Chapter 12: Determinants and Assessment of Cardiac Function

Noninvasive procedures that evaluate cardiac function include?

-Exercise Electrocardiogram -Echocardiogram (transthoracic)

During the physical assessment of cardiac function (inspection) the nurse should access?

-Peripheral assessment -Urine output -Edema

What are the nursing implications for a Transesophageal Echocardiogram (TEE)?

-Prior to the procedure, the nurse reviews the patient's chart, obtains a detailed history, and inserts a peripheral intravenous catheter. -Suction equipment should be available in case the patient vomits. -During the procedure, the nurse administers sedation, monitors vital signs and pulse oximetry saturations every 3 to 5 minutes, adjusts fluid and oxygen, and documents the patient's condition. -During and immediately after the procedure, the nurse monitors for complications, which include respiratory depression and aspiration.

Which conditions, if present in the patient, can result in decreased afterload?

-Septic shock -Depressed sympathetic NS -Vasodilating drugs

Venous pressure is influenced by which four factors?

-Systemic filling pressure -Venous muscle pump -Venous Peripheral Resistance -Right Atrial Pressure

What are the three major regulatory systems of arterial blood pressure?

-The renin-angiotensin-aldosterone system (RAAS) -The kidneys -The autonomic nervous system (ANS)

Invasive procedures that evaluate cardiac function include?

-Transesophageal Echocardiogram (TEE) -Cardiac Catheterization -Electrophysiology (EPS)

What are the four determinants of cardiac output?

1. Heart Rate (HR) 2. Preload 3. Afterload 4. Contractility

____________ is the resistance against which the ventricles pump blood.

Afterload

__________ is a function of peripheral resistance (PR) and cardiac output (CO)

Arterial pressure

After a cardiac catheterization, the nurse must monitor for which primary complication? A. Bleeding B. Paresthesia C. Increased urine output D. Pain at the site of vascular access

Bleeding

__________ is the amount of pressure exerted against blood vessel walls by circulating blood as it is pumped throughout the body.

Blood pressure

__________ is a cardiac-specific myocardial isoenzyme that is released 4 to 12 hours after the onset of myocardial necrosis and is very specific for myocardial damage.

CK-MB

What is the most accurate method used to determine cardiac output?

Cardiac Index (CI) = CO / BSA

_________________ determine presence and extent of coronary artery disease

Cardiac catheterization

____________ is the heart's ability to function as a pump.

Contractility

A patient has developed a heart rate of 150 bpm. This would have which effect on cardiac output?

Decrease

__________ afterload - warm flushed extremities

Decreased

What are examples of clinical conditions related to decreased preload?

Decreased blood volume -> Hemorrhage Dehydration Venous vasodilation (blood pools peripherally; decreased blood returns to right heart) Third spacing

If the venous valves are not working correctly (for example, in a person who has varicose veins, is paralyzed, or is not active), blood pools in the extremities rather than moving forward to the heart. This can lead to what condition?

Deep Vein Thrombosis (DVT)

Give clinical manifestations of too much preload to the right side of the heart..

Edema and Jugular Venous Distension (JVD)

________________ evaluates cardiac conduction system and classify cardiac arrhythmias

Electrophysiology Study (EPS)

_____________, commonly known as a "stress test," evaluates heart muscle and its blood supply during physical stress (exercise). If for some reason the patient cannot tolerate exercise, stress to the heart muscle is simulated with the administration of dobutamine, a positive inotropic drug.

Exercise ECG

What happens to the cardiac output, if SV is held constant (remains the same) and heart rate increases? decreases?

HR increases = CO increases HR decreases = CO decreases Rationale: If SV is held constant (remains the same), any change in HR results in an immediate change in CO.

How is the term cardiac cycle best defined?

Heart muscle activities during one complete heartbeat

Cardiac Output (CO) = ___ X ___

Heart rate (HR) multiplied by stroke volume (SV)

A patient with a normal heart has developed increased preload. This will result in which hemodynamic change?

Increase in stroke volume

__________ afterload - cool, clammy extremities

Increased Rationale: A cooling of the skin is brought about by the vasoconstriction of the arterioles as blood is shunted to the internal organs.

What are examples of clinical conditions related to increased preload?

Increased blood volume -> Heart or kidney failure Volume overload Excess dietary sodium

If HR decreases, SV _________ to compensate and maintain CO.

Increases

If SV falls, HR _________ to compensate and maintain CO.

Increases

In a patient with normal heart function, if blood pressure decreases and flow remains unchanged, peripheral resistance will change in which way to increase the blood pressure?

It will increase

What are the nursing implications for cardiac catheterization?

Pre procedure - check for allergies to iodine or seafood, get informed consent Procedure - most common route - femoral artery, monitor access site and distal pulses Post procedure - monitor for complications of: peripheral artery thrombosis or embolism, stroke, dye allergy, acute myocardial infarction, peritoneal bleeding

____________ is the amount of stretch in the myocardial fibers at the end of diastole and represents the volume of blood in the ventricle at the end of diastole.

Preload

A patient has severe tachycardia. How would this affect their stroke volume and cardiac output?

Severe tachycardia will decrease stroke volume and cardiac output

A patient has a blood pressure of 90/50 and a PAWP of 12 mm Hg. What is the CPP, and is it normal?

The CPP is 38 mm Hg, an inadequate CPP. Rationale: The coronary perfusion pressure (CPP) is derived by subtracting the pulmonary artery wedge pressure (PAWP) from the diastolic blood pressure (DBP). CPP should be maintained above 50 mm Hg to provide adequate blood flow to the myocardium.

What is a disadvantage to CK-MB levels?

The major limitation of CK-MB is that levels do not start to rise until 4 hours after the onset of myocardial damage. This can delay diagnosis and treatment of myocardial infarction.

The nurse preparing a patient for cardiac catheterization must notify the cardiologist with which information? A. The diabetic patient's fasting blood glucose is 244 mg/dL. B. The patient reports an allergy to shellfish. C. The patient's warfarin has been held for 5 days. D. The patient complains of nervousness.

The patient reports an allergy to shellfish.

___________ can appear in the blood as early as 1 to 3 hours after symptom onset and is a sensitive indicator of early myocardial infarction regardless of when chest pain began.

Troponin

What are examples of clinical conditions related to decreased afterload?

Vasodilation, Drugs that vasodilate (e.g., nitroglycerine), Septic shock, anaphylactic shock, or spinal cord injury

What are examples of clinical conditions related to increased afterload?

aortic or pulmonic stenosis, vasoconstriction, Drugs that vasoconstrict (epinephrine, norepinephrine)

A diminished level of consciousness, confusion, or agitation may be signs of decreased perfusion to _________.

cerebral tissue

Peripheral assessment: What are late signs of hemodynamic compromise?

changes in skin color and clubbing of the fingers

Palpation of radial pulse, S2 split, and pulse pressure (30-40 mm Hg) access ___________.

contractility

If afterload increases - stroke volume __________, CO __________, BP __________

decreases; decreases; increases

B-type natriuretic peptide (BNP) is a neurohormone released from the ventricular myocardium in response to ?

heart failure

If afterload decreases - stroke volume __________ , CO __________, SBP __________

increases; increases; decreases

The nurse must obtain (witness) ____________ before any invasive procedure.

informed consent

Rolling the patient onto the _____ side moves the heart closer to the surface of the body.

left

The mnemonic PQRST is helpful in organizing assessment data related to __________. Eliciting information about _________ (P),_________ (Q), _________ and _________ (R), _________ (S), and _________ (T) helps the nurse determine the origin.

pain; precipitating factors, quality, radiation and region, associated symptoms, timing and treatment strategies

A patient with a perfusion disorder may complain of __________, often described as a "skipping" or "thumping" of he heart.

palpitations

The cardiopulmonary vascular system consists of two interdependent major circuits, the __________ and __________ circuits.

pulmonary and systemic

Precordial palpation may produce a vibration, also known as a ________. This may correspond to a murmur, valvular stenosis, or increased afterload.

thrill

What are the two forms of echochocardiogram?

transthoracic echocardiogram and transesophageal echocardiogram