Cardiovascular system

Question 1

Physical exam

Answer 1

Inspection
Palpation
Auscultation
Percussion

Question 2

Palpation

Answer 2

Location and intensity of heartbeat
Heart rate
Trauma, deformity
Pain
Precordial thrill, fremitus

Question 3

Percussion method and use

Answer 3

Pleximeter and percussion hammer

To detect pain in the cardiac area

Question 4

Where is the area of cardiac dullness?

Answer 4

Diernhofer triangle- dullness on the left side

Question 5

Ancillary diagnostic methods

Answer 5

ECG
Echocardiography
Phonocardiography 
Blood pressure measurement 
Pericardiocentesis 
Cardiac catherisation
Lab tests

Question 6

ECG

Answer 6

Resting:
Base apex lead: most commonly used
(einthoven rarely)

Holter and telemetric:
At rest or
While exercising

Question 7

Lab tests

Answer 7

Blood tests

1. AST
2. CK in humans MB but in horses MM
3. LDH and 5 isoenzymes- mainly LDH1 (LDH2)
4. Cardiac troponin I and T

Question 8

Location of heart

Answer 8

Base: btw 2nd and 6th ICS
Twisted aniclockwise
Right side: cranially
Ledt side: Left and caudally

Question 9

Location of heart beat

Answer 9

Left: 3-5 ICS
Right: 3-5 ICS

Question 10

Heart sounds: S1

Answer 10

Beginning of systole

Initial movement of ventricle
AV valves tense, stopping of blood flow
Early part of ejection

Question 11

Heart sounds: S2

Answer 11

End of systole

Change in direction of blood flow
Closing of semilunar valves

Question 12

Heart sounds: S3

Answer 12

Termination of rapid ventricular filling

Can be heard at or caudal and dorsal to the apex beat

Question 13

Heart sounds: S4

Answer 13

Atrial contraction

Arrest of the distended ventricle

Question 14

Heart murmurs

Answer 14

Prolonged audible vibrations

Develop in a usually quiet part of the cardiac cycle

Question 15

The normal/ functional murmurs

Answer 15

Caused by vibrations after the ejection of blood during systole
OR
Rapid filling of the ventricles during early diastole

Question 16

Physiological (flow) murmurs

Answer 16

Systolic or Diastolic

Question 17

Systolic murmur

Answer 17

Caused by blood flow in aorta and pulmonary artery in early systole
Left side of thorax
PMI over aortic or pulmonary valves 
Grade 1-3/6 
Early-to-midsystolic 
Crescendo-decrescendo or decrescendo
Localised and brief

Question 18

Diastolic murmur

Answer 18

Caused by ventricular filling 
Common in young and thoroughbreds
Left side of thorax
PMI over mitral area
Grade 1-3/6 
Early diastolic (S2-S3) or late diastolic (S4-S1)
Musical/squeaking

Question 19

Classification of endocardial murmurs

Answer 19

Timing 
Duration
Grade
Point of maximum intensity PMI
Quality (shape)
Frequency
Radiation
Effect of changing heart rate

Question 20

Timing

Answer 20

Early
mid
late

Question 21

Grade

Answer 21

1/6: quiet-requires careful auscultation
2/6: quiet: heard when stethoscope placed over its PMI
3/6: audible over a wider area
4/6: loud and audible. no fremitus
5/6: fremitus and audible with loose contact with the thoracic wall
6/6: loudest even audible when the stethoscope is held apart from the thoracic wall

Question 22

PMI Pulmonary

Answer 22

Left 3rd ICS below point of the shoulder

Question 23

PMI Aortic

Answer 23

Left 4th ICS below point of the shoulder

Question 24

PMI mitral

Answer 24

Left 5th ICS halfway between shoulder and sternum

Question 25

PMI Tricuspid

Answer 25

Right 4th ICS

Question 26

Basic interpretation of ECGs

Answer 26

Aretfacts can be present, especially in exercise racehorses Heart rate Rhythm (R-R intervals): normal regularly irregular irregularly irregular-- atrial fibrillation Relationship between P waves and QRS complexes: each P wave is followed by a QRS complex each QRS complex is preceded by a P wave Duration and morphology of waves, duration of segments and intervals

Question 27

Unique to equine ECG

Answer 27

No Q wave Large negative deflection in the S-wave (not R wave)- but still the R waves are used to describe

Question 28

Sinus rhythm

Answer 28

Biphasic P | Positive T-wave that can be biphasic as well

Question 29

Atrial premature complex/ depolarization (APC/APD)

Answer 29

3rd cycle: P-wave is earlier than normal-- after this normal QRS and P, the P wave is not too early, the ventricular muscle can contract If P wave more premature- ventricular muscle still in refractory period and the stimulus doesn't get through AV node- no depolarization, no QRS complex and T-wave 5th cycle: almost no gap between T and P wave Can cause exercise intolerance

Question 30

Atrial fibrillation

Answer 30

Normal QRS complex and T wave No visible P waves- instead many small f-waves S-S intervals are very irregular, therefore irregular rhythm S sound not audible Exercise intolerance and poor performance Very common

Question 31

1st and 2nd degree atrioventricular block

Answer 31

1st and 2nd degree at the same time 1st cycle: P wave not directly followed by QRS complex, the duration of atrioventricular conduction through AV is longer Followed by 4 normal cycles T-wave (late) and P-wave (normal timing) almost together 2nd degree: ventricle muscles in refractory, no contraction, no QRS complex and no T-wave Block usually repeated after a few normal cycles, most of the 1st and 2nd degree are normal because of the strong vagal tone, this is why you can check if it is physio by walking the horse around- will become excited and the vagal tone won't be as strong and HR increases, so no more blocks

Question 32

2nd degree atrioventricular blocks

Answer 32

P wave not followed by a QRS NB!! ECG software can misinterpret T-waves for QRS complexes, giving a double HR- this is why auscultation is so important

Question 33

3rd degree (complete) atrioventricular blocks

Answer 33

Complete separation of atrial and ventricular depolarization- no conduction through AV node P wave is normal- indication that SA node is normal There is automatic pacemaker activity in ventricular muscle, it will contract even though there is no info coming through the AV node This is why we can see 3 ventricular contractions that are much slower Extreme level of exercise intolerance Resolution: pacemaker

Question 34

Ventricular premature complex/ depolarization (VPC/VPD)

Answer 34

Originates in ventricle Different wave forms: 1st (half one) normal and then no visible P-wave Every 2nd cycle abnormal CO decreases because the abnormal contraction can't produce same HMV Always clinical signs- exercise intolerance and poor performance

Question 35

Ventricular tachycardia VT (uniform)

Answer 35

Resting ECG is 140 bpm QRS and T-wave identifiable, but P-wave is not Can be temporary with sinus-rhythm Origin of the premature ventricular rhythm is the same

Question 36

Ventricular tachycardia (multiform)

Answer 36

HR very high Different wave form, variability in QRS complex Different origins in the ventricular muscles If sustained-- ventricular fibrillation--- heart stops