Anesthetic Management of a Parturient with Asymptomatic Second-Degree 2:1 Atrioventricular Block for Emergency Lower Segment Cesarean Section: A Case Report

In the complex machinery of the human body, the heart relies on a precise electrical system to keep its rhythm steady. This system sends signals from the upper chambers to the lower chambers, telling them when to squeeze and pump blood. Sometimes, this electrical pathway gets interrupted. A condition known as an atrioventricular block occurs when the signal is delayed or blocked entirely, causing the heart to beat too slowly. While some interruptions are minor and temporary, others are more serious, where the heart might skip a beat or two in a predictable pattern. For most people, this is manageable, but for a pregnant woman facing an emergency surgery, the stakes are incredibly high. The body of a pregnant woman is already under immense strain, and the drugs used to put a patient to sleep can further slow the heart. If the heart stops beating effectively during surgery, it endangers both the mother and the baby. The central question for doctors is how to manage these patients safely: should they insert a temporary electronic device to force the heart to beat faster before surgery begins, or can they proceed with careful monitoring and medication alone?

This story comes from a hospital in New Delhi, where a team of doctors faced a difficult decision regarding a twenty-six-year-old woman who was pregnant for the first time. She arrived at the emergency department with a baby in distress, requiring an immediate cesarean section to ensure the child's safety. During the initial check-up, the medical team discovered something unexpected in her heart. A standard test of her heart's electrical activity showed that for every two signals the upper chambers sent, only one reached the lower chambers. This is a specific type of heart block where the heart rate had slowed to forty-three beats per minute, yet the woman felt perfectly fine. She had no chest pain, no dizziness, and no history of heart trouble. The challenge was that she needed surgery immediately, but the anesthesia required for such a procedure could potentially make her heart stop completely.

The medical team, consisting of anesthesiologists, obstetricians, and heart specialists, gathered to weigh the options. The standard approach for a patient with this kind of heart block undergoing major surgery often involves placing a temporary pacemaker—a small device that sends electrical pulses to keep the heart beating at a safe speed. However, inserting this device takes time and carries its own risks, which was not ideal for an emergency situation where the baby needed to be delivered right away. The doctors decided to take a different path. They determined that because the woman was young, had no other heart disease, and her heart structure looked normal on an ultrasound, she might be safe enough to proceed without the pacemaker, provided they were prepared for the worst. They chose to use general anesthesia, which puts the patient to sleep, rather than a spinal block, because the drugs used for spinal anesthesia can sometimes cause dangerous drops in blood pressure and heart rate in these specific cases.

When the surgery began, the team was ready for any complication. They had a defibrillator, emergency drugs, and a temporary external pacemaker right next to the operating table. They selected specific medications known to be gentle on the heart. Instead of using common drugs that might slow the heart further, they used a sedative called etomidate, which is known for keeping blood pressure and heart rhythm stable. They also used a muscle relaxant that does not cause the heart to slow down. As the doctors prepared to intubate the patient to help her breathe, her heart rate dropped significantly to thirty-two beats per minute, a dangerous level. This was the moment the team had prepared for. They immediately started an infusion of a medication called isoprenaline, which acts like a gentle push to speed up the heart. Within moments, the heart rate climbed back up to a safer range between forty-five and fifty-six beats per minute.

The surgery proceeded smoothly with the heart rate remaining stable under the influence of the medication. The baby was delivered successfully and was healthy, with no need for resuscitation. The mother remained awake and stable throughout the recovery process. After the surgery, the infusion was stopped, and her heart continued to beat steadily on its own. She was monitored closely in the intensive care unit for two days, and her heart rhythm remained unchanged, never progressing to a complete block where the heart stops responding to signals. She was discharged home four days later with her healthy newborn.

This case suggests that for a carefully selected patient who is asymptomatic and has a healthy heart structure, it is possible to perform emergency surgery without inserting a prophylactic pacemaker. The key was not a single magic solution, but a combination of factors: a thorough assessment that the risk was low, the choice of anesthetic drugs that would not worsen the condition, and the immediate availability of medication to fix the heart rate if it dropped. The doctors found that by using etomidate to start the anesthesia and having isoprenaline ready to speed up the heart, they could navigate the surgery safely. The experience highlights that while the risk of a heart block turning into a complete stop is real, it can be managed with a tailored plan rather than a one-size-fits-all approach. The team concluded that individualized care, where the decision is based on the specific condition of the patient rather than a blanket rule, allows for safe outcomes even in high-pressure emergency situations.