Download - Cardiac Murmurs
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Cardiac murmurs1.What is a murmur?2.Pathophysiology of murmur3.Systolic or diastolic4.Physiological or pathological5.Grades of murmur6.Named murmurs7.Causes of murmur
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Auscultation has a reported sensitivity of 70 percent
and a specificity of 98 percent
for detection of valvular heart disease .
The sensitivity and specificity vary substantially with the expertise of the examiner.
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The character of a murmur is described by intensity frequency, low pitch/ high pitch timing, systolic/ diastolic shape, crescendo/ decrescendo location, and mitral/ aortic/ pulmonary/
tricuspid radiation. transmitted to which area…
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Intensity
The intensity of a murmur is determined by
The quantity and velocity of blood flow at the site of its origin
The transmission characteristic of the tissues between blood flow and stethoscope
The site of auscultation or recording, and the distance of transmission.
The intensity declines in the presence of obesity, emphysema, and pericardial effusion.
Murmurs are usually louder in children and in thin individuals.
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Intensity is graded on a 6 point scale
Grade 1 = very faint Grade 2 = quiet but heard immediately Grade 3 = moderately loud Grade 4 = loud with thrill Grade 5 = heard with stethoscope partly off the chest Grade 6 = no stethoscope needed
Grade of more than 4 is associated with thrill.
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Pitch — The frequency of the murmur determines the pitch,
high or low
The quality harsh, rumbling, scratchy, grunting, blowing, squeaky, and musical
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Configuration — The time course of murmur intensity corresponds to the "shape" of a diagram
murmurs are recognized:Crescendo (increasing)
Decrescendo (diminishing)
Crescendo-decrescendo (increasing-decreasing or diamond shaped)
Plateau (unchanged in intensity)
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Location — The location on the patient's chest where the murmur is
loudest is typically described as
apical or parasternal
Parasternal murmurs – intercostal space and right or left side of the sternum
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Timing — The duration of a murmur is assessed by the length of systole or diastole that the murmur occupies.
Systolic murmursMidsystolic (or systolic ejection)Holosystolic (or pansystolic)Early systolicLate systolic
Diastolic murmursEarly diastolicMid-diastolicLate diastolic (or presystolic)Continuous murmurs
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Systolic murmurs —
A systolic murmur starts with or after S1 and terminates before or at S2
Recognized by identifying S1 and S2 and timing them with thecarotid pulse.
Midsystolic(Ejection systolic)murmur – begins after S1 and ends before A2 or P2
Holosystolic (or pansystolic) murmur starts with S1 and extends up to A2 or P2 obscuring both S1 and S2
Early systolic murmur -obscures S1 and extends for a variable length in systole
but does not extend up to S2
Late systolic murmur - starts after S1 and obscures A2 or P2
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Ejection systolic murmur is related to flow of blood across the
semilunar valves
S1 occurs at the onset of isovolumic systole when ventricular pressure rises;
ESM begins at the end of isovolumics ystole when the ventricular pressure exceed the semilunar valve opening pressure.
The onset of ESM is therefore separated from S1 and the interval between S1 and the onset of the murmur is proportional to the duration of isovolumic systole
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The intensity of the ESM increases (crescendo) during acceleration of blood flow early in systole;
intensity declines (decrescendo) with the later deceleration of flow, resulting in a crescendo decrescendo (DIAMOND SHAPED) configuration.
Forward flow from the ventricle stops when ventricular pressure falls
below the aortic or pulmonary artery pressures, before the closure of the semilunar valves.
The murmur terminates with cessation of flow, before A2 or P2, depending upon whether the murmur is left or right sided, respectively.
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Causes of ESM
1.Flow murmurs across pulmonary area in anaemia and other hyperdynamic circulation
2.Aortic valve sclerosis3.Aortic/ pulmonary stenosis4.Idiopathic dilatation of pulmonary artery
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Aortic stenosis murmur is described as crescendo descrescendo murmur best heard in the aortic area conducted to carotid in sitting and leaning forward position breath held in expiration
S2 is soft here.Causes 1.Rheumatic 2.Bicuspid 3.Supravalvular AS
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Holosystolic murmur/ Pansystolic murmur
Usually regurgitant murmurs
They occur when blood flows from a chamber whose pressure throughout systole is higher than pressure in the chamber receiving the flow.
There are three causes of holosystolic murmurs:
1.MR2.Tricuspid regurgitation3.VSD
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The timing and duration of holosystolic murmurs are best explained by the hemodynamic changes of MR
Hemodynamically significant MR
regurgitant flow from the left ventricle to the left atrium begins with the
onset of isovolumic systole when pressure in the left ventricle just exceeds
pressure in the left atrium.
Throughout systole and extending to the early part of the isovolumic relaxation phase, the left ventricular pressure remains higher than the left atrial pressure.
Thus, the regurgitant flow continues throughout systole, and even after aortic valve closure, explaining the holosystolic character of the regurgitant murmur.
This also explains why A2 is often drowned by the murmur over the cardiac apex.
The same mechanism applies to TR and VSD
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MR TR VSD
Point of maximum intensity
Apex Tricuspid area
Lft. 3 rd or 4 th intercostal spaces
Changes with respiration
Increases with expiration
Increases with inspiration( CARVALLOS SIGN)
Increases with expiration
Heart sounds S1 soft S 1 soft, assc with loud P2
S1, S2 normal intensity
Assc features S3 gallop Raised JVP
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Mitral regurgitation — The holosystolic murmur of MR is high pitched and best heard with the diaphragm of the stethoscope and the patient in the left lateral decubitus position breath held in expiration
The direction of radiation follows the direction of the regurgitant jet into the left atrium.
When anterior leaflet is involved the murmur radiates towards axilla and when posterior leaflet is involved it radiates towards the sternum
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EARLY SYSTOLIC MURMURS Early systolic murmurs begin with S1, do not
extend to S2, and
generally have a decrescendo configuration.
Common causes 1.Acute MR 2.Chronic mild MR
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LATE SYSTOLIC MURMUR
A late systolic murmur starts after S1 and, if left-sided, extends to A2, usually in a crescendo manner
Mitral valve prolapse — Mitral valve prolapse is the most common cause of a late systolic murmur.
It is best heard with the diaphragm of the stethoscope, over or just medial to the cardiac apex.
It is usually preceded by single or multiple clicks
The murmur is heard as a whoop" or "honk," which is a high-frequency, musical, loud, and widely transmitted murmur, can appear intermittently in some patients with mitral valve prolapse and may be precipitated by a change of posture.
Papillary muscle dysfunctionTricuspid valve prolapse
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Diastolic murmurs — A diastolic murmur starts with or after S2 and ends at or before S1.
Early diastolic murmur starts with A2 or P2 and extends into diastole for a variable duration
Mid-diastolic murmur- starts after S2 and terminates before S1
Late diastolic (presystolic) murmur -starts well after S2 and extends up to the
S1
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EARLY DIASTOLIC MURMURS —
Early diastolic murmurs occur due to aortic or pulmonary regurgitation, typically start at the time of semilunar valve closure and their onset coincides with S2.
An aortic regurgitation murmur begins with A2; pulmonary regurgitation begins with P2.
Two common causes
1.Aortic reurgitation2.Pulmonary reurgitation
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The murmur of aortic regurgitation
Best heard with the diaphragm of the stethoscope.
Low-intensity, high-pitched
Heard with firm pressure applied with the diaphragm of the stethoscope over the left sternal border or over the right second interspace,
patient in sitting position and leaning forward with the breath held in full expiration
Not associated with thrill
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The radiation of an aortic regurgitation murmur is towards the cardiac apex
Radiation of the murmur to the right sternal border is more common in aortic regurgitation caused by aortic root or aortic cusp anomalies
The configuration of the aortic regurgitation murmur is usually decrescendo because the magnitude of regurgitation progressively declines.
The murmur is high-frequency and has a "blowing" character.
Occasionally the murmur can be musical in quality (diastolic whoop); this has been attributed to a flail everted aortic cusp.
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An Austin Flint murmur( Mid Diastolic Murmur) is usually associated with significant aortic regurgitation
Reversed splitting of S2, suggests significant aortic regurgitation.
Reduced intensity of S 1 is usually associated with an
elevated left ventricular end-diastolic pressure, which is more likely to occur in severe aortic regurgitation.
Physical findings of pulmonary venous and arterial hypertension and right-sided heart failure indicate hemodynamically significant aortic regurgitation.
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Pulmonic regurgitation is a result of pulmonic hypertension (Graham- Steell murmur) or residual after Tetralogy of Fallot repair in adults
The murmur of pulmonic regurgitation ,
is high-pitched and "blowing." decrescendo configuration differentiation from AR is difficult if by auscultation alone. The murmur increase in intensity during inspiration more
localized. It is best heard over the left second and third interspaces.
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Mid diastolic murmur
MID-DIASTOLIC MURMURS — Mid-diastolic murmurs result from turbulent flow
across the atrioventricular valves during the rapid filling
phase because of mitral or tricuspid valve stenosis and an abnormal
pattern of flow across these valves.
1.Mitral stenosis2.Tricuspid stenosis3.Atrial myxoma4.Right bunde branch block5.Austin flint murmur6.Flow murmur in VSD, ASD and PDA7.Carey coombs murmur
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Mitral stenosis —
The mid-diastolic murmur of mitral stenosis has a rumbling character and is best heard with the bell of the stethoscope over the left ventricular impulse with the patient in the left lateral decubitus position
The murmur is present both in sinus rhythm and in atrial fibrillation.
It characteristically starts with an opening snap.
The longer the duration of the murmur, the more severe is the mitral stenosis.
Associated with pre systolic accentuation.
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Tricuspid stenosis — Tricuspid stenosis may be associated with a mid-
diastolic rumble that is best heard along the left sternal border.
The most characteristic feature is the increase in intensity of the
murmur with inspiration (Carvallo's sign)
Atrial myxoma — Atrial myxoma may cause obstruction of the
atrioventricular valves and a mid-diastolic murmur.
In left atrial myxoma, the auscultatory findings can be similar to
those of mitral stenosis.
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Austin Flint murmur — An apical diastolic rumbling murmur has been described in patients with pure aortic regurgitation
Three mechanisms proposed
1.Fluttering of the mitral valve from the impingement by the aortic regurgitant jet
2.Premature partial closing movement of the mitral valve at mid-diastole due to the regurgitant flow, leading to functional mitral stenosis.
3. Murmur arises from the regurgitant jets that are directed at the left ventricular free wall
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Carey-Coombs murmur —
In acute rheumatic fevera mid-diastolic murmur over the left ventricular impulse Two causes
1.Acute mitral valvulitis.
2.First-degree atrioventricular block may contribute to a Carey-Coombs murmur.
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Continuous murmur — A continuous murmur
begins in systole and continues to diastole without interruption, encompassing the S2
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Cervical venous hum Heard in anaemia, disappears on compression
of jugular pulse
Hepatic venous hum Disappears with hepatic pressure
Mammary souffle Disappears upon pressing hard with
stethoscope
Patent ductus arteriosus left 1 st intercostal space
Coronary arteriovenous fistula lower intercostal spaces left
Ruptured aneurysm of sinus of Valsalva sudden , upper right sternal
border
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Bronchial collaterals Assc with TOF
High-grade coarctation Due to collaterals (SUZZMAN S SIGN)
Anomalous left coronary artery arising from pulmonary artery ( ALCAPA) ECG shows MI like
picture
Pulmonary artery branch stenosisPulmonary AV fistula outside
cardiacdullness
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Interventions that change murmur Carvallo's Maneuver
Inhalation will increase the amount of blood filling into the
right ventricle, thereby prolonging ejection time. This will affect the closure of the pulmonary valve.
All right sided murmurs increaseAbrupt standingSquattingValsalva maneuver. One study found the valsalva
maneuver to have a sensitivity of 65%, specificity of 96% in detecting Hypertrophic obstructive cardiomyopathy (HOCM).
Hand gripAmyl nitriteMethoxaminePositioning of the patient
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Named cardiac murmurs1.Carey coombs2.Graham steele3.Austin flint4. Gibsons murmur5.Rittons murmur
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S 2 / systolic murmur variation with posture
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Definition◦ The term “ palpitation” refers to unpleasant
awareness of one own heart beat.
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Normal palpitations occur with exercise, emotions, and stress, or after taking substances that increase adrenergic tone or diminish vagal activity.
Abnormal palpitations usually point to a cardiac arrhythmia.
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Clinical symptoms and signs◦ Flip-flopping in the chest
APCs, VPCs.◦ Rapid fluttering in the chest
Atrial or ventricular arrhythmias, including sinus tachycardia.
◦ Pounding in the neck ( frog sign) Dissociation of atrial and ventricular contractions
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Noncardiac disorders ◦ Anxiety ◦ Anemia◦ Fever ◦ Thyrotoxicosis◦ Hypoglycemia◦ Increased release of cathecolamine ◦ Electrolyte disturbances◦ Drugs ( epinephrine, amphetamine, etc)◦ Caffeine◦ Nicotine
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Cardiac disorders◦ Valvular heart disease◦ Congenital heart disease◦ Coronary heart disease◦ Marked cardiomyopathy◦ Acute left ventricular failure◦ Pericarditis ◦ Prosthetic valve◦ Electronic pacemakers
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Diagnosis evaluation 1. History taking 2. Physical examination 3. 12-lead electrocardiography (ECG) 4. Ambulatory monitoring or reassurance 5. Electrophysiologic study
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Elements in history of patient with complaints of paroxysmal palpitation◦ Characteristics of palpitation◦ Mode of onset◦ Mode of termination◦ Initiating factors◦ Associated symptoms◦ Incidence◦ Effects of previous treatments
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Tachycardias Atrial rates Ventricular rates Regularity Onset and termination
Sinus tachycardia 100 to 150 100 to 150 Regular gradual
Paroxysmal reentrant supraventricualr tachycardia
140 to 200 140 to 200 Usually regular abrupt
Paroxysmal automatic atrial tachycardia
100 to 180 100 to 180 Usually regular Usually abrupt
Paroxysmal atrial tachycardia with block
100 to 250, usually 120 to 180 with 2:1 block
Variable Regular or irregular
Gradual
Multifocal atrial tachycardia
100 to 180 100 to 180 Irregular gradual
Atrial flutter 220 to 350 Variable Regular or irregular
abrupt
Atrial fibrillation >350 Variable Irregular abrupt
Paroxysmal automatic AV-junctional tachycardia
100 to 180 with AV dissociation, usually NSR
100 to 180 Regular Usually abrupt
Paroxysmal ventricular tachycardia
With AV dissociation, usually NSR
140 to 200 Regular or slightly irregular
abrupt
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No predisposing factors : most Exercise or emotion : suggesting a role of
adrenergic system At rest or after exercise : suggesting a role
of the vagus.
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Chest pain Anxiety Fear Dizziness Syncope
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Atrial fibrillation
Atrio-ventricular nodal tachycardia
Circus movement tachycardia/
atrial tachycardia
Ventricular tachycardia
Blood pressure
Variable Fixed Fixed Variable
Heart sounds Variable Fixed Fixed Variable
Arterial pulsations
Irregular Regular Regular Regular
Jugular pulsations
Absent Frog+ Frog- Cannon waves
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Radio-frequency ablation◦ Most types of supraventricular tachycardia◦ Many types of ventricular tachycardia
Beta-blockers ◦ Isolated VPCs, APCs
Calcium-channel blockers.
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