trigeminy

Trigeminy is a pattern of heart rhythm in which premature heartbeats occur at regular intervals, specifically on every third beat. When this pattern involves premature ventricular contractions, it is typically referred to as ventricular trigeminy. The common presentation is two normal beats followed by a premature beat, repeated in a fixed sequence.

In clinical practice, trigeminy most often describes ventricular ectopy, though rarer forms involving supraventricular premature beats can be described as atrial trigeminy. The key feature is the regular grouping of three beats, with the third beat being ectopic. The ectopic beat may differ in its electrical origin, morphology, and timing compared with the normal sinus beat.

The clinical significance of trigeminy depends on the context. In healthy individuals, occasional trigeminy can be benign and incidental. In people with heart disease, electrolyte disturbances, or ischemia, a higher burden of premature beats or a persistent trigeminy pattern can be associated with symptoms such as palpitations, dizziness, or, in some cases, reduced heart function. The overall prognosis is guided by the presence of structural heart disease and the frequency of ectopic beats rather than the pattern alone.

Diagnosis is typically made with an electrocardiogram (ECG) and is often further assessed with ambulatory monitoring, such as a Holter monitor or event recorder, to quantify frequency and variability over time. Evaluation aims to identify underlying causes, including ischemia, electrolyte abnormalities, or cardiomyopathy.

Management focuses on treating any underlying condition and alleviating symptoms. For many, lifestyle modification (limiting caffeine or stimulants) and observation suffice. In symptomatic or high-burden cases, beta-blockers or other antiarrhythmics may be used, and catheter ablation can be considered for frequent, troublesome ectopy unresponsive to conservative measures.