From the Guidelines
For patients with palpitations, I recommend a comprehensive initial evaluation including a 12-lead ECG, complete blood count (CBC), basic metabolic panel (BMP), thyroid function tests (TSH, free T4), and cardiac biomarkers (troponin, BNP) to identify potential underlying causes. This approach is based on the principle of identifying and addressing potential life-threatening conditions first, such as cardiac arrhythmias or electrolyte imbalances that could lead to severe morbidity or mortality. The 12-lead ECG is crucial for immediately identifying arrhythmias or signs of cardiac ischemia 1. The CBC, BMP, and thyroid function tests help identify conditions like anemia, electrolyte abnormalities, and hyperthyroidism, which are common causes of palpitations and can significantly impact quality of life if left untreated 1. Cardiac biomarkers are essential for ruling out myocardial injury, which could necessitate urgent intervention to prevent further morbidity or mortality. If initial testing does not reveal the cause of palpitations but symptoms persist, additional tests such as ambulatory cardiac monitoring with a Holter monitor or event recorder, as suggested by 1 and 1, can be considered to capture intermittent arrhythmias. These tests are critical for diagnosing the underlying cause of palpitations, which is essential for guiding appropriate management and treatment to improve quality of life and reduce the risk of morbidity and mortality. Key points to consider in the evaluation of palpitations include:
- The importance of a thorough history and physical examination to define the nature of symptoms and potential underlying heart disease or other reversible conditions 1.
- The use of echocardiography to evaluate for structural heart disease, as recommended by 1, which is particularly important in patients with documented sustained supraventricular tachycardia.
- The consideration of additional tests like serum caffeine levels, toxicology screening for stimulants, and assessment for pheochromocytoma if clinically indicated, to cover all potential causes of palpitations. By prioritizing these evaluations and tests, healthcare providers can ensure that patients with palpitations receive timely and appropriate care, minimizing the risk of adverse outcomes and improving their quality of life.
From the Research
Laboratory Tests for Palpitations
- The evaluation of palpitations may involve laboratory tests, including electrocardiogram (ECG) and basic metabolic panel, as well as ambulatory ECG monitoring and electrophysiologic studies in some cases 2, 3, 4.
- A detailed history, physical examination, and ECG are essential in evaluating palpitations and may yield a probable diagnosis 3.
- Limited laboratory testing may be indicated in some cases, and cardiology referral may be necessary 3.
- Ambulatory electrocardiogram monitoring and/or electrophysiological study should be undertaken when the initial evaluation results are negative and the patient is suffering from heart disease, or if the palpitations are frequent or poorly tolerated and with a high probability of an arrhythmic origin 4.
Specific Laboratory Tests
- Complete Blood Count (CBC) may be useful in assessing cardiovascular and metabolic diseases, including palpitations, as it evaluates the total numbers and characteristics of cell components in the blood 5.
- Basic metabolic panel, including electrolytes, blood urea nitrogen, and creatinine, may be relevant in evaluating palpitations, especially if there are concerns about renal function or acid-base homeostasis 6.
- Other laboratory tests, such as Holter monitor, event monitor, transtelephonic electrocardiographic monitor, treadmill exercise stress test, echocardiography, and electrophysiologic studies, may be indicated in some cases to evaluate palpitations caused by a presumed cardiogenic cause 2.