Supraventricular tachycardia (SVT) is an irregular heart rhythm where the heart beats unusually fast. This rapid heartbeat originates in the upper chambers of the heart, above the ventricles. Normally, the heart beats between 60 and 100 times per minute at rest. During an SVT episode, the heart rate can suddenly increase, often ranging from 150 to 220 beats per minute, or even faster. This condition arises from faulty electrical signals that cause early or rapid beats in the heart’s upper sections. SVT episodes can last from a few seconds to several hours.
The Primary Sensations
The most direct and noticeable sensation during an SVT episode is a sudden, rapid acceleration of the heartbeat. Many describe this as a pounding, fluttering, or racing feeling in the chest. The heart rate can jump from a normal resting pace to over 150 beats per minute in an instant. The rapid beats might feel like the heart is “skipping” or “thumping” forcefully.
Some individuals report a distinct pounding sensation in their neck, which occurs due to the forceful contractions of the heart’s upper chambers. The rapid heart rate often begins and stops abruptly, without warning. This sudden shift in heart activity is a primary characteristic of how SVT feels.
Other Accompanying Symptoms
Beyond the direct heart sensations, SVT episodes can bring about several other physical symptoms, often as a consequence of the heart’s inability to pump blood efficiently at such a high rate. When the heart beats too quickly, its chambers may not have enough time to fully fill with blood between beats, which can reduce blood flow to the body. This can lead to feelings of lightheadedness or dizziness.
Other symptoms include shortness of breath, as the body struggles to get enough oxygen when blood circulation is compromised. Chest discomfort, though not always described as pain, can also occur. A general feeling of weakness or fatigue may set in, and some individuals report sweating or a sense of anxiety accompanying the rapid heart rate.
Variability in Experience
The experience of SVT can differ significantly among individuals, and even for the same person across different episodes. Some people might only notice a mild fluttering or rapid heartbeat, while others experience more pronounced and distressing symptoms. This variability is influenced by the exact heart rate achieved during the episode, which can range widely, and the individual’s overall health status. An individual’s perception of symptoms also plays a role, as some may be more sensitive to changes in heart rhythm than others.
When to Seek Medical Help
While SVT is often not considered life-threatening, certain symptoms during an episode warrant prompt medical attention. If an SVT episode is accompanied by chest pain, significant difficulty breathing, or fainting, immediate medical help should be sought. These symptoms suggest that the heart may not be effectively pumping blood, potentially leading to more serious complications.
Medical evaluation is also advisable if an SVT episode is prolonged or if symptoms are severe and do not resolve on their own. Even if symptoms are mild but recurring, it is important to consult a healthcare professional. A doctor can assess the specific type of SVT, determine the frequency and severity of episodes, and discuss appropriate management strategies.