Table 1

Gaps in knowledge to assess fragmented QRS (fQRS) as a potential prognostic candidate for primary prevention ICD placement in heart failure (HF) patients

Number	Focus areas
1.	Identify the different forms of fQRS, that is, narrow, wide, paced and PVCs, as part of routine patient screening (see figure 1).
2.	Specify location of the different fQRS forms according to coronary artery territory.
3.	Quantify proximity of fQRS to a myocardial scar/fibrosis region and functional status.
4.	Determine timing of fQRS formation during screening and post-implant follow-up.
5.	Separate ischaemic from non-ischaemic cardiomyopathy patients and investigate sex differences.
6.	Provide a full evaluation of appropriate and inappropriate ICD shocks and unresponsive ICD therapy events.
7.	Quantify the nature and type of arrhythmias that triggered ICD shocks and rate of arrhythmia (VT, VF).
8.	Provide ICD type (dual chamber, single chamber, bi-ventricular or subcutaneous).
9.	Provide ICD programming.
10.	Document status of co-morbidities (eg, obesity, diabetes, renal disease, liver disease, COPD, sleep apnoea and others).

COPD, chronic obstructive pulmonary disease; ICD, implantable cardioverter-defibrillator; PVC, premature ventricular contraction; VF, ventricular fibrillation; VT, ventricular tachycardia.