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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 4, July/August 2020
180
AFRICA
Family screening in black patients with isolated left
ventricular non-compaction: the Chris Hani Baragwanath
experience
Anneen L Basson, Mohammed R Essop, Elena Libhaber, Ferande Peters
Abstract
Background:
Isolated left ventricular non-compaction
(ILVNC), dilated cardiomyopathy (DCMO) and hypertrophic
cardiomyopathy (HCM) are diseases that may be present in
family members of patients with ILVNC. The primary aim
of this study was to identify the prevalence and spectrum
of cardiomyopathy in first-degree relatives of patients with
ILVNC. A secondary aim was to compare a strategy of clini-
cal screening, utilising only a clinical assessment and electro-
cardiogram (ECG), compared to one that included echocar-
diography for screening of family members of patients with
ILVNC.
Methods:
Eighty-three close relatives of 38 unrelated patients
from the ILVNC clinic at the Chris Hani Baragwanath
Hospital underwent a detailed clinical history, physical exam-
ination, ECG and echocardiogram.
Results:
Echocardiographic screening revealed unexplained
left ventricular (LV) dysfunction in 10 (12.05%) relatives. Nine
out of the 10 individuals satisfied the criteria for diagnosis
of DCMO. No cases of HCM or LVNC were identified. A
strategy of clinical assessment and ECG had a sensitivity
of 76% and a specificity of 42% versus the gold standard of
echocardiographic screening.
Conclusion:
Echocardiographic screening detected DCMO
in 10.8% of subjects. A strategy of clinical screening that
included electrocardiography was sub-optimal as a screening
strategy compared to echocardiographic screening.
Keywords:
family screening, left ventricular non-compaction
Submitted 8/4/19, accepted 29/1/20
Published online 11/3/20
Cardiovasc J Afr
2020;
31
: 180–184
www.cvja.co.zaDOI: 10.5830/CVJA-2020-003
Isolated left ventricular non-compaction (ILVNC) is a primary
myocardial disorder that is presumed to be genetic, according to
the American Heart Association.
1
The term isolated is used when
there is no evidence of accompanying congenital, valvular or
associated cardiomyopathy disorders. The prevalence of ILVNC
in sub-Saharan Africa is not clearly defined. Peters
et al.
found
in their series that 6.9% of patients in a tertiary cardiomyopathy
clinic had ILVNC.
2
Clinical findings are variable, ranging from
patients with asymptomatic disease to symptomatic patients who
develop congestive cardiac failure, arrhythmias, thromboembolic
events and sudden cardiac death.
3
ILVNC, dilated cardiomyopathy and hypertrophic cardio-
myopathy are diseases that may be present in family members
of patients with ILVNC. Hence, early identification of family
members may offer the opportunity for early detection of
complications of LVNC (such as arrhythmias and thrombi),
dilated cardiomyopathy and hypertrophic cardiomyopathy.
These individuals may require intervention with appropriate
therapy, which may translate into a potential benefit.
The aim of this study was to identify, during family screening,
the prevalence and spectrum of cardiomyopathy in family
members of patients with ILVNC. A secondary aim was to
determine the value of clinical screening, which utilises only a
clinical assessment and electrocardiogram (ECG), compared
with screening using echocardiography.
Methods
This retrospective study was undertaken at the Left Ventricular
Non-compaction Clinic, Chris Hani Baragwanath Hospital, on
existing clinical and echocardiographic records of first-degree
relatives of known patients with ILVNC. From January 2014
until July 2016, first-degree relatives of patients diagnosed
and followed up for ILVNC were invited to undergo family
screening.
After providing voluntary informed consent, family members
underwent a detailed clinical history. The family history was
considered abnormal if it was positive for non-ischaemic heart
failure, cardiomyopathy, documented supraventricular or
ventricular arrhythmias, or pacemaker/implantable cardioverter–
defibrillator placement. Thereafter, they underwent a clinical
examination followed by a resting ECG. The ECG was analysed
to measure the heart rate, and P-R, QRS and Q-T intervals.
The ECG was considered abnormal if it showed pathological Q
waves (> 40 ms or > 25% R waves in ≥ two leads), abnormal axis,
left ventricular hypertrophy, complete bundle branch block, or
non-specific intraventricular conduction delay.
A transthoracic echocardiogram was performed on all
subjects who were screened according to a standardised protocol
by three experienced, accredited sonographers using a Philips
IE 33 system, equipped with a standard S5-1 transducer. The
images were obtained according to a standardised protocol.
The data were transferred and analysed offline using Xcelera
workstation (Philips). All linear and volumetric chamber
Charlotte Maxeke Johannesburg Academic Hospital,
University of the Witwatersrand, Johannesburg, South Africa
Anneen L Basson, MB ChB, Dip HIV (SA), FCP (SA),
alzbas@yahoo.comMohammed R Essop, MB BCh, FACC, FCP (SA), MRCP
Elena Libhaber, BSc, MSc, PhD
Ferande Peters, MB BCh, FCP (SA), Cert Cardio (SA)