Rhythm Holter (ECG Holter)
24-Hour Continuous Heart Rhythm Monitoring
What Is a Rhythm Holter?
A rhythm Holter is a portable ECG device that continuously records your heartbeats for 24 hours. While a standard ECG performed in the clinic provides only a 10–15 second snapshot, a rhythm Holter monitors your heart’s electrical activity throughout the entire day. This makes it possible to detect rhythm disorders that occur intermittently—sometimes lasting only a few minutes per day.
If you have palpitations—if you sometimes feel your heart speeding up or becoming irregular—but your ECG appears normal when you visit the doctor, a rhythm Holter may be the right test for you. With small electrodes attached to your chest, the device records your heart rhythm second by second and shows how your heart is functioning during daily activities, while sleeping, and even at the moments you feel palpitations.
When Is a Rhythm Holter Performed?
The sensation that your heart is racing, becoming irregular, or “skipping a beat” is one of the most common reasons for seeing a doctor. However, these symptoms are usually temporary and may not occur during the medical examination. A standard ECG may appear normal, while your complaints persist.
A rhythm Holter records every heartbeat over 24 hours. You note the times when you feel palpitations in a diary, and your doctor can review how your heart was functioning at those moments. This helps determine whether there is a true rhythm disorder or whether you are simply sensing normal heartbeats more intensely.
Dizziness or fainting can have many causes, but heart rhythm disorders are among the important ones. Especially if the heart beats too slowly (bradycardia) or too fast (tachycardia), blood flow to the brain can decrease, leading to dizziness or even fainting.
A rhythm Holter shows how your heart is functioning during such episodes. If your heart rate is excessively slow or fast at the time of dizziness, a rhythm disorder may be the cause and treatment may be required. If the rhythm is normal during symptoms, other causes are investigated (low blood pressure, inner ear problems, etc.).
Atrial fibrillation (AF) is a common rhythm disorder in which the upper chambers of the heart beat rapidly and irregularly. In some patients it is continuous, while in others it occurs intermittently (paroxysmal). A rhythm Holter is ideal for detecting intermittent atrial fibrillation.
If you have previously been diagnosed with AF and are receiving medication, a rhythm Holter is used to assess how effective your treatment is. It evaluates how many hours you remain in AF during the day and how well your heart rate is controlled.
In patients who have had a heart attack, there is a risk of developing dangerous rhythm disorders in the post-attack period. Damaged heart tissue can trigger abnormal electrical impulses. These impulses may lead to serious rhythm problems such as ventricular tachycardia or fibrillation, which can be life-threatening.
A rhythm Holter may be used before discharge or afterward to investigate such high-risk rhythms. If dangerous arrhythmias are detected, preventive measures such as implanting a defibrillator (ICD) may be considered.
In patients with a pacemaker, a rhythm Holter may be performed to check whether the device is working properly. When the pacemaker stimulates the heart, these signals appear as special markers (spikes) on the ECG. A rhythm Holter helps assess whether the pacemaker is functioning regularly over 24 hours and whether your heart is responding appropriately.
In addition, if you still experience palpitations despite having a pacemaker, the cause can be investigated. It may be necessary to adjust pacemaker settings.
If you are taking medication for a rhythm disorder, it is important to determine whether it is truly effective. A single ECG performed in the clinic does not show whether the medication provides protection for the full 24 hours. A rhythm Holter can count how many abnormal rhythm episodes occur throughout the day.
By comparing Holter recordings before and after treatment, the success of therapy can be measured objectively. If arrhythmias are still frequent, the dose may be increased or a different medication may be tried.
Some rhythm disorders occur especially during sleep. In patients with sleep apnea, heart rhythm may slow down (bradycardia) or speed up during breathing pauses. If you wake up at night with palpitations or feel tired in the morning, evaluating your nighttime rhythm profile is important.
Because a rhythm Holter records throughout the night, it can detect rhythm changes during sleep. If severe nighttime bradycardia is present, pacemaker implantation may be necessary.
Common Types of Arrhythmias
Extrasystole (Extra Beat)
This is the most common rhythm disturbance and is usually harmless. Extra, early beats occur between normal beats. It can create a sensation that the heart “skipped” or “stuttered.” Many people may have hundreds of extrasystoles per day, and most have no clinical significance. However, treatment may be needed if they are very frequent or symptomatic.
Atrial Fibrillation (AF)
This is a condition in which the upper chambers of the heart (atria) contract rapidly and irregularly. The heart beats in a “fluttering” manner and the normal rhythm is lost. It is serious because it increases the risk of stroke and requires blood-thinning treatment. It may be continuous or intermittent.
Supraventricular Tachycardia (SVT)
This is a sudden-onset and sudden-ending episode of a very fast heartbeat (150–220 beats per minute). It is more common in younger people. Episodes may last seconds or hours. It may cause shortness of breath, chest pain, and dizziness.
Bradycardia (Slow Heart Rate)
This is when the heart rate drops below 60 beats per minute. It may be normal for athletes, but it can be problematic in older adults or people with heart disease. Severe bradycardia can cause dizziness, fatigue, and fainting. A pacemaker may be required.
Ventricular Tachycardia (VT)
These are rapid and irregular beats originating from the lower chambers (ventricles) of the heart. It can be life-threatening because it disrupts the heart’s pumping function. It is more common in patients who have had a heart attack or have heart failure. It requires urgent treatment.
AV Block (Conduction Block)
This is a delay or blockage in the transmission of electrical signals between the upper and lower chambers of the heart. Mild forms (first-degree block) usually do not cause problems, while advanced forms (second- and third-degree block) may require a pacemaker.
How Is a Rhythm Holter Performed?
Device Placement
The rhythm Holter procedure is very simple and completely painless. Small electrodes (usually 3–7) are attached to different areas of your chest. These electrodes detect the electrical activity of your heart and transmit it via thin cables to a small recording device worn on your belt or over your shoulder.
The device is about the size of a mobile phone, very lightweight, and does not interfere with daily activities. To ensure proper electrode adhesion, chest hair may be shaved if needed. For women, wearing a bra is generally not a problem, but care is taken to ensure the electrodes are not positioned underneath the bra.
What to Pay Attention to During the 24 Hours
- • Continue your normal daily life: Go to work, walk, and do your routine tasks. Staying still during the test does not give accurate results.
- • Do not expose the device to water: You must not shower or swim. You may clean yourself using a damp towel.
- • Do not touch the electrodes: Do not remove or try to reposition the electrodes.
- • Avoid metal detectors: Inform security personnel at airports or store entrances that you are wearing a medical device.
- • You can use a mobile phone: Contrary to older beliefs, modern devices are not affected by mobile phone use.
Keeping a Diary
The Daily Log Is Very Important
It is critically important to record your activities and symptoms in the diary provided over the 24-hour period. In particular, please note the following:
What to Record
- The time(s) you feel palpitations
- Episodes of dizziness or chest pain
- When you fall asleep and wake up
- The times you take your medications
- When you exercise or climb stairs
- Stressful moments (meetings, arguments, etc.)
Symptom Button
Some rhythm Holter devices have an “event record” button. When you feel palpitations, you press this button and the device marks that moment specifically. This allows your doctor to easily find and evaluate your rhythm at the time of symptoms.
What Do Rhythm Holter Results Mean?
After 24 hours, you return the device. The recordings are analyzed using computer software, and a detailed report is prepared. The following are evaluated in this report:
Information Included in the Report
Heart Rhythm Analysis
- 1. Average Heart Rate: Average number of beats per minute over 24 hours (normal: 60–100)
- 2. Minimum and Maximum Heart Rate: The slowest and fastest heart rates recorded, and the time they occurred
- 3. Number of Extrasystoles: Total number of extra beats during the day (supraventricular and ventricular separately)
- 4. Arrhythmia Episodes: Whether abnormal rhythms such as AF, SVT, or VT occurred, how many times, and how long they lasted
- 5. Pauses: Whether there were abnormally long pauses between heartbeats
- 6. ST-Segment Changes: Signs of reduced coronary blood flow (ischemia)
Symptom–Rhythm Correlation: The most important part is the relationship between the moments you feel palpitations and the actual rhythm recorded. Sometimes, when you feel palpitations, the rhythm is normal; in that case, your palpitations may be related to psychological factors or anxiety. Other times, you may not feel anything, yet the device records a significant arrhythmia; this “silent arrhythmia” can be dangerous.
Day–Night Comparison: Normally, your heart rate decreases while sleeping. However, some people experience excessive nighttime bradycardia, or conversely, nighttime episodes of rapid rhythm (such as paroxysmal AF). This information affects your treatment plan.
Advantages of Rhythm Holter Monitoring
Detects Intermittent Rhythm Disorders
While a standard ECG records only 10 seconds, a rhythm Holter records more than 100,000 heartbeats. The chance of capturing arrhythmias that occur only a few times per day is very high.
Finds the True Cause of Your Symptoms
It helps determine whether your palpitations are due to a rhythm disorder or anxiety. It eliminates unnecessary concerns or enables early detection of serious arrhythmias.
Measures Treatment Effectiveness
The effectiveness of your antiarrhythmic medications is evaluated objectively. Medication dose or type can be optimized.
Detects Life-Threatening Rhythms
Some rhythm disorders can cause sudden death (ventricular fibrillation, long pauses). Early detection makes life-saving treatments possible, such as implanting a defibrillator.
Related Cardiac Tests
Other tests used to assess your heart health:
Rhythm Holter Appointment
If you have palpitations, dizziness, or irregular heartbeats, monitor your heart rhythm for 24 hours with a rhythm Holter.
Book an Appointment: 0224 504 09 11Frequently Asked Questions
No, the device is very small and lightweight. The electrodes are attached to your chest with adhesive patches and do not cause pain. You can continue your daily activities comfortably. The only minor inconveniences are not being able to shower and having electrodes on your chest, but most people get used to it easily. It stays on during sleep and usually does not disrupt sleep.
No, the rhythm Holter device and electrodes are not water-resistant. You cannot shower, bathe, or swim for 24 hours. However, you may wipe other parts of your body with a damp towel. It is recommended to shower before the device is fitted. Since the monitoring usually lasts only 24 hours, this is not a problem for most people.
Because the electrodes contain medical adhesive, they may cause mild redness or itching in people with sensitive skin. This is usually mild and resolves within a few hours after the electrodes are removed. If you have had allergies to band-aids or medical tapes before, tell your doctor; hypoallergenic electrodes can be used.
Yes. Modern rhythm Holter devices are not affected by mobile phone use. In the past, people were advised to keep phones away from the device, but this is no longer necessary. You can use your phone normally and talk as usual. You should only avoid strong magnetic fields (such as MRI machines).
Yes—exercise is even recommended because the purpose of the test is to observe your heart rhythm during normal daily activities. You can walk, climb stairs, and do mild-to-moderate exercise. However, avoid very intense workouts, heavy lifting, or movements that might cause the electrodes to come off. Swimming is not allowed since the device cannot get wet.
The diary is critical because your doctor compares your symptoms with the rhythms recorded by the device. For example, if you felt palpitations at 15:00 and wrote it down, your doctor checks the rhythm at that time. If atrial fibrillation is present at that moment, it explains your palpitations. If the rhythm is normal, your palpitations may have another cause. Without a diary, this correlation cannot be established.
Some rhythm disorders occur very rarely—once a week or even once a month. A 24-hour Holter may not be sufficient for such rhythms. In that case, longer monitoring methods are used: 48-hour Holter, 7-day Holter, or implantable event recorders (loop recorders). Your doctor decides which duration is appropriate based on how often your symptoms occur.
After you return the device, the recordings are transferred to a computer and analyzed. Typically, the report is ready within 1–3 days. Prof. Dr. Özlem Arıcan evaluates your report in detail and explains what it means. If dangerous rhythm disorders are detected, you will be informed earlier and necessary urgent measures will be taken.