Heart murmurs and its causes

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"Heart Murmurs"[MeSH Terms]

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heart murmurs causes systolic diastolic continuous MSD Manual professional

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A heart murmur is an extra sound produced by turbulent blood flow through the heart or great vessels. Turbulence may result from increased flow, a narrowed valve/outflow tract, valve leakage, or an abnormal communication such as a septal defect or patent ductus arteriosus. Harrison’s Principles of Internal Medicine, p. 326.

Causes classified by timing

Timing/type	Typical causes	Classic features
Systolic ejection murmur	Innocent/flow murmur in children; fever, anemia, pregnancy, thyrotoxicosis; aortic sclerosis; aortic stenosis; pulmonary stenosis; hypertrophic obstructive cardiomyopathy; atrial septal defect due to increased pulmonary flow	Crescendo-decrescendo, usually between S1 and S2
Holosystolic/pansystolic murmur	Mitral regurgitation, tricuspid regurgitation, ventricular septal defect	Extends from S1 to S2 with uniform intensity
Late systolic murmur	Mitral valve prolapse, sometimes mitral regurgitation	Often follows a midsystolic click
Early diastolic murmur	Aortic regurgitation, pulmonary regurgitation	High-pitched, decrescendo murmur immediately after S2
Mid-diastolic murmur	Mitral stenosis, tricuspid stenosis; increased flow across AV valves, such as severe mitral regurgitation or ASD	Low-pitched rumble; mitral stenosis may have an opening snap
Continuous murmur	Patent ductus arteriosus most classically; arteriovenous fistula; ruptured sinus of Valsalva; venous hum in children	Heard during systole and diastole, continuing across S2

Important points

Systolic murmurs can be innocent or pathological.
Diastolic murmurs are pathological until proven otherwise.
Continuous murmurs generally indicate persistent abnormal flow, commonly a shunt. MSD’s auscultation review describes this timing-based approach.
A soft grade I-II midsystolic murmur in an asymptomatic child or young adult with an otherwise normal examination is often benign. Harrison’s Principles of Internal Medicine, p. 1886.
Echocardiography is generally indicated for a grade III or louder systolic murmur, a holosystolic or late systolic murmur, or most diastolic and continuous murmurs. Harrison’s Principles of Internal Medicine, p. 1886.

Common named murmurs to remember

Aortic stenosis: harsh ejection systolic murmur at right upper sternal border, radiates to carotids.
Mitral regurgitation: blowing holosystolic murmur at apex, radiates to axilla.
Tricuspid regurgitation: holosystolic murmur at lower left sternal border, louder with inspiration.
Ventricular septal defect: harsh pansystolic murmur at lower left sternal border.
Aortic regurgitation: early diastolic blowing decrescendo murmur along left sternal edge.
Mitral stenosis: opening snap followed by low-pitched mid-diastolic apical rumble.
Patent ductus arteriosus: continuous “machinery” murmur, usually left infraclavicular area.
Hypertrophic obstructive cardiomyopathy: systolic murmur that becomes louder with Valsalva or standing.
Mitral valve prolapse: midsystolic click with late systolic murmur.

Seek prompt medical evaluation if a murmur is associated with breathlessness, chest pain, fainting, cyanosis, palpitations, leg swelling, fever, or reduced exercise tolerance.

CNS examination

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"Neurologic Examination"[MeSH Terms]

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CNS neurological examination mental status cranial nerves motor sensory reflexes gait Merck Manual Professional

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CNS examination: systematic approach

A CNS examination evaluates higher mental functions, cranial nerves, motor system, sensory system, reflexes, coordination, gait, and meningeal signs. A practical sequence is:

General observation and consciousness
Higher mental functions
Cranial nerves
Motor system
Reflexes
Sensory system
Cerebellar function and gait
Meningeal signs, if indicated

This structure is consistent with the standard eight-part neurologic examination. Tintinalli’s Emergency Medicine, “Organizational Framework.”

1. General observation and level of consciousness

Observe the patient before beginning:

Posture, spontaneous movements, facial expression
Speech, behavior, hygiene
Gait on entering the room
Any involuntary movements, tremor, fasciculations, abnormal posture
Level of consciousness: alert, drowsy, stuporous, or comatose
If impaired consciousness, document Glasgow Coma Scale: eye opening, verbal response, motor response.

2. Higher mental functions

Assess:

Orientation: person, place, time
Attention/concentration: digit span, serial 7s, months backward
Memory: immediate recall, recent memory, remote memory
Speech and language: fluency, comprehension, naming, repetition, reading/writing
Mood, thought content, insight
Praxis: ability to perform a learned action, such as “show how to use a comb”
Executive function: similarities, planning, problem-solving

A brief normal statement can be:
“Patient is conscious, alert, cooperative, and oriented to time, place, and person. Speech, attention, memory, and language are normal.”

3. Cranial nerve examination

Cranial nerve	Examination
I Olfactory	Identify familiar smell in each nostril separately, if clinically relevant.
II Optic	Visual acuity, visual fields by confrontation, color vision, fundoscopy, pupillary afferent response.
III, IV, VI	Inspect pupils for size/equality; test direct and consensual light reflexes; assess extraocular movements in six directions; look for nystagmus, diplopia, ptosis.
V Trigeminal	Facial sensation in ophthalmic, maxillary, mandibular divisions; clench teeth; corneal reflex if indicated.
VII Facial	Raise eyebrows, close eyes tightly, show teeth, puff cheeks; assess facial symmetry.
VIII Vestibulocochlear	Whisper test; Rinne and Weber tests if hearing is abnormal. Assess balance when relevant.
IX, X Glossopharyngeal/Vagus	Listen for voice quality; observe palate elevation and uvular position while saying “ah”; assess gag reflex only if needed.
XI Accessory	Shoulder shrug and head turning against resistance.
XII Hypoglossal	Protrude tongue: look for wasting, fasciculations, and deviation; assess tongue power.

4. Motor system

Inspection

Look for:

Muscle bulk: wasting or hypertrophy
Fasciculations
Involuntary movements: tremor, chorea, dystonia, myoclonus
Abnormal posture or contractures

Tone

Move each limb passively:

Increased tone
- Spasticity: velocity-dependent, suggests upper motor neuron lesion
- Rigidity: lead-pipe or cogwheel, common in Parkinsonism
Reduced tone: lower motor neuron, cerebellar, or acute upper motor neuron lesions

Power

Test major muscle groups bilaterally and grade power using the MRC scale:

Grade	Power
0	No contraction
1	Flicker of contraction
2	Movement with gravity eliminated
3	Movement against gravity
4	Movement against resistance, but weak
5	Normal power

Also assess pronator drift: ask the patient to hold both arms outstretched, palms up, eyes closed. Downward pronation suggests subtle pyramidal weakness.

5. Reflexes

Deep tendon reflexes

Compare both sides:

Biceps: C5-C6
Supinator/brachioradialis: C5-C6
Triceps: C7-C8
Knee jerk: L3-L4
Ankle jerk: S1-S2

Grade them:

0 absent
1+ diminished
2+ normal
3+ brisk
4+ very brisk, with clonus

Superficial reflexes

Plantar response: stroke lateral sole from heel upward.
- Normal adult: flexor plantar response
- Extensor plantar response/Babinski sign: great toe extension with fanning of other toes, suggesting corticospinal tract dysfunction.

6. Sensory system

Test with the patient’s eyes closed, comparing both sides and moving from abnormal to normal areas.

Primary sensations

Light touch
Pain/pinprick
Temperature if necessary
Vibration: 128-Hz tuning fork at distal bony prominences
Joint position sense: move distal phalanx up or down

Cortical sensory functions

Only if primary sensation is intact:

Stereognosis: identify object placed in hand
Graphesthesia: identify a number traced on palm
Two-point discrimination
Sensory extinction: simultaneous stimulation on both sides

Map sensory loss according to:

Peripheral nerve distribution
Dermatomal pattern
Hemisensory pattern
Sensory level, suggesting spinal cord pathology

7. Cerebellar function, station, and gait

Coordination

Finger-to-nose test
Heel-to-shin test
Rapid alternating movements: dysdiadochokinesia
Rebound phenomenon, if necessary

Look for dysmetria, intention tremor, past pointing, decomposition of movement, and hypotonia.

Romberg test

Ask the patient to stand with feet together:

Eyes open
Eyes closed

A positive Romberg sign suggests impaired proprioception or vestibular dysfunction. Marked unsteadiness with eyes open suggests cerebellar dysfunction.

Gait

Observe:

Normal walking and turning
Tandem gait, heel-to-toe walking
Heel walking and toe walking
Arm swing, stride, base, symmetry, and balance

Common patterns:

Hemiplegic gait: circumduction of one leg
Spastic paraparetic gait: stiff, scissoring legs
Parkinsonian gait: shuffling, short steps, reduced arm swing
Cerebellar gait: broad-based, staggering
Sensory ataxic gait: stamping, worse without visual input
High-steppage gait: foot drop

8. Meningeal signs

Perform when meningitis or subarachnoid hemorrhage is suspected:

Neck stiffness
Kernig sign
Brudzinski sign

Do not force neck movement in suspected cervical spine trauma.

Example of normal CNS examination documentation

Patient is conscious, alert, and oriented to time, place, and person. Speech and higher mental functions are normal. Cranial nerves are intact. Muscle bulk, tone, and power are normal in all four limbs. Deep tendon reflexes are 2+ and symmetrical; plantar responses are flexor bilaterally. Sensory examination is normal for all modalities. Coordination is intact. Gait and tandem gait are normal. No neck stiffness or focal neurological deficit.

For acute neurological symptoms such as new facial droop, unilateral weakness/numbness, speech difficulty, sudden severe headache, seizure, or reduced consciousness, treat it as urgent and seek emergency assessment. A neurologic-exam review emphasizes serial assessment of consciousness, pupils, cranial nerves, strength, sensation, reflexes, and gait when deterioration is possible.

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