What is the best course of treatment for a pregnant female with right-sided heart issues and persistent vomiting?

Management of Pregnant Patient with Right-Sided Heart Disease and Persistent Vomiting

This patient requires urgent multidisciplinary evaluation with immediate focus on correcting electrolyte abnormalities from vomiting, as hyperemesis-induced hypokalemia and hypomagnesemia can precipitate life-threatening ventricular arrhythmias in the setting of right-sided heart disease. 1

Immediate Priorities

1. Assess Cardiac Stability and Arrhythmia Risk

• Obtain immediate ECG and continuous cardiac monitoring to evaluate for arrhythmias, as right-sided heart lesions combined with electrolyte derangements from vomiting create high risk for both supraventricular and ventricular tachyarrhythmias 2, 1

• Check electrolytes urgently (potassium, magnesium, sodium, chloride) as hyperemesis-induced hypokalemia and hypomagnesemia can trigger ventricular tachycardia even in structurally normal hearts, and the risk is magnified with underlying cardiac disease 1, 3

• Perform echocardiography to assess right ventricular function, degree of tricuspid regurgitation, and pulmonary pressures, as pregnancy's volume load can precipitate right heart failure in patients with pre-existing right-sided lesions 2

2. Determine Severity of Vomiting

• Calculate PUQE score (Pregnancy-Unique Quantification of Emesis) to objectively assess severity: mild (≤6), moderate (7-12), or severe (≥13) 2

• Assess for hyperemesis gravidarum if there is weight loss >5% of pre-pregnancy weight, dehydration, or ketonuria, as this requires more aggressive intervention 2

• Check liver enzymes and thyroid function, as 40-50% of hyperemesis patients have elevated transaminases and biochemical hyperthyroidism 2, 3

Specific Cardiac Considerations Based on Right-Sided Pathology

Pulmonary Stenosis

• Generally well tolerated even with moderate stenosis, as the pressure gradient increases with pregnancy's increased stroke volume 2
• Severe stenosis (peak gradient >64 mmHg) can precipitate right heart failure, atrial arrhythmias, or tricuspid regurgitation during pregnancy despite being asymptomatic pre-pregnancy 2
• Monthly or bimonthly cardiac evaluations with echocardiography are required if severe stenosis is present 2

Severe Pulmonary Regurgitation or Tricuspid Regurgitation

• Independent predictor of maternal complications, particularly when associated with RV dysfunction 2
• Pregnancy's volume load can cause irreversible RV dilatation and precipitate right heart failure 2

Ebstein's Anomaly

• Risk of shunt reversal and cyanosis during pregnancy if interatrial shunting present 2
• Increased arrhythmia incidence (often associated with Wolff-Parkinson-White syndrome) with worse prognosis 2
• Risk of paradoxical emboli requiring consideration of anticoagulation 2

Post-Surgical Repairs (Mustard/Senning, Tetralogy of Fallot)

• 10% risk of irreversible RV function decline during pregnancy 2
• Monthly cardiac surveillance mandatory to monitor systemic RV function and rhythm 2

Treatment Algorithm for Vomiting

Mild Symptoms (PUQE ≤6)

1. Dietary modifications: Small frequent bland meals (BRAT diet), avoid triggers, high-protein low-fat meals 2
2. Ginger 250 mg four times daily 2
3. Vitamin B6 (pyridoxine) 10-25 mg every 8 hours as first-line pharmacologic therapy per ACOG 2

Moderate Symptoms (PUQE 7-12) or Failure of First-Line

1. Add doxylamine 10-20 mg (FDA-approved, recommended by ACOG) combined with pyridoxine 2
2. Alternative: H1-receptor antagonists (promethazine or dimenhydrinate) as safe first-line antiemetics 2
3. Early intervention prevents progression to hyperemesis 2

Severe Symptoms or Hyperemesis Gravidarum

1. Hospitalization for IV hydration and electrolyte replacement 2
2. Thiamine 100 mg daily for minimum 7 days to prevent Wernicke encephalopathy, then 50 mg daily maintenance until adequate oral intake 2, 3
3. Step-up antiemetic approach per ACOG:
   • Metoclopramide as second-line (less drowsiness and dystonia than promethazine, no increased congenital defects) 2
   • Ondansetron reserved for hospitalized patients as second-line therapy; use cautiously before 10 weeks due to possible cardiac defect risk 2
   • Avoid ondansetron as first-line before 10 weeks per ACOG case-by-case recommendation 2
4. Methylprednisolone 16 mg IV every 8 hours for up to 3 days as last resort in refractory cases, with caution before 10 weeks due to slight cleft palate risk 2

Critical Management Considerations

Medication Safety in Cardiac Disease

• Beta-blockers are indicated for right heart disease during pregnancy (preferably metoprolol, avoid atenolol), but use cautiously if underlying bradycardia or junctional rhythm present 2
• Avoid metoclopramide if patient has bradycardia from cardiac disease, as it can worsen conduction 2
• Monitor for extrapyramidal effects with metoclopramide and phenothiazines; withdraw if symptoms occur 2

Arrhythmia Management

• For acute SVT: Vagal maneuvers first, then IV adenosine 6 mg, then IV metoprolol if adenosine fails 2, 4
• Immediate electrical cardioversion for any hemodynamically unstable tachycardia 2, 4
• Prophylactic beta-blockers (metoprolol or propranolol) for recurrent SVT 2, 4

Anticoagulation Considerations

• Consider anticoagulation if severe RV dysfunction develops, as peripheral and cerebral embolism are frequent complications 2
• Paradoxical emboli risk in Ebstein's anomaly or other lesions with interatrial shunting 2

Red Flags Requiring Immediate Escalation

• Hemodynamic instability, syncope, or sustained tachycardia 4
• Signs of right heart failure (elevated JVP, hepatomegaly, peripheral edema, hypotension) 2
• Inability to maintain hydration despite treatment 2
• Neurological symptoms suggesting Wernicke encephalopathy 2, 3
• Persistent weight loss >5% or ketonuria 2

Delivery Planning

• Vaginal delivery preferred with assisted second stage to minimize straining and reduce portal pressure surges 2
• Cesarean delivery increases bleeding risk from abdominal wall varices if portal hypertension present 2
• Mode of delivery guided by obstetric indications unless cardiac decompensation occurs 2
• Plan early cesarean delivery if ventricular function deteriorates to avoid worsening heart failure 2