The heart is a body organ formed by various components, including blood vessels, muscles, membranes, valves, the nervous system and the heart’s electrical system. Under normal conditions, all of these parts work together to ensure the heart functions properly, pumping blood efficiently without stopping. Disorders of one of the components of the heart can result in various types of heart disease, one of which is heart rhythm disturbances or arrhythmias.
Heart rhythm disturbances occur because there is a disturbance in the formation and/or transmission of electrical impulses from the atria to the ventricles of the heart. This results in an irregular heartbeat rhythm, which can be too slow or too fast. One type of arrhythmia that needs to be watched out for is ventricular arrhythmia, which is a heart rhythm disturbance that occurs in the heart chambers. More than 80 percent of arrhythmias in sudden death are ventricular arrhythmias.
According to Dr. Novita Gemalasari Liman, Sp.JP, FIHA, student of the Doctor of Medicine Study Program (Prodi), Faculty of Medicine (FK) Universitas Indonesia (UI), the most common type of ventricular heart rhythm disorder is idiopathic Premature Ventricular Complex (PVC), with a prevalence 5–12 percent in the general population. In cases of idiopathic PVC, around 88 percent of patients experience a decrease in heart pumping function so that the heart weakens.
In her research, Novita said that researchers at the University of California, Los Angeles, in 2019 found that PVC load follows a circadian rhythm, namely, a biological rhythm with a 24-hour period that functions to synchronize the function of the body’s internal organs with changes in the environment from morning to evening. This shows that the PVC load changes throughout the day, like the biological clock in our body. There are three types of circadian rhythms of PVC load, namely the fast type (domination of PVC load in the morning and afternoon), slow type (domination of PVC load in the evening), and the independent type (consistent PVC load throughout the day).
In this regard, Novita explored the parameters related to the circadian rhythm of idiopathic PVC so that it could be developed into one of the basic points for individualizing therapy according to the circadian rhythm of PVC. Novita performed a Holter examination for 24 hours to monitor the heart rhythm of PVC patients. Novita also took saliva samples at three different times of the day to see levels of certain hormones associated with stress. Additionally, she asked participants to fill out a questionnaire about their stress levels.
The research results showed that the circadian rhythms of fast, slow and independent types of PVC load were each specifically related to the system that produces hormones in stressful conditions, the autonomic nervous system, and psychological aspects. Assessment of the type of circadian rhythm of idiopathic PVC needs to be carried out routinely considering the differences in the underlying processes and possible differences in the course of the disease.
Novita hopes that her research can help in designing better treatments for PVC patients. For example, if someone has a dominant PVC heart rhythm in the morning, such as a fast type of PVC, antiarrhythmic therapy treatment will be given in the morning to make it more effective.
Thanks to the research entitled “Analysis of Cortisol Circadian Rhythms and Circadian Rhythms of Autonomic Nervous System Activity and Subjective Health Scales in Idiopathic Premature Ventricular Complexes”, Novita received a doctorate degree from FKUI. The doctoral promotion session was held in the Teaching Theater Room, 6th Floor of the Education Tower, IMERI FKUI Building, Salemba, Jakarta, on Monday (4/9). In the promotion trial, Novita was declared to have graduated with the title Summa Cum Laude at the age of just 30 years.
“I really like the term lifelong learning. I enjoy science because knowledge and skills enable me to improve the quality of life of patients. The reason I became a heart and blood vessel specialist is because it is one of the fields that serves patients with conditions that require emergency and life saving services,” said Novita.
The doctoral promotion session was chaired by the Dean of FKUI, Prof. Dr. Dr. Ari Fahrial Syam, Sp.PD-KGEH, MMB. The promoter for this doctoral promotion session was Professor of Heart and Blood Vessel Diseases, FKUI-RSPJN Harapan Kita, Prof. Dr. dr. Bambang Budi Siswanto, Sp.JP(K), FACC with co-promoter namely dr. Sunu Budhi Raharjo, Sp.JP(K), Ph.D and Dr. Dr. Ina Susianti Timan, Sp.PK(K), MARS. The examining team is chaired by Prof. Dr. Dr. Suhendro, Sp.PD-KPTI with members namely Prof. Dr. Franciscus D. Suyatna, Ph.D, Sp.FK; Prof. Dr. Dr. Salim Haris, Sp.S(K), FICA; Dr. Dr. Joedo Prihartono, MPH; Dr. Dr. Kristiana Siste, Sp.KJ(K); and guest examiner from Brawijaya University, Prof. Dr. Mohammad Saifur Rohman, Sp.JP(K), Ph.D.
