Cardio 3 Flashcards
Electrocardiogram: P wave
Atrial depolarization
Electrocardiogram: PR interval
Onset of atrial activation to ventricular activation
Electrocardiogram: QRS
- Ventricular depolarization
- Atrial repolarization
Electrocardiogram: ST interval
Ventricular depolarization
Electrocardiogram: QT interval
Time between ventricles contracting and refilling
Electrocardiogram: T
Ventricular repolarization
What is cardiac output?
amt of blood flowing through the systemic or pulmonary circuit per minute
Normal cardiac output at rest
5 L/min
Ejection fraction =
- Amt of blood ejected in a beat
- can be estimated with echocardiography
Stroke volume
Volume of blood ejected during systole
EF = (equation)
Stroke volume / end-diastolic volume
Normal EF =
50-75%
Decreased EF is a sign of
Ventricular failure
Decreased EF: below normal
36-49%
Decreased EF: severe ventricular failure
Under 35%
What will you see with pts with severe ventricular failure (low EF)
- fatigue with ADLs
- going into CHF
Preload =
Volume and pressure in ventricle at end of diastole
What is preload called?
Left ventricular end-diastolic volume
Laplace law
- length/tension relationship
- preload affects size of ventricle and ability to produce a forceful contraction
Frank Starling law of the heart
- myocardial stretch determines the force of myocardial contraction
- greater stress = stronger contraction
Afterload =
Resistance to ejection of blood from the ventricle
What is afterload determined by?
System vascular resistance in
- aorta
- arteries
- arterioles
Changes in preload, afterload, and contractility all interact to determine
- stroke volume
- cardiac output
CVD: How many Americans?
1 in 3
CVD: Half of all deaths from heart disease are
- sudden
- unexpected
CVD: Risk factors
- advancing age
- HTN
- obesity/sedentary lifestyle
- excessive ETOH consumption
- oral BC use over 35, with smoking
- abn cholesterol levels
- race
CVD: s/s
- chest, neck, arm pain/discomfort
- palpitations
- dyspnesa
- syncope (Fainting)
- cough
- diaphoresis
- cyanosis
- edema and leg pain (claudication) point to vascular complications
CVD: chest pain
Referral
May radiate to
- neck
- jaw
- upper tarp
- upper back
- shoulder
- UE (L most common)
CVD: chest pain
Pathologies include
Both acute and non-acute cardiac conditions
CVD: chest pain
Often associated with (s/s)
- nausea
- vomiting
- diaphoresis
- dyspnea
- syncope
CVD: palpitations
Irregular heartbeat (arrhythmia, dysrhytmia)
CVD: palpitations
Irregular heartbeat causes
- benign (caffeine, anxiety)
- serious but non-emergent (mitral valve prolapse)
- serious and urgent or emergent (aneurysm, heart block)
CVD: palpitations
Sensation
“Fluttering”
CVD: palpitations
When might these be within normal heart fxn?
- under 6 per minute OR
- lasting less than 2 mins
CVD: palpitations
More serious complications
- pain
- dyspnea
- fainting
- lightheadedness
CVD: palpitations
What may these be symptomatic of in addition to cardiac?
- thyroid dysfunction
- medication issue
CVD: dyspnea
This may indicate extent of CVD
Severity of dyspnea
DOE =
Dyspnea on exertion
What may DOE indicate?
- LV dysfunction
- pulmonary congestion
PND =
Paroxysmal nocturnal dyspnea
CVD: dyspnea
Where is PND often seen? What happens?
- frequently seen in CHF
- person awakes because of fluid overload in recumbant position
Orthopnea =
- breathlessness in recumbent position
- relieved by sitting upright
- # of pillows needed to relieve condition is a measure of severity of fluid overload
CVD: dyspnea
What would necessitate referral to PCP?
Inability to climb a flight of stairs without mod-severe SOB
