Introduction
Cardiac-inherited diseases such as hypertrophic cardiomyopathy or long QT syndrome (LQTS) are individually relatively rare but collectively common.1 Presenting symptoms include dyspnoea, syncope, arrhythmias and even sudden unexpected cardiac arrest.
Timely identification of cardiac-inherited diseases is paramount because there is extensive evidence that the risk of sudden death can be significantly reduced with a variety of management options, including β-blockers,2 ,3 implantable cardiac defibrillators (ICDs)4 ,5 and lifestyle modification.6 Studies of such autosomal-dominant conditions have shown that it is possible to identify up to 8–9 affected family members per proband.7 ,8 Non-ischaemic dilated cardiomyopathy (DCM) may be familial in up to 40%,9–11 and thorough investigation of non-coronary disease-related resuscitated sudden cardiac death (RSCD), including pharmacological provocative testing reveals an inherited cause in up to 60%.12
Therefore, consideration of familial cardiac-inherited diseases, even in seemingly isolated cases of structural or electrical disorders, and prompt diagnosis of a potential new proband is of vital importance regardless of their presentation, as many other unidentified family members may also be at risk.8 ,13 ,14
As a result of these combined observations, a proactive, integrated approach from cardiology and genetics professionals is recommended.15 ,16 Central to this is an in-depth, multigenerational family history (FHx). This has the potential to establish a diagnosis, avoid unnecessary, extensive and potentially expensive testing for underlying conditions, and can assist with devising a genetic testing strategy, interpreting genetic test results, and providing ongoing risk assessments for sudden cardiac death (SCD).14 ,17 However, to our knowledge, there are no other studies of the everyday practice of inpatient cardiology units to see if these guidelines are being adhered to, nor any to demonstrate the overall effect of their enforced introduction in these institutions.
New Zealand has a National Cardiac Inherited Disease Registry run by a multidisciplinary clinical and scientific network called the Cardiac Inherited Disease Group (CIDG).13 Two new part-time coordinators (both experienced cardiac nurses) in two large district hospitals each with a regional cardiology referral base noted FHx of people at high risk of having a cardiac-inherited disease was not always performed by the cardiology inpatient team, and that patients could be discharged without identification of the underlying aetiology of their symptoms. Since cardiac-inherited diseases remain a differential diagnosis in presentations such as syncope, heart failure or RSCD, the coordinators were aware that FHx could potentially improve accuracy of diagnosis and improve quality of care for the patient and their family. Therefore, we wanted to test the following hypotheses:
That documentation of family histories in inpatient hospital records was inadequate, and
That a multigenerational family tree obtained by a trained allied professional could lead to the increased detection of hitherto unrecognised familial cardiac disease.