Experiencing a sudden flutter, thump, or a feeling that the heart has skipped a beat is a common, and often unsettling, sensation. These feelings often prompt people to wonder if they are experiencing a serious cardiac event. This confusion frequently centers on the relationship between a general feeling, known as a palpitation, and a specific electrical event called a Premature Ventricular Contraction (PVC). Understanding the difference between this subjective feeling and the underlying physiological cause is important for anyone concerned about their heart rhythm.
What Are Palpitations?
Palpitations are defined as the subjective awareness of one’s own heartbeat, a sensation that is typically uncomfortable or unusual. People often describe this feeling as a racing, pounding, or fluttering in the chest, neck, or throat. The feeling may also manifest as an extra beat or a skipped beat, which can last for just a few seconds or minutes.
A palpitation is a symptom, not a diagnosis, and it does not always indicate a problem with the heart’s structure or function. Many common non-cardiac factors can trigger this sensation, including lack of sleep, strenuous exercise, or emotional states like stress and anxiety. Stimulants such as caffeine, alcohol, and nicotine are also frequent causes because they can increase adrenaline levels. Other non-cardiac conditions, such as iron deficiency anemia or an overactive thyroid, can also cause these noticeable changes in heartbeat.
Understanding Premature Ventricular Contractions (PVCs)
A Premature Ventricular Contraction (PVC) is a specific, measurable electrical event that disrupts the heart’s normal rhythm. The heart’s regular beat is initiated by an electrical signal from the sinoatrial (SA) node, the natural pacemaker. This signal travels through the heart in a coordinated way, causing the upper chambers and then the lower chambers (ventricles) to contract.
In a PVC, an electrical impulse originates unexpectedly from one of the ventricles, firing prematurely before the SA node’s signal arrives. This premature impulse causes the ventricle to contract too early, resulting in an extra heartbeat that is often less effective at pumping blood. This event is followed by a slight pause before the heart’s normal rhythm resets. PVCs are extremely common and are classified as a type of irregular heartbeat (arrhythmia).
The Critical Distinction: Sensation Versus Origin
The relationship between PVCs and palpitations is that one is the cause (the origin) and the other is the effect (the sensation). A PVC is a diagnosed electrical event, while a palpitation is the subjective feeling a person experiences. PVCs are one of the most frequent causes of the feeling described as a skipped beat or a heavy thump.
The feeling of a “skipped beat” is actually caused by the pause immediately following the premature contraction. During this compensatory pause, the ventricles have extra time to fill with blood, making the next normal beat particularly forceful and noticeable. This stronger-than-normal beat is what is often perceived as a thump or a heavy pound in the chest. Common factors that can trigger PVCs include elevated adrenaline from stress or exercise, electrolyte imbalances (like low magnesium or potassium), and substances like alcohol and tobacco.
When to Seek Medical Guidance
While PVCs are common and often harmless in otherwise healthy individuals, an evaluation is necessary to rule out underlying issues. It is recommended to consult a healthcare provider if palpitations are persistent, worsening, or cause significant distress. Medical attention is important if the sensations are accompanied by other symptoms such as dizziness, chest pain, light-headedness, or fainting.
A physician will use diagnostic tools such as an electrocardiogram (ECG or EKG) to record the heart’s electrical activity at rest. If the irregular beats are infrequent, a Holter monitor, a portable device worn for 24 hours or longer, may be used to capture the PVCs as they occur. This evaluation helps determine the frequency of the PVCs and whether they indicate a more severe arrhythmia or structural heart disease. Even if the PVCs are determined to be benign, lifestyle adjustments or medical treatment may be offered if the symptoms are significantly bothersome.