Med Surg Chapter 35 CV Assessment

P wave

begins with the firing of the SA node. It represents depolarization of the atria.

QRS complex

represents depolarization from the AV node throughout the ventricles. A delay of impulse transmission through the AV node accounts for the time between the beginning of the P wave and the beginning of the QRS wave.

T wave

represents repolarization of the ventricles.

Intervals between these waves (PR, QRS, and QT intervals) reflect the time

it takes for the signal to travel from 1 area of the heart to another. Changes in the timing often indicates a pathologic condition.          

The SNS plays a central role in BP regulation. Specialized Nerve Cells

called

baroreceptors to detect BP changes

When BP increases, baroreceptors send

impulses to the sympathetic

vasomotor center -> decreased heart rate.

When BP Decreases, The SNS is activated,

causing peripheral arteriole

constriction -> increased HR.

o Parasympathetic Nervous System in BP

▪ Helps reduce BP by decreasing heart rate via the vagus nerve, which

decreases cardiac output

Renal System in BP

▪ RAAS is essential for BP control. When kidneys detect decreased blood

flow, SNS stimulation, or low serum sodium, they secrete renin -> triggers

a cascade converting angiotensinogen to angiotensin I, then angiotensin II.

• These increase BP by causing Immediate Vasoconstriction, and

Indirect stimulation of aldosterone

S1 (First Heart Sound)

which represents closure of the tricuspid and mitral valves.

S2 (Second Heart Sound)

represents closure of the aortic and pulmonic valves.

These two together make a perfect “Lub Dup.” These are considered Normal.

S3 (Third Heart Sound) is a

low intensity vibration of the ventricular walls from decreased ventricular compliance during filling. It occurs closely after S2 Often called a “ventricular gallop”

-Normal: May be present in young adults.

-Abnormal: Indicates left sided heart failure, or mitral valve regurgitation.

S4 (Fourth Heart Sound) is

a low frequency vibration caused by atrial contraction. It precedes S1 and is called an “atrial gallop.”

Not normal usually, can be associated with a stiff ventricle

CV physical assessment:

Vital signs, inspect the skin for edema, color, temperature, palpate upper and lower extremities, auscultate, skin moisture (dry, diaphoretic)

Blood flow through the heart:

Vena cava → Right atrium → Tricuspid → Right ventricle → Pulmonary valve → Pulmonary arteries (deoxygenated blood) → Lungs → Pulmonary veins (oxygenated blood) → Left atrium → Mitral → Left ventricle → Aortic valve → Aorta → Body

Low sodium diet patient education:

Healthy adults should restrict sodium intake to 2,300 mg/day or less.

o Common High Sodium Foods, “Salty Six”: AVOID

▪ Bread

▪ Lunch Meat

▪ Pizza

▪ Soup

▪ Sandwiches

o Teach patients to carefully read labels on OTC medications and foods and understand what they mean

o Teach that sodium restriction may be enough to control blood pressure or allow

for lower medication doses.

How to stimulate the vagus nerve?

Bearing down or holding breath

Vagal Maneuvers can be used therapeutically to slow the heart rate in certain

dysrhythmias, particularly SVT.

Echocardiogram

An echocardiogram uses ultrasound waves to record the movement of heart

structures. It provides information about:

The ejection function EF, which is the percentage of blood ejected from the left ventricle during systole. Normal EF is 55-65%

PMI assessment

Point of Maximal Impulse, AKA The Apical Pulse, and represents the pulsation of

the apex of the heart.

We are actually feeling ventricular contraction

PMI or apical pulse is located:

5th intercostal space left midclavicular line

Where is the blood flow altered when a patient has a tricuspid valve problem?

right atrium and right ventricle

A patient has a severe blockage in the right coronary artery. Which heart structures would the nurse expect to be affected by this blockage?

atrioventricular (AV) node

left ventricle
right ventricle

Which part of the vascular system prevents hemostatis?

endothelial layer of arteries

Which homeostatic mechanism is stimulated to compensate for a rise in blood pressure?

baroreceptors that inhibit the sympathetic nervous system, causing vasodilation

Which action does the P wave on the ECG represent?

firing of the SA node and depolarizing the atria

Which subjective data related to the cardiovascular system would the nurse plan to obtain?

Smoking history
Spiritual preference
Number of pillows used to sleep.

Which heart valve is heard best at the left midclavicular line at the level of the 5th ICS?

Mitral

Which condition is likely to cause a pulse deficit of 23 beats?

dysrhythmias

Which finding is expected in the assessment of an 81-year-old patient?

difficulty isolating apical pulse

Which item would the nurse zero to establish accurate hemodynamic monitoring for a patient?

pressure monitoring system to phlebostatic axis

Which nursing responsibilities are priorities when caring for a patient returning from cardiac catheterization?

a. monitor vitals and EKG
b. check catheter insertion site and distal pulses