Cardiology as a branch includes the diagnosis, causes and treatment of the disorders of the heart structure and function. It is a medical specialty aimed at are and preservation of the function of the heart and the arteries. However, a distinction should be made between a cardiovascular surgeon – a person who performs an open heart surgery and a cardiologist who is responsible for multiple types of tests, diagnostic and therapeutic procedures such as angioplasty. There is a difference between heart of cardiac disease which affects only the heart and a cardiovascular disease which affects the heart and the blood vessels.
ECG/EKG is a diagnostic test of the heart’s electrical function. Each change of the appearance of the waves that are presented in the ECG record is in favor of some form of deviation in a specific cardiac function. Furthermore, it is used for: detection of deviations in the cardiac rhythm; detection of a cause of chest pain or chest pressure due to infarction; insufficient blood supply of the heart, pericarditis; Check of the action of a previously prescribed therapy; Check of the function of an implanted pacemaker. It is performed by applying electrodes directly on the skin of the chest and the legs and arms. The electrodes are connected to a machine which transfers the record of the activity on paper.
24-hour ECG Holter also examines the electrical function of the heart, however in a period of 24 hours, and sometimes even 48 hours. In this case, same as in the usual ECG, detection is performed of deviations of the heart rhythm, however within a longer period of time because some conditions that impair the rhythm occur temporarily or in a state of dream, change of body position, psychological stress of physical activity. After the application of the electrodes, they are attached to a small monitor that is worn on a belt around the waist and the electrodes are fixed to the body with a flexible network. Bathing and swimming is not allowed during the entire period of wearing. Physical activity is recommended, however with caution because of the risk of disconnecting the cable from the monitor. The patient gets a small booklet where he/she writes the activities for the entire period by hours. After the determined period, the electrodes are removed and disconnected from the monitor and then the entire record is extracted in a computer and it is analyzed for possible deviations in the heart’s electrical function.
Ambulatory blood pressure – Holter is used for measurement of blood pressure in people within a period 24/48 hours while performing everyday activities. A cuff is placed around the left forearm, similarly to normal blood pressure measurement. The cuff is connected to a monitor which is worn on a belt worn around the waist and it measures the pressures, every 30 minutes during the day, and every 60 minutes at night. It is recommended to stay still and hold the arm upright at moments of inflation of the cuff. While carrying it, the patients should not bathe and they should make sure to prevent eventual detachment of the cuff from the monitor. Patients get a booklet where they write their activities by hours. The purpose of this diagnostic method is to monitor the variations in blood pressure within a predetermined period and to determine the proper drug therapy or to modify the therapy that has been already determined.
Transthoracic echocardiography is a standard non-invasive diagnostic technique which provides a moving image of the heart cavities by using ultrasound that is guided through the chest by means of a tube. The probe releases sound waves that reflect the structure of the heart rejecting from the probe, and it receives them again. Then by means of a computer they are converted into a moving image on a monitor. This technique allows an assessment of the pumping force of the heart, the condition of the valves (heart murmur), a change in its dimensions, indirect detection of an infarction, pulmonary hypertension, endocarditis, pericarditis, heart failure, diastolic function and ventricular dyssynchrony.
Transesophageal echocardiogram is an alternative type of the previous diagnostic method. It is performed through a special probe attached to the end of a flexible hose that is introduced into the esophagus with previously applied local anesthesia. The image during TEE is clearer and has more diagnostic importance primarily due to the proximity of the esophagus and the heart. TEE has two main advantages: primarily it provides the cardiologists a better insight into the cardiac structures, especially of the heart wall and the structure and function of the heart valves. Second, the application during cardiovascular surgery and cardiac interventions. Other indications for its use include: investigation of a cause of stroke due to the existence of a small canal in the compartment of the atria which cannot be seen in TTE; Detection of clots in the heart cavities in people with arrhythmia; diagnostics of endocarditis; assessment of the function of implanted artificial valves and assessment of the structure of the aortic wall.
Coronary (cardiac) stress test is used for assessment of the effects of physical strain on the heart.
The very test involves accelerated walking on a treadmill by simultaneous monitoring of the electrical activity of the heart and occasional check of the blood pressure. The indications for the performance of such a test include: angina symptoms; in conditionally healthy patients with more risks for cardiovascular diseases; assessment of the origin of symptoms such as shortness of breath and fatigue; provoking irregular rhythm; check of the effect of an antihypertensive therapy, etc. Before the commencement of the test, a consent form is signed, and electrodes are attached in order to monitor the electrical activity of the heart. During the test, at each following level there is an acceleration and an increase of the treadmill’s inclination. And the vital parameters are monitored during the entire test: blood pressure, heart rate (pulse) and rhythm. If a problem occurs in terms of deviations of the normal activity of the heart or symptoms such as chest pain, dizziness, fatigue or breathlessness, the test is immediately terminated. After the test, the patient rests for 2-3 minutes. The doctor then evaluates the record and provides an assessment of the test and a recommendation for a following examination, intervention or recommendation for a mode of life.
Stress echocardiography is used in people who for various reasons are not able to be diagnosed with a coronary (cardiac) stress test. During this test, the heart muscle is stimulated with medications as if it was subjected to a physical activity. Primarily standard ECG electrodes are placed on the patient. An intravenous cannula is placed in the veins of one hand through which a medication is inserted – usually dobutamine, starting from the lowest dose and the dose is increased every 3 minutes. During the test, the heart rate increases similarly to a condition of physical strain. The heart rate is constantly monitored through transthoracic echo that apart from the detection of possible ECG signs of reduced cardiac blood supply or changes in the rhythm, also indirectly monitors the heart action and mobility of the walls and the septum in echo. Once the envisaged number of heartbeats is reached, the test is terminated or it is terminated in an event of a symptom such as chest pain, breathlessness, wheezing or dizziness. Once the intake of the medication is completed, the heart function is monitored on echo until the heart beats normalize for another several minutes.
It is a non-invasive method with numerous purposes, however it is usually used to assess the risk of a stroke in adults up to 50 years of age caused by persistent foramen ovale – PFO or a channel in the cardiac atria that is normally lost after birth. If it remains open after birth, blood and clots pass from the right atrium rich in clots which enter the left atrium and through arterial circulation they clog small arteries in the brain tissue causing a stroke. An intravenous cannula is placed on the veins of one arm of the patient, which provides a contrast with air bubbles. At the same time the patient is asked to close the nose and to maximally tighten the abdomen, that is, to tighten the nose and then to abruptly release it, and the whole time the probe of the echo-device is placed on the artery of one of the temples and it registers the number of bubbles that will pass. The bigger and the more important is the channel, the greater is the number of passed bubbles. In an event of a positive test, the patient is scheduled next examination and an intervention is planned for resolution of the condition without a surgery.