Cardiac lecture II, 14.2.25 Flashcards
Most common congenital heart disease in cats?
ventricular septal defect
Causes right-sided systolic mumur
Causes a systolic murmur on the right side of the chest as blood from the LV flows into the RV upon systolic contraction.
Atrial septal defects cause what type of murmur?
They don’t actually cause a murmur because the LA and RA pressures are so similar at any one time (5 vs 10 mmHg) there’s no rushing of blood from higher pressure cavity to lower.
PDA murmur type
Persistent ductus arteriosus causes a continuous mumur that is louder in systole, quiter in diastole. This type of murmur is almost pathognomic for PDA.
The term “to-and-fro murmur” describes a murmur that occurs both in systole and in diastole (eg, in an animal with subaortic stenosis and aortic insufficiency).
Cardiac troponin I is used frequently for human cardiac infarcts. What about in animals?
Animals don’t get the same types of infarcts/heart a ttacks that humans get so cardiac troponin I (‘i’) is not used as often/ is not as useful in animals (but can be used in specific cases in animals).
Explain Problem based vs disease based approaches to diagnosis.
The problem-based approach focuses on the patient’s specific symptoms or complaints without assuming a specific disease at the start. It is more systematic and broad-based.
The disease-based approach focuses on identifying a specific disease based on established patterns of symptoms, signs, and test results. It relies on a clinician’s knowledge of diseases and their presentations.
For every problem, you must have a
differential diagnosis on your list.
And for every differential on your list, it must match with a problem on your problems list.
Before entering consulting room (2)
– Know the signalment (species, breed, sex)
– Make sure you have the details of the correct patient.
Common presenting complaints that can indicate heart disease. (8)
Summarising the history back to the owner helps to (2)
– Helps to ascertain the correct history
– Helps the owner to expand history
What is signposting in the context of vet med?
Signposting – explaining the next steps to the owner
– What you have already done
– What you are planning to do
Clinical sign of low cardiac output. (6)
exercsie intolerance
syncope
pallor/prolonged CRT
cyanosis
prerenal azotemia
arrhythmias
Clinical signs of (congestive) left-sided heart failure. (8)
Signs of pulmonary congestion and edema:
+/- cough
pulmonary crackles
tachypnea
orthopnea
hemoptysis
cyanosis
arrhythmias
secondary right sided signs
Clinical signs of (congestive) right-sided heart failure. (7)
Signs of systemic venous congestion like jugular distension.
hepatic/splenic congestion
pleural effusion
ascites
small pericardial effusion
subcutaneous edema
arrhythmias
Cardiac patient physical exam should definitely include (5)
– Auscultation
– Jugular distension/pulsation
– Both femoral pulses’ palpation for strength and syncronicity
– Thoracic palpation (in some cats you can feel cardiomegaly even)
– Abdominal palpation for organomegaly, masses fluid
Describe jugular pulsation. (4)
Pulsation of the jugular is abnormal and can indicate:
– Arrhythmias
– Pulmonary hypertension
– Pulmonic stenosis
– Right-sided heart failure
With the animal in a standing or sitting position, the jugular veins should be examined for the presence of abnormal distention and pulsation. A normal jugular vein will be distended and may pulsate when an animal is laterally recumbent.
Describe jugular distension. (4)
Distension of the jugular is abnormal if not actively occluded, thus can indicate:
– Right-sided heart failure
– Pericardial disease
– Heart base tumour
– Mediastinal mass
With the animal in a standing or sitting position, the jugular veins should be examined for the presence of abnormal distention and pulsation. A normal jugular vein will be distended and may pulsate when an animal is laterally recumbent.
Describe Thoracic (2) and
abdominal (3) palpation in cardiac patients.
When palpating the Thoracic, look for:
– Elasticity
– Location of the apex beat (cardiac enlargement, lung lobe collapse, diaphragmatic hernias, masses, pleural effusion)
When palpating the Abdomen pay attention to:
– Ascites (ballottement may occur if ascites is present)
– Organomegaly
– Masses
The apex beat (lat. ictus cordis) is the pulse felt by hand at the point of maximum impulse (PMI).
Femoral pulse Findings and what they indicate.
– Absent
– Erratic
– Hypokinetic (weak and low-amplitude pulse)
– Hyperkinetic (strong, bounding)
– Pulse deficits
– Pulsus alternans
– Pulsus paradoxus
– Absent - thromboembolism
– Erratic – atrial fibrillation / other arrhythmias
– Hypokinetic – heart failure, hypotension, hypovolemia, aortic stenosis
– Hyperkinetic – aortic regurgitation, fever, high sympathetic tone, PDA, severe anemia, severe bradycardia
– Pulse deficits - arrhythmias
– Pulsus alternans – severe DCM
– Pulsus paradoxus – cardiac tamponade
First heart sound (S1):
Second heart sound (S2):
First heart sound (S1): closure of the atrioventricular (AV) valves (mitral and tricuspid valves) at the onset of systole
Second heart sound (S2): closure of the semilunar valves (aortic and pulmonic valves) at the end of systole
In dogs, cats, and ferrets, S1 and S2 are the only heart sounds normally audible.
Pulsus alternans =
alternating (beat-to-beat) variability of pulse strength due to decreased ventricular performance
e.g. severe DCM
Pulsus paradoxus =
Pulsus paradoxus is when your systolic blood pressure drops more than normal when you inhale. Normally, when you breathe in, your blood pressure drops a tiny bit, but in pulsus paradoxus, the drop is larger than 10 mmHg, which is unusual.
e.g. cardiac tamponade
this can push on the heart making it harder for the left side of the heart to fill properly. As a result, the left ventricle doesn’t pump as much blood with each heartbeat, causing the systolic blood pressure to drop more than usual during inspiration.
Mechanism by which aortic regurgitation causes a hyperkinetic pulse.
Conditions that cause a hyperkinetic pulse generally lead to a state where there is either increased cardiac output or decreased vascular resistance, both of which result in a pulse that feels strong and forceful.
In aortic regurgitation, blood flows backward from the aorta into the left ventricle during diastole because the aortic valve doesn’t close properly. This leads to volume overload in the left ventricle.
The left ventricle compensates by increasing its stroke volume (the amount of blood pumped out with each contraction). This results in a stronger and more forceful pulse (bounding pulse).
Patent Ductus Arteriosus (PDA) connection between what structures?
Mechanism by which PDA causes a Hyperkinetic pulse.
abnormal connection between the aorta and the pulmonary artery
This allows blood to flow abnormally from the aorta to the pulmonary artery (higher pressure to lower), leading to increased blood flow through the left side of the heart.
To handle this increased flow, the left ventricle works harder, pumping more blood with each beat, which results in a hyperkinetic pulse.
Murmur auscultation.
Name the 4 Factors affecting blood turbulence.
laminar vs turbulent flow
The Reynolds number involves:
- fluid density
- fluid velocity (pressure gradient affects)
- pipe bore aka diameter of blood vessels
- dynamic viscosity (anemia can affect)
Give approximate pressures of the heart atria and ventricles.
Lowest in the right atrium - 5 mmHg.
Next lowest in the left atrium - 10 mmHg.
Highest in the left ventricle - 150 / 5.
Moderate-low in the right ventricle - 25 / 2.
If there are septal defects present, blood flow goes from higher area of pressure to lower, so from left heart to right heart.
Pressure gradients in the aorta and pulmonary artery?
aorta is high pressure (systemic vascular resistance) ca 150/80
pulmonary artery 25/5 (not super high pressure cause its going into the lungs)
A patent ductus arteriosus would cause blood from the aorta to move into the pulmonary artery.
Stethoscope diaphragm for… and bell for…
Stethoscope diaphragm for high requency sounds and bell for low frequency sounds.
S1:
S2:
The first heart sound (S1) represents closure of the atrioventricular (mitral and tricuspid) valves as the ventricular pressures exceed atrial pressures at the beginning of systole.
S1 is normally a single sound because mitral and tricuspid valve closure occurs almost simultaneously.
The second heart sound (S2) represents closure of the semilunar (aortic and pulmonary) valves.
Transient heart sounds can include: (3)
– Systolic clicks
– Increased S2, split S2
– Gallop (S3, S4) – use the bell of your stethoscope!
Murmurs – how to describe them? (6)
■ Timing (systole, diastole, continuous, to-and-fro)
■ Duration
■ Location (heart base vs apex, left vs right side)
■ Intensity/loudness (amplitude of vibrations)
■ Frequency (pitch)
■ Quality (timbre) muscial, squeaky etc.
Duration of murmurs can be described as: (4)
- Early systolic
- Holosystolic
- Pansystolic
- Early diastolic
The terms “holosystolic” and “pansystolic” are often used interchangeably. Some people use the term holosystolic to mean that the murmur is audible throughout systole but does not obscure the heart sounds, and pansystolic to refer to murmurs which obscure the heart sounds.
Describe intensity/loudness of heart murmurs.
Graded I-VI
I: veyr soft, heard in quiet room
II: soft, but easily heard
III: moderate intensity
IV: loud murmur but no thrill
V: loud with a palpable thrill
VI: very loud, heard with stethoscope lifted
