Sewickley Veterinary Hospital
1104 Ohio River Blvd.
Sewickley, Pa 15143
Heart murmurs are sounds
that are produced as a result of a disturbance in blood flow. Murmurs are classified according to a variety
of characteristics, including their timing, grade, configuration, and location. Some heart murmurs
can lead to heart failure while others are not progressive. Without performing diagnostic test, we cannot
predict the progression of the disease or decipher the underlying cause of the murmur.
heart failure may include coughing, weakness, open mouth breathing, abdominal
breathing, increased respiratory effort, an enlarged distended abdomen and
Scale for Murmurs
The grade of the murmur does not necessarily equal or
indicate the severity of disease.
-Grade I-barely audible
-Grade II-soft, but easily heard with a stethoscope
-Grade III-intermediate loudness; most murmurs which are
related to the mechanics of blood circulation are at least grade III.
-Grade IV-loud murmur that radiates widely, often including
opposite side of chest
-Grade V-very loud, audible with stethoscope barely touching
the chest; the vibration is also strong enough to be felt through the animal's
-Grade VI-louder that grade V, audible with stethoscope
barely touching the chest; the vibration is also strong enough to be felt
through the animal's chest wall.
In order to
determine exactly what is causing these symptoms, the veterinarian must differentiate
between a wide range of abnormal heart sounds. They also must differentiate
between abnormal lung and heart sounds and listen to see if timing of abnormal
sound is correlated with respiration or heartbeat. The location and radiation of the murmur, as
well as the timing during cardiac cycle, is another way to determine the
underlying cause. This can be
accomplished by conducting a variety of tests.
testing can include x-rays, blood work, ECG (electrocardiogram), echocardiogram
(ultrasound of the heart), and blood pressure monitoring among other things. Unless heart failure is evident, your pet will
usually be treated on an outpatient basis. Routine exams, blood work and annual chest
x-rays are recommended in order to monitor the progression of the heart murmur
and its associated disease. The course of treatment will be determined
based on the associated clinical signs.