Numbering aberrant rhythms
Encyclopedia
Bigeminy is a descriptor for a heart
arrhythmia in which abnormal heart beats occur every other concurrent beat. A typical example is with bigeminal premature ventricular beats, also known as a premature ventricular contractions/complexes
(PVC). Following the PVC there is a pause and then the normal beat returns - only to be followed by another PVC. The continuation of this pairing of beats is an example of bigeminy.
These descriptors can increase depending on the number of beats involved in the abnormal system. If every other beat is abnormal, you can describe it as bigeminal. If every third beat is aberrant, it is trigeminal; every fourth would be quadrigeminal. Typically, if every fifth or more beat is abnormal, the aberrant beat would be termed occasional.
Bigeminy is contrasted with couplets, which are paired abnormal beats. If, for example, these concurrent PVCs number three, they are called triplets and are considered as a brief run of non-sustained Ventricular tachycardia
or NS-VT.
PVCs are not the only aberrant beat that makes use of these adjectives; others are premature atrial contraction
s, parasystole
, and escape complexes.
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
arrhythmia in which abnormal heart beats occur every other concurrent beat. A typical example is with bigeminal premature ventricular beats, also known as a premature ventricular contractions/complexes
Premature ventricular contraction
A premature ventricular contraction , also known as a premature ventricular complex, ventricular premature contraction , ventricular premature beat , or extrasystole, is a relatively common event where the heartbeat is initiated by the heart ventricles rather than by the sinoatrial node, the...
(PVC). Following the PVC there is a pause and then the normal beat returns - only to be followed by another PVC. The continuation of this pairing of beats is an example of bigeminy.
These descriptors can increase depending on the number of beats involved in the abnormal system. If every other beat is abnormal, you can describe it as bigeminal. If every third beat is aberrant, it is trigeminal; every fourth would be quadrigeminal. Typically, if every fifth or more beat is abnormal, the aberrant beat would be termed occasional.
Bigeminy is contrasted with couplets, which are paired abnormal beats. If, for example, these concurrent PVCs number three, they are called triplets and are considered as a brief run of non-sustained Ventricular tachycardia
Tachycardia
Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
or NS-VT.
PVCs are not the only aberrant beat that makes use of these adjectives; others are premature atrial contraction
Premature atrial contraction
Premature atrial contractions , also known as atrial premature complexes or atrial premature beats , are a common cardiac arrhythmia characterized by premature heartbeats originating in the atria...
s, parasystole
Parasystole
Parasystole is a kind of arrhythmia caused by the presence and function of a secondary pacemaker in the heart, which works in parallel with the SA node. Parasystolic pacemakers are protected from depolarization by the SA node by some kind of entrance block. This block can be complete or...
, and escape complexes.
Examples
- Bigeminal premature ventricular contractions = Normal, PVC, Normal, PVC...
- Trigeminal premature atrial contractions = Normal, Normal, PAC, Normal, Normal, PAC...
- Quadrageminal premature ventricular contractions = Normal, Normal, Normal, PVC; Normal, Normal, Normal, PVC...
- Occasional escape complexes: Normal, Normal, Normal, Normal, Pause, Escape...
- Bigeminal Couplets: Normal, Normal, PVC, PVC, Normal, Normal, PVC, PVC...
- NS-VT: Normal, Normal, PVC, PVC, PVC, PVC, Normal, Normal, PVC....etc