Arrhythmia

Arrhythmias, also known as cardiac arrhythmias, are defined as any irregularity in the heartbeat, encompassing rhythms that are too fast, too slow, or simply abnormal. A resting heart rate exceeding 100 beats per minute in adults is termed tachycardia, while a rate below 60 beats per minute is called bradycardia. While some arrhythmias produce no symptoms, others may cause palpitations or a sensation of a pause between beats. More serious cases can lead to lightheadedness, fainting, shortness of breath, chest pain, or a decreased level of consciousness.

Although most arrhythmias are not serious, certain types increase the risk of complications such as stroke or heart failure, and some can result in sudden death. These conditions arise from problems within the heart’s electrical conduction system. Diagnosis often involves an electrocardiogram (ECG) or a Holter monitor.

Other drugs

Arrhythmias are broadly categorized into four groups: extra beats (including premature atrial, ventricular, and junctional contractions), supraventricular tachycardias (such as atrial fibrillation, atrial flutter, and paroxysmal supraventricular tachycardia), ventricular arrhythmias (including ventricular fibrillation and ventricular tachycardia), and bradyarrhythmias, which stem from sinus node dysfunction or atrioventricular conduction disturbances. Treatment varies widely. Medications like beta blockers or antiarrhythmic agents such as procainamide can be used for fast heart rates, though the latter may have significant side effects with long-term use. Pacemakers are commonly employed for slow heart rates, and blood thinners help reduce complication risks for those with irregular rhythms.

Sudden arrhythmic death syndrome

In severe or unstable cases, controlled electric shocks via cardioversion or defibrillation may be administered urgently. Arrhythmias affect millions, with atrial fibrillation impacting about 2% to 3% of the population in Europe and North America as of 2014. Globally, sudden cardiac death accounts for roughly half of all cardiovascular disease deaths and about 15% of all deaths, with around 80% of these sudden deaths resulting from ventricular arrhythmias. While arrhythmias can occur at any age, they are more common in older individuals, and normal heart rates in children vary with age.