intro to cardiac Flashcards
What makes S1 sounds?
The “ lub” is the first heart sound, commonly termed S1, and is caused by turbulence caused by the closure of mitral and tricuspid valves at the start of systole
What makes s2 sounds?
The second sound,” dub” or S2, is caused by the closure of aortic and pulmonic valves, marking the end of systole.
Diastole
relaxation-ventricles fill in preparation for contraction, all 4 relax together
Systole
contraction of atria and ventricles, atria contract first then ventricles
cardiac output
amount of blood pumped by each ventricle in liters per minute 4-6 L/min
SA node rate
60-100 impulses/min
AV node
30-40 impulses/min
repolarization
resting
depolarization
contraction
stroke volume
the amount of blood ejected from one of the ventricles per heartbeat 60-130 Ml
Preload
degree of stretch of the ventricular cardiac muscle fibers at the end of diastole
Afterload
resistance to ejection of blood from the ventricle
Normal BP
120/80
When is BP considered high
> 140/90
Pulse pressure
the difference between the systolic and diastolic pressures
Normal: 30-40 mm Hg, indicates how well pt maintains cardiac output
Pulse deficit
difference apical and radial pulse rates
Thrill
A vibration where abnormal, turbulent blood flow is present. Detected with palm of hand. Associated with a loud murmur. May indicate valvular heart disease, septal defect or stenosis.
The period between S1 and S2 corresponds with ____
ventricular systole
What is hemodynamic monitoring?
The use of pressure monitoring devices to directly measure cardiovascular functioning
Where are patients requiring hemodynamic monitoring cared for?
Critical care units
MAP what is the norm
60-70 mmHg for adequate perfusion. It is an approximation of the average pressure in the systemic circulation through the cardiac cycle
What is the cvp?
The pressure in the superior vena cava. It is measured with a central venous line.
Normal CVP
2-6 mmHg
Elevated CVP indicates
increase in blood volume as a result of sodium and water retention, excessive IV fluids, alterations in fluid balance or kidney failure
What does a decreased CVP indicate
a decrease in circulating blood volume and may be a result of fluid imbalances, hemorrhage or severe vasodilation, with pooling of blood in the extremities that limits venous return
Measuring CVP-where is the transducer
At the right atrium, at the mid axillary line at the fourth intercostal space. The zero point on the transducer needs to be at the level of the right atrium.
How should the patient be positioned for CVP
Pt supine with HOB at 45 degrees and relaxed so that a false reading is not received
