Heart Palpitations: Causes and When to See a Doctor

This study is quite old, but its main conclusions remain valid and fit practice well. First, most palpitations have a cause that can be recognized at the first visit: conversation, examination, ECG and simple laboratory tests. Second, cardiac (43%) and psychiatric (31%) causes sit within the same large group of patients, and anxiety and panic attacks often coexist with real arrhythmias or intensify them through heightened attention to the heartbeat. Third, the prognosis with palpitations is in most cases good, though symptoms tend to recur.

The study describes a population of patients presenting to a doctor at one center in the 1990s, so the proportions of causes may look somewhat different today, and access to long-term ECG monitoring is better than it was then. The practical rule remains: not every palpitation is an arrhythmia and not every arrhythmia causes palpitations, and decisions on further diagnostics are based on alarm symptoms, history and the ECG result.

The most common triggers of palpitations include: caffeine and energy drinks, alcohol (especially in larger amounts and in the evening), nicotine, strong stress and anxiety, panic attacks, short sleep, dehydration, fever and infections, intense exertion, a heavy meal, and also hormonal changes in the cycle, pregnancy and perimenopause. Add drugs and stimulants: pseudoephedrine and other nasal decongestants, some bronchodilators, thyroid hormones in excess, some supplements of the fat-burner and pre-workout type with a large dose of stimulants.

This result is often misunderstood. It does not mean that caffeine never causes palpitations. The data concern long-term, average coffee consumption and the risk of developing atrial fibrillation in the population, not one person's reaction to a large stimulant dose. In many people a large amount of coffee or an energy drink, especially on an empty stomach, under stress or after a poor night, heightens the perception of the heartbeat or of premature beats. Reactions to caffeine differ between individuals, partly through metabolism genes, so it is best to observe your own response. More on caffeine in the knowledge base entry.

In practice a good start is to keep a symptom diary for 2–4 weeks: when the palpitations appear, how long they last, what was happening (coffee, alcohol, stress, exertion, body position, time of day), and what the pulse is then. Such a record makes the conversation with the doctor much easier and helps decide whether longer ECG monitoring is needed.

Non-cardiac conditions that can cause palpitations include above all an overactive thyroid (on the thyroid see the entry on TSH and thyroid hormones), anemia and iron deficiency (entry on iron), low glucose, electrolyte disturbances (potassium that is too low or too high, low magnesium, calcium, which we cover in the entries on electrolytes and on magnesium), dehydration, fever, pregnancy, sleep apnea, postural tachycardia syndrome (POTS) and rarer tumors that secrete catecholamines. So in a person with palpitations basic diagnostics include not only an ECG but also a blood count, TSH, electrolytes and glucose.

Medication causes also include drugs that themselves lengthen the QT interval or favor arrhythmias (some antibiotics, antipsychotics, antidepressants, antihistamines and others), and the use of psychoactive substances (amphetamine, cocaine, cannabinoids). If palpitations began after starting a new drug or supplement, note the name and date and discuss it with a doctor; do not stop regularly prescribed drugs without consultation.

Finally, anxiety. Panic attacks produce palpitations, sweating, breathlessness and a sense of impending doom. That does not mean 'it is just nerves', because anxiety and arrhythmias can occur together, and the belief that it is 'surely nerves' can delay the diagnosis of an arrhythmia. Good practice is to do an ECG and basic tests and then, if no cardiac cause is found, to consider psychological support. We describe breathing techniques and stress reduction in the entry on chronic stress.

Heart rhythm disturbances are generally divided into too slow (bradyarrhythmias) and too fast (tachyarrhythmias), regular and irregular. The most common cause of the 'skip' feeling is extra atrial or ventricular beats: after a premature beat there is a compensatory pause, and the next beat is stronger, giving the impression of a 'stop' and a 'kick'. They are usually harmless in people without heart disease, but their assessment depends, among other things, on their number (arrhythmia burden), symptoms and the image of the heart; we describe the topic in a separate article on extrasystoles.

Paroxysmal supraventricular tachycardia gives a sudden, regular, very fast heartbeat (usually 150–220/min) that starts and stops abruptly; it often affects younger people and may be triggered by caffeine, alcohol or stress. Atrial fibrillation gives an irregular, usually fast heartbeat, may be paroxysmal, and its important consequence is an increased risk of stroke, so it requires diagnosis and assessment of the indications for anticoagulation. Ventricular tachycardia is rarer but serious, especially in people with heart disease or with fainting.

While a single episode of palpitations usually does not need urgent diagnostics, recurrent episodes lasting more than a dozen minutes, starting suddenly and ending suddenly, with accompanying breathlessness, chest pain or dizziness are a clear indication for consultation. Age and coexisting disease matter too: hypertension, diabetes, obesity, sleep apnea and excessive alcohol favor atrial fibrillation. We write about the links of omega-3 fatty acids with atrial fibrillation in a separate article.

The first step is a history, measurement of pulse and blood pressure, an examination of the heart and a resting ECG, which assesses rhythm, width of complexes, intervals and traces of past disease (described in the entry on the resting ECG). If palpitations are infrequent, the ECG is usually normal because it records only a dozen seconds. Longer monitoring is then needed: Holter ECG for 24–48 hours if symptoms occur daily, or longer recorders if they are rare. We describe them in the entry on Holter ECG and ambulatory blood pressure monitoring.

The advantage of extended monitoring comes from simple statistics: rhythm disturbances are often transient and paroxysmal, so the longer we record, the greater the chance of catching an episode. The choice of method depends on the frequency of symptoms: a Holter for daily symptoms, a 7–14-day patch for symptoms every few days, an event recorder activated by the patient for rarer episodes, and for very rare but serious ones (fainting) sometimes an implantable loop recorder. The decision is made by the doctor.

Complementary tests are echocardiography (structure and function of the heart, valve disease, cardiomyopathies; entry on echocardiography), an exercise test when palpitations are linked to exertion (entry on the exercise test), blood tests (blood count, TSH, electrolytes, glucose, and if indicated troponin and NT-proBNP; entry on cardiac markers) and, less often, an electrophysiological study. Indications for tests are set by the doctor on the basis of symptoms and risk.

The conclusion is twofold. On the one hand, the watch notifications were rare (0.52% of participants) and, when they appeared, agreed with atrial fibrillation on the ECG to a considerable degree (84% positive predictive value in concordant recordings). On the other hand, fibrillation was found in only 34% of those who put on a patch several days later, which may result from its paroxysmal nature and the delay (on average 13 days) between the notification and applying the patch. The watch is thus a tool for detecting a possible arrhythmia in people without symptoms, not a tool for ruling out disease: the absence of a notification does not mean no arrhythmia, and a notification requires confirmation on an ECG.

The single-lead ECG function in a watch can be useful as a recording during an episode of palpitations: if you make a recording during symptoms and keep the file, the doctor can look at it, which is sometimes the first 'evidence' of the type of rhythm. Remember the limitations, though (a single lead, interference, no assessment of ischemia, algorithms with false positives and inconclusive results). A watch does not replace a 12-lead ECG, a Holter or a conversation with a doctor. We write about sensor accuracy in the article comparing Oura and Whoop.

The second myth is the belief that every palpitation indicates heart disease. Single, short episodes, especially after coffee, alcohol, stress or exertion, are common and usually harmless. What matters are frequency, duration, accompanying symptoms and the presence of heart disease or risk factors.

Palpitations are common and in most cases benign, but it is a symptom that should be neither ignored nor over-dramatized. The most sensible path is: note the symptoms, rule out simple factors (caffeine, alcohol, lack of sleep, drugs), get an ECG and basic blood tests, and if symptoms recur, turn to longer ECG monitoring. A watch is a helpful witness to events, but diagnostic decisions belong to the doctor. For people with anxiety the key is to separate two questions: is the heart healthy, and how do I cope with feeling its beat.