Michele Landolfi (1878 - 1959) medico italiano

Michele Landolfi (1878-1959) was an Italian physician.

Chief Editor of the Italian journals “Folia Medica” and “Riforma Medica” and long time Professor of Medical Semiotics at the University of Naples. Landolfi was founder and first President of the Neapolitan section of Associazione Volontari Italiani del Sangue (AVIS)

Landolfi studied pulmonary tuberculosis and invented the phonacoscope (fonacoscopio) to aid in diagnosis. Best remembered for Landolfi sign in severe aortic regurgitation which he described in 1909

  • Born on March 3, 1878 in Airola, Italy
  • 1902 – Graduated medical school in Naples as a pupil of Leonard Bianchi (1848–1927), Pietro Francesco Castellino (1864–1933) and Antonio Cardarelli (1831–1927)
  • 1903 – Assistant to Domenico Capozzi (1829–1907) at the l’Ospedale degli Incurabili, Naples
  • 1904 – Lecturer at III Clinica medica di Gaetano Rummo
  • 1906 – Invented and patented the ‘fonacoscopio‘ for the diagnosis of pulmonary tuberculosis
  • 1919 – Ran for local government for the “Democratico sociale”
  • Professor of Semiotica Medica nell’Università di Napoli “Federico II”
  • Honors include: Commendatore della Corona d’Italia and Cavaliere dell’Ordine Mauriziano
  • Died on March 7, 1959 in Napoli

Medical Eponyms
Landolfi sign (1909)

Rapidly alternating systolic constriction and diastolic dilation of the pupil occurring in severe aortic regurgitation. Believed to be an exaggeration of the physiologic circulatory hippus in the iridal vessels due to high pulse pressure and large stroke volume

Pupillary hippus is the spasmodic, cyclical and bilaterally in-phase fluctuations in pupil size in the absence of external influences such as luminance, mood and fixation. Its mechanism remains unclear but is hypothesised to be due to the continuous neurologic antagonism of the SNS and PSNS as well as respiratory and cardiac activity.

Landolfi examined twenty-four patients with grave aortic insufficiency, and found in one circulatory hippus.

…rhythmic movement of narrowing and dilatation of the pupil independent of the will of the patient and the ambient lighting….because the changes of the iris were synchronous to the movements of the heart, narrowing of the pupil corresponded to ventricular systole and dilatation to diastole.

The phenomenon was accentuated by keeping the subject standing, administering foxglove [digitalis], running, or compressing the femoral or abdominal aorta. In contrast, it became less obvious when the patient was lying down, kept at prolonged rest, or when he took bromides or inhaled nitrite.

The pathological cardiovascular hippus, that is the rhythmic hippus that is synchronous with movements of the heart and very accentuated manifest during systole only in pure well compensated aortic insufficiency. The sign when it exists is therefore pathognomonic of this affection, but its absence has no meaning.

Landolfi 1909

The patient suffered from arteriosclerosis with aortic insufficiency and hypertrophy of the left ventricle. A rapid alternate contraction and dilatation of pupil was observed. He was also able to produce this sign in three other patients after giving fifteen drops of tincture of digitalis a day for four days. He also observed the circulatory hippus in a dog with experimental aortic insufficiency after the administration of heart stimulants.

New York Medical Journal 1909

Clinical Examples
Case 1

Rapid alternate constriction and dilation of the left pupil occurring synchronously with heartbeat [Saini et al. Am J Med. 2017]

Landolfi sign: Saini et al. Am J Med. 2017

Case 2

A 73-year-old man with severe aortic regurgitation. Ocular exam revealed pupil dilation and constriction synchronized with his heartbeat. [N Engl J Med 2019; 381:e29]

Landolfi’s sign NEJM 2019

Case 3

Landolfi sign in a 45 yo female patient with aortic regurgitation admitted for native aortic valve endocarditis

Landolfi sign

Key Medical Attributions
Phonacoscopy (fonacoscopio)

While studying pulmonary tuberculosis, Landolfi and Ranieri Papale described a new method of combined auscultation and percussion. They went on to develop the phonacoscope for the diagnosis of disease which he patented and marketed with Carlo Erba in Milan.

  • Device: Bell-shaped resonating chamber containing a percussive hammer.
  • Technique: The patient holds the instrument on the anterior thoracic wall and provides a uniform percussion note for the physician to detect by listening to the posterior chest.
  • Use: Eliminates the variability of a clinician’s percussion note. Useful in diagnosing pneumonia and pleurisy with effusion, pulmonary tuberculosis and other lung conditions that change the acoustic conduction of the thoracic cavity. 

Major Publications



Eponymous terms


Emergency Medicine Trainee based in Perth, Western Australia. Keen interest in ultrasound, rural health and water-based activities.

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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