Dysrhythmia
Recognition
MONITORING SYSTEMS
• Although
varied, all heart monitors have the same
basic components, including an oscilloscope or screen
for viewing and a printer for a hard copy of the ECG.
• Remember how to interpret the ECG paper. Time is
measured horizontally, and electrical amplitude is
measured vertically.
ECG Monitoring and Dysrhythmia
Recognition
A breakdown of the
ECG paper.
ECG Monitoring and Dysrhythmia
Recognition
ANALYZING THE ECG
Interpreting ECG’s is nothing more than assessing five
parameters of the rhythm and applying a few rules.
Rate
• Regularity
• QRS width
• P waves
• P-R Interval
•
ECG Monitoring and Dysrhythmia
Recognition
Patient Assessment
• Cardiovascular common complaints:
•
•
•
•
•
Chest pain
Dyspnea
Fainting
Palpitations
Fatigue
• Ensure scene safety.
• Anticipate the need for other resources.
• Look for clues to identify the potential problem
Primary Assessment
•Form a general impression.
•Observe general appearance.
•Assess for apparent life threats.
•Determine level of consciousness.
Primary Assessment
•Airway and breathing
•Determine airway patency.
•Check open airway for rate, quality,
and effort of breathing.
•Consider oxygen therapy initiation.
Primary Assessment
• Circulation
• Check pulse:
• Conscious: radial pulse
• Unconscious: carotid pulse
• Note rate, regularity, and overall quality.
• Assess skin color and condition.
Primary Assessment
•Transport decisions
•Determine if immediate transport is
needed.
•If unsure, continue assessment
until answer can be determined.
History Taking
• Chest pain is often the presenting symptom of Acute
Myocardial Infarction (AMI).
• Use OPQRST.
• Dyspnea is another chief complaint of ACS.
• A first indicator of left-sided heart failure
•
•
•
•
•
•
•
When did it start?
Suddenly or gradually?
Continuous or intermittent?
During activity or at rest?
Does any position make it better or worse?
Ever had it before?
Cough? Associated symptoms?
History Taking
• Palpitations: sensation of abnormally fast or irregular heartbeat
• Often caused by dysrhythmia
• Inquire about:
• Onset, frequency, and duration
• Previous episodes
• Patients may also report:
• Feeling of impending doom
• Feeling nausea or having vomited
• Inquire about medical history.
Medications for Patients with
Cardiovascular Diseases
• Patients may be
taking a wide variety
of medications.
• It is not always
possible to identify
the problem based on
medications.
Case Study
• January 2016 CE Cardiovascular Emergencies
Part 1
•You and your partner are enjoying the rare treat of a quiet
Sunday shift. You are watching television, and your partner is
studying for final exams. You are about to drift off when the pager
disrupts the tranquility. You are dispatched to the medical school
library for an unknown medical emergency. On arrival you and
your partner are led to the third floor stacks where you find a 22year-old man complaining of palpitations.
Part 1 (cont’d)
Primary Assessment
Recording Time: 0 minutes
Appearance
Young, well-nourished man; appears
anxious and nervous
Level of Consciousness
A (Alert to person, place, and day)
Airway
Open
Breathing
Normal rate, adequate volume
Circulation
Strong and rapid radial pulses with pink,
warm, diaphoretic skin
Part 1 (cont’d)
What are some potential causes of
palpitations?
What questions would you like to ask your
patient at this time?
Part 2
•You ask your partner to obtain an initial set of vital signs while
you begin your patient assessment. When asked about the
palpitations, the patient tells you that they began about 45
minutes ago while he was studying for finals. He is a first-year
medical student and needs to do well on finals to avoid being
placed on academic probation. He admits to being awake for the
past 36 hours with the help of “Monster” energy drinks and
caffeine pills.
Part 2 (cont’d)
•His last oral intake was pizza last night around 11:00 PM. He
denies any medical history or allergies and emphatically denies
the use of any drugs other than the caffeine pills.
Part 2 (cont’d)
Vital Signs
Recording Time: 5 minutes
Skin
Pink, warm, and diaphoretic
Pulse
210 beats/min, regular; strong radial pulses
Blood Pressure
112/74 mm Hg
Respirations
20 breaths/min, nonlabored
SaO2
95% on room air
What Rhythm is your patient in ?
Remember ….. SVT Rate > 150
Part 2 (cont’d)
What are some of your concerns based on this
information?
What interventions should you consider at this
point?
Part 3
•Your partner has applied the cardiac monitor and is giving
oxygen at 4 L/min via nasal cannula. The cardiac monitor
displays a narrow complex tachycardia at a rate of 212
beats/min. While looking for a site to insert an intravenous (IV)
line, you ask the patient to bear down hard as if he were having a
bowel movement. There is no change in his rate and rhythm. You
insert an 18-gauge IV catheter in his right forearm and prepare to
administer 6 mg of adenosine (Adenocard).
Part 3 (cont’d)
•You rapidly administer the 6 mg of adenosine, followed by a 10mL fluid bolus. The monitor showed a transient decrease in the
HR to 165 beats/min, which quickly picked back up to a rate of
206 beats/min. Anthony tells you that he experienced “the
strangest sensation” in his chest when you gave him the
medication and asks what you gave him.
Part 3 (cont’d)
Reassessment
Recording Time: 11 minutes
Skin
Pink, warm, and diaphoretic
Pulse
206 beats/min, regular; strong distal pulses
ECG
Supraventricular tachycardia
Blood Pressure
110/78 mm Hg
Respirations
20 breaths/min, nonlabored
SaO2
99% on nasal cannula at 4 L/min of oxygen
Pupils
Equal and reactive to light
Part 3 (cont’d)
How does adenosine work?
What should you tell your patient before you
administer adenosine?
Part 4
•Since the initial dose of adenosine caused a transient drop in the
HR, you decide to administer 12 mg of adenosine after 2 minutes
has passed. This time, you let Anthony know that you will be
administering the medication and give it followed by a 10-mL
flush. The monitor showed a 3-second period of asystole followed
by a gradual increase in the HR to approximately 210 beats/min.
After waiting 2 minutes, you administer another 12 mg of
adenosine, the third and final dose, with similar results.
Part 4 (cont’d)
Reassessment
Recording Time: 17 minutes
Skin
Pink, warm, and diaphoretic
Pulse
210 beats/min, regular; strong distal pulses
ECG
Supraventricular tachycardia
Blood Pressure
114/76 mm Hg
Respirations
18 breaths/min, nonlabored
SaO2
99% on nasal cannula at 4 L/min of oxygen
Pupils
Equal and reactive to light
Part 4 (cont’d)
How should your treatment proceed?
Part 5 (cont’d)
•After about a minute passes, you note that the HR on the
cardiac monitor begins to steadily decrease, finally stabilizing at
94 beats/min. Both you and Anthony can breathe a sigh of relief.
You contact the receiving ED, give your report, and receive no
further orders.
•On arrival at the ED, a diltiazem drip is started. He is admitted
overnight for observation on the telemetry floor. After an
uneventful night, Anthony is discharged home with strong
suggestions not to overindulge in energy drinks and caffeine pills
and to find healthier study habits!
Part 5 (cont’d)
Reassessment
Recording Time: 25 minutes
Skin
Pink, warm, and dry
Pulse
94 beats/min, regular; strong distal pulses
ECG
Normal sinus rhythm
Blood Pressure
124/76 mm Hg
Respirations
18 breaths/min, nonlabored
SaO2
99% on nasal cannula at 4 L/min of oxygen
Pupils
Equal and reactive to light
Part 5 (cont’d)
Per ALS Code 7 of our SMOs what are the 5 signs of
hypoperfusion?
How should you treat this patient if he started to display
signs of hypoperfusion ?
What is the first and second dose of this treatment?
Skill Drills
1. ALS Pt. Assessment with Cardiac Monitoring
2. Synchronized Cardioversion
SMO Review
• ALS Code 1  Initial Medical Care / Routine Cardiac Care
• ALS Code 7  Tachycardias
References
• Region 7 Standing Medical Orders, 2011 edition
• American Academy of Orthopedic Surgeons, “Emergency Care
in the Streets, 7th Edition,” Chapter 17, 2014
• American Heart Association, “Advanced Cardiac Life Support
Textbook”, May 2011.