Merkur, a Croatian trade association, was founded on January 19, 1873 in Zagreb with the goal of improving the socioeconomic position of merchants. As the number of members constantly grew, especially between 1920 and 1930, so did the desire to improve the healthcare for their members.

An initiative to build a new sanatorium emerged within the Merkur society. Since the financial resources for the construction a new sanatorium could not be secured, the society decided to buy the Pogorelac villa on Florianski put, which is today called Zajčeva Street. The adaptation of the villa to the needs of the sanatorium began, and the Merkur sanatorium was opened on January 6, 1930 with 36 patient beds.

After three expansions, the Merkur sanatorium, now with 333 beds, changed its name to the dr. Ozren Novosel General Hospital in 1959, and the first department founded in the sanatorium, the Internal Medicine Department, became the Internal Medicine Clinic. In 1974 the dr. Ozren Novosel General Hospital became the Internal Medicine Clinic, but went back to its original name, University Hospital (UH) “Merkur”, on May 30, 1992.

The first clinic in UH “Merkur”, the Internal Medicine Clinic, continued its professional rise and opened the Intensive Care Unit (ICU) on November 11, 1970, from which the Coronary Care Unit (CCU) was formed in 1976. The CCU had five beds, four General Electric vital function monitors, one defibrillator, and one joint ECG device from the RIZ company.

The First CCU head nurse was Milka Rogić who headed the CCU and ICU together with Štefica Čuljat until 1986 when Dubravka Rovčanić became head nurse. The first unit head for the CCU was Dr Dženana Rezaković. Another mobile vital function monitor was acquired during this period, as well as an EV-800 respirator and a new Siemens defibrillator. In 1989/90, Biserka Sedić became head nurse, and Dr Rezaković was replaced by Dr Stjepan Kranjčević. On October 1, 1993, Zdenka Ćurić became head nurse, and Dr Darko Počanić replaced Dr Stjepan Kranjčević in 1994. Since its foundation, the CCU accepted critically ill with acute coronary syndrome (ACS) or life-threatening arrhythmias. As soon as it was opened, the CCU performed implantation of both temporary and permanent pacemakers in addition to vital function monitoring and reanimation procedures. Permanent pacemakers were implanted in the surgical department’s operating halls and monitored in the CCU until the invasive procedure laboratory was opened in 2007.

Over the course of 1996/1997 the CCU was completed renovated with money from grants collected by Dr Stjepan Kranjčević. In addition to changing the electrical and plumbing systems and completely replacing the furniture, a medical gas supply system was installed as well (O₂, vacuum, and air). A new monitoring system was bought, as well as a new respirator, ECG, and an AT-10 ergometry machine from the Schiller company. Zdenka Ćurić and Dr Darko Počanić led the CCU until June 1, 2014. The CCU was reorganized and merged with the ICU into a new department called the Department for Arrhythmias, Acute Coronary Syndrome, and Intensive Medicine, whereupon Petra Kušter became the head nurse and Dr Darko Počanić the head of the new department. The department formally comprises 12 beds (5 CCU + 7 ICU). This department employs two subspecialist physicians, one cardiology resident, and the department head. The team includes 21 nurses (9 with bachelor’s degrees and 12 with vocational nursing school, of which 5 are attending the Zagreb Health Studies college, and the head nurse Petra Kušter).

The healthcare team comprises:

The CCU is equipped with a monitoring system by the Dräger company, while the ICU has a monitoring system made by the Elektroničar company. Together they have four respirators, one Oxylog ventilator, three defibrillators, two electrocardiographs, two emergency carts, three single-lead and one dual-lead portable pacemaker, and one extracorporeal membrane oxygenation device that has been lended to the University Hospital for Infectious Diseases "Dr Fran Mihaljević", Zagreb due to lack of personnel trained to use it.

The acquisition of a mobile echocardiography device for both units is planned because the transportation of patients to the echocardiographic laboratory can represent a life-threatening risk for patients.

Within the hospital budget (every unit has its special limit), the CCU is responsible for patients with acute coronary syndrome, arrhythmias, and pacemaker (single-lead, dual lead, ICD, CRT) and loop recorder acquisition.

We have recorded a constant increase in admissions over the past five years (Table 1), and the existing space has become too small, as has the financial limit which has been reduced by 20% in the last three years.

The ICU (which forms the new department with the CCU) treats the most critical patients with hematological, gastroenterological, and nephrological issues and consequently also patients with pre-transplant and post-transplant issues. Such patients require on-call specialists from all branches of internal medicine and nurses who have the knowledge and skills to respond to all the challenges of modern medicine. In order to improve monitoring and treatment quality for patients at our department, cardiologists have been organizing a readiness program over the last three years, with a tendency to also introduce call duty for cardiologists.

The members of the Merkur society were proud of their sanatorium. The Merkur newsletter published (in November of 1937) an editorial article titled “Our Pride” which said: “The Merkur sanatorium is an expression of our virtues. It is a document of our love for one another, our self-sacrifice, and our altruistic work. It is the strongest proof of our social consciousness. It is the burning focus of our humane efforts.”

True to this quote, the staff of the Department for Arrhythmias, Acute Coronary Syndrome, and Intensive Medicine (Figure 1) strive to create a center of excellence that will improve the overall quality of the clinic and of the hospital as a whole.