The Early Development of Cardiology in Zurich–A Personal Account Part I ^†

Thanks to the outstanding surgical talent and competence of Åke Senning, since 1961 head of cardiovascular and visceral surgery at the University Hospital of Zurich, the indications for operative corrections were gradually extended to most congenital and acquired heart diseases. His influence considerably stimulated and challenged all those working in the field of heart disease in the Medical Clinic (Paul Lichtlen) and in the Policlinic (Ernst Lüthy) and led ultimately to the development of an official Cardiology Division (Wilhelm Rutishauser) in 1970. Children and adults with acquired and congenital diseases of the heart underwent catheterisation and angiography for a more accurate and quantitative diagnosis. Echocardiographic and Doppler methods only came later. Pressure measurements with fluid-filled and catheter-tip manometers allowed for a precise evaluation of gradients at stenosed valves and dye-dilution and thermodilution permitted flow measurements necessary for the calculation of valve areas. The dye-dilution method allowed for the measurement of right to left and left to right shunts on all levels of the circulation and was superior to the estimation of shunts by oxygen saturation of blood samples. The upstream sampling by dye and thermodilution made the assessment of the severity of valvular regurgitations more accurate before echocardiographic and nuclear methods became available. The characterisation of ventricular function by measurement of dP/dt with tip-manometers during pacing, handgrip and ergometric exercise allowed the study of the performance of the heart. Of considerable interest was the alteration of ventricular function during ischaemia induced with the above-mentioned stress tests in the catheterisation laboratory. A big step forward was the use of angiography in a quantitative way. Densitometry made possible the appreciation of stenoses in vessels more precisely than the measurement of diameter reduction. Cine- and videodensitometry allowed the measurement of blood flow by angiography in individual vessels in conscious men, which was impossible before without the introduction of these devices. The perspective that utilisation of catheters would one day lead to therapeutic interventions on vessels and the heart–reserved until then for surgery–was fascinating and a major impetus. Initiating dilatation of narrowed coronary arteries needed vision and courage. Grüntzig’s previous successes with percutaneous treatment of iliac and femoral stenoses gave us confidence. After careful experiments in dogs with artificial coronary stenoses and intraoperative dilatation Andreas Grüntzig performed the first successful coronary angioplasty on 16 September 1977 on a 36-year-old patient, who is still alive today. Bernhard Meier, responsible for the medical ward of this patient, carefully described the circumstances, later followed Grüntzig to Atlanta and has devoted his life to interventional cardiology.