Premature ventricular contractions (PVCs) occur commonly and have been detected in up to 60% of people. PVCs were believed to cause no negative issues to one’s health, but recent evidence has shown that frequently occurring PVCs can impair the pumping ability of the heart. PVCs in the presence of existing heart disease are associated with an increased risk of sudden death. For this reason, managing PVCs safely and effectively has become important.
What are PVCs?
PVCs occur when the normal pathway of electrical conduction from the atria (upper chambers) to the ventricles (lower chambers) of the heart is disrupted and an electrical impulse begins spontaneously at some location in the ventricles.
This results in the ventricles contracting earlier, before the next expected beat, and this leads to the ventricles not filling up properly. A heartbeat triggered by a premature ventricular contraction is therefore a less efficient one as the normal amount of blood being pumped out of the heart to the rest of the body is now reduced.
Quite often, PVCs don’t cause any symptoms, but patients may complain of a fluttering sensation in the chest. On an electrocardiogram (ECG), they show up as abnormal QRS complexes (a QRS complex is the wave of depolarisation which coincides with ventricular contraction). 24-hour ECG monitoring is often required to detect them.
What causes PVCs?
Certain heart pathologies such as ischemic heart disease following a heart attack, cardiomyopathies, valvular diseases such as mitral valve prolapse, and myocarditis can cause PVCs.
Certain drugs and stimulants such as digoxin, tricyclic antidepressants, caffeine, alcohol and nicotine as well as imbalances in calcium, potassium and magnesium levels may also precipitate PVCs.
What are the implications of having PVCs?
Patients, with normal functioning hearts, experiencing more than 1000 PVCs over a 24-hour period may struggle with symptoms including chest pains, breathlessness, palpitations, dizziness, fainting and reduced exercise tolerance. Other complications include heart failure and an increased risk in developing a stroke and sudden death.
How are PVCs treated?
Anti-arrhythmic medications can be used to treat PVCs, but many of them have serious side effects.
A more popular type of treatment for PVCs is catheter ablation. Here, the area in which the abnormal electrical activity is occurring is located and destroyed by radiofrequency energy being directed towards this area.
Ablation versus medical therapy.
Medications can be used as a first-line measure to control PVCs, but ablation may offer a better long-term solution. Factors which play a role in deciding on ablation include patients not wanting to be on chronic medication, anti-arrhythmic drugs causing moderate to severe side effects and ablation therapy being very effective in suppressing PVCs and reversing ventricular dysfunction and cardiomyopathies within 4 months after the procedure is done.
How safe is catheter ablation?
Ablation is a relatively safe procedure with most complications being minor and including pain, bruising, bleeding or infection at the puncture site. More serious complications can occur, but they are rare, and can include traumatic damage to blood vessels, puncture of the heart, damage to the heart’s wiring system, blood clot formation and a heart attack.
So when should ablation be considered?
Ablation is considered when a patient is symptomatic and medical therapy is not effective, not tolerated or not preferred by the patient, when there is PVC-mediated cardiomyopathy or when PVCs are causing ventricular fibrillation.