The Magic of Christmas

‘Try not to panic,’ Lara murmured, but Ellen didn’t even look in her direction. It was clear that all her hope for the future was fixed on Christian, who was studying the ECG machine. It purred softly as it produced a trace and he watched for a moment, his eyes narrowed. ‘Her ECG is showing regular narrow complex tachycardia with retrograde P waves.’

Interested, Lara leaned forward to take a closer look. ‘Mmm. There’s a shortened PR interval and a delta wave.’

Christian glanced at her in astonishment. ‘Yes,’ he murmured, ‘there is.’

‘So…’ Why was he staring at her? ‘Do you want to try adenosine or go straight for cardioversion?’ She knew that some doctors were reluctant to give adenosine in the emergency setting.

He was still staring. ‘We’ll give her 6 milligrams of adenosine by rapid IV push and see if we can get her back into sinus rhythm.’ He paused and she nodded to indicate that she understood that there was always the chance that the patient might develop a life-threatening arrhythmia.

‘So we’ll just have this within grabbing distance,’ she said quietly, moving the defibrillator next to the trolley.

Then she prepared the drug and handed it to Christian, who checked it and inserted the syringe into the venflon.

‘What’s happening?’ Ellen moaned, rubbing her hand over her chest. ‘What’s happening?’

‘Ellen, the conduction system of your heart isn’t working properly and your heart is being overstimulated. That’s why you’re feeling the way you are. The drug I’m giving you should prevent some of the electrical impulses getting through and slow the heart.’ Christian depressed the syringe to push the drug into the vein then dropped the empty syringe onto the tray next to him.

‘I’ll do you a rhythm strip,’ Lara said, programming the ECG machine and then standing to one side so that he could see the printout.

Ellen gave a sigh. ‘I’m feeling a bit better. But my face feels really hot.’

‘That’s a side effect of the drug we just gave you. Nothing to worry about.’ Christian’s gaze flickered to the monitor. ‘I’m going to refer you to the cardiologists, Ellen. They’ll want to do some more tests.’

‘Do you know what’s wrong?’

He looped the stethoscope back around his neck. ‘The electric currents that control your heart aren’t working properly. Put simply, they’re taking a short cut.’

‘I’m a lawyer. I don’t need the simple version.’

Christian studied her for a moment. ‘All right. Do you know anything about normal conduction pathways in the heart?’

‘No, but I’m a fast learner.’

Christian pulled a piece of paper and a pen out of his pocket and swiftly drew a diagram. ‘In the normal heart, electrical impulses start in the sinoatrial node in the right atrium—the atria are the chambers at the top of your heart—’ his pen flew over the page to illustrate his point ‘—and pass through the atrioventricular node to the ventricles in the bottom of your heart. The atrioventricular node limits the electrical activity that passes through to the ventricles and acts as a break on the heart rate. That’s what happens in the normal heart.’

Ellen looked at the drawing and gave a hollow laugh. ‘And that’s not me, right?’

‘Sometimes there’s an extra electrical pathway that bypasses the normal process and conducts electricity at a higher rate—there’s no filter, if you like. The result is that the heart can beat very quickly and that causes the symptoms you felt today.’

Lara studied the ECG again. ‘If she has an accessory pathway, why does the QRS complex look normal?’

‘Because ventricular depolarisation can occur through the normal pathway. It’s a combination of pre-excitation and normal conduction.’

‘You’ve lost me.’ Ellen sighed. ‘So how did I get this extra pathway? Was I born with it?’

‘Yes, it’s congenital. Some people have more than one. Basically it happens when the atria and the ventricles fail to separate completely.’

‘But why hasn’t it been picked up before?’

‘Because the majority of the time the normal pathway is used.’

‘And can it be fixed?’

‘Extremely successfully.’ Christian folded the ECG strip and attached it to the notes. ‘We’ll refer you to the cardiologists and they’ll carry out electrophysiological studies—basically, looking at the conduction of your heart.’

Ellen frowned. ‘And then?’

‘If they think you’re an appropriate candidate, then they may do something called radiofrequency ablation—to put it simply, they destroy the extra electrical pathway by sending an electric current through it.’