Cardiovascular Journal of Africa: Vol 30 No 4 (August 2019)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 4, July/August 2019 216 AFRICA
Unmasking right ventricular dysfunction in chronic
rheumatic mitral regurgitation
Ruchika Meel, Ferande Peters, Elena Libhaber, Mohammed R Essop
Abstract
Aims: Right ventricular (RV) systolic function is an impor-
tant predictor of mortality but has been poorly studied in
chronic rheumatic mitral regurgitation (CRMR). We studied
RV systolic function using speckle-tracking echocardiography
(STE) in patients with CRMR.
Methods: Seventy-seven patients with CRMR and 40 healthy
controls were enrolled in a cross-sectional study at Chris Hani
Baragwanath Hospital between January and October 2014.
RV peak systolic strain (PSS) and left ventricular (LV) global
longitudinal strain (GLS) were measured using Philips Qlab
9 STE software.
Results: RVPSS was lower in CRMR patients compared to
the controls (–16.8 ± 4.5 vs –19.2 ± 3.4%, p = 0.003) with no
difference in conventional RV systolic function parameters
( p = 0.39). RVPSS was lower in severe CRMR compared to
moderate CRMR patients (–14.3 ± 4.23 vs –18 ± 4.18%, p <
0.0001). CRMR patients with LV systolic dysfunction had a
greater reduction in RVPSS and LVGLS compared to those
with preserved LV systolic function (p = 0.001). LVGLS and
significant tricuspid regurgitation (TR) were independent
predictors of RVPSS (p < 0.001).
Conclusion: In CRMR patients, RVPSS was a more sensitive
marker for detecting earlier RV systolic dysfunction than
traditional RV functional parameters.
Keywords: right ventricle, rheumatic mitral insufficiency, speckle-
tracking echocardiography
Submitted 15/12/18, accepted 16/4/19
Published online 24/5/19
Cardiovasc J Afr 2019; 30: 216–221
DOI: 10.5830/CVJA-2019-020
Systolic dysfunction of the right ventricle (RV) is a known
predictor of mortality after acute myocardial infarction or
coronary artery bypass grafting, and in heart failure and
primary pulmonary hypertension (PHT).1-4 In addition to left
ventricular (LV) parameters, RV systolic function provides
adjunctive information in the decision-making process regarding
surgical intervention in mitral regurgitation (MR).5,6
Pre-operative RV function is an important determinant of
intra-operative and postoperative outcomes in MR and therefore
has prognostic implications.5,7 Additionally, RV dysfunction
may have important implications in terms of predicting greater
haemodynamic impairment of the LV and secondary PHT due
to MR.8,9 Furthermore, it has been suggested that there may be
direct involvement of the RV by the rheumatic process, resulting
in necrosis of the myocytes, fibrosis and calcification of the
myocardium, with resultant RV dysfunction.10
Recently, newer imaging techniques such as speckle-tracking-
derived RV strain have emerged, which offer several advantages
over traditional echocardiographic parameters for assessing
overt and subclinical RV systolic dysfunction.6,10,11,12,13 There are
no studies that have assessed RV function in chronic rheumatic
mitral regurgitation (CRMR). We therefore aimed to (1) study
RV systolic function using speckle-tracking echocardiography
(STE) in patients with CRMR; and (2) determine the predictors
of RV free-wall peak systolic strain (PSS) in CRMR.
Methods
We conducted a cross-sectional study at the Chris Hani
Baragwanath Academic Hospital. Patients were enrolled
between January and October 2014. All patients were screened
and patients deemed to have moderate or severe CRMR were
referred for possible inclusion in the study. A total of 91 patients
with presumed CRMR underwent clinical evaluation, resting
electrocardiogram and detailed echocardiographic assessment
according to a pre-determined protocol.
The inclusion criteria were patients aged 18 years or older
with echocardiographic features of moderate or severe CRMR.
Patients were excluded if they had significant aortic valve
disease, concurrent mitral stenosis with a valve area of less
than 2 cm2, documented ischaemic heart disease, pre-existing
non-valvular cardiomyopathy, prior cardiac surgery, congenital
or pericardial disease, pregnancy, severe systemic disorders
such as renal failure, uncontrolled hypertension (systolic blood
pressure > 140 mmHg and diastolic blood pressure > 90 mmHg),
were on medication or had severe anaemia (haemoglobin < 10 g/
dl). Fourteen patients were excluded due to the following: atrial
fibrillation, anaemia, renal dysfunction and inadequate image
quality.
The final sample included 77 patients. Forty age- and
gender-matched controls were also included in the study. All
healthy volunteers with no known diseases and adequate
echocardiographic windows were recruited from the community
following an advertisement for the study. A tolerance of five
years was allowed for age matching. The study was approved
by the University of the Witwatersrand Ethics Committee
(M140114).
Division of Cardiology, Chris Hani Baragwanath
Academic Hospital and University of the Witwatersrand,
Johannesburg, South Africa
Ruchika Meel, MB ChB, MMed (Int Med), Cert Card (SA), PhD,
Ferande Peters, MD
Elena Libhaber, PhD
Mohammed R Essop, MD