An electrocardiogram (ECG) is a non-invasive medical test that measures the heart’s electrical activity, translating it into a wave pattern on a graph. Because symptoms of anxiety, such as chest pain and a racing heart, closely mimic those of heart disease, many people undergo an ECG to check their cardiac health. Anxiety and stress can directly influence the heart’s electrical system, which can lead to temporary changes that are visible on an ECG reading.
How Anxiety Affects Heart Rhythm and Rate
The body’s response to anxiety activates the sympathetic nervous system, known as the “fight or flight” response. This activation triggers a swift release of stress hormones, primarily adrenaline (epinephrine) and cortisol, into the bloodstream. This system prepares the body for a perceived threat, even when that threat is psychological rather than physical.
Adrenaline directly influences the heart by increasing the rate at which the sinoatrial (SA) node, the heart’s natural pacemaker, fires. This hormonal surge increases the force of contractions, causing the sensation of a pounding or racing heart (palpitations). Chronically elevated cortisol levels can also have a sustained effect on cardiovascular function.
Common ECG Patterns Associated With Anxiety
The most frequent ECG finding associated with acute anxiety or panic is Sinus Tachycardia, a faster-than-normal heart rate originating from the heart’s natural pacemaker. This appears as a regular, rapid rhythm, typically exceeding 100 beats per minute. Sinus tachycardia is considered a benign finding when linked to a reversible cause like anxiety.
Anxiety can also trigger ectopic beats, which are extra or “skipped” heartbeats that interrupt the normal rhythm. These may show up as premature atrial contractions (PACs) or premature ventricular contractions (PVCs), often felt as a flutter or a thump in the chest. Heightened sympathetic activity can cause subtle, non-specific changes in the T-wave, which represents the electrical recovery phase of the ventricles. These T-wave changes are transient and resolve as the anxiety subsides.
Hyperventilation, which often accompanies a panic attack, can also influence the ECG. Rapid, shallow breathing alters carbon dioxide levels in the blood, affecting the heart’s electrical stability. Anxiety-related findings are usually temporary and disappear once the psychological distress is relieved, differentiating them from true arrhythmias.
Differentiating Anxiety Symptoms From Cardiac Disease
Distinguishing between symptoms caused by anxiety and those from a serious cardiac condition is a common and complex diagnostic challenge for medical professionals. Both panic attacks and heart attacks can present with chest pain, shortness of breath, dizziness, and a rapid heartbeat. The doctor must carefully consider the context of the symptoms, as an isolated ECG finding is rarely enough for a definitive diagnosis.
A detailed patient history is paramount, including whether the symptoms are related to physical exertion or occur only during periods of emotional stress. Chest pain caused by a heart attack is often described as a crushing pressure or squeezing sensation that may radiate to the jaw, neck, or left arm. In contrast, anxiety-related chest pain is frequently described as a sharp, fleeting sensation or generalized chest tightness.
Specific “red flag” symptoms mandate immediate medical attention to rule out an organic heart problem. These include chest pain accompanied by profuse sweating, pain that worsens with physical activity, or an episode of fainting. The diagnostic process often involves ruling out cardiac disease through tests, such as blood work to check for specific heart muscle enzymes and an exercise stress test. If the resting ECG is inconclusive, a doctor may recommend a Holter monitor, a portable device worn to record heart activity, capturing any intermittent irregularities that might be missed during a brief office visit.