P038: ACUTE TACHYARRHYTHMIA PRESENTING DURING CESAREAN SECTION FOLLOWING SPINAL ANESTHESIA
Charles Tindley, DO; Amie Hoefnagel, MD
University of Florida College of Medicine-Jacksonville
Introduction/ Background: Acute tachyarrhythmia during cesarean section (c-section) follow spinal anesthesia is a rare but potentially life-threatening condition. Pregnancy increases the risk of cardiac arrhythmia due anatomical and hemodynamic changes of pregnancy. Maternal blood volume increases by 30-50% during pregnancy causing atrial and ventricular stretching. Other physiological changes including increased heart rate, cardiac output and sympathetic output further increase the risk for cardiac arrhythmia1. The most common tachyarrhythmia in pregnancy is supraventricular tachycardia (SVT). Prevalence of SVT in pregnancy is approximately 24 per 100,000 pregnancies2.
Spinal anesthesia, widely used for c-section, can significantly alter maternal hemodynamics and potentially trigger arrythmias. While rare, prompt diagnosis and treatment is important for improved maternal and fetal outcomes. We present a case of a 37-year-old female who undergoing a repeat cesarean section who developed acute supraventricular tachyarrhythmia following administration of spinal anesthesia.
Case Description: A 37 year old female G3P1 with no significant past medical history presented for a repeat cesarean section at 40w5d. Spinal anesthesia with 1.6ml 0.75% hyperbaric bupivacaine w/ 150mcg Morphine and 15mcg fentanyl was administer at L3-4 interspace. ASA standard monitors were placed, and the patient was positioned supine. Significant hypotension following spinal occurred with mean arterial pressure of 40-50. Administration of phenylephrine and ephedrine were given. Prior to surgical incision, patient developed a supraventricular tachycardia with a rate between 150-170. Patient remained hemodynamically stable during the arrhythmia however, complained of dyspnea and chest pain. Patient was initially treated with esmolol and labetalol as due to hypertension, with gradual decline in heart rate to 110bmp. The patient subsequently complained of productive cough which was pink and frothy. Diagnosis of pulmonary edema was suspected. Lung exam revealed bilateral rhonchi. Pulse oximeter showed a mild decrease in saturation in the high 80’s. Patient was placed on supplemental oxygen with improved saturation and dyspnea. Lasix was then administered. The remainder of the surgery was without any further episodes of arrhythmias. Post op workup reveled mild pulmonary edema on chest radiograph, elevated troponins, Echo 40-45% with mildly enlarged RV and LV, and ST depression on the inferior leads. Patient went for cardiac angiogram which was negative. Patient recovered without further arrhythmia and was subsequently discharged.
Methods: A literature review was performed using PubMed database. Search included keywords “tachyarrhythmia in pregnancy”, “supraventricular tachyarrhythmia during cesarean section” and “spinal anesthesia induced tachyarrhythmia.”
Discussion: Acute tachyarrhythmia can lead to a catastrophic hemodynamic collapse and myocardial damage. Prompt recognition, treatment and close follow up are essential for improving morbidity and mortality. Treatment in pregnancy warrants special consideration given both maternal and fetal effects. Treatment of acute narrow complex tachyarrhythmia in pregnancy generally follows the American Heart Association algorithm for acute tachyarrhythmias. First line treatment of stable patients includes vagal maneuvers, adenosine, beta-blockers and calcium channel blockers. While most anti-arrhythmic medications cross the placenta special considerations should be given to pharmacologic treatment. Treatment of unstable patients warrants immediate synchronized cardioversion which is considered safe and can be used in any trimester3.