Detecting and Treating Urgent Asymptomatic Arrhythmias With Mobile Cardiac Outpatient Telemetry

Dr. Robert Sangrigoli is co-author of a clinical study on Mobile Cardiac Outpatient Telemetry (MCOT) , which was presented at the 2003 NASPE Scientific Sessions.¹ In this study, the investigators found that MCOT detected serious arrhythmias in 53% of patients who had previously been monitored with Holter and/or event recording, where no arrhythmia had been detected. MCOT led to a change in treatment in 34% of all patients studied.

MCOT Case Study

The patient is a 71-year-old woman with a history of hypertension. She has a long history of feeling shaky with associated extreme fatigue. In the past, Holter and event monitoring were prescribed, but the results were negative for arrhythmia. She had been treated for anxiety, which was believed to be the cause of the symptoms. When referred to a cardiologist, she was on low-dose Sotalol for a remote history of atrial fibrillation (AF). Sotalol Theory was discontinued and CardioNet Mobile Cardiac Outpatient Telemetry (MCOT) was prescribed by the cardiologist to evaluate the symptoms. On 10/29, the patient was enrolled in MCOT. Baseline recording indicated normal sinus rhythm. On 11/2, MCOT triggered automatically and sent a wide QRS complex tachycardia at a rate of 205 bpm. The patient did not indicate any symptoms. The physician was notified immediately, and the patient was contacted by the CardioNet monitoring center. The patient stated that on reflection, she did feel some symptoms, but they were not strong symptoms. She was directed to the ER, where her cardiologist performed carotid sinus pressure, abruptly terminating the tachycardia. The patient was then taken to the EP lab, where her clinical tachycardia was easily induced, demonstrating a focal right atrial tachycardia which conducted with aberrancy. She underwent successful mapping and ablation of the tachycardia. CardioNet MCOT was prescribed again to evaluate the recurrence of atrial tachycardia as a follow-up to the ablation. On 12/17, the patient was enrolled in MCOT. Baseline indicated normal sinus rhythm. On 12/21, the MCOT triggered automatically and transmitted rapid AF at a rate of 180. The patient did not indicate any symptoms at the time of the event. The physician was contacted for new MCOT diagnosis of rapid AF. MCOT did not detect any further episodes of atrial tachycardia. The patient was placed back on sotalol. Anticoagulation was not prescribed, as the patient has a history of cerebral aneurysm, and there was a concern for bleeding risk. She has been taken off anxiolytics and has had no recurrence of shaky feelings or episodes of extreme fatigue.

Physician's Comments

CardioNet's mobile cardiac telemetry diagnosed not one, but two essentially asymptomatic arrhythmias. The patient s atrial tachycardia was picked up via CardioNet s automatic arrhythmia trigger as the patient, although in reality symptomatic, presumed her symptoms to be her typical anxiety. Accurate diagnosis of the cause of her symptoms led to both definitive treatment and discontinuation of unnecessary anxiolytic medication. Once cured of her atrial tachycardia, Cardionet MCOT again picked up a serious asymptomatic arrhythmia, AF. The patient, determined by her neurosurgeon not to be a warfarin candidate, was placed on sotalol for AF suppression. MCOT will be an integral part of her ongoing arrhythmia management, monitoring for drug efficacy as well as potential drug toxicity, particularly if dosing changes are considered (bradycardia, QT prolongation, ventricular arrhythmia).