Heart Failure, Diagnosis
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History & Clinical Signs
-Cough
-Dyspnea
-Tachypnea
-Orthopnea
-Exercise Intolerance
-Syncope
-Lethargy
-Ascites
-Peripheral Edema
-Weight Loss
-Capillary Refill Time: under 3 seconds is normal; over 3 seconds is abnormal
-Mucous Membrane Color:
Pallor=pale skin/mucus membrane; suggests poor peripheral circulation due to vasoconstriction, decreased hemoglobin in the blood (anemia), or shock
Cyanosis=blue skin/mucus membrane discoloration; Suggests adequate hemoglobin, but inadequate oxygenation; Seen with Pleural effusion/pulmonary edema, right to left shunt within the circulation causing deoxygenated blood to mix with oxygenated blood
- Signs of heart failure are directly related to which side is affected.
- The above signs are characteristic of cardiac problems, but can also be the signs of other diseases involving different body systems.
- A good physical exam including signalment, history, observation, palpation, percussion, and auscultation are necessary to identify true cardiac problems.
Physical Exam
1. Observation
-Clinical signs: (listed above)
2. Palpation
-Precordium:(Left side of the chest behind the elbow where heart contractions are easily palpated and auscultated)
Heart Rate, Rhythm, Character
Apex Beat
Palpable Thrill
-Pulse: (Rate, Rhythm, Character)
Dog: Femoral Pulse; Palpate heart
Horse: External Maxillary/Facial Artery; Transverse Facial Artery; Median Artery; Digital Artery; Metatarsal Artery
Cattle: External Maxillary/Facial Artery; Middle Coccygeal Artery; Median Artery
Pulse Deficits (Seen with Arrhythmias)
Jugular Pulses and/or Jugular Venous Distension and/or Enlarged Ventral Abdominal Veins (Indicates High Venous Pressure)
-Abdomen:
Pitting Edema
Ascites
Splenomegaly
Hepatomegaly
Fluid Thrill (Fluid movement causes a palpable vibration)
3. Percussion
A method of diagnosis performed by flicking a body part with fingers and the resulting sound helps determine size, position, and density of the underlying structures.
-Thorax: Lack of resonance if the lung has solidified; Detection of fluid line
-Abdomen: Detection of fluid thrill
4. Auscultation
A method of diagnosis performed by listening to sounds inside the body. Auscultation can be performed with or without a stethoscope. Abdominal, cardiac, pulmonary, and thoracic auscultation can all be performed.
Cardiac auscultation is used to listen to heart sounds & heart murmurs.
Heart Sounds
Cardiac Auscultation Species Differences:
Dog & Cat
Normal Heart Sounds: S1 (closure of atrioventricular valves; heard best at left heart apex) & S2(closure of semilunar valves; heard best at left heart base); Lub-Dup sound
Abnormal Heart Sounds: S3 & S4 occur during diastole and should not be audible in dogs and cats. If either one is present, this is called a GALLOP RHYTHM and suggests poor ventricular filling. Du-Lub-Dup sound.
Horse
Normal Heart Sounds: S1 & S2, S3 & S4; S3 is audible in many horses and marks the end of ventricular filling.
Ox
Normal Heart Sounds: S1 & S2, S4; Healthy farm animals do not have an audible S3 as in the horse.
Heart Murmurs
-Heart Murmurs=abnormal heart sounds due to turbulent blood flow. Heart murmurs are characterized based on their timing, location, intensity, radiation, pitch, and shape.
Electrocardiography (ECG)
-Not needed in the diagnosis of heart failure
-Can be used to recognize arrhythmias or conduction problems
Radiology
-Cardiac enlargement +/-
Right-Sided Heart Failure:
-Ascites
-Hepatomegaly
-Pleural Effusion
Left-Sided Heart Failure:
-Pulmonary edema
-Pulmonary venous distension
Echocardiography
-Used to determine the cause of heart failure