From the Guidelines
For a 29-year-old female with palpitations and near-syncope episodes, I recommend a comprehensive cardiac and metabolic workup, including initial laboratory studies such as a complete blood count, comprehensive metabolic panel, thyroid function tests, and cardiac biomarkers like troponin, as well as a 12-lead ECG, ambulatory cardiac monitoring, echocardiogram, and exercise stress testing if symptoms are exertion-related, as outlined in the guidelines by 1. The selection of diagnostic tests should be based on the patient's clinical presentation, risk stratification, and a clear understanding of the diagnostic and prognostic value of any further testing, as stated in the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1. The following laboratory studies and tests are recommended:
- Complete blood count to assess for anemia
- Comprehensive metabolic panel to evaluate electrolyte abnormalities (particularly potassium, magnesium, and calcium)
- Thyroid function tests (TSH, free T4) to rule out hyperthyroidism
- Cardiac biomarkers like troponin to exclude myocardial injury
- 12-lead ECG to identify arrhythmias or conduction abnormalities
- Ambulatory cardiac monitoring (Holter monitor for 24-48 hours or event recorder for longer periods) to capture episodes during symptoms
- Echocardiogram to assess structural heart disease and cardiac function
- Exercise stress testing if symptoms are exertion-related
- Drug screening if substance use is suspected
- Tilt-table test if vasovagal syncope is suspected, as recommended in the guidelines by 1. These tests are crucial because palpitations with near-syncope in a young female could indicate various conditions ranging from benign causes like anxiety to serious arrhythmias such as supraventricular tachycardia or long QT syndrome, as discussed in the guidelines by 1 and 1.
From the Research
Suggested Lab Studies for Palpitations and Near Syncope
The following lab studies are suggested for a 29-year-old female with palpitations and near syncope episodes:
- 12-lead electrocardiography (ECG) to guide further investigations 2, 3, 4
- Echocardiogram to evaluate cardiac structure and function 2, 3
- Ambulatory electrocardiographic monitoring (Holter monitor) to detect arrhythmias 2, 3, 4
- Event monitor or transtelephonic electrocardiographic monitor to capture episodes of palpitations 3
- Treadmill exercise stress test to evaluate cardiac function during exercise 3
- Electrophysiologic studies to evaluate the electrical activity of the heart 3, 5
Considerations for Diagnostic Work-up
The intensity of the diagnostic work-up will depend on the frequency, nature, and severity of symptoms 2. The patient's history, physical examination, and laboratory tests will guide further investigations 3, 4. If the patient experiences hemodynamic compromise, admission to an inpatient setting may be necessary to complete the diagnostic workup 3.
Special Considerations for Female Patients
Palpitations are common in women, especially during the luteal phase of the menstrual cycle, during pregnancy, and during the perimenopausal period 5. In female patients, a correlation between ovarian hormones and occurrence of paroxysmal supraventricular tachycardia has been reported 5. Therefore, the patient's menstrual history and hormonal status should be considered during the diagnostic work-up.