Management and follow-up
bradycardia, supraventricular, tachycardia, death, palpitations, ventricular beats, asystole, dizziness, atrial fibrillation, pre-syncope
ATRIAL TACHYCARDIA, PACS, ASYSTOLE, ATRIAL FIBRILLATION, HEART
Baseline data, including age, medical and obstetric history, clinical presentation (including New York Heart Association [NYHA] functional class [FC]), prescribed medication, 12-lead ECG, and transthoracic echocardiogram were recorded at the first visit.All patients received 24 h-Holter monitoring with a continuous 2-channel ECG (SEER Light recorder, General Electric). Heart rate (including minimum, average, maximum rates), proportion of time in bradycardia (i.e., ≤ 60 bpm) or tachycardia (i.e., ≥ 100 bpm), burden of premature atrial and/or ventricular complexes (PACs, PVCs), as well as occurrence of supraventricular and/or VAs over the 24 h monitoring period were recorded. Non-sustained VT was defined as ≥ 3 ventricular beats at ≥ 100 bpm beats per minute detected on 24 h-Holter monitoring.As per randomisation schedule, ten patients received an ILR (REVEAL XT, Medtronic®, Midrand, South Africa). The device was implanted under local anaesthetic and inserted subcutaneously in the left parasternal area of the chest, as guided by pre-implantation testing. The ILR was interrogated at the regular follow-up visits or when patients were symptomatic. The ILR would detect episodes of tachycardia and define these as either atrial tachycardia, atrial fibrillation or VT. As per out of box settings of the device, the ILR diagnostic algorithm detected VT when ≥ 16 ventricular beats had a VT interval of ≤ 340 ms. Episodes of bradycardia were detected when the bradycardia interval was ≥ 2000 ms for ≥ 4 s and asystole when no QRS complexes were detected for ≥ 3 s. Patients were asked to trigger the ILR remote button, when symptomatic of palpitations, dizziness or pre-syncope. All 24 h-Holter recordings and ILR readings (with a documented ECG strip for adjudication) were reviewed by an electrophysiologist and cardiologist (AC) and two fellows in Cardiology (JH, CV). Patients were followed-up for at least 12 months and up to 3 years. Poor outcome was determined as a composite of all-cause death, heart transplantation, readmission to hospital, or failure to show an LV improvement of > 10 units at follow-up.