Unit 4 Clinical Evaluations of the Heart

What is congestive heart failure?

A clinical syndrome that can result from heart disease in all four categories, characterized by fluid accumulation due to a failing heart.

Define heart failure.

A clinical syndrome where the heart fails to pump an adequate volume of blood to meet tissue oxygen demands and prevent fluid accumulation.

What is forward failure in heart failure?

A condition where the ventricles struggle to pump blood forward, leading to low output and clinical signs such as fainting, pallor, cyanosis, hypokinetic pulse, and azotemia.

What is backward failure?

Also known as congestive heart failure, it occurs when blood backs up in the heart, leading to pulmonary edema (left-sided) or cavitary effusions and liver enlargement (right-sided).

What are the manifestations of left-sided backward failure?

Pulmonary edema.

What are the manifestations of right-sided backward failure?

Cavitary effusions (pleural, peritoneal, pericardial), liver enlargement (hepatomegaly), and right heart enlargement.

What causes fluid accumulation in backward failure?

Blood backs up into the venous system, leading to increased filtration and decreased reabsorption, causing fluid to leak through capillaries.

What is progressive left ventricular dilation?

A condition characterized by systolic dysfunction, (where there is less outflow from the ventricle and progressive dilation of the left heart), sodium and water retention by RAAS in the kidneys, and vasoconstriction by RAAS.

How does the RAAS system contribute to heart failure?

It causes sodium and water retention in the kidneys, increasing blood volume (inflow) to the ventricle and increasing preload.

What is the effect of RAAS-induced vasoconstriction in heart failure?

Arterial vasoconstriction increases afterload (resistance to outflow), while venous vasoconstriction increases preload (venous return to the ventricle).

What is the significance of a cardiovascular exam?

It is a key part of the physical exam, as cardiovascular abnormalities can indicate systemic disease or isolated heart disease.

What general features can be observed in heart disease during a visual assessment?

Cachexia, abdominal distension, mucous membranes, and peripheral edema.

Venous assessment

Visual assessment of the jugular vein in standing patients

What does jugular pulsation indicate in standing patients?

It appears as a wave-like motion in the jugular vein; abnormal in small animals and normal in the lower 1/3 of the neck in large animals.

Where is jugular pulsation abnormal in large animals?

Higher than 1/3 up the neck

What is jugular distension?

It occurs when the jugular vein remains full of blood, indicating potential cardiovascular issues.

What are some causes of jugular pulsation and distension?

Right heart pressure/volume overload, obstruction by mass or thrombus, and pericardial effusion.

What three features are evaluated during arterial assessment?

Strength, symmetry, and timing of the pulse.

What does a hypokinetic pulse indicate?

A narrow pulse pressure, weak, thready pulse caused by decreased stroke volume due to conditions like subaortic stenosis or hypovolemia.

What does a hyperkinetic pulse indicate?

A wide pulse pressure, bounding pulse caused by increased stroke volume due to conditions like PDA or severe aortic regurgitation, bradycardia, decreased vascular resistance, high sympathetic tone.

What is a synchronous pulse?

A pulse that is felt almost immediately after a heartbeat is heard.

What is a delayed pulse?

A pulse that is felt later than expected after hearing a heartbeat.

What is a pulse deficit?

When a heartbeat is heard but no pulse is felt.

Symmetry

Refers to whether the right and left arterial pulses are the same strength

How is symmetry assessed in arterial pulses?

By palpating the right and left arterial pulses simultaneously to compare strength.

Where is the femoral artery palpated in small animal patients?

In the femoral triangle.

Where should arterial pulses be felt in large animal patients?

facial artery on the medial aspect of the ramus of the mandible is the safe location

What is the function of a flexible (tunable) diaphragm on a stethoscope?

It behaves as a bell with gentle pressure and as a diaphragm with firm pressure.

What is the best use of the bell on a stethoscope?

To listen to low-frequency sounds such as heart sounds and gallops.

Gentle pressure

What is the best use of the diaphragm on a stethoscope?

To listen to high-frequency sounds such as murmurs.

Firm pressure

Precordium

palpation of the chest wall

Heart beat palpated on the left side of the chest near the elbow (L apex)

What is a precordial thrill?

The ability to feel the vibrations of a murmur during palpation of the chest wall.

Where is S1 best heard?

At the left apex of the heart.

Where is S2 best heard?

At the left base of the heart.

Where is S3 and S4 best heard?

At left apex.

What does the Point of Maximal Intensity (PMI) refer to?

The location on the chest where a heart murmur is loudest.

Left vs right & apex vs base

Grade

Loudness of the murmur.

Scale of I (softness) to VI (loudest).

What are the timing classifications of heart murmurs?

Murmurs can be systolic, diastolic, or continuous.

When is a murmur heard in relation to aortic stenosis?

During systole when the aortic valve is open.

When is a murmur heard in relation to mitral regurgitation?

During systole when the mitral valve opens.

When is a murmur heard in relation to aortic regurgitation?

During systole when the aortic valve is open.

What is a continuous murmur associated with?

Patent ductus arteriosus (PDA).