Midterm Flashcards
(98 cards)
1
Q
What is normal sinus rhythm (NSR)?
A
60-100 BPM
2
Q
Syncope
A
Sudden fainting spell
Can indicate a decrease in CO / function
3
Q
What causes angina?
A
Rapid arrhythmias that increase the oxygen demands of the myocardium
4
Q
What is the most common arrhythmia that can lead to sudden death?
A
Ventricular arrhythmia
5
Q
Why do arrhythmias happen?
A
- Mnemonic: HIS DEBS
- H - Hypoxia
- I - Ischemia & Irritability
- S - Sympathetic Stimulation (Exercise, etc)
- D - Drugs
- E - Electrolyte Disturbances (imbalances of Ca, Mg, hypokalemia)
- B - Bradycardia (sick sinus syndrome)
- S - Stretch
6
Q
What lead yields the most information in rhythm strips?
A
Lead II
7
Q
Holter Monitor vs. Event Monitor
A
Holter Monitor
- Ambulatory monitor
- Portable EKG w/ a memory
- Patient wears for 24-48 hrs
- 1-2 leads (1 limb, 1 precordial)
Event Monitor
- Better for rhythm disturbances that happen so infrequently that a Holter monitor is likely to miss it
- Record 3-5 mins of data, but is initiated by the patient when he/she experiences symptoms (palpitations)
- Sent over phone lines for evaluation
8
Q
Rhythm Analysis Steps
A
- Calculate Rate
- Determine regularity
- Assess the P waves
- Determine PR interval
- Determine QRS duration
9
Q
Rhythm Analysis
Step 1: Calculating Rate
A
Option 1:
- Count # R waves in a 6 sec rhythm strip, then multiply by 10
- Reminder: all rhythm strips in the modules are 6 seconds in length
- Interpretation: 9x10 = 90 BPM
Option 2
- Find an R wave that lands on a bold line
- Count the # of large boxes to the next R wave. If the 2nd R wave is 1 large box away, the rate is 300, 2 = 150, 3 = 100, 4 = 75, etc.
- Memorize the sequence: 300-150-100-75-60-50
- Interpretation: approx 95 BPM
Option 3
- Divide 300 by the # of large squares b/t R waves. Ex: 300/4 squares = 75
Option 4
- Count the total # of small squares b/t R waves and dividing 1500 by this total
- Most accurate but too TEDIOUS!
10
Q
What does an absence of a P wave indicate?
What do irregular P waves indicate?
A
Absence: The rhythm originated below the atria
Irregular: Origins of depolarization are from different foci in the atria
11
Q
PR Interval
A
Normal: 0.12 - 0.20 seconds (3 - 5 boxes)
PR interval is the beginning of atrial depolarization to the beginning of ventricular depolarization
Prolonged PR Interval = delay in conduction
12
Q
QRS Complex Duration
A
Duration: Normal - 0.04 - 0.12 sec (1-3 boxes)
Wide QRS Complex = inefficient means of conduction, initiation of rhythm in ventricles
13
Q
What are the 4 types of arrhythmias?
A
- Arrhythmias of Sinus Origin
- Sinus Tachycardia / Bradycardia
- Sinus Arrhythmia
- Sinus Arrest
- Asystole
- Nonsinus Pacemakers
- Junctional Escape Rhythm
- Ectopic Rhythms
- Paroxysmal Supraventricular Tachycardia
- Atrial Flutter
- Atrial Fibrillation
- Multifocal Atrial Tachycardia
- Paroxysmal Atrial Tachycardia
- Premature Ventricular Contractions (PVCs)
- Conduction Blocks
- Preexcitation Syndromes
14
Q
Sinus Tachycardia
A
Rate > 100 BPM
Seen normally in exercise
Or abnormally in congestive heart failure (CHF), severe lung disease, or hyperthyroidism
15
Q
Sinus Bradycardia
A
Rate < 60 BPM
Seen normally in well conditioned athletes or enhanced vagal tone resulting in fainting
or abnormally as an early stage in an acute MI
16
Q
Sinus Arrhythmia
A
Normal, but slightly irregular
Reflects variation in HR w/ inspiration and expiration
Inspiration = accelerates HR
Expiration = decelerates HR
17
Q
Sinus Arrest
A
Occurs when sinus node stops firing
If nothing else were to happen –> asystole (flat line)
Fortunately, other myocardial cells can spring in to action and take over pacing = escape beats
18
Q
Asystole
A
Prolonged electrical inactivity
No CO / no blood flow
Treatment: CPR & Epinephrine IV
19
Q
Nonsinus Pacemakers
A
- SA node: 60-100 bpm
- Atrial foci: 60-75 bpm
- Junctional foci (AV node): 40-60 bpm
- Ventricular foci (His bundle, bundle branches & purkinje system): 20-40 bpm
Anything below 40 bpm originates below atrium / AV node
20
Q
Junctional Escape Rhythm
A
Of all escape rhythms, this is most common
Depolarization originates near AV node and usual pattern of atrial depolarization does not occur, thus…
NO P waves!
21
Q
What are the mechanisms of Ectopic Rhythms?
A
Enhanced automaticity
Re-entry (beat from another circuit fires off)
22
Q
Paroxysmal Supraventricular Tachycardia
A
- Regular narrow (QRS) complex tachycardia
- P waves are retrograde if visible
- Rate: 150-250 bpm
- Initiated by premature supraventricular beat and persisted by reentrant pathway
- Treatment: Carotid massage - slows or terminates
- Commonly involve re-entry loop mechanism
23
Q
Carotid Massage
A
- Can help diagnose & terminate an episode of PSVT
- Baroreceptors sense changes in pressure which cause reflex response from brain to heart via vagus n. to slow HR (increase BP, decrease HR)
- Goals: Terminate the arrhythmia or slow it down to try and find p waves –> diagnosis
- Interrupts re-entry circuit
- You must listen for tubulent flow first b/c person may have a plaque blockage in carotid and you could loosen it and cause it to go to brain –> stroke
24
Q
Atrial Fibrillation
A
- Irregularly irregular, w/o discernable P waves
- Undulating baseline
- Atrial rate: 350-500 bpm
- Ventricular rate: variable
- Carotid massage: may slow ventricular rate
- Narrow QRS complex
- Wavering baseline
*
25
Atrial Flutter
* Regular, saw toothed
* 2:1, 3:1, 4:1, etc. block (# of flutter waves: per QRS complex)
* Atrial rate: 250-350 bpm
* Ventricular rate: 1/2, 1/3, 1/4, etc. of atrial rate
* Carotid massage: increases block
26
Multifocal Atrial Tachycardia
* Irregular w/ a rate of 100-200 bpm
* At least 3 diff p wave morphologies from different atrial foci
* Aka. wandering atrial pacemaker when rate \< 100 bpm
* Carotid massage: no effect
* Common w/ people w/ COPD
27
Paroxysmal Atrial Tachycardia
* Regular
* Rate: 100-200 bpm
* Characteristic warm up period in the automatic form
* Carotid massage: no effect, or only mild slowing
28
Premature Ventricular Contractions
* Aka. PVC's most common of the ventricular arrhythmias
* QRS is wide and bizarre b/c ventricular depolarization does not follow normal conduction
* Bigeminy = 1 nl sinus beat to 1 PVC
* Trigeminy = 2 nl sinus beats to 1 PVC
* 3 PVCs in a row = run of V-Tach
When to worry:
* Frequent
* 3 or more in a row
* Multiform PVCs, in which they vary in their site of origin and hence their appearance
* PVCs falling on the wave of the previous beat --\> R on T phenomenon; T-wave is a vulnerable period of cardiac cycle
* Any PVC occurring in the setting of an acute myocardial infarction
29
Ventricular Tachycardia
* Run of 3 or more consecutive PVCs
* Rate: 120-200 bpm and may be slightly irregular
* Sustained VT is an emergency preceding cardiac arrest
* Can be uniform or polymorphic (Torsades De Pointes)
30
Ventricular Fibrillation
* Preterminal event
* **Seen almost solely in dying hearts**
* **Most frequently encountered in adults who experience sudden death**
* Course or fine - no true QRS complexes
* No CO: CPR / defibrillation immediately
31
Accelerated Idioventricular Rhythm
* Benign rhythm seen during an AMI
* Regular rhythm occurring at 50-100 bpm
* Represents a ventricular escape focus that has accelerated sufficiently to drive the heart
* Rarely sustained, does not progress to VF, and rarely requires treatment
32
Torsades de Pointes
* "Twisting of the points"
* Form of VT usually seen in patients w/ prolonged QT intervals - prolonged QT can progress to this
* Prolonged QT: congenital or results from electrolyte disturbance (hypocalcemia, hypomagnesemia, hypokalemia), during MI, some drugs, PVC on T wave
* Replenishing Mg or Ca can often stop this
33
What is a myocyte?
* Cardiac cell
* **Electrically polarized at rest**
* Inside of cell is negatively charged compared to the outside
* Polarity is maintained by membrane pumps (controlling distributions of ions - sodium, potassium, chloride, and calcium) necessary to keep the inside of cells **electronegative**
34
Na+ / K+ Pump
Maintains membrane electrical polarity
3 Na+ outside for every 2 K+ inside
ATP is needed to keep cell polarized (in this state)
35
Types of Heart Cells
Pacemaker cells
Electrical Conducting Cells
Myocardial Cells
36
Pacemaker Cells
Electrical power source of the heart
* Depolarize spontaneously
* Rate of depolarization is determined by the innate electrical characteristics of that cell and the external neural and hormonal input
* Each depolarization serves as a source of a wave of depolarization that initiates one complete cycle of cardiac contraction and relaxation
37
Electrical Conducting Cells
The hard wiring of the heart
38
Myocardial Cells
The contractile machinery of the heart
39
Action Potential
* A record of one electrical cycle of depolarization and repolarization of a single cell
* This one action potential stimulates neighboring cells to depolarize until the entire heart has been depolarized and contracts
40
Sinus Node
* Dominant pacemaker of the heart
* Located in RA
* Rate: 60-100 bpm
* Altered by autonomic ns
* Automaticity: all heart cells possess ability to behave as a pacemaker. Suppressed unless SA node fails
41
What is automaticity?
all heart cells possess the ability to behave as a pacemaker. Suppressed unless the SA node fails
42
Intrinsic Pacing:
Dominant Pacemaker Rate
Escape Pacemaker Rates (AV junction, Bundle Branches, Purkinje Network)
* Dominant Pacemaker: 60-200 bpm
* Escape Pacemaker:
* AV Junction: 40-60 bpm
* Bundle Branches: 30-40 bpm
* Purkinje Network: 20-30 bpm
43
Electrical Conducting Cells
* Hard wiring of the heart
* Ventricular conducting system has been precisely defined
* Existence of discrete atrial conducting pathways still debated
44
Characteristics of an EKG Wave
Duration: measured in fractions of a sec
Amplitude: measured in millivolts (mV)
Configuration: shape and appearance of a wave
45
What is the time interval of small and large squares on the EKG?
Small Squares = 0.04 sec
Large Squares = 0.2 sec
46
What is the voltage interval of small and large squares on the EKG?
Small Squares = 0.1 mV
Large Squares = 0.5 mV
Vertical Axis = voltage
47
What is the AV node and what is its purpose?
Slows conduction from the atria to the ventricles to allow the atria to finish contracting before the ventricles begin to contract
This delay permits the atria to empty their volume of blood completely into the ventricles before the ventricles contract
48
What are the 3 parts of ventricular conduction?
* Bundle of His
* Bundle Branches
* Terminal Purkinje Fibers
49
EKG:
What marks the beginning of ventricular depolarization and contraction?
QRS Complex
50
Where is the wave of atrial repolarization on the EKG?
It is obscured by the QRS complex
51
What does the PR Interval indicate?
Start of atrial depolarization to start of ventricular depolarization
Delay in conduction at AV node
Duration: 0.12 - 0.2 sec (3-5 mm)
52
What does the ST segment indicate?
End of ventricular depolarization to the start of ventricular repolarization
An elevation or depression by \> 1mm significant and indicates pathologic process
53
What does the QT interval indicate?
Beginning of ventricular depolarization to the end of ventricular repolarization
Duration proportional to HR
Composes 40% of the normal cardiac cycle (R-R interval)
54
EKG:
Positive Deflection
Negative Deflection
_Positive Deflection:_ wave of depolarization towards a positive electrode. Also, a wave of repolarization away from a positive electrode
_Negative Deflection:_ wave of depolarization away from a positive electrode. Also, a wave of repolarization toward a positive electrode
55
Biphasic Wave
A depolarizing wave moving perpendicular to a positive electrode
56
12-Lead EKG
* 6 Limb Leads: 2 electrodes on arms and 2 electrodes on legs
* Standard Leads: 3
* I: RA, LA
* II: RA, Legs
* III: LA, Legs
* Augmented Leads: 3
* AVL: LA, other limbs
* AVR: RA, other limbs
* AVF: Legs, Arms
* 6 Precordial Leads: 6 electrodes placed across the chest
* Horizontal plane of heart
* + with a - central terminal
57
What are the views of the heart on a 12 Lead EKG?
* V1,2,3,4 = Anterior
* I = biphasic wave
* II, III, IV = variable
* I, AVL, V5,6 = Left Lateral
* Toward current = + wave
* II, III, AVF = Inferior
* III = perpendicular to current, biphasic p wave
* AVR = None
58
Septal Q Wave
Represents depolarization of the interventricular septum (L --\> R)
Tiny negative deflection in the left lateral leads: I, AVL, V5, and V6
59
What leads show the smallest and largest R wave?
V1 = smallest
V5 = largest
60
What does the T wave indicate?
* Ventricular repolarization
* Repolarization begins in the last region of the heart that depolarized and travels in the opposite direction of depolarization
* Tall T waves in same leads w/ tall R waves
61
How are the interspaces b/t the ribs numbered?
Interspace b/t 2 ribs is numbered by the rib above it
62
Where does the inferior tip of the scapula lie?
At the level of the 7th rib
63
What vertebrae are most prominent when the neck is flexed?
C7 and T1
64
At what landmarks do the lungs hit?
* Apex of lung rises 2-4 cm above clavicle
* Lower border of lung crosses the 6th rib at the mid clavicular line and the 8th rib at the midaxillary line
* Lower border of the lung lies at the T10 spinous process
65
What are the landmarks of the tracheal bifurcation?
* Anterior = sternal angle
* Posterior = T4
66
What are some potential sources of chest pain?
* Myocardium: angina pectoris, myocardial infarction
* Pericardium: Pericarditis
* Aorta: dissecting aortic aneurysm
* Trachea and large bronchi: bronchitis
* Parietal Pleura: pericarditis, pneumonia
* Chest wall, incl. the musculoskeletal system and skin: costochondritis, herpes zoster
* Esophagus: reflux, esophageal spasm
* Extrathoracic Structures such as neck, gallbladder, and stomach: cervical arthritis, biliary colic, gastritis
67
T or F:
Lung tissue contains pain fibers
False
Pain in lung conditions arises from inflammation of the parietal pleura
68
What is hemoptysis?
Coughing up of blood fro the lungs
69
Smoking:
* % / # of Americans that smoke
* # of deaths per year
* Comparison to Non-Smokers in terms of:
* Lung cancer
* COPD
* Heart Disease
* Stroke
* Peripheral Vascular Disease
* 22.5% of adults / 46M Americans smoke
* Leading cause of preventable death
* 440,000 deaths each year (20% of annual US mortality)
* 35K deaths from 2nd hand smoke
* Risk of death compared to non-smokers:
* Lung Cancer: 22x male, 12x female
* COPD: 10x
* Heart Disease: 2-4x
* Stroke: 2x
* Peripheral Vascular Disease: 10x
70
What is included in an initial survey of someone for a pulmonary exam?
* Inspect pt for signs of respiratory difficulty
* Assess patient's color for cyanosis
* Listen to pt's breathing - wheezing?
* Inspect neck - contraction of SCM? Supraclavicular contraction? Is trachea midline?
* Shape of chest
71
What is tactile fremitus?
Vibration felt on a pt's chest
72
How is chest expansion tested?
Placing hands and feeling breathing on anterior and posterior chests
73
Chest Percussion
1. Hyperextend middle finger of left hand and press distal interphalangeal joint firmly on surface
2. Position R. forearm close to surface w/ right middle finger partially flexed, relaxed and ready to strike
3. Strike pleximeter finger w/ R middle finger
4. Withdraw striking finger
Done on posterior thorax
74
What are the 3 types of normal breath sounds?
1. Vesicular:
* Soft intensity, low pitch
* Gentle sighing sounds - air moving through smaller a/w
* Best heard on inspiration - longer than exp phase
* Best heard at base of lungs
2. Bronchovesicular:
* Moderate intensity, mod pitched "blowing" sounds - air moving thru lg a/w
* Equal inspir & expir phases
* 1st and 2nd intercostal spaces b/t scapula and lateral to sternum
3. Bronchial (tubular):
* High-pitched, loud "harsh" sounds - air moving through trachea
* Short inspir, long expir phase
* Best heard over trachea
75
What are the 4 types of adventitious breath sounds?
1. Crackles (rales):
* Fine, short, interrupted crackling sounds, alveolar = high pitched
* Caused by air moving thru mucus or fluid
* Heard at bases of lower lung lobes
* Not altered by coughing
2. Gurgles (rhonchi)
* Continuous, low pitched, coarse, harsh
* Best heard on expir.
* Can be altered by coughing
* Air passing thru narrowed passages - result of swelling, tumors, etc.
* Best heard over trachea and bronchi
3. Friction Rub:
* Superficial grating or creaking sounds
* Heard during inspir. and expir.
* Rubbing together of inflammed pleural sfcs
* Heard most often in areas of greatest thoracic expansion
4. Wheezing:
* Continuous, high pitched squeaky musical sounds
* Best heard on expir.
* Air passing thru narrowed passages - result of swelling, tumors, etc.
* Heard over all lung fields
76
Whispered Pectoriloquy
Pt whispers a sequence of words. Listen w/ a stethoscope. Normally, only faint sounds heard. However, over areas of tissue abnormality, the whispered sounds will be clear and distinct
77
Bronchophony
Pt says '99' in a normal voice. Listen to chest w/ a stethoscope. The expected finding is that the words will be indistinct. Bronchophony is present if sounds can be heard clearly
78
Egophony
While listening to chest w/ a stethoscope, ask patient to say the vowel 'e'. Normal lung tissue = same 'e' will be heard. If lung tissue is consolidated, 'e' sound will change to a nasal 'a'
79
Tidal Volume
500mL
Amount of air inspired during normal, relaxed breathing
80
Inspiratory Reserve Volume (IRV)
3,100mL
Additional air that can be forcibly inhaled after the inspiration of a normal tidal volume
81
Expiratory Reserve Volume (ERV)
1,200 mL
Additional air that can be forcibly exhaled after the expiration of a normal tidal volume
82
Residual Volume
1,200 mL
Volume of air still remaining in lungs after ERV is exhaled
83
Total Lung Capacity (TLC)
6,000 mL
Max amt. of air that can fill the lungs (TLC = TV + IRV + ERV + RV)
84
Vital Capacity (VC)
4,800 mL
Total amt of air that can be expired after fully inhaling
(VC = TV + IRV + ERV = approx. 80% TLC)
Value varies according to age and body size
85
Inspiratory Capacity (IC)
3,600 mL
Max amt. of air that can be inspired
(IC = TV + IRV)
86
Functional Residual Capacity (FRC)
2,400 mL
Amt. of air remaining in lungs after a normal expiration
FRC = RV + ERV
87
Forced Expiratory Volume (FEV1)
Volume of gas exhaled in one second by a forced expiration from full inspiration
88
Vital Capacity / Forced Vital Capacity
Vital Capacity: total volume of gas exhaled from slow, complete expiration after a maximal inspiration
Forced Vital Capacity (FVC): Vital Capacity measured w/ a forced expiration
89
Normal FEV1 / FVC Ratio
80%
The % of forced vital capacity exhaled in the first second
90
Obstructive vs. Restrictive Lung Disease
Obstructive Lung Disease (COPD, Asthma)
* Difficulty exhalig all the air from the lungs
* Exhaled air comes out more slowly (b/c of damage or narrowing)
* At end of a full exhalation, an abnormally high amt of air may still linger in the lungs
* FEV1 reduced
* **FEV1/FVC \< 70% (reduced)**
Restrictive Lung Disease (Pulmonary Fibrosis, Sarcoidosis)
* Results from a condition causing stiffness in the lungs themselves
* FEV1 & FVC are equally reduced
* **FEV1/FVC ratio normal or \>80%**
91
What is a flow volume loop?
Begins on x-axis (volume axis): at thestart of thetest both flow and volume are equal to zero. After the starting point, the curve rapidly mounts to a peak: Peak Expiratory Flow
After the PEF the curve descends (the flow diminshes) as more air is expired. A normal, non-pathological F/V loop will descend in a straight or convex line from top (PEF) to bottom (FVC)
The forced inspiration that follows the forced expiration has roughly the same morphology, but the PIF (Peak Inspiratory Flow) is not as distinct as PEF
92
Chronic Obstructive Disease and Restrictive Disease Flow Volume Loops
Chronic obstructive disease loop has more volume than normal
Restrictive disease loop has less volume b/c of compliance
93
Arterial Blood Gas (ABG)
* Measures the acidity (pH), the partial pressure of oxygen (pO2) and carbon dioxide (pCO2) in arterial blood and bicarbonate level HCO3. Can also measure various electrolytes.
* PaO2: indicates that the patient is not oxygenating properly and is hypoxemic
* PaO2 \< 60 --\> need supplemental O2
* PaO2 \< 26 --\> risk of death
* PaCO2: indicator of CO2 production and elimination. High PaCO2 indicates underventilation, low PaCO2 = hyper or overventilation
* HCO3- indicates whether a metabolic problem is present. Low = metabolic acidosis, high = metabolic alkalosis
* O2 content = amt. of oxygen in blood
* O2 sat = how much Hgb in RBC is carrying O2
* This test is used to determine gas exchange (which reflects the gas exchange at the alveolar-capillary membrane)
* An ABG test uses blood drawn from an artery (usually radial a.)
94
What are normal ABG ranges for:
pH
pCO2
pO2
HCO3
O2 Sat
pH: 7.35 - 7.45
## Footnote
pCO2: 35-45
pO2: 80-100
HCO3: 22-26
O2 Sat: 95-100%
95
Rigid Bronchoscopy
* General Anesthesia
* Straight, hollow metal tube
* Used in massive bleeding, etraction of large obstructing objects, biopsy of tracheal or main stem bronchus tumors and bronchial carcinoids, facilitation of laser therapy
96
Ventilation-Perfusion Scan
| (VQ Scan)
* Type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood w/in a patient's lungs in order to determine the ventilation/perfusion ratio
* The **ventilation** part of the test looks at the ability of air to reach all parts of the lungs
* The **perfusion** part evaluates how well blood circulates w/in the lungs
* Commonly done in order to check for the presence of a blood clot or abnormal blood flow inside the lungs (such as a pulmonary embolism - PE)
97
Heaviest organ of the body
Skin
16% of body weight
98
Functions of the skin
* Homeostasis
* Provides boundaries forbody fluids, protecting underlying tissues from microorganisms, harmful substances and radiation
* Modulates body temp and synthesizes vitamin D
