Exam of the cardiovascular system Flashcards
Detailed exam of the cardiovasc system: order
Heart
Blood vessles: arterial, venous, capillary
Blood: mucous membranes, anemia, polycythaemia, dehydration
Physical exam:
Inspection (heart and vessels)
Palpation (heart and vessels)
Percussion (heart)
Auscultation (heart)
Inspection of the heart
Abnormalities of the thorax e.g injury or malformation
Heart beat- the apex beat in cat and dog
-it’s location and possible dislocation
-intensity/strength and if it is increased or decreased
Palpation of the heart
To detect pain
Location of the heart beat- diclocation can be caused by e.g tumour, abscess or pneumothorax
Strength/intensity of heart beat
-increased: exercise, cardiac hypertrophy
-decreased: heart disease, fluid, thickened chest wall
To detect fremitus which can be endo, peri or extra pericardial (the endo is caused by turbulent flow of blood)
Percussion of the heart
Primary goal in smalls is to detect: - fluid accumulation -space occupying lesions -PTX To locate the area of cardiac dullness- absolute or relative
Causes of alterations in the area of cardiac dullness
Enlargement of cardiac dullness is when dullness is detected in the lower part of the chest
Dilation, hypertrophy
Pericardial effusion
Cardiac dislocation
False enlargement: other organs or space occupying lesions e.g tumour, abscess, hernia
Fluid accumulation- causes a horizontal line of dullness and the Diernhofer triangle disappears
Auscultation of the heart
Maximum audibility of the valves
1-4 normal heart sounds
Alterations of the heart sounds: FRIDA
frequency, rhythm, intensity, demarcation, additional
FRIDA: Frequency
Coincides with pulse
Starts in aorta coincides with closing of the valves
Pulse deficit is always patho!
Exam: simultaneous ausc and palpation of pulse
Normal values are different depending on species
Changes: tachy or bradycard
FRIDA: rhythm
Normally regular
Arrhythmia is patho and is usually accompanied by pulse deficit
FRIDA: intensity
Normally uniformly strong and even
Pounding: increasing over first and second sounds
Reduced heart sounds means decreased CO- can be caused by pericardial/pleural effusion or obesity
FRIDA: demarcation
Distinctness of the cardiac sounds
Smalls- the 1 and 2 sounds are the most pronounced
Patho: gallop sounds (cardiomyopathy) where 3 can be heard: either 1,2,3 or 4,1,2
Splitting of heart sounds e.g in the 2nd heart sound closure of the aortic and pulmonary valves at different times- can be caused by cor pulmonale
FRIDA: additional sounds
MURMURS!!!
Endocardial or extracardiac
Endocardial murmurs
Caused by turbulence
- Location: points of maximal intensity
- Relation to phase of cardiac cycle: systolic or diastolic
- Frequency/pitch
- Character/quality/shape: continuous, crescendo, decrescendo
- Conduction
Morphological: valve, septal, vessel
Functional: innocent murmurs, anaemia causing decreased blood viscosity
Extracardiac murmurs
Pericardial or pleuro-pericardial or pleuro-pleural
VARIABLE! location and intensity can be heard during different phases of the cardiac cycle
Extremely rare in smalls
Further/ additional exams
Radiography
Echocardiography
US
What can thoracic radiography diagnose
Cardiac enlargement
Pulm edema
Extracardiac diseases
How US pictures are formed
Sound waves encounter tissues of different densities, sound wave is reflected back to probe and is detected as an echo
When the sound waves penetrate fluid, no echos will be reflected from it and the area appears black in the image
Acoustic impendance
Constant value for material in question
Calculated based on density and the acoustic speed of US within the material
Technique of US
Transducer can be linear or sector with the necessary frequency
Linear: in a row- supf organs e.g tendons
Sector: cone shaped, smaller contact surface- deeper organs
For echocardiography
SECTOR transducers only- needs to fit btw ribs
Diagnostic possibilities of US and echocardiography
Exam of the cardiac chambers
Valvular disorders
Contrast echocardiography- shunts, septal defects
Doppler echocardiography- blood flow disorders
Technique for echocardiography
Lateral recumbency
Exam from the right hemithorax
Views for echocardiography
Right parasternal transducer view
- long-axis plane gives 4 chamber view
- short-axis plane changes the angle 90 degress and gives a cross-sectional view of the heart
Quantitative
-gives the left atrial to aortic ratio which is very important to assess left heart failure and severity
What can be diagnosed specifically with echocardiography
Dilated cardiomyopathy– dogs
Hypertrophic cardiomyopathy– cats
Pericardial fluid and mass
ECG, what is it?
Measures amplitude and time of potential differences of electrical current generated through depolarization and repolarization of cardiac structures
Principles of the ECG
Intracardial- invasive and obsolete
Epicardial
Measurement on surface of body
Voltage measured with height of wave- the positivity or negativity of wave is determined by the positioning of the electrodes and the main direction of the electric axis in the heart
Einthoven ECG- triangle measurement
Electodes on 3 limbs: negative to right arm, positive to left hind
Interpretation of the waves
P-wave: SA depolarization
Q-wave: potential is travelling in the pukinje fibers- small negative wave
R-wave: ventricular depol
S-wave: repolarization of base of heart- small negative wave
T-wave: end of ventricular repolarization
Goldberg vs Einthoven ECG
Goldberg: measurement btw one point and the average of the other 2
30 degree angles therefore more precise
Einthoven- P waves are not always visible!!
Artefacts of an ECG
Movement- sometimes not all leads are affected
Electrical- 50Hz interference from the ‘normal’ electricity in power outlets
Electrode reversal- wrong placement
Indications for ECG?
The main ones:
Arrhythmia, tachycardia, bradycardia
Monitoring anaesthesia
Others:
Effect of cardiac or cardiotoxic drugs
Cardiac effects of electrolyte distrubances
Enlargement of cardiac chambers
First steps in ECG analysis?
Check the quality i.e if there are artefacts
Check if there is electrode reversal
Are the P-waves visible?- if not increase speed or use chest leads or modified limb leads
Recognise and name the waves
Determine the heart rate- count the QRS complexes
Measure distance btw 2 beats i.e the RR distance
Morphology of ECG waves
Segment= distance without the wave Interval= includes the wave P-wave: atrial depolaeization QRS: ventricular depol Size of the R and P wave: magnitude of depolarization, measured from the baseline PQ: beginning of depol in sinus node to reaching the ventricle QT: time for ventric depol ST segment: almost flat
Examination of the blood vessels: arterial system
Digital palpation, pulse pressure- PULSE
Blood pressure measurement- direct or indirect- sphygmomanometry
Blood flow registration- Doppler US
Pulse wave velocity
Pulse quality
Depends on size
Difference btw systolic and diastolic BP is pulse pressure
What is systemic arterial BP
CO x total peripheral resistance
Factors determining CO and TPR
Heart rate Ejection volume -circulating blood -heart contraction -integrity of cardiac structures
Total peripheral resistance
- vessel diameter: small vessels
- elasticity of the vessels: large
- blood viscosity: PCV
Parameters to measure when taking the pulse
Frequency
Rhythm
Quality-
…size, compressibility(strength) and duration of the pulse waves
Abnormal findings of the pulse quality
Irregular
Uneven
Size: when large is hyperkinetic, small is hypokinetic
Compressibility: hard has to do with cardiac function, soft has to do with vascular tone
Examination of the venous system
Inspection
Palpation
Measurement of central venous P
Examine the jugular vein
Venous system: parameters
Degree of fullness- venous stasis compression test
Movement within veins
Physio movements within the vein
Resp, diastolic, false (carotis pulse)
Max at ventral 1/3 of neck
Disappears with compression test
Patho vein pulse
Systolic
Pronounced over the ventral 1/3 of neck
Persists after compression test
Congested jugular vein
ALWAYS patho!!
Blood pressure measurement: central venous pressure
Direct: catherization- Indirect: -examination of peripheral veins -hepatojugular reflux test -dogs: collapse of v. saphena during lifting of hindlimb in lateral recumbent position
Exam of the capillary system
Exam of the mucus membranes
Colour
CRT
Fullness of caps
Livid- empty
Light red- increased fullness of arterioles
Violet- congestion
Systemic arterial pressure
Need to understand that blood pressure is not equal to pulse pressure, blood pressure cannot be examined by palpation
How to calculate systolic-diastolic values
Pulse pressure= systolic pressure minus diastolic pressure
How to calculate mean arterial pressure (MAP)
Diastolic pressure+pulse pressure
divided by 3
Blood pressure depends on…
Anatomical place- the arterial tree Body position Heart rate Blood pressure itself SAP more affected than DAP or MAP
Indications for measuring blood pressure
To reveal secondary hypertension in case of known predisposing diseases
Search for cause of target organ damage
To monitor the effect of BP lowering drugs
In shock- to avoid hypotension
Monitor anaesthesia- to avoid hypotension
Causes of hypertension
Situational, stress induced Measurement error Kidney diseases Adrenal gland e.g Cushing's Hyperthyroidism
Conseqeunces of hypertension- target organ damage
Eye- cornea and retinopathy, maybe permanent blindness
Brain
Heart
Kidney- proteinuria
Most often no clinical signs
Methods of measuring blood pressure
Direct/invasive: arterial cannulation! but this is painful and sedation is required
Indirect/non-invasive: Doppler, oscillometry
General technique for measuring the blood pressure
Calm environment, acclimatization
Take mean of 3-5 measurements
If very high- has to be repeated at least 30 mins later
Cuff-size is 30-40% limb or tail circumference
-if too big the measurement is higher!
Doppler method
Better in cats vs dogs
Oscillometry
Determination of the mean arterial pressure (MAP)
Use the a. caud. med on the tail but if the tail is not possible use the FL a. brachialis
Additional tests
Blood tests: ANP, BNP, troponin, endothelin Phonocardiography (PCG) Non-selective angiocardiography Cardiac catherization Radionuclide imaging Serology for e.g Lyme
