It was a strange current that is calledfunny

A bit of luck, a good dose of perseverance and a pinch of intuition in engineering. This is the basis of a scientific story ingredients. Dario DiFrancesco is one of the researchers who will leave his name in the history of cardiology. At the end of the 1970s, he continued his post-doctoral research in the most prestigious British universities: Oxford and Cambridge. In the laboratory of Physiology of these European temples of biomedical research, he discovered one of the most amazing secrets of the functioning of the human machinery: the electrical signal that pilot the heart rate. Just thirty years, the Milanese who does not hesitate to sing Arias of Opera in the medical Congress, affects the jackpot. He comes to identify the "conductor" that beats the measurement of the heart muscle. "A few tens of thousands of specific cells located in the upper part of the heart beat spontaneously." This signal is then passed to the entire muscle. "This is the real pacemaker of the heart", indicates the Milanese researcher. This discovery opens a new track of research among cardiologists. By modulating the signal, can vary the frequency of the pulses. This new concept immediately arouses the interest of the pharmaceutical industry which sees a new runway to open to prevent cardiac disorders, such as angina (angina pectoris) and ischemia (lack of movement).

Thirty years after the discovery of Dario DiFrancesco, Servier laboratory presented Saturday at the Congress of the European society of Cardiology in Munich, the results of a survey () which confirms the interest of medicalized regulation of the heart. The Italian researcher will only draw a honorary benefit of the industrial impact of its work. But in June, he had received in Paris one of the most beautiful European scientific prizes awarded by the fondation Lefoulon-Delalande: EUR 500 000 for the "discovery of the ion channels involved in the regulation of the heartbeat." The award was presented under the dome of the Institute and for the occasion Dario DiFrancesco has recovered its French past. "This award has been one of the happiest moments of my life." After England, I almost come and work in Orsay. "But, in fact, I too like the Italy," indicates this simply pleased to live scientist and saying "just curious".

Enormous impact for the sick

In fact, the Italian researcher has detected a signal on an area of the heart called "sinus node" (see illustration). "It was a strange current that is called"funny"." "Immediately, it has realized its importance", says the scientist. The surface of these very localized contractile cells is lined receptors and channels which are gateways in the cell factory. The first receive information and stimuli in the external environment: "adrenaline speeds up heart rate and acetylcholine slows." The latter let ions to control electric current. Under the effect of signals of different forms, the cell is polarized and depolarizes, it contracts and relaxes alternately. Heartbeats that arise in the sinus node spread to the whole muscle.

This phenomenon is automatic. Cells in a rabbit sinus node placed in a supportive environment in vitro pulsate spontaneously. By altering the shape of the current Funny (If), it can adjust the pace of work of the heart pump, without altering its power for the rejection of the blood. It is sufficient to find a molecule that closes the ion channel and acts as a kind of biological fuses. In the heart, the impact of this regulation is huge. "Beyond 70 beats per minute, the risk of ischemia increases 70 ", says Jean-Paul Vilaine, Director of cardiovascular research at Servier.

Alternative treatment

According to the French laboratory, a decrease in heart rate 10 beats per minute brings a significant gain in people with cardiovascular disease. The cardiac frequency selective inhibitor developed (ivabradine) is now an alternative to existing treatments (-blockers and calcium channel blockers). In France, about 2 and a half million patients suffer from coronary problems and there annually between 120,000 and 130,000 infarction. "When the heart rate exceeds 80 beats per minute, the risk of rupture of atherosclerotic plaque is tripled," adds Arnaud Lallouette, Director of cardiovascular science division in the French industrialist.

Since the early work of Dario DiFrancesco, four channels of slightly different shape allowing the Funny current have been identified in the body (HCN channels). Their respective genes have been discovered and cloned. The HCN4 form predominates in the heart, but other variants are present in the brain. At the time, hopefully treat epilepsy by acting on ion channels and operating signal discovered by Dario DiFrancesco thirty years ago.