Implantable Loop Recorders

Mar 09, 2021

In the current era of medical advances, improved diagnostic tools are available not only to confirm diagnosis but also to provide better treatment plans. As an electrophysiologist, I would like to highlight the importance of implantable loop recorders.

There are common symptoms that our general practitioners and emergency physicians encounter, such as dizziness, breathlessness, loss of consciousness, general fatigue, palpitation and “bouncing chest”. These subjective complaints have vast differential diagnoses and very commonly, many of those suffering need further tests and referrals to cardiologists accordingly.

Loop recorders have now been approved and indicated to detect paroxysmal atrial fibrillation and cardiac syncope potentially due to high degree AV block and slow sinus rate.

In particular, this small device has a special ability to record and monitor heart rhythm in real time with good diagnostic yield for as long as 3 years. Its superiority over the usual holter monitor is explained by the more accurate and longer duration of the tracings, and nowadays, the majority of the implantable loop recorder companies provide substantial support for remote monitoring. This unique feature allows for any abnormalities to be transmitted and analysed by the implanting cardiologist to detect arrhythmias early, regardless of the presence of symptoms and to give prompt treatment.

To illustrate, I would like to share my recent experience from working at Wollongong Hospital. One of my patient’s loop recorder inserted for syncope showed a 7 second sinus arrest, as indicated by the loss of continuity of the P waves (Figure 1), concurrently with the clinical event of syncope. This abnormal rhythm was immediately communicated to me and the patient was subsequently admitted for an urgent pacemaker implant.

Figure 1

My patients generally tolerate the procedure well as it is relatively simple with very low risk of complications. We use local anaesthetic injection and the incision size is as small as a finger nail, making it even smaller than common minor surgeries, such as ingrown nail surgery.

Figure 2

I would encourage our colleagues to consider referring patients with the above ‘red flags’ of physical findings (Figure 2), as adapted from the European Society of Cardiology guideline, for a formal electrophysiologist consultation.

Dr Subiakto is available locally through Wollongong Public and Private Hospitals for inpatient admission, and the Cardiac Centre NSW for outpatient consults. He is keen to provide cardiology services for the Illawarra and Shoalhaven regions.