Cardiology General Knowledge Flashcards
How is the HR estimated from an EKG?
Method 1:
300 / “no. of boxes between QRS intervals”
Method 2:
“no. of QRS complexes in 10 sec.” x 6
How many seconds in one small box on ECG?
0.04 sec = 40 ms (5 small boxes is 0.2 seconds = 200 ms)
The normal PR interval is
120–200 ms, which corresponds to 3–5 small boxes on an ECG.
What is the normal QRS duration?
Between 0.08 and 0.10 seconds (80 and 100 milliseconds).
What are the normal QT intervals on an EKG?
Less than 430 ms for males
Less than 440 ms for children
Less than 450 ms for females
What is the calculation for stroke volume?
EDV- ESV
What is the calculation for ejection fraction?
SV/EDV
What are the clinical signs of decompensated heart failure (DHF)?
Progressive dyspnea, hypoxemia, diffuse pulmonary crackles, and an S3 (extra, low-pitched, early diastolic sound) are consistent with decompensated heart failure (DHF).
What are the clinical signs of cardiogenic shock?
Hypotension, cool extremities, diminished pulses, and evidence of poor organ perfusion (eg, elevated serum creatinine likely due to decreased renal blood flow) suggest markedly low cardiac output and cardiogenic shock.
High PCWP and low BP likely means that a patient has … ?
cardiogenic shock
When giving positive inotropes and chronotropes, what happens to the SV, LEDV, and EF?
The increase in myocardial contractility leads to higher left ventricular stroke volume, resulting in decreased left ventricular end-systolic volume; therefore, ejection fraction is increased. The increased cardiac output (stroke volume * heart rate) improves perfusion and decreases vascular congestion, resulting in clinical improvement of severe DHF.
Left atrial pressure (LAP) =
The normal left atrial pressure (LAP), which is normally the same as pulmonary capillary wedge pressure (PCWP) typically ranges between 6–12 mmHg.
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Left heart pathology results in a PCWP that is high. When the PCWP is normal, there is nothing wrong with the left heart.
Right atrial pressure (LAP) =
2–8 mmHg
________ (right/left) heart failure will presents with pulmonary findings (i.e., dyspnea, orthopnea, paroxysmal nocturnal dyspnea)
left heart failure
This is because left-heart problems cause a backup of pressure onto the pulmonary circulation, leading to increased pulmonary capillary hydrostatic pressure, thus, transudation of fluid into the alveolar spaces (pulmonary edema). Sometimes this can also cause pleural effusion.
How does pregnancy alter a patient’s cardiac output, preload and afterload?
CO increases
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Preload increases
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Afterload decreases
What is the right sinus of Valsalva?
The right sinus of Valsalva is a dilation or enlargement of the aortic root, specifically the part of the aorta that lies between the aortic valve and the ascending aorta.
When is the RV perfused?
during systole.
When is the LV perfused?
during diastole.
What are the waveforms in normal JVP?
a-wave = atrial contraction
c-wave = bulging of tricuspid valve (carotid pressure)
x-decent = right atrial relaxation
v-wave = venous filling of right atria
y-decent = diastolic filling of right ventricle after opening of tricuspid valve
