Carabello sign
Carabello sign
Carabello Sign – Clinical Cardiology
The Carabello sign is a classic bedside clinical sign described in patients with severe aortic stenosis (AS).
🔹 Definition
When a clinician places the finger on the carotid pulse of a patient with severe aortic stenosis, the upstroke of the pulse feels initially sharp, but then the rise abruptly slows down and becomes plateau-like.
This produces the impression of a “spike and dome” pattern on palpation.
🔹 Mechanism
- In severe AS, the left ventricular outflow is obstructed.
- Early in systole, the left ventricle generates high pressure and blood enters the aorta quickly (initial spike).
- As systole progresses, the fixed obstruction at the aortic valve limits further ejection, leading to a slowed late rise (dome).
- This tactile finding corresponds to the slow-rising anacrotic pulse.
🔹 Clinical Importance
- Bedside clue to severe aortic stenosis.
- Correlates with the anacrotic notch on the carotid pulse tracing.
- Helps differentiate severe fixed obstruction (AS) from other causes of systolic murmurs.
🔹 Related Signs in Aortic Stenosis
- Parvus et Tardus pulse → small and delayed carotid upstroke.
- Gallavardin phenomenon → murmur radiating to the apex.
- Systolic thrill in aortic area.
✅ In short:
Carabello sign is the palpable “spike and dome” carotid pulse in severe aortic stenosis, reflecting the initial rapid ejection followed by delayed rise due to fixed obstruction.
Carabello Sign & Clinical Signs of Aortic Stenosis — 20 MCQs
Q1
The Carabello sign describes which palpatory carotid finding in severe aortic stenosis?
Answer B. Carabello sign = tactile “spike and dome”: brisk early upstroke then delayed/plateaued late rise due to fixed outflow obstruction in severe AS.
Q2
Which pulse description best matches the classic carotid pulse in severe aortic stenosis (parvus et tardus)?
Answer C. “Parvus et tardus” = weak (small) and late (delayed) carotid upstroke typical of significant aortic outflow obstruction.
Q3
The systolic murmur of aortic stenosis is classically described as:
Answer B. AS typically produces a harsh systolic ejection murmur that crescendos then decrescendos, best heard at the right upper sternal border and radiating to the carotids.
Q4
Which bedside maneuver increases the intensity of the aortic stenosis murmur?
Answer B. Valsalva (strain) reduces venous return and LV volume — for AS the murmur may become softer or paradoxically louder depending on physiology; classical teaching often tests maneuvers to differentiate AS from HCM; the exam-style answer here emphasizes Valsalva as a provocative maneuver used in auscultatory testing. (Note: for hypertrophic obstructive cardiomyopathy murmur typically increases with Valsalva; AS often decreases with reduced flow.)
Q5
The murmur of aortic stenosis most commonly radiates to:
Answer A. AS classically radiates to the carotids due to transmission of the systolic ejection murmur into the great vessels.
Q6
Which of these is typically absent in severe, long-standing calcific aortic stenosis?
Answer B. An ejection click (from a mobile valve) is usually absent in severe calcific AS because the valve cusps are immobile and heavily calcified; ejection clicks are more common in bicuspid valves or earlier disease.
Q7
Which physical sign indicates severe AS and peripheral hypoperfusion during exertion?
Answer A. Severe AS may cause exertional syncope due to inability to increase cardiac output during activity; it’s a classic symptom indicating advanced disease.
Q8
A decreased intensity of S2 (soft or single S2) in AS is because:
Answer B. Reduced mobility of the calcified aortic valve produces a soft or single (often diminished A2) second heart sound.
Q9
Which additional finding suggests left ventricular hypertrophy in chronic aortic stenosis?
Answer C. Chronic pressure overload causes concentric LV hypertrophy producing a sustained, forceful (heaving) apex impulse rather than lateral displacement seen in volume overload.
Q10
Which statement about intensity of AS murmur and severity is most accurate?
Answer B. Murmur loudness depends on transvalvular flow — severe AS with low output can produce a quieter murmur, so intensity alone is not a reliable guide to severity.
Q11
Which arrhythmia can particularly worsen symptoms in AS due to loss of atrial contribution to LV filling?
Answer A. AF eliminates organized atrial contraction, reducing LV preload; in stiff, hypertrophied ventricles (as in AS), loss of atrial kick significantly reduces cardiac output and worsens symptoms.
Q12
Which imaging/diagnostic test is the gold standard for assessing aortic valve area and severity?
Answer B. Doppler echocardiography (TTE) is the principal noninvasive test to quantify valve area, gradients, and LV function in AS; other tests may supplement but TTE is the standard initial diagnostic tool.
Q13
Pulsus bisferiens (two systolic peaks) is most characteristically associated with:
Answer B. Pulsus bisferiens classically occurs in HOCM and in combined AS+AR conditions; it’s not a typical feature of isolated AS alone.
Q14
Which historical symptom triad is most suggestive of severe symptomatic AS?
Answer C. Classic symptomatic triad of severe AS: exertional angina, exertional syncope, and heart failure (breathlessness/exertional intolerance).
Q15
Which of the following physical findings is a reliable bedside clue to left ventricular hypertrophy due to AS?
Answer B. Pressure overload produces concentric hypertrophy resulting in a sustained, heaving apical impulse rather than lateral displacement (which suggests volume overload).
Q16
Which sign differentiates aortic stenosis from mitral regurgitation on auscultation?
Answer B. AS murmur is an ejection systolic murmur best at the right upper sternal border and radiating to carotids; MR is holosystolic, best at apex, radiating to the axilla — useful distinguishing features.
Q17
Which of the following is an indication for aortic valve replacement in severe symptomatic AS?
Answer C. Symptomatic severe AS is a standard indication for aortic valve replacement (surgical or transcatheter), regardless of age or comorbidity considerations individualized by heart team.
Q18
Which chest X-ray finding is commonly seen in chronic severe AS?
Answer B. CXR may show aortic valve calcification and post-stenotic dilation of the ascending aorta; cardiomegaly can occur but classic LV dilation is less prominent than in volume overload conditions.
Q19
Which physical exam finding is most likely when severe AS is combined with low cardiac output?
Answer B. Severe AS with low output produces weak, low-volume peripheral pulses and often a narrow pulse pressure due to reduced stroke volume.
Q20
Which auscultatory feature would suggest aortic sclerosis rather than significant aortic stenosis?
Answer B. Aortic sclerosis is valve thickening/calcification without significant gradient — you may hear a systolic murmur but carotid upstroke remains relatively normal and there is no hemodynamically significant obstruction.
