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Abstract
The case concerns a difficult but successful right ventricular outflow tract ectopy catheter ablation in a fit and well 33-year-old man with a 16-year history of symptomatic premature ventricular contractions (PVCs). Beta blockade medication had become ineffective in suppressing the PVCs, and a 24-hour Holter monitor revealed a high burden of ectopy (10%). An echocardiogram and cardiac MRI showed a structurally normal heart. During the procedure, it became impossible to uncurve the catheter, and it lodged in the patient’s right femoral artery. Immediate collaboration with interventional cardiology and interventional radiology was required to resolve the issue. The case demonstrates that excellent teamwork and calling rapidly on input from subspecialties are integral to overcoming unexpected events and to achieve a safe and successful outcome. The patient involved was a medical student at the time and as one of the coauthors offers a unique insight.
- interventional radiology
- interventional cardiology
- arrhythmias
- pacing and electrophysiology
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Background
Premature ventricular contractions (PVCs) refer to depolarisation signals that originate from the ventricles. Patients who are symptomatic can usually be treated with antiarrhythmic medication and/or cardiac catheter ablation.1 Catheter ablation is more effective at treating PVCs than antiarrhythmic drugs, with a recurrence rate in one study of 19.4% vs 88.6%, respectively.2 The rate of major complications is low, at about 2%, with most complications due to vascular access issues such as pseudoaneurysm, haematoma and arteriovenous fistula.3
Case presentation
A 33-year-old final-year medical student presented with a 16-year history of right ventricular outflow tract (RVOT) PVCs which had gradually increased in frequency to 1 in 8–10 beats, with intermittent episodes of dizziness, and necessitated beta blockade (40 mg propranolol three times a day) since 2013. PVCs were still experienced despite cutting out key triggers, including caffeine, sugar, alcohol and stress. The patient had no relevant medical or surgical history and did not have any allergies. His father had been diagnosed with atrial fibrillation and his mother experiences PVCs but not to the same frequency. There is no family history of sudden death or cardiomyopathy. Furthermore, there is no smoking history or excessive alcohol consumption (less than 14 units per week). The patient reported no chest pain, breathlessness, collapse or sudden loss of consciousness.
Investigations
A 12-lead ECG taken on 18 April 2019 (figure 1) showed three ventricular ectopic beats with a morphology in keeping with the RVOT. A 24-hour Holter monitor showed a high burden of ventricular ectopics (10%). Echocardiography and cardiac MRI revealed a structurally normal heart, good biventricular function and no valvular abnormality, with no evidence of fibrosis or cardiomyopathy.
12-lead ECG showing sinus rhythm with frequent ventricular ectopics with left bundle branch morphology and inferior axis, in keeping with a right ventricular outflow tract origin.
Differential diagnosis
Given the investigations and patient history, the key differential diagnosis would be arrhythmogenic right ventricular cardiomyopathy, which should be excluded.
Treatment
Medical treatment comprises beta blockade, which had diminished the PVCs but had not completely eliminated them. Interventional treatment involves RVOT ventricular ectopy catheter ablation, which was performed.
The procedure started successfully, but on mapping the left ventricular outflow tract (LVOT) through the right femoral artery (RFA) the catheter broke (F-curve ThermoCool SmartTouch, Biosense, Diamond Bar, California, USA). This was swapped with a different catheter (D-curve ThermoCool SmartTouch, Biosense), but on mapping it became impossible to uncurve the catheter and it lodged in the short sheath (figure 2). An interventional cardiologist was called and was able to snare the catheter from the left femoral artery (Amplatz Goose Neck Snare, Medtronic, Minneapolis, Minnesota, USA), although was unable to free the catheter. An interventional radiologist was then called and was able to snare the catheter at the tip and deflect the catheter back to a straight position using a Needle’s Eye Snare (Cook Medical, Bloomington, Indiana, USA), allowing its removal. The 8F RFA short sheath could not be reused as its distal extremity was found to have doubled-back on itself. The distal tip was snared to straighten the sheath, and it was replaced by a 9F short sheath. This was done without any damage to the femoral artery.
Fluoroscopy image of the broken ablation catheter snaring from the left femoral artery.
A decision was made to continue with the procedure using a new ablation catheter (D-curve ThermoCool SmartTouch, Biosense) as there was no obvious vascular damage on arterial angiography. Both the LVOT and RVOT were successfully remapped. The origin of the PVC was located posterior to the tricuspid valve, close to the bundle of His (figure 3). During ablation, there was a single steam pop and a transthoracic echocardiogram was performed. There was no pericardial effusion apparent and none at the end of the procedure. Ablation was continued and there was loss of ectopy as soon as radiofrequency energy was applied again. There were no ventricular ectopics apparent at this time, and after waiting for more than 30 min there were no further ventricular ectopics.
Electroanatomical map of the right ventricular outflow tract, modified left lateral view. Red tags: radiofrequency ablation lesions at the site of the earliest activation; yellow tags: His bundle location.
Outcome and follow-up
The patient was monitored overnight and discharged the next day without any complication.
Follow-up arrangements included a 48-hour Holter monitor 8 weeks postprocedure and a cardiac outpatient appointment 12 weeks postprocedure. The 48-hour Holter monitor was entirely normal with no ventricular ectopics present whatsoever. At outpatient follow-up the patient reported no adverse outcomes and was very happy with the result. The defective catheter was sent back to the manufacturer, and further analysis did not show mechanical problems with the deflection system, and therefore it is likely that the catheter could not be deflected back due to kinking in the vascular sheath.
Discussion
The case demonstrates the benefit of a multidisciplinary teamwork. While there are a number of skills common between the subspecialties of cardiac electrophysiology, interventional cardiology and interventional radiology, situations can develop where particular skill sets and equipment are required. Effective teamwork between colleagues and situational awareness were important to manage this rare complication and ensure a safe and effective outcome for the patient.
Patient’s perspective
The palpitations had been bothering me for a number of years as I am very aware of my heartbeat and I was keen to get the problem sorted out once and for all. I also wanted to stop taking beta blockers, which for me had side effects including lethargy and sleep disturbance. Leading up to the operation, I had an echocardiogram, cardiac MRI and a 24 hours ECG. The investigations were organised efficiently and once it was decided to proceed with the operation, I was able to schedule this at a convenient time. The doctors had explained the operation very clearly, that it would involve local anaesthetic and sedation rather than general anaesthetic and I felt re-assured that all my questions and concerns had been dealt with.
During the operation itself, it was necessary to map the LVOT in order to pinpoint the location of the ectopic beats more accurately. Unfortunately, the first catheter broke in my right femoral artery but was able to be removed. The second catheter also broke and had become kinked in the artery. It was at this point that the consultant called in an interventional cardiologist and an interventional radiologist to remove the catheter, which required access via the left femoral artery. Although I was worried, the team took the time to explain to me what was happening and reassure me that everything possible was being done. I was in some pain as the catheter was being removed and also experienced a migraine but the team were quick to respond with pain relief.
Afterwards, the operation proceeded quickly and smoothly. I stayed in hospital overnight given the length of the operation and for monitoring. Having not eaten since the previous evening, I was delighted that the consultant even bought me a sandwich! Which just goes to show the level of compassion and dedication of a team focussed on patient care. I now have sinus rhythm and am medication-free. Furthermore I can sleep better, no longer experience dizziness and my anxiety levels have reduced, so a fantastic result all round!
Learning points
Unforeseen complications can occur during routine procedures.
It is sometimes necessary to rapidly call on specialist input to overcome unexpected events.
The case demonstrates excellent multidisciplinary teamwork in managing an unforeseen complication, and a safe outcome was achieved.
Acknowledgments
The authors would like to acknowledge the following: Professor Simon Redwood (consultant interventional cardiologist), Dr Athanasios Diamantopoulos (consultant interventional radiologist), Lucy Jarrett-Smith (cardiac physiologist), Banjoh Olasunkanmi (radiographer) and Vanessa Vizcarra (catheter laboratory nurse).
Footnotes
Contributors The idea for this case report was developed by JD and MW. JD and TN drafted the case report under the supervision of MW. Imaging was provided by TN and MW.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.