hello.may it help u

1. Physical examination of cardio vascular system and different
technique use to diagnose the cardiovascular diseases
Submitted by Dr Abhishek Hota
1st yrVEPM
ADM NO-05VEPM/14
SUBMITTED TO
Dr R. C. patra
H.O.D. OF Dept ofclinical
medicine ethics and jurisprudence
DEPARTMENT OF CLINICAL MEDICINE ETHICS AND JURISPRUDENCE
COLLEGE OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY
ORRISHA UNIVERSITY OF AGRICULTURE AND TECHNOLOGY

2. 1
Physical examination of cardio-vascular system and different techniques used in
cardio-vascular disease diagnosis
A complete and thorough physical examination is critical to every veterinary patient. In
patients that present with a history or clinical signs indicative of cardiovascular disease, the
physical examination is an irreplaceable tool in the diagnostic process.
There are four way to examine
1. Inspection ,2. Palpation 3. Auscultation 4. Percussion
1.Inspection……
Observe your patient, when it is relaxed and breathing normally if possible. Note any
coughing, muscle wasting, or abdominal distention. Record the rate, depth, and effort of
respiration. The normal respiratory rate in small animals is ~ 18 - 30 breaths/minute.
1. Tachypnea = increased respiratory rate
2. Dyspnea = distressed and labored breathing
Inspiratory dyspnea is characterized by a prolonged, labored inspiratory effort, and a
quicker, easier expiratory phase. Inspiratory dyspnea usually indicates an upper airway
disorder.
.
Expiratory dyspnea is characterized by a prolonged, labored expiratory effort and
indicates an intra thoracic airway disorder (e.g., chronic bronchitis, pulmonary edema due to
congestive heart failure, etc.) and/or a restrictive disorder (e.g., pleural effusion). Intra thoracic
disease will frequently cause both inspiratory and expiratory dyspnea.
Orthopnea is a term applied to respiratory distress that is exacerbated by recumbency.
Animals showing orthopnea assume a standing or sitting position with elbows abducted and
neck extended. Movement of the abdominal muscles that assist ventilation is often
exaggerated. Such animals vigorously resist being placed in lateral recumbency.
Examine oral, and ocular (+/- genital) mucous membranes.
Mucous membranes allow you to assess hydration, cardiac output, and oxygenation. Normal
mucous membranes are pink and moist, with a capillary refill time of < 2 seconds. Pale mucous
membranes may indicate decreased cardiac output, anemia, or peripheral vasoconstriction.
Peripheral vasoconstriction occurs with hypothermia and shock. Cyanotic mucous membranes
(blue-colored) indicate an increase in the concentration of deoxygenated hemoglobin. Cyanosis
is seen with right-to-left shunting defects (such as tetralogy of Fallot), severe respiratory
disease secondary to any disorder impairing oxygenation, or marked hypothermia.
“Differential” cyanosis describes patients whose oral mucous membranes are normal colored,
but genital mucous membranes are cyanotic. This is a unique finding characteristic of a right-to-
left shunting patent ductus arteriosus. Differential cyanosis occurs because the ductus
arteriosus is “downstream” of the blood vessels which supply the head.
Examine the jugular veins.
It is often necessary to clip the area over the jugular veins to visualize jugular pulsations or
jugular distention, although persistent jugular distention can frequently be palpated. Persistent

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jugular distention is an important indicator of right heart failure. It is commonly seen with
pericardial effusion, but also occurs with other causes of
right-sided congestive heart failure (e.g., dilated cardiomyopathy). A jugular pulse that extends
more than about one third of the way up the neck usually indicates tricuspid regurgitation.
2.Palpation……
Thoracic palpation of the precordial impulse allows you to assess the strength and location of
the apex beat. The apex beat is the point on the chest where you feel the heart beating the
strongest against your hand. (The apex beat is sometimes incorrectly
called the point of maximal intensity (PMI). The term PMI is used to describe the location of a
murmur ).
The left ventricular apex is the largest part of the heart and therefore the apex beat is
normally found at or just below the costo-chondral junction in the left fifth intercostal space. A
caudally displaced apex beat may indicate cardiomegaly, or a cranial mediastinal mass causing
caudal displacement of the heart. A right-sided apex beat may indicate right-sided
cardiomegaly, or a mass displacing the heart to the right. A hypokinetic apex beat suggests
decreased contractility, or may be the result of obesity or pericardial effusion diminishing the
precordial impulse. During palpation, note any vibration felt over the heart. This is called a
thrill, and it is associated with turbulent blood flow in the heart. A thrill on palpation may be
the first indication that a murmur is present.
3.Auscultation ………
Ideally, the animal should be standing during auscultation to maintain the normal anatomic
position of the various valve areas of auscultation. All valve areas MUST be ausculted. Begin
your cardiac auscultation at the apex beat. The apex beat is a convenient “landmark” for the
mitral valve area of auscultation in normal animals. The aortic valve area of auscultation is
located one intercostal space further cranially (i.e., left fourth intercostal space) just above the
costochondral junction. The pulmonic valve area of auscultation is usually located one
intercostal space further cranially (i.e., left third intercostal space) just above the sternum. The
tricuspid valve area of auscultation is located on the right side at about the level of the
costochondral junction between the third to fifth intercostal spaces. This is usually just across
from the apex beat on
the left. One should also auscult the left side of the chest high in the axilla (about the second
intercostal space). This is the location that the continuous murmur of a patent ductus arteriosus
is heard best.
Begin auscultation by identifying the heart sounds.
The first heart sound (S1) is produced by vibrations of the heart at the beginning of
contraction, and is associated with closure of the AV valves. S1 is loudest over the mitral valve
area, and is louder, longer, and lower pitched than the second heart sound (S2). S2 is produced
by vibrations of the heart at the end of systole and is associated with closure of the pulmonic
and aortic valves. S2 is heard loudest by moving the stethoscope cranially to the left heart base.
S2 is shorter and higher pitched than S1. In dogs and cats (in contrast to horses and cows), it is

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always abnormal to hear the third and fourth heart sounds (S3 and S4). S3 is associated with
rapid ventricular filling after the mitral valve opens in early diastole. S4 is associated with atrial
contraction topping off the ventricle in late diastole. The presence of S3 or S4 is recognized
when a gallop rhythm is heard during auscultation. While it is relatively easy to recognize a
gallop rhythm , it is usually extremely difficult to know exactly which additional heart sound you
are hearing (i.e. S3 or S4).
To identify the precise nature of the gallop, phonocardiography is generally required. However,
from a practical perspective, this distinction is of academic importance only. you have a gallop
rhythm in a small animal, you have cardiac pathology which needs to be pursued. Muffled heart
sounds may indicate the presence of pericardial or pleural effusion. It can also occur in animals
that are overweight, or have intrathoracic masses.
Determine the heart rate.
Normal heart rate for the dog ranges from 70 beats/min in larger dogs to as high as 220
beats/min in puppies. Normal heart rates for cats and kittens range from 140 - 240 beats/min.
A slower than normal heart rate is termed a bradycardia, and a faster than normal rate is
termed a tachycardia. Abnormalities in heart rate or rhythm must be identified and
characterized. There are two normal rhythm variations in the dog. Normal sinus rhythm has
regular beat with a normal rate. A normal sinus arrhythmia has a normal to slow heart rate, and
is characterized by cyclic increase and decrease in heart rate. This is sometimes specifically
associated with respiration, and results in an increase in heart rate during inspiration and a
decrease in heart rate with expiration. Respiratory sinus arrhythmia is common in dogs, but
very uncommon in the cat. Sinus arrhythmias are associated with increased vagal tone, and are
usually a sign of a health heart. However, a very exaggerated sinus arrhythmia can occur
secondary to other disease processes, the most common of these being chronic gastrointestinal
disease, chronic pulmonary disease, increased intracranial pressure, and increased intraocular
pressure. Common rate and rhythm abnormalities include the following:
 Beats that occur prematurely, and that are associated with pulse deficits. These are
termed extra systoles (e.g., atrial and ventricular premature complexes).
 Bursts or runs of extrasystoles are termed paroxysmal tachyarrhythmias (e.g., with
paroxysmal atrial and ventricular tachycardia).
 A remarkably irregular tachyarrhythmia is termed a chaotic tachyarrhythmia (e.g., as
occurs with atrial fibrillation).
 A persistent regular tachycardia (e.g., with a continuous supraventricular or ventricular
tachycardia) or a persistent regular bradycardia (e.g., with complete AV block).
Any abnormality in heart rate and/or rhythm that is detected during auscultation is a clear,
unambiguous indication to perform electrocardiography to determine the precise nature of the
rate and/or rhythm abnormality.
The canine heart projects into both thoracic cavities, particularly the left, from the third to
the sixth intercostal space. The long axis of the heart is rotated cranially so that it lies at an
angle with the base more cranial than the apex. The base of the heart is fixed by the great veins
and arteries while the apex can move freely within the pericardial sac. The so-called right and

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left sides of the heart are more correctly understood to be the dextro-cranial and levo-caudal
sides because the left ventricle lies behind and slightly left of the right ventricle.
The left ventricle is more conical and massive than the right ventricle which is more crescent
shaped.
Landmarks
If the dog is standing square, much of the heart lies medial to the triceps mass. A horizontal
line drawn through the point of the shoulder lies slightly above the level of the heart valves. As
opposed to using features of the forelimbs (e.g. the point of the shoulder and position of the
olecranon) to locate heart valves, palpation of the apex beat is more accurate because its
position is independent of the dogs forelimbs.

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Internal landmarks for the heart valves largely rely upon their positions relative to intercostal
spaces and costochondral junctions. The following guidelines (Tilley and Goodwin, 2001) may
be helpful for auscultation:

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The Apex Beat
The apex beat is an impact vibration produced at the start of ventricular contraction as the
heart hits the chest wall. In the normal dog it is palpated on the left side, ventrally in about the
fifth intercostal space. The apex beat should be identified by palpation before the heart is
listened to. It is important in lesion localization because the mitral valve lies close by and S1 is
loudest at this point.

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Palpation of the Apex Beat
Cardiac Auscultation
Cardiac auscultation should be performed in a quiet room free of excessive noise. Cardiac
auscultation should also be performed as soon as the animal enters the exam room or when
the dog is stressed since this increases the probability that a transient or subtle murmur will be
detected. The probability of detecting a murmur increases with stress because sympathetic
activation increases heart rate, cardiac contractility and cardiac output. Turbulent flow, which
gives rise to murmurs, is more likely at higher blood velocities.
Cardiac auscultation should proceed in a logical manner. The apex beat (mitral valve area)
should be palpated and the heart rate measured either by cardiac auscultation or palpation of
the femoral pulse. The femoral pulses should be palpated in each hindlimb and compared for
fullness, sharpness and regularity. Next the femoral pulse should be palpated simultaneously
with cardiac auscultation in order to detect pulse deficits due to arrhythmias. Each valve should
be ausculted in the order Mitral, Aortic, Pulmonic (acronym MAP). Some palpate the apex beat
(mitral valve area) and move cranially from there. However, if you wish to auscult in a particular
intercostal space it is easier if you start counting spaces from the last rib (13th) cranially.

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Basic Cardiac Function
The cardiac cycle consists of two phases: Systole (ventricular contraction) and diastole
(ventricular relaxation). At rest, systole occupies one-third of the cardiac cycle while diastole
occupies two-thirds of the cardiac cycle. The normal rhythm originates from the sino-atrial
node. When the rhythm is completely regular (the timing of the heart sounds remain in a
uniform, repeating cycle) it is called a normal rhythm. Sinus rhythm refers to the normal
rhythmic contractions of the heart initiated after the sino-atrial node discharges. It may be
completely regular or the interval between beats may wax and wane. This is referred to as sinus
arrhythmia and is normal in dogs. An ECG (electrocardiogram) is required to confirm the
presence of sinus rhythms or arrhythmias. In the following table the width of the columns

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represent the duration of the audible characteristics of the cardiac cycle.
Audible Sounds Detected During Aucultation
Research has revealed that there are four main sounds produced during the cardiac cycle of
which only the first and second are normally heard in canines. The third and fourth heart
sounds are pathological if ausculted.
Normal
S1 - The first heart sound (lub) is the result of the closure of the left and right
atrioventricular valves (mitral or bicuspid and tricuspid valves respectively).
S2 - The second heart sound (dup) is the result of the closure of the pulmonic and aortic
(semilunar) valves.
Pathological
S3 - The third heart sound is the result of the addition of more blood into a partially filled
ventricle thus creating turbulence and sound waves.
S4 - The fourth heart sound is the result of atrial contraction. Although S4 is labelled the fourth
heart sound; if present; it will be heard at the start of the cardiac contraction cycle.
The First and Second Heart Sounds
Listen to the recordings of isolated heart sounds and see if you can detect the differences in
duration, intensity and pitch. S1 is slightly longer in duration and of lower pitch than S2. More
reliable clues are the timing of the sounds and that S1 is louder than S2 when you listen at the
apex beat (Left4).

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A Comparison of S1 and S2
The Third and Fourth Heart Sounds
In canines, the third and fourth heart sounds (S3 and S4) are not heard in normal animals and
their presence is an indication of pathology. The presence of S3 is often associated with dilated
cardiomyopathy (DCM) or chronic volume overloads due to acquired mitral insufficiency while
S4 is associated with hypertrophic cardiomyopathy, pressure overloads (semilunar valvular
stenosis) or chronic hypertension (Fox, 1988). Since S3 and S4 are both low frequency sounds,
they are best heard with the stethoscope bell.
Qualities of S3 and S4

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Other Normal Sounds
Other normal sounds include those sounds produced by the gastrointestinal tract and the
respiratory tract. Both gut and respiratory sounds are clearly distinguishable from cardiac
sounds. The gut sounds will be variable and irregular in timing while the respiratory sounds are
consistent and regular in timing.
Artifactual sound
During cardiac auscultation you can hear additional sounds produced by movement or the
environment. In order to eliminate these sounds the location where auscultation is being
performed should be free of excessive noise, the dog should be properly restrained and the vet
should take care in handling the stethoscope. To reduce the sound of hair rubbing against the
stethoscope, the dogs coat may be moistened with alcohol over the target area.

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Normal Resting Heart Rate Values for Canines
The "normal" heart rate for canines varies with the age, physical size, breed, level of arousal
and physical condition of the animal . Smaller dogs have faster heart rates than larger ones.
Compare the recordings from an adult Poodle with that from a Greyhound, and use your watch
to practice taking the heart rate. As a general rule, clinicians will take the heart rate over a
period of 10 or 15 seconds depending on how tachycardic the animal is.
Arrhythmias
An arrhythmia or dysrhythmia is a deviation from the regular rhythm. In dogs this may be
normal or abnormal and may result from abnormal cardiac impulse formation, conduction, rate
or regularity.
Regularity
Regularity refers to the predictability of an arrhythmia. Some arrhythmias occur in a
predictable fashion and are said to be regularly irregular. These rhythms may be normal (e.g.
sinus arrhythmia) or pathological. In others the onset of the next beat is completely
unpredictable and the rhythm is said to be irregularly irregular (e.g. atrial fibrillation).
Irregularly irregular rhythms are pathological in origin.
Classification of Arrhythmias
Origin
Supraventricular arrhythmias arise from the atria or AV node whereas ventricular arrhythmias
arise from the ventricles.
Rate
Arrhythmias with slow rates are bradyarrhythmias while those with fast rates are
tachyarrhythmias.
Regularity
Fibrillation is a rapid, irregular, chaotic rhythm while tachycardia is a rapid but regular rhythm.

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Normal Sinus Impulse Formation
Sinus Arrhythmia
Sinus arrhythmia is a regularly irregular sinus rhythm which is a normal finding in most dogs
(especially brachycephalic breeds). SinusArrhythmia is characterized by slight variations in the
S1-S1 interval. These variations are related to changes in vagal tone to the heart and are often
associated with inspiration (negative pressure created in the thorax) or use of sedative or
anesthetic drugs. You can demonstrate sinus arrhythmia by palpating the radial artery on your
wrist. Once you feel your pulse take a big deep breath and you should feel your pulse quicken
and then slow down as you exhale.
Altered Sinus Impulse Formation
Sinus Bradycardia (Slow Heart Rate)
Sinus bradycardia has a regular rhythm and may result from systemic disease (renal failure),
toxicities, increased vagal tone, elevated intracranial pressure or compression of the eyeball,
hypothermia, hypothyroidism or drugs (tranquilizers, propranolol, morphine, various
anesthetics) Sinus bradycardia is diagnosed when the heart rate is less than 65 beats / minute
and an ECG shows sinus rhythm.
Sinus Tachycardia (Increased Heart Rate)
Sinus tachycardia; often caused by stress; is the most common arrhythmia observed in dogs
and has a regular rhythm. Sinus tachycardia may result if there is increased metabolism and
oxygen demand or increased requirement for cardiac output (pain, fright, excitement),
pathology (fever, shock, anemia, hypoxia, hyperthyroidism) or pharmacological agents
(atropine, epinephrine, ketamine) . Sinus tachycardia is diagnosed when the heart rate is
greater than 160 beats / minute for most dogs (>180 bpm for small / toy breeds or >220 bpm in
puppies) and an ECG shows sinus rhythm
Altered Supraventricular Impulse Formation
Atrial Fibrillation
Atrial fibrillation is a common pathological arrhythmia in dogs . Auscultable characteristics of
atrial fibrillation include a completely unpredictable rhythm, sometimes called a "jungle-drums"
rhythm. Listen for long diastolic pauses between some beats and very short intervals between
others. Sometimes the beats are so close together that S2 is not generated and two S1 sounds
follow each other. The other hallmark of atrial fibrillation is a pulse deficit. Sometimes this can
be detected because there is a large disparity between the heart rate and the pulse rate. If the
heart beat is slow it is more reliably detected by simultaneous auscultation and palpation of the
pulse. Normally every S1 heart sound is followed by a pulse wave.
Abscence of a wave is called a pulse deficit.
The most common causes of atrial fibrillation are chronic atrioventricular valvular insufficiency
in small breeds, dilated cardiomyopathy in large breeds, and congenital heart defects. Less
common causes include heartworm disease, cardiac trauma, digitalis toxicity and severe
metabolic disorders . Auscultable or palpable characteristics of atrial fibrillation include

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inconsistently filled femoral pulses, detection of an S1 without an S2 and a pulse deficit.
Disrupted Impulse Conduction
Second Degree Atrioventricular (AV) Block
Second degree AV block may be of two types: Mobitz I, usually type A or Mobitz II, usually type
B. The two types of second degree AV block are best distinguished by ECG. Mobitz I is a normal
finding in dogs, especially in young animals and disappears with exercise. Mobitz II is
pathological in origin and will not disappear with exercise. Both types of second degree AV
block are manifested by a dropped beat detectable during auscultation. By exercising and
immediately ausculting the dog, you can determine if the AV block is a Mobitz I (the dropped
beats have disappeared) or Mobitz II (the dropped beats are still auscultable). Second degree
AV blocks can be associated with sinus arrhythmia, increased vagal tone, supraventricular
tachycardia, electrolyte imbalances or drugs (digitalis, intravenous atropine, xylazine)
Murmur
Murmurs are sounds produced by turbulent blood flow. Rapid flow, a wide vessel, low blood
viscosity and an uneven or constricted vessel wall all predispose to cardiac murmurs. They can
be physiological, for example high blood flow though the aortic outflow tract. Pathological
murmurs reflect heart disease, for example degeneration and roughening of a valve surface.
Veterinarians require a uniform method of describing murmurs to facilitate communication
between each other via a common understanding. Five parameters have been developed that
serve to describe all of the important aspects of a murmur. Of the five parameters, the most
important ones are position in the cardiac cycle, intensity, duration and pattern of intensity.
The point of maximal intensity (PMI) identifies the location where the murmur is heard loudest
and is often described using the valve location nearest (e.g. Mitral valve area).
In describing the duration of murmurs, pan refers to a murmur that obliterates both heart
sounds either through systole or diastole but does not obliterate any heart sounds. Holo refers
to a murmur that lasts throughout stystole or diastole but does not obliterate any heart sounds.
A continuous or machinery murmur lasts throughout most or all of systole and diastole and
may or may not obliterate heart sounds. Early- and late- describe murmurs that are positioned
closer to one heart sound than to another. Crescendo, decrescendo or diamond are terms that
describe the intensity profiles of murmurs as increasing, decreasing or increasing and then
decreasing in loudness. Musical and blowing and are terms used to describe the frequency
profile of a murmur. Grade refers to the absolute intensity of murmurs determined on a 6 point
scale where the higher the grade the more severe the murmur (Example: Grade 2 versus
a grade 5 regurgitant murmur).

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Research shows that most clinicians correctly describe the grade of a murmur. Localization of
the murmur to systole or diastole is less consistent. A clue is the timing of the heart sounds
(systolic murmurs occur in the short pause), however loud murmurs can be perceived as being
of longer duration than they really are . Another useful method is to palpate the pulse during
auscultation. Pan- or holo-systolic murmurs should be heard coincident with the pulse wave.
Problems and Strategies for Murmur Localization
On the left side, the pulmonic and aortic roots lie next to each other and it is difficult to
separate their respective valvular sounds.
Both produce sounds that are best heard cranio-dorsally on the left side of the thorax at the
second or third intercostal spaces. Since the aortic valve is more centrally located and produces
louder sounds some aortic murmurs are also heard on the right side. Mitral valve problems
produce sounds that are heard more caudally centered on the fourth or fifth intercostal space.
On the right side, tricuspid and ventricular septal defects produce murmurs that are heard
ventrally around the fourth or fifth intercostal space. A problem with localizing the origin of
murmurs is that loud murmurs can radiate over a wide area and on both sides of the thorax.
Despite this, the point at which they are loudest is often close to the lesion.

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Sometimes it may prove challenging to correctly identify the likely origin of a murmur.
Generally by following a logical process like the one outlined here, insight may be gained into
the type of murmur being dealt with. First of all the stethoscope should be moved around to all
the valve areas on each side of the thorax in order to ascertain where the PMI is located and
which; if any; valve is involved. With the location of the PMI known the murmur's intensity may
be accurately graded and the character and quality judged. Finally, by simultaneously ausculting
the PMI and palpating the femoral pulse an accurate indication of the position and duration of
the murmur within the cardiac cycle may be obtained. Additionally, note that by examining the
animal as soon as it enters the exam room or when it is stressed, the probability of detecting a
transient or subtle murmur increases because the intensity increases in accordance with the
sympathetic effects of stress.
The Most Common Murmurs Afflicting Dogs and their Features
In order of prevalence:
Mitral Regurgitation
Mitral Reguritation, the result of mitral insufficiency, allows backflow of blood into the left
atrium. Typical features of mitral regurgitation include a normal to increased arterial pulse, a
PMI located at the left apex, a plateau or decrescendo quality and systolic position in the
cardiac cycle. Mitral regurgitation is most often the result of acquired valvular disease (e.g.
mitral valve endocardiosis) and is usually observed in older dogs.
Patent Ductus Arteriosus
Patent ductus arteriosus results when the ductus arteriosus fails to close properly (functional
closure normally occurs by 72 hours after birth while anatomic closure is complete within the
first few weeks). PDA is therefore most commonly seen in young dogs with a higher prevalence
in purebreds and females . This murmur will feature an increased arterial pulse, a normal to
increased venous pulse, a PMI located at the left base and a machinery or continuous quality as
it is present throughout most or all of systole and diastole .
Tricuspid Regurgitation
Tricuspid regurgitation, the result of tricuspid insufficiency, allows backflow of blood into the
right atrium. Like mitral regurgitation, tricuspid regurgitation is most often caused by acquired
valvular disease and is usually observed in older animals. Features of a tricuspid regurgitant
murmur include an increased venous pulse, a PMI located at the right apex, a plateau or
decrescendo quality and a systolic position in the cardiac cycle .
The following two diagrams represent the locations where specific cardiac pathologies will be
auscultated best.

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Heart murmurs are classified according to several criteria.
Murmurs are caused by turbulence disturbing the normal laminar flow of blood. They are
most often caused by dysfunctional valves or septal defects. Characterization of murmurs is
based on several criteria, of which timing in the cycle, location or point of maximal intensity
(PMI) of the murmur, and intensity (loudness) are the most important.
 Timing and duration in the cycle:
If the murmur occurs between S1 and S2, it is systolic (common in small animals). If it occurs
between S2 of one beat, and S1 of the following beat, it is diastolic (extremely uncommon in
small animals).

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A murmur is early systolic if it ends by mid-systole. The same duration criteria are applicable to
diastolic murmurs, although most do not extend throughout diastole. Continuous murmurs
(e.g., such as heard with left-to-right shunting patent ductus arteriosus) are heard throughout
the cardiac cycle, and peak in intensity at about the time of S2.
 Location and radiation:
Location (or PMI) refers to the position of the stethoscope at which the murmur is heard the
loudest. We frequently describe location as the valve area at which the murmur is heard
loudest, e.g., “the murmur is heard loudest at the mitral valve” or “at the pulmonic valve”.
Alternatively, less specific descriptions are used such as “the murmur is heard loudest at the
left apex” (typical for mitral regurgitation), or “far forward and high over the left heart base”
(typical for a left-to-right shunting patent ductus arteriosus). In addition to PMI, most
pathologic murmurs radiate to other areas. Correct recognition of the PMI and pattern of
radiation is can be very helpful in identifying the specific cardiac abnormality.
 Intensity or loudness:
Grade 1/6: Softest murmur audible in a quiet room after minutes of listening
Grade 2/6: Soft, readily heard, but focal over one valve only
Grade 3/6: Prominent, easily heard, radiates to other areas
Grade 4/6: Loud, radiates widely, but not accompanied by a palpable thrill
Grade 5/6: Loud and accompanied by a palpable thrill
Grade 6/6: So loud that it can be heard with the stethoscope held off the thorax
The intensity scale is subjective. Classification of a murmur can vary between observers
especially when different stethoscopes are used (e.g., the diameter of the stethoscope
diaphragm will make a considerable difference in the loudness of a murmur). Murmurs which
occur in a structurally normal heart are called as innocent, physiological, or functional. Innocent
murmurs are often heard in young puppies and kittens as soft systolic murmurs heard best at
the mitral or aortic valves. These murmurs do not radiate, and they should disappear by 3 to 4
months of age. The cause of innocent murmurs is not known, but is possibly related to the
lower packed cell volume of young animals. Physiological murmurs or Functional murmurs are
common in animals that are anemic and occur as a result of changes in blood viscosity (which
results in disruption of normal laminar blood flow). These are soft murmurs that resolve with
resolution of the underlying disease. Occasionally, otherwise healthy animals with very
vigorously beating hearts will also have physiologic murmurs. Pathologic murmurs are
secondary to valve abnormalities or septal defects. Often, it is not possible to distinguish
physiologic from pathologic murmurs on physical examination, and additional diagnostics are
needed. The loudness of a murmur does NOT necessarily correlate with the seriousness of the
defect.
 Less common heart sound abnormalities include splits and clicks.
Usually, the right and left AV valves (tricuspid and mitral) close almost simultaneously, so that
only one heart sound (S1) is heard.
Similarly, the semilunar valves (pulmonic and aortic) close nearly simultaneously producing a
single S2. However, splitting of the heart sounds will occasionally be detected. Splitting of S2
due to delayed closure of the pulmonic valve is the most commonly detected split heart sound
in dogs and cats. Pulmonary hypertension (e.g., as occurs with heartworm disease) is the most
important cause of S2 splitting. Split S1 sounds are very rare and usually due to a conduction

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abnormality. A systolic click is an extra heart sound that is occasionally heard between S1 and
S2 during systole. They are usually mid to late systolic sounds, relatively high pitched, and
labile. The exact cause of systolic clicks is not known, but they are thought to be due to buckling
of the
mitral or tricuspid valves in early degenerative valve disease. Clicks are most common in small
breed, older dogs.
 Auscultation of the respiratory system must be systematic and complete.
Ideally, the animal should be standing and relaxed when you perform auscultation of the
respiratory system and they should not be panting. If necessary the animal’s mouth must be
gently held shut during auscultation. The entire thorax should be systematically ausculted.
Normal breathing should be almost silent.
The following terminology is used to describe abnormal lung sounds:
Crackles (which are frequently classified as course or fine) are discontinuous sounds usually
heard during inspiration. Crackles are caused by various pulmonary disorders (e.g., chronic
bronchitis, pulmonary edema) in which some of the smaller airways are collapsed during the
early phase of inspiration, then suddenly open with a crackling sound as inspiration progresses.
Crackles with a low to normal heart rate suggest primary pulmonary disease (increased vagal
tone). Crackles with an elevated heart rate suggest congestive heart failure (increased
sympathetic tone).
Wheezes (which may be further classified as high-pitched and low-pitched) are continuous
musical or whistling sounds generated by air passing through narrowed airways (e.g., with
intrathoracic tracheal collapse). Wheezes that arise from intrathoracic disorders are usually
more pronounced during expiration.
Muffled breath sounds may occur with conditions such as pleural effusions. With a pleural
effusion, careful auscultation of your patient in the standing position will frequently reveal a
fluid line - normal breath sounds in the dorsal lung fields, and muffled breath sounds in the
ventral lung fields.
Bronchovesicular sounds – this is the sound of increased air movement. It can be a normal
finding in an animal breathing heavily, or may be a sign of early pulmonary abnormalities.
 Pulses are characterized in terms of rate, rhythm, and quality.
At some point during auscultation, it is very important to simultaneously palpate the pulses.
The femoral artery is usually the most convenient to locate. Pulses should be synchronous with
cardiac auscultation. In a patient with a normal rhythm, the heart rate and pulse rate will be
equal. Pulse deficits indicate an arrhythmia is present. Assessment of pulse quality can be very
useful. Hyperkinetic pulses are excessively strong. These occur in states of increased cardiac
output such as anemia, and with a left-to-right shunting patent ductus arteriosus.
Hypokinetic pulses are those that are weak. This occurs with poor cardiac output and subaortic
stenosis. The term variable (or sometimes unequal) is used to describe pulses that vary in
strength from one beat to the next (e.g., with atrial fibrillation). It is important to remember
that palpation of the pulse does not estimate the blood pressure, as you are merely palpating
the difference in systolic to diastolic pulse pressure.

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 Abdominal palpation may reveal signs of right-sided congestive heart failure.
Right sided congestive heart failure leads to congestion of the abdominal viscera, which may
manifest as hepatomegaly and ascites. Ascites is recognized on physical examination as
abdominal distention with a fluid wave. Consequently, a thorough abdominal palpation forms
an integral part of a complete examination of the cardiovascular system.
4.Percussion:
It is done to see the enlargement of the dullness of the cardiac region
 Left border- apex
 Right border- right sternal margine
Cardiac causes: cardiomegaly, pericardial effusion, pulmonary artery dilatation, dilated
cardiomyopathy.
See if the dullness extends beyond apical impulse as in case of pericardial effusion
Respiratory causes: pleural effusion, hydropneumothorax, collapse fibrosis.
To find out cause of displaced heart due to lungs condition
Presence of diaphragm hernia and eventration of diaphragm could be suspected.
Other techniques used to diagnose cardiovasculardiseases
Cardiovascular diseases are diagnosed using an array of laboratory tests and imaging studies.
The primary part of diagnosis is medical and family histories of the patient, risk factors, physical
examination and coordination of these findings with the results from tests and procedures.
Some of the common tests used to diagnose cardiovascular diseases include:
Blood Tests
Laboratory tests are used to detect the risk factors for heart diseases. These include detection
of the fats, cholesterol and lipid components of blood including LDL, HDL, Triglycerides.
Blood sugar and Glycosylated hemoglobin is measured for detection of diabetes. C-reactive
protein (CRP) and other protein markers like Apolipo protein A1 and B are used to detect
inflammation that may lead to heart diseases.
During a heart attack, heart muscle cells die and release proteins into the bloodstream. Blood
tests can measure the amount of these proteins in the bloodstream. High levels of these
proteins are a sign of a recent heart attack.
One of the markers of heart attack is the Cardiac Troponin-T. Other biomarkers include
fibrinogen and PAI-1, high levels of homocysteine, elevated asymmetric dimethylarginine and
elevated brain natriuretic peptide (also known as B-type) (BNP)
EKG/ECG (Electrocardiogram)
This is a simple and a painless test that records the heart’s electrical activity. The patient is
strapped to the instrument with several patches or leads placed over his or her chest, wrists

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and ankles. A small portable machine records the activities of the heart on a strip of graph
paper.
The test shows how fast the heart is beating and its rhythm. The strength and timing of the
electrical signals as they pass through the heart are also seen. An EKG/ECG can help detect a
heart attack, attacks of angina, arrhythmias etc.
Stress Testing
For this test, the patient is made to work hard e.g. run on a treadmill or exercise while the leads
of EKG/ECG are placed over their body. Those who cannot exercise are given pills to raise their
heart rate. The test detects the effects of the exercise on the heart.
In patients with atheroisclerosis and coronary heart diseases the arteries that are narrowed by
plaques cannot supply adequate blood to the heart muscles while it is beating faster. This may
lead to shortness of breath and chest pain. The EKG/ECG pattern, arrhythmias etc. also show
the possibility of a coronary artery disease.
Echocardiography
This test uses sound waves to create a moving picture of the heart. This is also a painless test
where a probe is rolled over the chest and the machine creates the image of the heart on the
monitor. This provides information on the shape, size, workings, valves and chambers of the
heart.
Echocardiography may also be combined with Doppler to show the areas of poor blood supply
to the heart. It shows the areas of the heart muscle that are not contracting normally, and
previous injury to the heart muscle.
Coronary Angiography and Cardiac Catheterization
This test is an invasive test. A dye is injected into the veins to reach the coronary arteries. This is
done via coronary catheterization. Thereafter detailed pictures of the blood vessels of the heart
are taken using special imaging methods. This is called coronary angiography.
Cardiac catheterization involves threading of a thin, flexible tube called a catheter via a blood
vessels in the arm, groin (upper thigh), or neck. The tube is inserted under imagin guidance till it
reaches the heart. Coronary angiography detects blockages in the large coronary arteries.

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Chest X Ray
This is a test that shows the shape and size of the heart lungs and major blood vessels. This is a
test seldom used in diagnosis of heart diseases as it does not provide added information over
echocardiography and other imaging studies.
Electron-Beam Computed Tomography or EBCT
EBCT helps to detect the calciumdeposits or calcifications in the walls of the coronary arteries.
These are early markers of atherosclerosis and coronary heart disease. This is not a routine test
in coronary heart disease.
Cardiac MRI
Cardiac MRI (magnetic resonance imaging) that uses radio waves, magnets, and a computer to
create pictures of the heart. This gives a 3D image of the moving as well as still pictures of the
heart.
Phonocardiography
It allows the recording and measurement of heart sounds. A special microphone is placed
directly over the various ares of the thorax used for heart auscultation and heart sound is
recorded graphically on moving paper or on a oscilloscope
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