Proper stethoscope use:

Many cardiac disorders do not fall into the “audible” range, and to have the best chance of detecting audible cardiac disturbances, proper use of the stethoscope is imperative. Consider the following:

• Double lumen, shorter tubing provides best sound reproduction
• Use a quiet room, and close the patient’s mouth to reduce panting. Whenever possible, reduce patient anxiety to promote ease of breathing.
• The diaphragm – better for high frequency sounds (most systolic murmurs, clicks, and breath sounds)
• The bell – better for low frequency sounds (diastolic murmurs, and gallop sounds). If the bell is pressed tightly to the skin, the skin will function like a diaphragm and so the utility of using a bell will be lost.
• Only auscultate a patient when in the standing or sitting position. Auscultation of the patient in lateral or dorsal recumbency can result in creating false murmur like sounds (perhaps rubbing sounds) and/or impairs our ability to localize the PMI for a “real” murmur.

Normal heart rate, respiratory rate ranges for dogs and cats

Some important clinical terminology:

• Bradycardia = slow heart rate
• Tachycardia = fast heart rate
• Tachypnea = fast respiratory rate
• Dyspnea = difficulty breathing

Physical Examination Findings Related to the Cardiovascular System:

Mucous membranes: a capillary refill time >2 seconds suggests decreased cardiac output, although this finding is usually only present in severe heart failure. Cyanosis can be due to decreased ventilation, decreased oxygen diffusion across the alveoli.

Jugular vein distension or pulsation: the jugular vein can be evaluated with the animal standing. Vein distension or pulsations are consistent with right-sided heart disease.

Hepato-jugular reflux (HJR) response: This test checks for the presence of jugular distension or jugular pulsations when pressure is placed in the region of the cranial abdomen in a ventral to dorsal direction. The animal should be standing or in sternal recumbency to perform this test. A positive testresult indicates that there is severely elevated pressure in the right atrium or right ventricle. If one were to classify an elevated pressure in the right heart as mild, moderate or severe; venous distension indicates a severe elevation in pressure, a positive HJR indicates a moderate elevation in pressure. Patients with a mild elevation in pressure to the right heart cannot be identified on physical examination.

Precordial palpation is palpation of the chest wall over the cardiac region. It is useful to:

• Detect a thrill – a thrill refers to a vibration on the chest wall due to fluid turbulence within the heart that also causes a heart murmur on auscultation. Only the very loudest heart murmurs will be accompanied by a thrill
• Detect dysrhythmias (pulse and precordial beats should match in the normal patient; when there is desynchrony this indicates an arrhythmia)

The arterial pulse may be classified as weak, normal, or strong. This can be subjective and is based on clinical experience. Pulse strength is related to blood pressure.

Physical examination findings consistent with heart disease may include:

• Slow capillary refill time (> 2 sec)
• Pale or cyanosed mucous membranes
• Dry or tacky mucous membranes
• Cool extremities or reduced rectal temperature
• Jugular venous distension or positive hepato-jugular reflux test
• Dyspnea, cough, harsh lung sounds, wheezes, or crackles on auscultation
• Thrill on precordial palpation
• Hepatomegaly and/or splenomegaly
• Abdominal effusion
• Subcutaneous edema
• Weak femoral arterial pulse
• Pulse deficits with irregular cardiac rhythm
• Muffled heart sounds, gallop rhythms, heart murmurs, or arrhythmias may be detected on cardiac auscultation