What is the appropriate urgent evaluation and management for a 17‑year‑old female with daily morning nausea and vomiting, intermittent palpitations, syncope, and a history of anxiety, depression with prior suicide attempt, diabetes mellitus, and polycystic ovary syndrome?

Urgent Evaluation and Management of a 17-Year-Old with Morning Nausea, Vomiting, Palpitations, and Syncope

This patient requires immediate pregnancy testing, urgent cardiac evaluation with 12-lead ECG and continuous telemetry monitoring, and hospital admission given the combination of syncope with palpitations—a high-risk presentation that carries 18–33% one-year mortality if a cardiac cause is missed. 1

Immediate Life-Threatening Considerations

Pregnancy Must Be Excluded First

• Pregnancy is the most common endocrinologic cause of nausea and vomiting in any woman of childbearing age and must be the first test ordered. 2, 3
• Morning nausea and vomiting in a 17-year-old female with PCOS (which does not prevent pregnancy) makes this diagnosis critical to exclude immediately. 2
• The combination of pregnancy with syncope and palpitations could indicate peripartum cardiomyopathy or arrhythmia, which are life-threatening. 1

Cardiac Syncope Is High-Risk and Requires Urgent Exclusion

• Syncope accompanied by palpitations strongly suggests an arrhythmic cause and is a Class I indication for immediate hospital admission and cardiac monitoring. 1, 4
• Cardiac syncope carries 18–33% one-year mortality versus 3–4% for non-cardiac causes, making rapid cardiac evaluation mandatory. 1, 4
• The absence of prodromal symptoms (no mention of nausea, diaphoresis, or warmth before syncope) is a high-risk feature suggesting cardiac rather than vasovagal etiology. 1, 4

Mandatory Initial Assessment (Within First Hour)

History—Critical Elements to Document

• Position during syncope: Supine onset suggests cardiac cause; standing suggests reflex or orthostatic mechanism. 4, 5
• Activity at onset: Exertional syncope is high-risk and mandates cardiac evaluation. 4, 5
• Timing of palpitations: Palpitations immediately before syncope strongly indicate arrhythmic cause. 1, 4
• Prodromal symptoms: Absence of nausea, diaphoresis, blurred vision, or dizziness before syncope favors cardiac etiology. 1, 4
• Diabetes control: Hypoglycemia can cause both nausea and syncope; obtain recent glucose logs and HbA1c. 1
• Medication review: Metformin can cause nausea; antihypertensives, diuretics, and QT-prolonging agents (including psychiatric medications for depression) can precipitate syncope. 1, 4
• Psychiatric history: Suicide attempt history raises concern for intentional overdose or medication non-adherence. 1, 5

Physical Examination—Specific Findings to Assess

• Orthostatic vital signs in lying, sitting, and standing positions: A systolic drop ≥20 mmHg or standing systolic <90 mmHg defines orthostatic hypotension. 1, 4
• Cardiovascular examination: Assess for murmurs (aortic stenosis, hypertrophic cardiomyopathy), gallops (heart failure), irregular rhythm (atrial fibrillation), and signs of structural heart disease. 1, 4
• Volume status: Check for dehydration from vomiting—dry mucous membranes, decreased skin turgor, tachycardia. 2, 3
• Neurological examination: Assess for focal deficits that would suggest intracranial pathology rather than syncope. 1, 4

12-Lead ECG—High-Risk Abnormalities to Identify

• QT prolongation (QTc >500 ms): Suggests Long QT syndrome, especially concerning in a patient on psychiatric medications. 1, 4
• Conduction abnormalities: Bundle-branch blocks, bifascicular block, Mobitz II, or third-degree AV block require urgent pacing consideration. 1
• Pre-excitation patterns: Wolff-Parkinson-White or Brugada patterns indicate inherited arrhythmia syndromes. 1, 6
• Signs of structural disease: Left ventricular hypertrophy, Q waves suggesting prior infarction, or epsilon waves (arrhythmogenic right ventricular cardiomyopathy). 1, 6

Urgent Laboratory and Diagnostic Testing

Immediate Laboratory Tests (Order Stat)

• Urine pregnancy test: Mandatory first test in any reproductive-age female with nausea and syncope. 2, 3
• Point-of-care glucose: Exclude hypoglycemia as immediate reversible cause. 1
• Complete blood count: Hematocrit <30% is a risk factor in syncope evaluation; assess for anemia from occult bleeding. 4
• Comprehensive metabolic panel: Assess electrolytes (hypokalemia, hypomagnesemia prolong QT), renal function (metformin toxicity), and glucose control. 1, 4
• Magnesium and phosphate: Electrolyte abnormalities can cause both arrhythmias and nausea. 5
• Thyroid-stimulating hormone: Hyperthyroidism can cause palpitations, nausea, and syncope. 2

Cardiac Monitoring and Imaging

• Continuous cardiac telemetry: Initiate immediately for any patient with syncope and palpitations. 1, 4
• Transthoracic echocardiography: Order urgently to exclude structural heart disease, valvular abnormalities, or cardiomyopathy. 1, 4
• Consider Holter monitor or event recorder: If telemetry is non-diagnostic but arrhythmic suspicion remains high. 1, 4

Tests NOT Indicated Initially

• Brain CT/MRI: Diagnostic yield only 0.24–1% without focal neurological findings; not recommended. 1, 4
• EEG: Yield only 0.7%; reserve for suspected seizure activity. 1, 4
• Comprehensive laboratory panels: Order only targeted tests based on clinical suspicion. 1, 4

Differential Diagnosis—Organized by Urgency

Life-Threatening Cardiac Causes (Exclude First)

• Arrhythmias: Ventricular tachycardia, torsades de pointes (especially with QT-prolonging psychiatric medications), supraventricular tachycardia, or bradyarrhythmias. 1
• Inherited arrhythmia syndromes: Long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia. 1, 4
• Structural heart disease: Hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, congenital heart disease. 1

Metabolic and Endocrine Causes

• Pregnancy: Most common endocrine cause of morning nausea in reproductive-age females. 2, 3
• Diabetic ketoacidosis: Can present with nausea, vomiting, and altered mental status mimicking syncope. 1
• Hypoglycemia: Diabetes with poor control or medication non-adherence. 1
• Adrenal insufficiency: Can cause orthostatic hypotension, nausea, and syncope. 2

Gastrointestinal Causes of Morning Nausea

• Cyclic vomiting syndrome: Recurrent episodes of nausea and vomiting, often morning predominant, associated with autonomic dysfunction including postural orthostatic tachycardia syndrome (POTS). 1
• Gastroparesis: Common in diabetes; causes nausea, vomiting, and can trigger vasovagal syncope. 7, 8
• Functional nausea and vomiting: Chronic symptoms without structural cause, but syncope suggests additional pathology. 7, 8

Autonomic and Reflex Causes

• Postural orthostatic tachycardia syndrome (POTS): Heart rate increase ≥30 bpm on standing (≥40 bpm in adolescents), associated with nausea, palpitations, and presyncope. 1
• Vasovagal syncope: Nausea and vomiting are prodromal symptoms; syncope after prolonged standing or in hot environments. 1
• Vagovagal reflex from vomiting: Vomiting can trigger bradycardia and complete heart block via esophageal distension. 9

Psychiatric and Medication-Related Causes

• Medication effects: Psychiatric medications for depression can prolong QT interval; antihypertensives can cause orthostatic hypotension. 1, 4
• Intentional overdose: History of suicide attempt raises concern for self-harm. 1, 5
• Pseudosyncope: Conversion disorder in patients with psychiatric history, but cardiac causes must be excluded first. 1

Management Algorithm

Step 1: Immediate Stabilization and Risk Stratification

1. Obtain urine pregnancy test while simultaneously placing patient on continuous cardiac telemetry. 2, 3
2. Perform 12-lead ECG and assess for high-risk features. 1, 4
3. Check point-of-care glucose and orthostatic vital signs. 1
4. Establish IV access and initiate fluid resuscitation if dehydrated from vomiting. 2, 3

Step 2: Hospital Admission Criteria (This Patient Meets Multiple)

• Age <18 years with syncope and palpitations: High-risk presentation. 1
• Palpitations immediately before syncope: Strong arrhythmia indicator. 1, 4
• Diabetes mellitus: Co-morbidity that increases cardiac risk. 1
• History of psychiatric illness: Potential medication effects or intentional overdose. 1, 5
• Recurrent symptoms: Daily morning nausea and vomiting with intermittent syncope. 1, 4

Step 3: Inpatient Cardiac Evaluation

• Continuous telemetry monitoring for minimum 24–48 hours to capture arrhythmias. 1, 4
• Transthoracic echocardiography to exclude structural heart disease. 1, 4
• Cardiology consultation for interpretation of ECG abnormalities and consideration of electrophysiology study if arrhythmic cause suspected. 1, 4
• Consider implantable loop recorder if initial monitoring is non-diagnostic but clinical suspicion remains high. 1, 4

Step 4: Address Gastrointestinal Symptoms

• If pregnancy is positive: Obstetric consultation for hyperemesis gravidarum management. 2
• If pregnancy is negative and cardiac causes excluded: Consider cyclic vomiting syndrome, especially given association with POTS and autonomic dysfunction. 1
• Gastroenterology consultation if symptoms persist after cardiac and metabolic causes excluded. 1, 8
• Trial of antiemetic therapy: Ondansetron for symptomatic relief while diagnostic evaluation proceeds. 1, 8

Step 5: Psychiatric and Medication Review

• Psychiatry consultation to assess suicide risk, medication adherence, and optimize psychiatric medication regimen. 1, 5
• Review all medications for QT-prolonging agents, especially antidepressants and antipsychotics. 1, 4
• Assess for intentional overdose given history of suicide attempt. 1, 5

Common Pitfalls to Avoid

• Assuming vasovagal syncope without cardiac evaluation: Palpitations before syncope mandate arrhythmia exclusion. 1, 4
• Failing to obtain pregnancy test: Pregnancy is the most common endocrine cause of morning nausea in reproductive-age females. 2, 3
• Overlooking medication effects: Psychiatric medications can prolong QT interval; diabetes medications can cause hypoglycemia. 1, 4
• Ordering brain imaging without focal neurological findings: Diagnostic yield <1%; wastes time and resources. 1, 4
• Discharging patient without cardiac monitoring: Syncope with palpitations is high-risk and requires inpatient evaluation. 1, 4
• Missing cyclic vomiting syndrome: Morning nausea and vomiting with autonomic symptoms (palpitations, syncope) suggest CVS with POTS. 1
• Ignoring psychiatric history: Suicide attempt history raises concern for intentional overdose or medication non-adherence. 1, 5
• Attributing all symptoms to anxiety: Anxiety can coexist with cardiac disease; both must be evaluated. 1, 5

Disposition

This patient requires hospital admission for continuous cardiac monitoring, urgent echocardiography, and comprehensive evaluation of syncope with palpitations—a high-risk presentation that cannot be safely evaluated in the outpatient setting. 1, 4 The combination of daily morning nausea and vomiting with intermittent syncope and palpitations in a young female with diabetes, PCOS, and psychiatric history demands exclusion of life-threatening cardiac arrhythmias, pregnancy complications, and metabolic derangements before considering functional or psychiatric diagnoses. 1, 4