Cardiac Arrhythmia

A cardiac arrhythmia is an irregular heartbeat. The National Heart, Lung, and Blood Institute describes it as a problem with the rate or rhythm of the heartbeat: the heart may beat too quickly (tachycardia), too slowly (bradycardia), or with an irregular pattern. Many arrhythmias are harmless. Others, such as ventricular fibrillation, can cause sudden cardiac arrest within minutes.

Common types include atrial fibrillation, ventricular tachycardia, and heart block. Causes range from heart disease and high blood pressure to thyroid problems, electrolyte imbalances, stimulants, and certain medications. Some drugs can lengthen the QT interval on an electrocardiogram, which raises the risk of a dangerous rhythm called torsades de pointes.

In drug injury litigation, an arrhythmia claim usually needs three things: a documented diagnosis such as an ECG, evidence of when the patient took the product, and a medical opinion linking the two. Drug and supplement labels often list rhythm problems as possible side effects, so a case may turn on whether the warning was adequate and whether the risk was known earlier than the label admitted. Energy drinks, weight loss supplements, and some antibiotics and heart drugs have all been the subject of such claims.

Because every patient's heart history is different, these are nearly always individual cases or mass torts rather than class actions. If you had a rhythm problem after starting a product, save your ECG results, discharge papers, and the product itself. Our page on supplement mislabeling covers claims about undisclosed stimulants.