Understanding Heart Sounds:
The Technician’s Role in
Helping the Cardiac Patient
Krista Peterson BA, CVT, VTS (Anesthesia)
Technician’s Role in Helping The
Cardiac Patient
• Technician’s role is changing
• Find ways to support DVM’s and help provide the highest quality care to patients
• Many opportunities for technicians to use skills to help cardiology patients
4/3/2015
• Review the anatomy of the heart
• Understand the connection between electrical, mechanical, and acoustic events in the cardiac cycle
• Discuss abnormal heart sounds and what they can mean to our patients
• Learn how to successfully perform a thorough physical exam and obtain a good clinical history
Heart sound
Physical
Exam
Patient
History
Diagnosis!
These three things can help point the way to the correct diagnosis.
1

• Cardiac Cycle And The Generation of Heart Sounds
– Understanding how electrical, mechanical and acoustic events relate important when performing a CV exam
– Electrical events (depolarization) always precede mechanical activation (contraction)
Systolic vs. Diastolic
–
Systolic
• Ventricular contraction
• 1/3 of cardiac cycle
– Diastolic
• Ventricular relaxation
• 2/3 of cardiac cycle
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• Four main sounds produced during cardiac cycle: S1, S2,
S3, S4
• Usually only 1 st (S1) and 2
(S2) can be heard nd http://jamanetwork.com/data/Journals/JAMA/4975/joc50029f1.png
• Normal Heart Sound
– S1 (lub) results from L and R
AV valves closing
–
S2 (dup) results from
Pulmonary and Aortic valves closing
• Pathological Heart Sounds
–
S3, S4
– More on these later!
Abnormal Heart Sounds: Murmurs
• What is a murmur?
– Sounds produced by turbulent blood flow.
– Physiologic (innocent), functional or pathologic
– Different murmurs: deciphering murmur can point to disease
2

Heart Murmurs: What Causes Them?
– Physiologic
• Stress
•
Rapid heart rate
• Puppies/kittens <16 weeks
– Functional (caused by extra-cardiac problem)
• Fever
• Infection
• Pregnancy
• Low blood viscosity
– Anemia
– Hypoproteinemia
• Usually low intensity
(quiet murmurs)
• Do not cause heart related symptoms or clinical signs
Heart Murmurs: What Causes Them?
– Pathologic
• Sturctural abnormalities in the valves, septae or arteries and veins of the heart
–
Leaky valves
(degenerative valves)
– Narrowed valves
(stenosis)
– Holes in the heart
(septal defects, PDA)
•
•
Congenital (born with it)
• Acquired (develops later in life)
Extra-cardiac (hyperthyroid) http://uvahealth.com/Plone/ebsco_images/6715.jpg
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• Degenerative valve • Septal Defect
• Patent Ductus Arteriosus http://www.lucinafoundation.org/assets/ventriculardefect.jpg
http://neonatalechoskills.com/PDA%20Heart%20pic.JPG
http://www.heart-valve-surgery.com/Images/mitral-valve-regurgitation-diagram_3.jpg
http://o.quizlet.com/ynJrN8WpUSt6pN23IplqCQ_m.png
• Uniform method of describing murmurs
• 5 parameters
– Location
– Timing (position in cardiac cycle)
– Intensity
• Graded I-VI
– Quality (duration and pattern of intensity)
– Character (pitch)
How To Describe a Murmur: Location
• Location
– Point of maximal intensity (PMI) –location where murmur is loudest
– Often refer to valve location nearest
– Knowing position of the heart/anatomy is important!
3

Position of Heart in The Patient
How To Describe a Murmur: Timing
• Timing (position in cardiac cycle)
• Occur during Systole (vast majority)or Diastole
– Early or Late
– Holo: Lasts throughout systole or diastole but does not obliterate heart sounds
– Pan: Lasts throughout systole or diastole and obliterates heart sounds
– Continuous : Last throughout most or all of systole and diastole
– Use femoral pulse wave to help determine timing
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How To Describe a Murmur: Intensity
– Loudness of a murmur reflects the amount of turbulence
– Loudness does not always correlate with severity of disease
– Official Scale
• 6 point scale –higher more severe the murmur
How To Describe a Murmur: Intensity
Official Scale
Graded I-VI
• Grade I –Not easily heard, comes and goes
• Grade II -Distinct (always there) but very soft
• Grade III -Distinct, low to moderate intensity
• Grade IV -Very loud but no thrill
• Grade V -Very loud, palpable thrill
• Grade VI -Very loud, can be heard with stethoscope 1” away from chest wall.
Simple version
– Soft
•
Grade 1 &2
• Did I hear that?
• Focal with no radiation
– Moderate
•
Grade 3 & 4
•
Easy to hear
•
Some radiation
– Loud
• Grade 5 &6
• Whoa!
• Good radiation
• Palpable precordial thrill
How To Describe a Murmur: Quality
• Quality
– Describes the phonocardiographic shape of the murmur
4

How To Describe a Murmur: Character
• Character describes the pitch and frequency of a murmur
– Blowing, honking, harsh, noisy, musical
Parameter
Intensity
Timing
Location
Quality
Character
Description
Grade I –Not easily heard, comes and goes
Grade II-Distinct (always there) but very soft
Grade III-Distinct, low to moderate intensity
Grade IV-Very loud but no thrill
Grade V-Very loud, palpable thrill
Grade VI-Very loud, can be heard with stethoscope 1” away from chest wall.
Systolic, Diastolic, Pan, Holo, Early, Late,
Continuous
Pulmonic, Aortic, Mitral, Tricuspid
Plateau, crescendo, decrescendo, diamond
Blowing, musical, honking, harsh, noisy
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Gallop Sounds
– Occur during diastole
– Not normally audible in dogs and cats
– Lower in frequency, harder to hear
– Ventricular diastolic dysfunction
– Best hear over cardiac apex
– S3 (ventricular gallop)
– S4 (atrial or presystolic gallop)
Gallop Sounds
– S3 (ventricular gallop)
• Low frequency vibrations during rapid ventricular filling phase
• Ventricular dilation with myocardial failure and poor compliance
• Best heard over cardiac apex
“Tennessee”
– S4 (atrial or presystolic gallop)
• Low frequency vibrations –blood flow into ventricles during atrial contraction
• Occurs with abnormal ventricular relaxation/ increased ventricular stiffness
• Think cats!
“Kentucky”
• Systlolic Clicks
– Mid to late systolic sounds
– Best heard over mitral valve
– DVD, valve prolapse
– Often associated with murmur
• Ejection Sounds
– Early systolic
– Best heard over left base
– Valvular pulmonary stenosis
• Pericardial Knock
– Rare
– Early diastolic
– Caused by restrictive pericardium checking ventricular filling
5

Physical Exam of the Cardiac Patient Physical Exam of the Cardiac Patient
• Important tool- Stethoscope!
• Components
–
Binaurals
• Ear pieces should form tight seal in canals
– Bell
•
Amplifies low frequency sounds
•
Applied with light pressure
– Diaphragm
• Amplifies high frequency sounds
• Hold firmly against patient’s skin
• How to use a stethoscope
– Use in a quiet room
– Binaurals should follow direction of ear canals
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• Physical Exam is one of the most important tools to help the cardiac patient!
• Systemic Physical Exam-consistent with each patient
– Head to tail approach
• General appearance
– Breed
– BAR vs. Depressed
– Overall appearance
•
• Muscle wasting
Unthrifty
• MM color/CRT
– Tissue perfusion
– Oxygenation
• Jugular wave
– R sided heart failure http://www.vetnext.com/fotos/IMC07886.jpg
• Feel for Precordial Pulse
– Find PMI with palms
– L>R
– Intensity
– Thrill
• Heart Auscultation
– Find Apex Beat-start there
– Listen for a long time!
– Heart rate
– Feel femoral artery while aucultating
• Heart projects into both thoracic cavities L>R
• Between 3 rd to 6 th intercostal space
• Feel for Apex Beat (aka PMI)
– Vibration produced at start of
V contraction
– Normally palpated on the L side
– 5 th intercostal
–
S1 loudest at this point
• Dogs - in order MAP (Left), T
(Right)
• Cats –sternal, front, back, L, R
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• Arrhythmias
– NSR
– RSA
– Tachycardia
– Bradycardia
– Extrasystole
– Pause/arrest
• Arterial Pulse qualityfemoral artery
– Bounding
– Normal
– Hypokinetic
– Pulse deficits
• Respiratory Rate effort
– Effort
• Inspiratory vs. expiratory
– Lung sounds
• Harsh lung sound
• Crepitus/rhonchus
• Ascites
– Fluid wave
– R sided failure http://vet.uga.edu/ivcvm/courses/VPAT5200/01_circulation/edema/images
/dogabdomenedema.jpg
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– Dyspnea
– Coughing
– Exercise intolerance
– Ataxia/syncopal episodes
– Appetite
– Vomiting and/or diarrhea
– Heartworm status
– Recent stressful events
Questions?
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