Clinical Heart (Struc.)

Question 1

Cardiac Auscultation

• Four Heart Sounds Possible
• Only 2 typically heard in normal small animals (may be more audible in Large)

S1 = Closure of the AV valves (L&R) at the onset of ventricular Systole
S2 = Closure of the Semilunar valves (Pulmonary and Aortic) at the end of ventricular systole
(S1 and S2: normal lub dub sound)

S3 = Rapid ventricular filling during diastole (relaxation). NOT normally ausculted in small animals
Associated with congestive heart failure and cardiomyopathy
S4 = Sound of Atrial systole (contraction). NOT normally ausculted in small animals

Associated with filling of non-compliant ventricles (hypertrophic cardiomyopathy)

lub swish = swish means bad pathologic semilunar valve (one of the semi lunar valves is allowing blood back into the ventricles)

(And you can you can almost you can almost imagine the blood being ejected through in a turbulent manner, Making that vibration)

Question 2

Left sided or right sided? Did I hear it during systole or diastole?
KNOW Ah. Is it. Do we hear it during. Do we hear it during S1 or S2?
And do we hear it? Left sided, Right sided. And those four places that we marked on the chest.

Crescendo means it comes to a peak like as opposed to a Decrescendo, like decreasing flowing downward kinda sound

Question 3

linear, laminar mean the same thing

Those all mean the same thing. Water flowing in a straight line with no turbulence, a deep, wide river, so to speak.

And then when a valve does close, you just hear a lub or a dub really sharp sounds that we’re used to (2nd one in pic - top right)

But when you let a little blood through these little curlicues here are trying to represent white water relative to the river, turbulence 90 plus percent of the time. But I just don’t want you to say that’s a guaranteed valvular disease because I hear a murmur.

Murmur: The sound of turbulent blood flow (ABNORMAL)

1) Abnormal flow pattern
- Ex: Valvular insufficiency (valve does not close completely – allowing regurgitation)

2) Abnormal vessel diameter
- Ex: narrowing (aortic stenosis)

3) Abnormal blood viscosity
- Ex: Anemia causes low viscosity

Question 4

heart and the Kidneys

Cardiac output = Heart Rate X Stroke Volume

Stroke volume can be altered by contractility AND / OR Changes in Blood Volume

(low water then kidneys hold on to more electrolytes
And that’ll hold on to more volume so our heart can compensate and our kidneys can compensate if the heart’s unable to pump blood perfectly.)

e.g. sinking boat/ship
stroke volume: bigger bucket instead of mug
rate: how fast ur doing it (younger person would do it faster than older person)

Question 5

Mitral Insufficiency
- Some of the blood leaks through the valve back into the left atrium
- Cardiac output (CO) goes down

• Body responds by increasing HR. Initially, this is enough to bring cardiac output back to normal … but dz progresses
• Now Kidneys compensate by retaining water and electrolytes→increasing blood volume and pressure→Increasing pre-load (end diastolic volume)
• This will also help in short term (CO goes up), but will also increase the amount of blood regurgitated through the faulty valve
• The Heart must compensate to the increased “work”→Left Ventricle enlarges to hold more volume = “Dilated Cardiomyopathy”
  (like a DOUBLE EDGED SWORD)

Snowball Effect
- End Result without therapy:
- 1st Congestive heart failure
- Left side of the heart cannot enlarge any more. Blood pressure continues to rise→more regurgitation occurs→pressure in the lungs increase→eventually causes fluid build up called “pulmonary edema”

• 2nd Myocardial failure
• Heart muscle fails to pump fluid forward.

Question 6

Mitral Valve insufficiency:
* Eventually causes a reduction of flow to the left side of the heart.

• Draw it in!
  Right side of the heart is still pumping well

Pulmonary circulation is congested→increase pressure of vessels inside the lungs→Pulmonary edema (fluid in the lungs)
increased Respiratory rate and effort / Coughing decreased Exercise tolerance

(congested pulmonary circulation: You might even hear musical sounds like almost like a whistle. Through those congested airways, you might hear crackles and wheezes)

pic: Schematic drawing: 1, Left ventricle; 2, aorta; 3, capillary bed of head, neck, and forelimb; 4, abdominal aorta; 5, liver; 6, capillary bed of intestines; 7, portal vein; 8, capillary bed of kidneys; 9, capillary bed of caudal part of the body; 10, caudal vena cava; 11, cranial vena
cava; 12, right ventricle; 13, pulmonary trunk; 14, capillary bed of lungs; 15, pulmonary vein; 16, hepatic veins.

Question 7

Tricuspid insufficiency (regurgitation)

• Very similar disease process (pathophysiology) as mitral dz
• Instead of Left congestion, we have RIGHT sided heart congestion
• Pressures of the systemic circulation increase and start “LEAKING”
• The lining of the cavities of our bodies (thorax / abdomen) have tiny vessels that can become “leaky” under stress of high pressure.
• Abdominal cavity and organs are lined by Peritoneum. Between the body wall and organs is the peritoneal space.
• Excessive fluid in the peritoneal space = “Ascites”
• Thoracic cavity and organs are lined by Pleura. Between the body wall and organs is the pleural space.
• Excessive fluid in the plural space = “Plural Effusion”

peritoneum build up (ascites) easy to see Because your belly gets so pendulous with fluid in there. It’s easy to see (pericardium not usually seen - heart)

Question 8

Tricuspid valve insufficiency

• Eventually causes a reduction in flow to the right side of the heart
• Draw it in!

LEFT side of the heart is still pumping well
SYSTEMIC circulation is congested→high pressure in vessels of body cavity linings (abdomen and chest)

Abdomen is lined by peritoneum. Accumulation of fluid in the peritoneal space is called “Ascites”
→Distended abdomen

Chest is lined by plura. Accumulation of fluid in the plural space is called “Plural effusion”
→Increased Respiratory effort and rate

(4th intercoastal space where tricuspid lives
- It was tricuspid valve disease in the first place because of when and where you heard it, when S1, where right sided fourth rib space
think its tricuspid but also a big fat old lab so that’s one more piece of evidence. It shouldn’t be ever your diagnosis, but it’s like, wow, this keeps piling up with more evidence

So utilize all data in front of you and one of them is signalment).

Question 9

Dilated Cardiomyopathy
- Boxers and Doberman Pinchers most frequently
- in contractility of cardiac muscle
- Initially compensate by increasing HR
- Eventually the orientation of the mitral valve is effected (As valves don’t grow along with size of cardiac dilation so valves like tips of fingers don’t touch each other anymore)

• Mitral valve insufficiency ensues (not always, just making a link that if you alter the heart’s shape enough, the valves are going to be altered, too)

FYI below
Dilated cardiomyopathy can also happen in cats!
- Directly related to Taurine deficiency in diet
- Very rare in household cats due to commercially available balanced nutrition

Question 10

Feline Hypertrophic Cardiomyopathy
- Exact cause unknown
- there is a definitive genetic predisposition (like the breeds: Ragdoll, Maincoon)
- Ventricular walls become thickened
- Pumps well, but cannot relax during diastole
- Decreased Cardiac Output (CO)
- Malalignment of valves (especially the mitral)

ANS (diff topic with image)

Answer 10

rare for puppies to have tricuspid disease

Way more likely for one of the natural. Shunts.

If you’re in a womb, you don’t breathe. And if you don’t breathe? There’s no point in sending a lot of blood out to your lungs.
Right. Most of it can get shunted, skip the lungs and get off to circulation systemically.
So how does Mother Nature skip shunt the lungs?
sending deoxygenated air out into aorta -> BAD because ductus which means connection between the arteries is still open thus PDA

PDA is a still open shunt between the big arteries of the heart, the pulmonary artery and the aorta.

You would hear a murmur, and then you’d have to start thinking to yourself, Gosh, what is the most likely cause of this? neonatal PDA has got to be up there on my list.

Just born three days ago. I hear a murmur. Boy, a PDA would be on my list as a two year old to two day old, but not as a two year old.

Question 11

How else can Mother Nature skip the lungs (shunt)?

The lungs were shunting away and sending that blood elsewhere through something called the foramenal valve - It’s literally saying an oval shaped hole. It’s an oval-shaped hole between the two atria.
And it’s normal if you’re a fetus.
two days after birth. both the PDA, and the foramenal hole should close so all the blood from the right ventricle goes out to the lungs, gets oxygen and comes back.but now and again the duct stays open (patent) and the foramenal valve stays open (patent)

Either way, you could hear a murmur. And they’re not going to fit the perfect.
I’ve given you some pattern of where valves live and the point of maximal intensity and even the times at which you would hear S1 versus S2.
These wouldn’t fit that perfectly. So it might throw you when you first hear it, except that it’s a brand new baby puppy.
So you’ve got to put those higher on your list. There are other holes in the heart that are congenital that should never be there.
Right.

The PDA should be there as a fetus. The foramenal valves should be there as a fetus. But then other times they’re just genetic. so Accidents where in there’s a hole somewhere else.
slide to just for me to say that Don’t just hear a murmur and say, Oh, it’s a puppy. must be a PDA! could be elsewhere and PDA should probably be near the top. And so too should patent foramenal valve
But it’s not a definitive diagnosis. It could be elsewhere. Get your ultrasound out.

But don’t just give something, a diagnosis based on age or just on sound alone good enough.

go through the last slides