What are evidence-based methods to reduce tachycardia (abnormally fast heart rate)?

From the Guidelines

To lower heart rate effectively, using either a beta blocker or a nondihydropyridine calcium channel antagonist is recommended, as stated in the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1. When considering the management of heart rate, it's crucial to prioritize methods that have a strong evidence base, particularly those that reduce morbidity, mortality, and improve quality of life.

• The use of beta blockers, such as metoprolol or atenolol, is supported by guidelines for controlling resting heart rate in patients with atrial fibrillation and heart failure with preserved ejection fraction (HFpEF) 1.
• Nondihydropyridine calcium channel antagonists are also recommended for patients with HFpEF, offering an alternative for those who may not tolerate beta blockers 1.
• In acute settings, intravenous beta-blocker administration or a nondihydropyridine calcium channel antagonist can be used to slow the ventricular response to atrial fibrillation, with caution in specific patient populations 1.
• Additionally, lifestyle modifications such as regular aerobic exercise, deep breathing exercises, meditation, adequate hydration, and reducing intake of stimulants like caffeine, alcohol, and nicotine can contribute to lowering heart rate and should be encouraged alongside pharmacological treatments.
• The assessment of heart rate control during exercise and adjustment of pharmacological treatment to maintain a physiological range is particularly useful in symptomatic patients during activity, highlighting the importance of a tailored approach to heart rate management 1.

From the FDA Drug Label

Metoprolol is a beta 1-selective (cardioselective) adrenergic receptor blocker. Clinical pharmacology studies have demonstrated the beta-blocking activity of metoprolol, as shown by (1) reduction in heart rate and cardiac output at rest and upon exercise, Animal and human experiments indicate that metoprolol slows the sinus rate and decreases AV nodal conduction There is a linear relationship between the log of plasma levels and reduction of exercise heart rate. In several studies of patients with acute myocardial infarction, intravenous followed by oral administration of metoprolol caused a reduction in heart rate, systolic blood pressure and cardiac output

Evidence-based way to lower heart rate:

• Metoprolol, a beta 1-selective adrenergic receptor blocker, has been shown to reduce heart rate in various studies 2, 2, 2.
• The mechanism of action involves slowing the sinus rate and decreasing AV nodal conduction.
• A linear relationship exists between plasma levels of metoprolol and reduction of exercise heart rate.
• Administration of metoprolol has been demonstrated to cause a reduction in heart rate in patients with acute myocardial infarction. Key points:
• Metoprolol is effective in reducing heart rate.
• The drug should be used with caution, especially in patients with certain medical conditions, such as heart failure or bronchospastic disease.
• Dosage and administration should be carefully managed to avoid adverse effects, such as bradycardia.

From the Research

Evidence-Based Methods for Lowering Heart Rate

• Diaphragmatic breathing has been shown to be effective in reducing physiological and psychological stress, which can contribute to a lower heart rate 3, 4
• Deep breathing techniques, including diaphragmatic breathing, have been found to decrease stress levels, improve mood, and lower heart rate in healthy adults 5, 6
• The frequency and duration of diaphragmatic breathing exercises can vary, but one study suggests that breathing at a rate of less than 10 breaths per minute for 10 minutes, twice a day, for 4 weeks can be effective in producing positive outcomes 4
• In contrast, the use of β-blockers has been shown to decrease heart rate, but may also reduce daily physical activity and have other negative effects 7

Key Findings

• Diaphragmatic breathing can decrease systolic and diastolic blood pressures, reduce heart rate, and have a relaxing effect in hypertensive or prehypertensive individuals 4
• Deep breathing techniques can improve mood and reduce stress levels, as measured by self-reported evaluations and objective parameters such as heart rate and salivary cortisol levels 5, 6
• The evidence suggests that diaphragmatic breathing may be a useful, low-cost, non-pharmacologic intervention for reducing stress and lowering heart rate 3, 4