11/01/2026
🫀 The Sixth Heart Sound – the Bulgarian Discovery That Changed Cardiology
Did you know that one of the very few world-recognized medical discoveries made by a Bulgarian is related to the sound of the heart? 🔊🫀 This is not a myth, but science — and behind it stands Professor Ivan Mitchev.
📌 For decades, medicine accepted that the heart has four sounds, with only the first and second used routinely in clinical practice. In 1968, however, Professor Mitchev proved the existence of the sixth heart sound — objectively recorded, scientifically analyzed, and accepted by the international cardiology community. This was not a hypothesis, but a fact that entered medical textbooks.
🔍 What makes this discovery so important? The sixth heart sound provides additional insight into the functional state of the myocardium, especially in early pathological changes. This allows for better diagnostics, earlier disease recognition, and more informed clinical decision-making.
🎓 Professor Mitchev was not only a discoverer. He was a physician, a teacher, and the founder of a medical school — a man who demonstrated that Bulgarian medicine can contribute at a global level, not merely follow established foreign models.
❗ In an era of fast medicine and rigid protocols, it is worth remembering that true progress comes from observation, critical thinking, and the courage to challenge what is “accepted.” That is exactly what Ivan Mitchev did.
