Warning: This application is for educational purposes only and does not replace a medical diagnosis. The Polar H10 belt is not a medical device and the predictions given by this application could be wrong. If you think you are experiencing heart rhythm disturbances, please consult your doctor. 

What are extrasystoles?

There are two types of extrasystoles:

Ventricular Extrasystoles (Ventricular Premature Beats):

• Origin: These arise from the ventricles, which are the lower chambers of the heart.

• Causes: They can be triggered by stress, caffeine, alcohol, or underlying heart conditions.

• Symptoms: May cause a sensation of a skipped beat or fluttering in the chest. Often felt as palpitations.

• Risk: Generally benign in a healthy heart but can be concerning if they are frequent or in the presence of heart disease.

Supraventricular Extrasystoles (Supraventricular Premature Beats):

• Origin: These originate from the atria or the AV node, which are the upper chambers of the heart.

• Causes: Similar triggers to VPBs, including stress, caffeine, and underlying heart issues.

• Symptoms: Can also cause palpitations or a fluttering sensation. Sometimes less noticeable than VPBs.

• Risk: Typically harmless in healthy individuals but warrant attention if they occur frequently or in individuals with heart conditions.

In most cases, extrasystoles are benign, especially in individuals with healthy hearts. Extrasystoles are common and can occur in people of all ages, even those with healthy hearts. However, in some cases, frequent extrasystoles can be a sign of an underlying heart condition. The number of extrasystoles that is considered "too many" varies depending on the individual and the specific type of extrasystole. In general, however, most doctors would consider more than a few extrasystoles per minute to be excessive.

Here are some possible interpretations of too many extrasystoles:

• Benign extrasystoles: In many cases, frequent extrasystoles are simply a variation of normal heart rhythm and do not indicate any underlying heart disease.This is especially true if you are otherwise healthy and have no other symptoms.

• Underlying heart condition: In some cases, frequent extrasystoles can be a sign of an underlying heart condition, such as coronary heart disease, heart failure or cardiomyopathy. These conditions can damage the heart muscle and make it more likely to have abnormal heartbeats.

• Other medical conditions: In some cases, frequent extrasystoles can be caused by other medical conditions, such as electrolyte imbalances, thyroid problems, or sleep apnea.

• Medications or substances: Certain medications or substances, such as caffeine, alcohol, and nicotine, can also trigger extrasystoles.

If you are experiencing frequent extrasystoles, it is important to see a doctor to get a diagnosis and determine the best course of treatment. Treatment for extrasystoles may not be necessary if they are benign and not causing any symptoms. However, if they are caused by an underlying heart condition or other medical condition, treatment will be necessary to address the underlying cause.

Here are some things you can do to help manage extrasystoles:

• Reduce stress: Stress can trigger extrasystoles, so it is important to find ways to manage stress, such as through exercise, yoga, or meditation.

• Avoid caffeine and alcohol: Caffeine and alcohol can also trigger extrasystoles, so it is best to avoid them or limit your intake.

• Get enough sleep: Getting enough sleep is important for overall health and can also help to reduce extrasystoles.

• Eat a healthy diet: Eating a healthy diet can help to improve heart health and may also help to reduce extrasystoles.

• Talk to your doctor: If you are experiencing frequent extrasystoles, it is important to talk to your doctor to get a diagnosis and determine the best course of treatment.

The POLAR H10  bluetooth connection allows you to record  in real time on your Android device, the electrocardiogram (ECG) as well as your heart rate and in the case of a physical exercice, the accelerometer sensor data from the POLAR H10. 

Morphology of extrasystoles:

The identification of different forms of extrasystoles requires a good signal quality. It is best to moisten slightly the belt in order to improve signal quality.  Some exercises can make it difficult to obtain a good quality signal. Therefore, to identify the different forms of extrasystoles, it may be preferable to make a recording at rest.

The interpretation of multiform extrasystoles is a bit complex and generally warrants a more thorough medical evaluation compared to uniform extrasystoles. "Multiform" means that the extra heartbeats originate from different locations within the heart. This is in contrast to uniform extrasystoles, which all appear to originate from the same spot. Multiform extrasystoles means that the extra beats have varying morphologies (shapes) on the ECG. This indicates that they are arising from multiple different foci within the atria (for supraventricular) or ventricles (for ventricular). The presence of multiple origins can sometimes suggest a more irritable or unstable myocardium (heart muscle). While multiform extrasystoles can sometimes be benign, they can also be associated with:

• • Increased myocardial irritability: The heart muscle may be more prone to generating ectopic beats.

  • Underlying heart disease: This is a more significant concern, as it could indicate structural or functional abnormalities in the heart.

  • Increased risk of more serious arrhythmias: In some cases, multiform ventricular extrasystoles may be associated with a higher risk of developing more dangerous ventricular arrhythmias like ventricular tachycardia or ventricular fibrillation.

  • Medications or substances: Certain medications or substances (like caffeine, alcohol, or some drugs) can sometimes contribute to multiform extrasystoles.

  • Electrolyte imbalances: Imbalances in electrolytes like potassium or magnesium can also trigger these.

Multiform Supraventricular Extrasystoles : These are generally less concerning than multiform ventricular extrasystoles, but they still warrant investigation to rule out underlying atrial issues or other contributing factors.

• Multiform Ventricular Extrasystoles : These are generally considered more concerning than uniform ventricular extrasystoles and are a stronger indicator for a more thorough cardiac evaluation. The presence of multiform ventricular extrasystoles often suggests a more irritable ventricle and a potentially higher risk.

Couplets, triplets and runs ("burst"):

The presence of couplets, triplets, or runs of extrasystoles on an ECG is a significant finding and generally warrants a more thorough medical evaluation. These patterns indicate a higher degree of electrical instability in the heart compared to isolated extrasystoles. Couplets are two consecutive extrasystoles, triplets three consecutive extrasystoles and runs more than three consecutive extrasystoles, sometimes also referred to as a "burst".

These patterns, especially triplets and runs, suggest a higher likelihood of developing more sustained and potentially dangerous arrhythmias. This is particularly concerning with ventricular extrasystoles, as runs of ventricular extrasystoles can degenerate into ventricular tachycardia or ventricular fibrillation, which are life-threatening arrhythmias.

The presence of couplets, triplets, or runs can be indicative of underlying heart conditions, such as coronary artery disease, cardiomyopathies, heart failure, myocardial ischemia (reduced blood flow to the heart muscle), electrolyte imbalances or drug toxicity.

Ventricular couplets, triplets, and runs: these are generally more concerning than their supraventricular counterparts. They can indicate a more unstable ventricular myocardium and a higher risk of serious ventricular arrhythmias.

Supraventricular couplets, triplets, and runs: while generally less life-threatening, they can still cause significant symptoms and may indicate underlying atrial issues like atrial fibrillation or atrial flutter.

Longer runs are more likely to cause palpitations, dizziness, lightheadedness, or even syncope (fainting).

The detection of couplets, triplets, or runs of extrasystoles, especially ventricular, requires prompt medical evaluation. The doctor will assess the overall risk based on the type, frequency, and duration of the extrasystoles, as well as the presence of any underlying heart conditions.

• The P wave represents atrial depolarisation of right atrium and then left atrium in chronological order. The normal duration of the P wave is less than 0.12 seconds and its amplitude should be less than 0.25 mV. Peaked P waves (> 0.25 mV) occurs when the right atrial depolarisation last longer  (right atrial enlargement). In that case the combination of the right and left waves results in a higher peak. When the left atrial depolarization last longer (left atrial enlargment), it results in a waveform larger than normal. The common abnormalities are called: P mitrale when we observe a large and bifid P wave due to left atrial enlargement often caused by mitral stenosis, P pulmonale in the case of high amplitude P wave due to right atrial enlargement usually caused by pulmonary hypertension, Inverted P wave when the electric impulse is generated outside of the sinoatrial node.

The duration of the P wave tends to increase during exercise.

• The ST segment normally represents an electrically neutral area between ventricular depolarization (QRS complex) and repolarization (T wave) and should be flat on the ECG. The beginning of the ST segment is called the J point. Any displacement of the ST segment above or below baseline (the reference being the PR segment) is often measured at the J point. However it must be noted that during exercise, the J point is often depressed with an upsloping ST segment. For that reason it is recommended that during exercise, the measurement should be done at J-60 or J-80 points which are located respectively at 60ms and 80 ms (ST80) after the J point. A displacement (elevation or depression) is considered as normal between -0.1mV and +0.1mV. There are many causes for ST segment elevation including myocardial infarction, pericarditis, left ventricular hypertrophy and benign early repolarization. The causes for ST segment depression include myocardial ischemia, hypokalaemia and left ventricular hypertrophy.

• The T wave is located after the QRS complex. It represents ventricular repolarisation. The T wave amplitude should not exceed 1mV and should be positive. T waves which are high and narrow are observed in hyperkalaemia. Inverted T waves (negative) occur for example in myocardial ischaemia and infarction, bundle branch block and ventricular hypertrophy but are normal in children and adolescents. The T wave amplitude may increase during exercise.

• The QT interval represents the total duration of ventricular depolarization and ventricular repolarization. The normal duration of the QT interval should be less than 0.45 s. The QT interval shortens at faster heart rates and lengthens at slower heart rates. Common causes of a prolonged QT (>450ms) are hypokalaemia, hypomagnesaemia, hypocalcaemia, hypothermia, myocardial ischemia and some drugs (antiarrhythmic, antidepressants and antibiotics). The duration of the QT interval tends to decrease during exercise.

• The R wave is located after the P wave and represents early ventricular depolarisation. R wave is the largest wave but its amplitude should be less than 2mV. High amplitude R wave may be due to ventricular hypertrophy.

Heart Rate Recovery (HRR) is a measure of how quickly your heart rate returns to its resting rate after exercise. It's calculated by taking the difference between your peak heart rate during exercise and your heart rate one minute after stopping.  HRR is a strong indicator of cardiovascular health. A faster recovery rate generally suggests better heart health and fitness levels. Normal values for Heart Rate Recovery (HRR) can vary based on factors like age, fitness level, and overall health. Typically, elite athletes have a 1-minute HRR of 30-40 beats per minute (bpm) or more, reflecting excellent cardiovascular fitness. For the general population, a 1-minute HRR of 12-20 bpm is considered average for active adults.

Distribution of extrasystoles according to activity:

Extrasystoles at rest refer to premature heartbeats that occur when you're not engaged in physical activity. These can be felt as skipped or extra heartbeats and are often benign, especially in healthy individuals. However, they can sometimes indicate underlying heart conditions or be triggered by factors like stress, fatigue, or electrolyte imbalances.

When they happen during exercise, they can be a normal response to physical stress, especially in athletes, but they can also indicate underlying heart conditions. It's important to consult a healthcare professional if you experience frequent extrasystoles during exercise, as they can help determine the cause and appropriate management.  When extrasystoles happen at rest and disappear during exercice, they are usually benign and due to stress conditions.

When they happen during recovery after exercise, it can be a sign of several things:

• Normal Physiological Response: In some cases, extrasystoles during recovery can be a normal response to the stress of exercise, especially in well-trained athletes.

• Underlying Heart Condition: They can also indicate an underlying heart condition, such as cardiomyopathy or coronary artery disease.

• Increased Risk of Cardiovascular Events: Studies have shown that frequent and complex extrasystoles during recovery can be associated with an increased risk of cardiovascular mortality, especially in asymptomatic individuals.

Heart Rate Zones:

Heart rate zones are ranges of heartbeats per minute (bpm) that correspond to different intensity levels of exercise. These zones help you understand how hard you're working during physical activity and can guide your training for specific goals. Here are the main heart rate zones:

• Very Light Zone (50-60% of Maximum Heart Rate):

Light activity, ideal for warming up and cooling down. Improves overall health and aids in recovery.

• Endurance Zone (60-70% of Maximum Heart Rate):

Moderate activity, great for burning fat. Improves cardiovascular endurance and burns a higher percentage of calories from fat.

• Aerobic Zone (70-80% of Maximum Heart Rate):

Sustained moderate-to-high activity, ideal for improving cardiovascular and respiratory endurance. Enhances aerobic capacity, builds endurance, and improves heart and lung function.

• Anaerobic Zone (80-90% of Maximum Heart Rate):

High-intensity activity, ideal for improving peak performance and increasing lactate threshold. Builds muscle strength and power, increases speed and anaerobic capacity.

• VO2 Max Zone (90-100% of Maximum Heart Rate):

Maximum effort, typically not sustained for long periods. Pushes your limits, improves overall performance and anaerobic capacity.

A Metabolic Equivalent of Task (MET) is a unit that measures the amount of energy expended during physical activities. It provides a standardized way to quantify the intensity of different exercises and activities by comparing them to the energy expenditure at rest. 1 MET represents the energy expended at rest. For exemple, If you engage in an activity that has a MET value of 6, you are expending six times the energy that you would while at rest. To calculate the calories burned during a physical activity, we use the following formula that involves BMR and MET:

Calories burned = BMR × MET /24 × duration in hours

Calories burned using mean heart rate:

We utilize the following formulas to calculate calories burned according to heart rate (Note that those formulas are valid for heart rates between 90 and 150 bpm):

For women:

Calories burned = Duration(minutes) × (0.4472×Average Heart Rate - 0.1263×weight in kg + 0.074×age in years - 20.4022) / 4.184

For men:

Calories burned = Duration(minutes) × (0.6309×Average Heart Rate + 0.1988×weight in kg + 0.2017×age in years - 55.0969) / 4.184

To calculate weight loss, knowing that one kg of body fat corresponds to 7700 calories, we assume that weight loss is proportional to the calories spent.