From the Guidelines
Tachycardia in a young adult is most commonly caused by supraventricular tachycardia (SVT), which encompasses many tachyarrhythmias, including atrial and ventricular rates >100 b.p.m. at rest, and is often triggered by atrial and/or atrioventricular nodal tissues 1.
Common Causes of Tachycardia
- Physiological sinus tachycardia: may result from pathological causes, including infection with fever, dehydration, anemia, heart failure, and hyperthyroidism, in addition to exogenous substances, such as caffeine, drugs with a beta-agonist effect, and illicit stimulant drugs 1
- Junctional tachycardia: a rapid, occasionally irregular, narrow-complex tachycardia, typically seen in infants postoperatively, after cardiac surgery for congenital heart disease, but can also occur in adults, often with a relatively benign course 1
- Tachycardia-mediated cardiomyopathy: can occur at any age and has been described in a broad range of both ventricular and supraventricular arrhythmias, including inappropriate sinus tachycardia, and is characterized by LV dilatation without hypertrophy 1
Key Factors to Consider
- Symptoms: palpitations, chest discomfort, fatigue, light-headedness, shortness of breath, anxiety, dizziness, dyspnoea, and syncope
- Triggers: stressors, such as infection or volume loss, and exogenous substances, such as caffeine and illicit stimulant drugs
- Underlying conditions: heart failure, hyperthyroidism, and congenital heart diseases It is essential to evaluate the patient's clinical history, physical examination, and electrocardiogram (ECG) to determine the underlying cause of tachycardia and develop an appropriate treatment plan 1.
From the Research
Causes of Tachycardia in Young Adults
The causes of tachycardia in young adults can be physiological or pathological in origin 2. Some of the possible causes include:
- Congenital or hereditary conditions, such as coronary artery anomalies and inherited cardiomyopathies (e.g., hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy) 3
- Ventricular tachycardia, which can be sustained, incessant, or nonsustained, and may be associated with subtle abnormalities of cardiac size or function 4
- Hypertrophic cardiomyopathy, a genetic disorder characterized by left ventricular hypertrophy and a nondilated left ventricle with preserved or increased ejection fraction 5
- Tachycardia-induced cardiomyopathy, a reversible condition that can develop in response to persistent tachycardia 6
Risk Factors for Sudden Cardiac Death
Certain conditions can increase the risk of sudden cardiac death in young adults, including:
- Hypertrophic cardiomyopathy, particularly in adolescents and young adults 5
- Ventricular tachycardia or fibrillation, which can be precipitated by underlying cardiac conditions 3, 4
- Family history of sudden cardiac death, which can indicate a genetic predisposition to cardiac disorders 3, 5
- Severe cardiac hypertrophy, which can increase the risk of sudden cardiac death 5
Importance of Early Diagnosis and Treatment
Early diagnosis and treatment of tachycardia and underlying cardiac conditions are crucial to prevent complications, such as sudden cardiac death and cardiomyopathy 3, 4, 5, 6. Prompt treatment can lead to the resolution of symptoms and improvement of ventricular function, highlighting the need for physicians to consider tachycardia-induced cardiomyopathy in the differential diagnosis of new-onset heart failure 6.