Understanding Sleep Apnea and Its Relation to Cardiovascular Disease: An Interview with Bulgarian Cardiologist Dr. Petar Kalaidjiev

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Dr. Petar Kalaidjiev from the Cardiology Clinic of UMBAL “Tsaritsa Joanna – ISUL” was the only presenter from Bulgaria who took part with a poster in the European Congress on Acute Cardiovascular Diseases about a month ago. The Bulgarian cardiologist presented to the prestigious audience his work in the field of sleep apnea and acute heart failure, as well as the experience of the Cardiology Clinic of the “Tsaritsa Joanna – ISUL” UMBAL in the management of these diseases. There are generally two types of sleep apnea – obstructive and central. The difference between them is in the mechanism by which the disease-specific breathing stops during sleep, or the so-called, occur. “apneas” (translated from Latin “lack of breathing”). This is what he shared with FACTS.

– Dr. Kalajjiev, what people should know about sleep apnea. How many people go through the ISUL Cardiology Clinic each year?

– In Bulgaria, sleep apnea is among the diseases that are underestimated to a certain extent. Different specialists from different fields deal with sleep apnea, and this disease was part of my dissertation. In it, I studied patients with acute heart failure and sleep disorders. In the ISUL clinic, about 100 patients a year pass with sleep apnea as a concomitant disease. To a greater extent, the obstructive type of sleep apnea prevails. I analyzed the data of sleep apnea in the aspect of cardiovascular diseases – how it affects the underlying disease, the work of the heart and blood vessels.

– What are the symptoms, what are the unpleasant consequences of sleep apnea…

– We are talking about a condition in which normal sleep cycles are disturbed. Healthy sleep – we have four phases, and in the first phase, the so-called “rapid eye movement” phase, instead of resting, the body has an increase in heart rate, blood pressure, etc., then in the remaining three phases, the active rest of the body. In sleep apnea, due to cessation of breathing and reduction of oxygen flow during sleep, these cycles are disrupted. Conditions are created for an outpouring of stress hormones and a load on the autonomic nervous system. When this is repeated several times every night, a person’s general condition suffers, daytime sleepiness, increased heart rate and blood pressure, and all the negative consequences of these manifestations appear.

– Can we talk about an age limit for the disease? People at what age most often suffer from sleep apnea in her…

– Sleep apnea is a disease that develops over many years. Cases where it affects children are very rare. In most cases, sleep apnea begins to develop after the age of 25-30 and gradually things get worse over the years. Respectively, if measures are not taken, severe forms are reached, when clinical manifestations are already observed. We are talking about daytime sleepiness, falling asleep behind the wheel… These are the most dangerous things that sleep apnea is known for. Also of concern are fatigue, general discomfort, frequent falling asleep in everyday life – even at the table when eating while resting in front of the TV.

– A study proves that in about 40% of cases with sleep apnea, people also develop arterial hypertension. Is there a dependency…

– Addiction lies mainly in the release of stress hormones and the activation of the sympathetic nervous system. This is what happens with these episodes of waking up and suffocating during sleep. This leads to the narrowing of the arterial vessels and violation of their own regulation. We should know that hypertension is very quickly controlled with sleep apnea therapy. In my practice, I mainly deal with heart failure and its relation to sleep apnea. So it’s a good idea to test heart failure patients for sleep apnea as well, and it’s especially important for people who are overweight. This is because in people with heart failure and overweight, we have up to 60% co-morbidity – sleep apnea. In obstructive sleep apnea, the addition of a device to help patients sleep at night significantly affects heart failure symptoms, improves heart function, reduces hospitalizations, and ultimately improves the quality of life of these patients.

– How people are tested for sleep apnea. What is the research?

– A holter is placed, which has several sensors that measure breathing, saturation, pulse, chest movement. The device is put on, one sleeps with it in the evening at home – and then the data is analyzed. This is a much lighter version, because in the previous forms of the test, the patient sleeps in a quiet room in a hospital facility, and this is much more uncomfortable for him. Now the patient sleeps at home, in a familiar environment, thus getting as close as possible to his normal daily routine and normal sleep.