Cardio & Pulmonary Flashcards
Name the 4 valves in the heart.
Tricuspid valve
Mitral valve
Pulmonary valve
Aortic valve
Where is the tricuspid valve located?
Between the right atrium and the right ventricle
Where is the mitral valve located?
Between the left atrium and the left ventricle
What are the 3 layers of the the heart walls?
Endocardium - Smooth surface for blood to flow
Myocardium - The muscle layer
Pericardium - Lubricates the heart and prevents too much diastole
What is diastole?
Phase of heart rhythm where the heart relaxes and blood fills the heart, usually the ventricles.
What is systole?
Phase of heart rhythm where the heart (usually the ventricles) contract and pump blood into the pulmonary and aortic trunks.
Describe the conduction or electrical system of the heart.
The electrical impulse begins in the sinoatrial (SA) node, located in the posterior right atrium. It travels through the walls of the atria, causing contraction, then it goes to the atrioventricular (AV) node near the tricuspid valve where the signal is slowed before entering the ventricles, allowing time for atria to fill. The impulse then continues through the ventricular walls, causing contraction.
What are the components of normal sinus rhythm on the ECG?
P wave: Atrial contraction
QRS complex: Ventricular contraction
T wave: Repolarization
What is arrhythmia?
Abnormal rhythms that deviate from normal sinus rhythm.
What is bradycardia?
Heart beating too slowly, < 60 bpm
What is tachycardia?
Heart beating too quickly, > 100 bpm
What is fibrillation?
Uncoordinated contractions of the heart
What is the most common arrhythmia managed by emergency physicians?
Atrial fibrillation or A-fib
True or False: Atrial fibrillation or A-fib is a life-threatening condition.
False. However, it can lead to blood pooling in the atria which are more likely to clot, leading to thrombosis and stroke.
What causes atrial fibrillation?
Abnormal electrical signals received by atria
What are the symptoms of atrial fibrillation?
Feeling of pounding or irregular heart beat
Shortness of breath
Tiredness
Dizziness or fainting
True or False: When patients are in rapid a-fib (> 120 bpm) they are often considered not appropriate for therapy.
True.
What is ventricular tachycardia?
Fast heart rhythm originating in one of the ventricles
What is ventricular fibrillation?
Uncoordinated contractions of the ventricles
True or False: Ventricular tachycardia requires immediate BLS interventions.
False. It is not immediately life-threatening, but could potentially be life-threatening as it could lead to ventricular fibrillation, asystole, and sudden death.
True or False: Ventricular fibrillation requires immediate BLS interventions.
True.
What are the two devices for arrhythmia?
Pacemaker
Implantable cardioverter defibrillator (ICD)
What does a pacemaker generally treat?
A slow heart rhythm
What do pacemakers do?
Monitors rhythm and generates electrical signals if needed
True or False: Wearers of pacemakers require lifelong follow-up.
True.
What does a implantable cardioverter defibrillator (ICD) generally treat?
Dangerous fast rhythms
Ventricular fibrillation
What do implantable cardioverter defibrillators (ICDs) do?
Continuously monitor rhythm and pace the heart if sensing a HR that is too fast. Send out one or several shocks to return the heart to normal rhythm if needed.
True or False: Wearers of implantable cardioverter defibrillators (ICDs) require lifelong follow-up.
True.
What is a precaution specific for implantable cardioverter defibrillators (ICDs)?
Avoid electromagnetic fields.
What are the post-pacemaker/ICD precautions?
No lifting, pushing, pulling more than 5 lbs, and no lifting arm above 90 degrees on side of insertion for ~6-8 weeks.
What is ischemia?
A restriction in blood supply, generally due to factors in the blood vessels (damage or dysfunction)
What is the most common cause of cardiac ischemia?
Atherosclerotic plaques in the coronary arteries
True or False: Healthy arteries have smooth, flexible walls that accommodate changes in blood flow.
True.
What is the function of the coronary arteries?
The coronary arteries branch off the aorta and supply the outer muscles of the heart with blood.
Which part of the heart walls do the coronary arteries supply?
Myocardium
What are the processes involved in coronary artery disease (CAD)?
Plaque forms, and the artery narrows, forming blood clots. Plaque ruptures, and the blood clots block the artery.
What are the non-modifiable risk factors for coronary artery disease (CAD)?
Age (men > 45, women > 55)
Genetics
Male gender (estrogen is a protective factor)
Ethnicity
What are the general modifiable risk factors?
Exercise, diet, medication
What is acute coronary syndrome?
The range of clinical presentations of coronary artery disease from unstable angina to acute myocardial infarction
True or False: Angina is not a disease.
True. It’s a symptom of coronary artery disease and does not cause lasting damage to the heart.
How does angina feel?
Chest pain or discomfort (heaviness, tightness)
Levine’s sign - Squeezing, heaviness in the neck, arms, shoulder blades, etc.
Sweating, fatigue, nausea, shortness of breath, lightheadedness
What is angina a warning sign of?
That the heart is unable to balance oxygen demand and oxygen supply.
What is stable angina?
Predictable pattern of occurrence
Caused by consistent precipitating factors
Controlled by rest and nitrates
What is unstable angina?
A change in previously established stable pattern, or a new onset of severe angina
Occurs without a cause
Lasts longer than typical stable angina
Does not respond well to nitro
Often the result of a ruptured unstable plaque
What is an unstable angina a warning sign of?
That a heart attack may happen soon
What is myocardial infarction?
Irreversible myocardial necrosis or cell death
Complete coronary occlusion by a thrombus or plaque rupture
What are the 2 types of myocardial infarction?
ST elevation myocardial infarction (STEMI)
Non-STEMI (NSTEMI)
Compare STEMI and NSTEMI in terms of occlusion.
STEMI - Complete occlusion of a single vessel. > 2 hours.
NSTEMI - Partial occlusion. 20 mins - 2 hours.
Compare STEMI and NSTEMI on loss of myocardium.
STEMI - Loss of large amounts of myocardium (full wall thickness injury).
NSTEMI - Loss of a small amount of myocardium.
Compare STEMI and NSTEMI on mortality.
STEMI mortality is 2 times greater than NSTEMI initially.
Compare STEMI and NSTEMI on troponin and CK levels.
They both have increase in troponin and CK levels.
What do troponin and CK levels indicate?
Troponin - Cardiac muscle death
CK levels - Any muscle death
What is used to diagnose myocardial infarctions?
ST segment depression/elevation in ECG
Troponin and CK levels
Compare STEMI and NSTEMI on ECG.
STEMI - ST segment is elevated.
NSTEMI - ST segment is depressed, or T wave is inverted.
What is cardiac arrest?
Abrupt cessation of normal circulation of blood due to failure of the heart to contract effectively.
True or False: Cardiac arrest can lead to myocardial infarctions.
False. Myocardial infarctions can lead to cardiac arrests.
How does cardiac arrest present, and how is it clinically diagnosed?
Cardiac arrest causes lack of oxygen to the brain, leading to loss of consciousness and abnormal or absent breathing.
Clinically diagnosed by absence of a pulse.
True or False: Cardiac arrests only occur due to cardiac distress.
False. Cardiac arrests can also occur due to non-cardiac causes, such as drowning or trauma.
What are the treatments for cardiac arrest?
Cardiopulmonary resuscitation (CPR) - Provide circulatory support
Defibrillation
Therapeutic hypothermia - Prevent reperfusion injury
What is the indication for defibrillation in cardiac arrest?
Shockable rhythm (e.g. ventricular fibrillation) is present. AED will not shock asystole.
What are the post-cardiac arrest considerations?
“Down time” - How long were they down?
Cardiogenic shock or damage to organs
Pain post-CPR, e.g. cracked ribs
Psychosocial effects, e.g. PTSD
What are the treatments for coronary artery disease and angina?
Medications - Nitro, beta-blockers, calcium channel blockers, lipid lowering
Interventional procedures - Angioplasty, stenting, bypass surgery
Lifestyle changes
True or False: After a cardiac event, we want to encourage remodeling of tissue.
False. We want to prevent remodeling so that the heart doesn’t grow back thick and weird.
What is heart failure?
A progressive condition where the heart weakens and results in impaired ability of the ventricles to pump blood and decreased cardiac output.
What is the cardiac cycle used as an indicator for?
Health of the heart
Blood pressure measurements are [atrial/ventricular] [systole/diastole] over [systole/diastole].
Ventricular systole over diastole
What is stroke volume vs. cardiac output?
Stroke volume - Amount of blood ejected in each contraction
Cardiac output - Amount ejected in 1 minutes
What is a normal stroke volume?
50-70 ml
What is a normal cardiac output?
4.7 L/min
How is stroke volume measured?
Through echocardiogram
What determines the preload?
Venous return - Dehydration, varicose veins, etc.
What determines the afterload?
Systemic circulation, e.g. high blood pressure
What is preload?
The left ventricular pressure at the end of the diastole
What is afterload?
The systemic vascular pressure that the heart must overcome to pump blood into the body
What is the ejection fraction (EF)?
The fraction of blood ejected by the (left) ventricle, relative to end diastolic volume.
Stroke volume/EDV.
What is the normal range of ejection fraction?
50-70%
What is end diastolic volume (EDV)?
Volume of blood in the ventricle after filling. ~120 ml
What does EF mean functionally?
EF is indicative of the heart’s pumping action. Less than 50% is indicative of reduced pumping action, and 35-40% may confirm diagnosis of systolic heart failure.
How is EF usually measured?
Echocardiography or cardiac catheterization
True or False: An individual can have heart failure with normal EF.
True. This would be diastolic heart failure with preserved ejection fraction (PEF).
What range of EF may require an implantable cardiac defibrillator (ICD), and why?
< 30%. May be at risk of life-threatening irregular heartbeats.
What are the heart failure treatment goals?
Slow progression of syndrome.
Control symptoms.
Improve function and QoL.
What are the etiology for most heart failures?
Ischemia (~2/3rds of heart failures) with or without myocardial infarction
What is cardiomyopathy?
Heart muscle disease, or deterioration of the function of the myocardium.
What are the 3 types of cardiomyopathy?
Dilated - Typical with ischemic disease
Hypertrophic - Usually due to systemic disease
Restrictive - Usually due to systemic disease
What is the EF levels in hypertrophic and restrictive cardiomyopathies?
Normal EF levels, because these types are often due to diastolic failure.