Ventricular Arrhythmias
Ventricular arrhythmias are abnormal electrical rhythms that start in the heart’s lower chambers (ventricles). They range from occasional extra beats that cause no harm to sustained rhythms that can compromise circulation and require urgent treatment.
Key points
- A stray electrical signal starting in the heart’s lower chambers, rather than its natural pacemaker, produces a less efficient beat.
- Occasional extra beats are usually harmless, but a sustained rapid or chaotic rhythm can cause dizziness, fainting, or cardiac arrest.
- Underlying causes range widely, from coronary artery disease and cardiomyopathy to low blood-salt levels and inherited faults in the heart’s electrical circuitry.
- Medicines like sotalol and flecainide work by slowing or stabilising the heart’s electrical conduction to suppress abnormal beats.
What goes wrong in the ventricles
The heart’s electrical system normally fires in a top-to-bottom sequence. When a signal originates in the ventricles instead of the natural pacemaker, the resulting beat is often less efficient. Isolated ventricular ectopic beats are common and usually benign. Ventricular tachycardia (sustained rapid beating) and ventricular fibrillation (chaotic, disorganised rhythm) are more serious and can cause dizziness, loss of consciousness, or cardiac arrest.
Underlying causes include coronary artery disease, cardiomyopathy, electrolyte imbalances (low potassium or magnesium), and inherited ion-channel disorders. These conditions are seen worldwide, with cardiomyopathy and coronary disease being significant contributors.
Managing the rhythm
Treatment depends on the type and severity of the arrhythmia. Antiarrhythmic medicines work by slowing conduction in the ventricles or making the heart muscle less excitable. Sotalol combines beta-blocking and rhythm-stabilising properties and is widely used for ventricular tachycardia. Flecainide reduces the speed at which electrical signals travel through the ventricles, suppressing abnormal beats. Both sit within the broader field of heart and blood-pressure medicines.
Any new episode of sustained palpitations, chest pain, or fainting should be assessed promptly by a cardiologist, as the right choice of treatment depends on the underlying cause and a full cardiac evaluation.