A sensation that your heart has fluttered, skipped, or paused is often a sign of a premature heart beat. These irregular beats are extra contractions that occur earlier than expected, interrupting the heart’s normal, steady rhythm. The medical terms for these common occurrences are Premature Ventricular Contractions (PVCs) and Premature Atrial Contractions (PACs).
PACs originate in the heart’s upper chambers, the atria, while PVCs start in the lower chambers, the ventricles. Following the premature beat, the heart typically pauses to reset, and the next normal beat is often felt more forcefully, which is the sensation people usually describe as a “skipped beat” or a “thump.” These extra beats are widespread and frequently occur in healthy individuals without any underlying heart disease.
External Triggers and Lifestyle Factors
Many premature heartbeats are not caused by a disease but rather by temporary factors related to daily habits and exposure to certain substances. These external triggers often increase the body’s level of stimulating hormones, which can destabilize the heart’s electrical system. Elevated levels of adrenaline, a stress hormone, can make the heart muscle cells more sensitive and prone to firing an impulse prematurely.
Consumption of caffeine, found in coffee, tea, and energy drinks, is a stimulant that can provoke extra beats. Nicotine and the use of alcohol also disturb the heart’s electrical pathways, increasing the likelihood of an abnormal beat originating in the atria or ventricles. These substances heighten cardiac stimulation, pushing the heart toward an irregular rhythm.
A lack of sleep and high levels of anxiety or stress are contributors. Stress and insomnia disrupt the autonomic nervous system’s balance, leading to the release of adrenaline and norepinephrine, which can trigger an early contraction. Additionally, some over-the-counter medications, particularly cold and flu remedies containing decongestants like pseudoephedrine, act as stimulants and can increase the frequency of premature beats.
Internal Medical Conditions
While lifestyle factors are common, premature heartbeats can also be symptoms of underlying medical conditions that affect the heart’s structure or the body’s systemic balance. Scarring to the heart muscle, such as that caused by a previous heart attack, can interfere with the normal path of electrical signals. This damage creates areas of electrical instability where an impulse can spontaneously fire, leading to a PVC.
Underlying heart conditions like coronary artery disease, which reduces blood flow to the heart muscle, or heart failure, which weakens the heart’s pumping ability, can cause frequent premature beats. Structural abnormalities, such as hypertrophic cardiomyopathy or congenital heart defects, alter the heart’s physical architecture. This creates a favorable environment for electrical impulses to travel along abnormal routes, known as reentry pathways.
Systemic issues can also destabilize the electrical signals. Electrolyte imbalances, specifically low levels of potassium (hypokalemia) or magnesium (hypomagnesemia), are disruptive to the heart muscle cells. These minerals are essential for the proper flow of electrical currents across cell membranes, and an imbalance can make the cells electrically unstable, promoting premature firing.
Conditions that increase the body’s metabolism or place additional strain on the cardiovascular system are associated with more frequent premature beats. An overactive thyroid gland, known as hyperthyroidism, floods the body with hormones that accelerate the heart rate and increase excitability. Similarly, anemia forces the heart to work harder to deliver oxygen, and chronic high blood pressure (hypertension) can cause thickening of the heart muscle, both of which increase the risk of electrical instability and premature contractions.
Identifying Warning Signs and Symptoms
Although most premature beats are benign and do not require treatment, a high frequency or association with certain symptoms may signal a more serious underlying condition. The physical sensation of a skipped beat or a flutter is common, but medical attention is warranted when these beats are accompanied by other signs. Symptoms such as dizziness, lightheadedness, or fainting (syncope) suggest that the heart’s irregular rhythm is significantly impairing blood flow to the brain.
Experiencing chest pain or pressure in conjunction with premature beats requires immediate evaluation. Shortness of breath indicates that the heart may not be effectively pumping blood, which can be a sign of heart failure or reduced blood flow. A high frequency of premature beats, particularly if they occur in rapid succession, can also increase the risk of developing a weakened heart muscle over time.
A doctor will use diagnostic tools to understand the nature and frequency of the premature beats. An Electrocardiogram (ECG or EKG) provides a snapshot of the heart’s electrical activity at rest. To capture less frequent events, a Holter monitor may be used; this portable device records the heart’s rhythm continuously over 24 hours, helping to correlate symptoms with the actual electrical events.