The innocent cardiac murmur: an anesthetic approach Gert Poortmans Adj-kliniekhoofd Anesthesie UZ Leuven
Definition: An innocent murmur: a murmur in the absence of structural t or physiological i l cardiac disease. Aka: functional, inorganic, innocuous, dynamic, benign Normal: important message for parents Exercise Competitive activities Endocarditis prophylaxis
Extent of the problem: CHD: 0,8-1% neonates 0,1 0,2% preschool and schoolchildren Murmur: common finding Neonates: 60% 16% innocent??? Preschool and schoolschildren: 72%: 8-96% Maximum incidence between 3 and 7 yrs.
The innocent / pathology ratio increases with age. In the child younger than 6 months, the combination of structural heart disease with a cardiac murmur is more prevalent then in the elder in which the vast majority of murmurs represent the normal state.
Clinical questions Is there a cardiac abnormality that represents a significant hemodynamic risk during anesthesia and surgery Is there a predisposition to infectious endocarditis Need for further technical evaluation: echo
The goal is to discriminate between innocent murmurs and pathological l murmurs on clinical i l grounds. History Physical examination, appearance
History: The goal of the history taking is to exclude arguments indicating a heightened ht risk for structural t pathology. Personal history Family history
Personal History Obstetric history Infections: teratogenic in first trimester Medications: lithium, valproate... Drugs Gestational diabetes: PDA, CoA, TGV, VSD +30% Perinatal history Prematurity IUGR Low birth weight: 1500g > 50% CHD Previous disease: history of respiratory infections Growth and development Poor weight gain, failure to thrive Habits: exercise tolerance of peers, feeding history
Family History CHD in relatives (first degree) Increased risk 3-10x HOCM: sudden death Autosomal dominant inheritance 20 60% Maternal lupus
Physical examination, appearance: Tachypnoea, nasal flairing, clubbing, cyanosis Acrocyanosis, central cyanosis Anemia, pallor, jaundice, hepatomegaly Pectus excavatum, carinatum Pulses: upper and lower limbs
Acrocyanosis or peripheral cyanosis: cold, vasoconstricted: perioral, perinasal, nailbeds Decreases with activity Central cyanosis: involvement of the warm mucous membranes: tongue, buccal mucosa Increases with activity
Cardiac Murmurs: Classification Timing Systolic ( early, mid, late), diastolic, continuous Intensity Grades: 1-6 Location Point of maximum intensity and radiation Duration Configuration Pitch Diamond shaped, rectangular, tapering Frequency range Quality Musicality: harmonics, overtones
Murmurs: clinical approach Intensity Location, radiation Timing
Types of innocent murmurs: Still s murmur. Pulmonary flow murmur. Supraclavicular or carotid bruit. Transient peripheral pulmonary stenosis murmur. Venous hum. Mammary soufflé
Still s murmur Most common Most typically 2-6 yrs: 75 85% Early systolic Musical DD: small VSD, HOCM Origin?? False tendons in LV Fysiologic i narrowing of flvot Dynamic vibrations in LV blood mass
Pulmonary flow murmur 8 12 yrs Early to mid-systolic Localised Noise Increased by supine position, pectus excavatum, fever, post-exercise, straight back or kyphoscoliosis DD: ASD, PS
Supraclavicular or carotid bruit Adolescents, young adults Aortic Arch branching in brachiocephalic arteries Supraclavicular fossa Decreases with shoulder hyperextension DD AS, MI, CoA, PS
Transient peripheral pulmonary stenosis murmur Neonate Disappears by 6 wks 6 mths Radiation to axilla and back 50% of innocent murmurs in neonates Acute angling and caliber difference between MPA en R/L PA
Venous hum 3 8 yrs Lateral to the sternocleidomastoid muscle Extending to infraclavicular R > L Increased by sitting Increased by looking away Turbulence at confluence of VJI, VS and VCS
Innocent murmurs share a common physiology. They are situated t at tthe upper range of normal physiology, higher velocities, greater caliber differences and angles
Innocent vs Pathological Systolic exc. Venous hum Never solely diastolic Short Low intensity No thrills No accessory sounds or clicks Located exc. Transient Pulmonary Stenosis flow murmur Varies with physiological maneuvers No relevant history No symptoms Normal exerciseercise tolerance
Algoritm: Cardiac murmur: Symptoms History Yes Technical investigations Anesthetic ti plan AB-profylaxis No Auscultation
Auscultation Properties of innocent murmur Yes No Technical investigations Anesthetic ti plan AB-profylaxis Proceed with surgery
What have we learned today?
1 The incidence of innocent cardiac murmurs is high. 2 The ratio of innocent on pathological murmurs increases with age. 3 The clinical diagnosis on innocence can only be made in the absence of symptoms. 4 An innocent murmur has no influence on anesthetic ti conduct of the case.