- Email: [email protected]
Identification of high risk long QT syndrome patients using mean Holter QTc
e18
of these are offered referral to a tertiary centre for assessment and screening for suspected heritable cardiac conditions. In Victoria, a unique team of nurses lead this system to ensure that all potentially at-risk families are offered the opportunity for clinical assessment and consultation. A specialist nurse employed by the Victorian Institute of Forensic Medicine (VIFM) has been instrumental in establishing a system whereby forensic pathologists have a simple way of flagging families requiring referral. This nurse is pivotal in contacting families, using clinical skills to ascertain important and relevant history and answering the questions of the family. Concurrently, specialist nurses are employed through Royal Melbourne Hospital (RMH) and Royal Children’s Hospital (RCH) to review, triage and action these referrals. They document/verify family histories, organise appropriate clinical screening and manage clinic bookings. All three groups work closely, cohesively and ‘share’ families to create a seamless model of care which is age appropriate and provides ease and equity of access to consistent care. Providing the first entry point into the hospital system, the nurse specialists are a pivotal part of a multidisciplinary team that provide a professional, yet comfortable way for families to approach the difficult issues which need to be explored. In addition to clinical service, the nurse relationship between VIFM, RMH and RCH has provided an effective platform for research studies and the translation of research findings into clinical practice. http://dx.doi.org/10.1016/j.hlc.2014.07.047
047 Identification of high risk long QT syndrome patients using mean Holter QTc K. Waddell-Smith 1,2,3,4*, J. Li 3, H. Hinds 4, J. Crawford 4, J. Skinner 1,4 1
Starship Children’s Hospital, Auckland, New Zealand The National Heart Foundation of New Zealand 3 The University of Auckland, Auckland, New Zealand 4 Auckland City Hospital, Auckland, New Zealand * Corresponding author. 2
Risk assessment in long QT syndrome (LQTS) relies on cardiac symptoms and serial QT length on 12 lead ECG. Waiting for these exposes the patient to risk. We hypothesised that mean QTc on a single Holter is superior to initial ECG in assessing risk. Methods: Patients included had possible LQTS and a Holter monitor with 24 hour beat-to-beat QTc analysis. There were 66 patients aged 10 months to 69 years: 32 KCNQ1 positive, 13 KCNH2 positive and 21 genotype negative relatives. Results were compared with normative data from 34 healthy individuals. A single cardiac technician analysed the QTcB (Bazett rate correction) between 40-120BPM (only) as recorded by LifeCard CF monitors and Del Mar Impressario software. The technique uses semi-automated measurement with manual correction and end QT defined by zero crossing point. On 12 lead ECG, the longest QTcB from lead II or V5 using the tangent technique was calculated.
Abstracts
Results: Mean Holter QTc>95th limit for gender (males: 443ms, females: 461ms) was more closely associated with cardiac events than QTc>500ms on first ECG, and was similar to the highest QTc recorded from any of the patient’s ECGs over 1845 patient years. Holter QTc
First ECG QTc
Highest
>95th limit
>500ms
ECG QTc
0.63
0.33
0.52
Sensitivity
0.29
0.06
0.64
Specificity
0.89
0.7
0.64
Positive Predictive Value
Conclusion: Mean Holter QTc (as described) identified those at highest risk better than initial ECG, and similarly to serial ECGs in LQT1 and LQT2. Replication in larger cohorts is suggested. http://dx.doi.org/10.1016/j.hlc.2014.07.048 048 The inpatient cardiology visit: Missing the opportunity to detect inherited heart conditions K. Waddell-Smith 1,2,3,4*, T. Donoghue 4, M. Graham 4, S. Oates 4, J. Crawford 4, J. Li 3, J. Skinner 1,3,4 1
Starship Children’s Hospital, Auckland, New Zealand The National Heart Foundation of New Zealand 3 The University of Auckland, Auckland, New Zealand 4 Auckland City Hospital, Auckland, New Zealand * Corresponding author. 2
Background: We hypothesised that cardiac inherited diseases (CID) frequently go undetected during hospital admission due to failure to take a thorough family history (FamHx). Methods: Two experienced cardiology nurses were educated in CID and employed as part-time regional CID registry coordinators within their tertiary adult cardiology services. Over a six month period they identified inpatients who were potentially affected by CID (such as non-ischaemic dilated cardiomyopathy (DCM) and resuscitated sudden cardiac death (RSCD)) and obtained a three generation family tree with focus on CID, heart failure and sudden death. Their findings were compared with the FamHx taken originally by ward medical staff. Results: 36 patients were identified (RSCD (14), DCM (13) other (9)). 21 (58%) had no documentation of FamHx during their index inpatient admission. Another 14 patients had some documentation of FamHx, although it was insufficient to either identify or exclude a familial basis for the presenting condition. Additional factual errors were noted in 4 patients (eg. failure to recognise an obligate LQTS carrier). Detailed three generation pedigree obtained by the trained representative revealed a probable genetic aetiology in 22 patients (61%; DCM (8), HCM (4), LQTS (1), other (6; 3 remain uncertain), and cascade screening is underway in these families. Conclusion: Family histories taken during inpatient cardiology admission are usually either absent or inaccurate. The appointment of dedicated CID staff, and obtaining a full
of these are offered referral to a tertiary centre for assessment and screening for suspected heritable cardiac conditions. In Victoria, a unique team of nurses lead this system to ensure that all potentially at-risk families are offered the opportunity for clinical assessment and consultation. A specialist nurse employed by the Victorian Institute of Forensic Medicine (VIFM) has been instrumental in establishing a system whereby forensic pathologists have a simple way of flagging families requiring referral. This nurse is pivotal in contacting families, using clinical skills to ascertain important and relevant history and answering the questions of the family. Concurrently, specialist nurses are employed through Royal Melbourne Hospital (RMH) and Royal Children’s Hospital (RCH) to review, triage and action these referrals. They document/verify family histories, organise appropriate clinical screening and manage clinic bookings. All three groups work closely, cohesively and ‘share’ families to create a seamless model of care which is age appropriate and provides ease and equity of access to consistent care. Providing the first entry point into the hospital system, the nurse specialists are a pivotal part of a multidisciplinary team that provide a professional, yet comfortable way for families to approach the difficult issues which need to be explored. In addition to clinical service, the nurse relationship between VIFM, RMH and RCH has provided an effective platform for research studies and the translation of research findings into clinical practice. http://dx.doi.org/10.1016/j.hlc.2014.07.047
047 Identification of high risk long QT syndrome patients using mean Holter QTc K. Waddell-Smith 1,2,3,4*, J. Li 3, H. Hinds 4, J. Crawford 4, J. Skinner 1,4 1
Starship Children’s Hospital, Auckland, New Zealand The National Heart Foundation of New Zealand 3 The University of Auckland, Auckland, New Zealand 4 Auckland City Hospital, Auckland, New Zealand * Corresponding author. 2
Risk assessment in long QT syndrome (LQTS) relies on cardiac symptoms and serial QT length on 12 lead ECG. Waiting for these exposes the patient to risk. We hypothesised that mean QTc on a single Holter is superior to initial ECG in assessing risk. Methods: Patients included had possible LQTS and a Holter monitor with 24 hour beat-to-beat QTc analysis. There were 66 patients aged 10 months to 69 years: 32 KCNQ1 positive, 13 KCNH2 positive and 21 genotype negative relatives. Results were compared with normative data from 34 healthy individuals. A single cardiac technician analysed the QTcB (Bazett rate correction) between 40-120BPM (only) as recorded by LifeCard CF monitors and Del Mar Impressario software. The technique uses semi-automated measurement with manual correction and end QT defined by zero crossing point. On 12 lead ECG, the longest QTcB from lead II or V5 using the tangent technique was calculated.
Abstracts
Results: Mean Holter QTc>95th limit for gender (males: 443ms, females: 461ms) was more closely associated with cardiac events than QTc>500ms on first ECG, and was similar to the highest QTc recorded from any of the patient’s ECGs over 1845 patient years. Holter QTc
First ECG QTc
Highest
>95th limit
>500ms
ECG QTc
0.63
0.33
0.52
Sensitivity
0.29
0.06
0.64
Specificity
0.89
0.7
0.64
Positive Predictive Value
Conclusion: Mean Holter QTc (as described) identified those at highest risk better than initial ECG, and similarly to serial ECGs in LQT1 and LQT2. Replication in larger cohorts is suggested. http://dx.doi.org/10.1016/j.hlc.2014.07.048 048 The inpatient cardiology visit: Missing the opportunity to detect inherited heart conditions K. Waddell-Smith 1,2,3,4*, T. Donoghue 4, M. Graham 4, S. Oates 4, J. Crawford 4, J. Li 3, J. Skinner 1,3,4 1
Starship Children’s Hospital, Auckland, New Zealand The National Heart Foundation of New Zealand 3 The University of Auckland, Auckland, New Zealand 4 Auckland City Hospital, Auckland, New Zealand * Corresponding author. 2
Background: We hypothesised that cardiac inherited diseases (CID) frequently go undetected during hospital admission due to failure to take a thorough family history (FamHx). Methods: Two experienced cardiology nurses were educated in CID and employed as part-time regional CID registry coordinators within their tertiary adult cardiology services. Over a six month period they identified inpatients who were potentially affected by CID (such as non-ischaemic dilated cardiomyopathy (DCM) and resuscitated sudden cardiac death (RSCD)) and obtained a three generation family tree with focus on CID, heart failure and sudden death. Their findings were compared with the FamHx taken originally by ward medical staff. Results: 36 patients were identified (RSCD (14), DCM (13) other (9)). 21 (58%) had no documentation of FamHx during their index inpatient admission. Another 14 patients had some documentation of FamHx, although it was insufficient to either identify or exclude a familial basis for the presenting condition. Additional factual errors were noted in 4 patients (eg. failure to recognise an obligate LQTS carrier). Detailed three generation pedigree obtained by the trained representative revealed a probable genetic aetiology in 22 patients (61%; DCM (8), HCM (4), LQTS (1), other (6; 3 remain uncertain), and cascade screening is underway in these families. Conclusion: Family histories taken during inpatient cardiology admission are usually either absent or inaccurate. The appointment of dedicated CID staff, and obtaining a full