Left ventricular remodeling and its correlates among adolescents with perinatally acquired HIV in South Africa.

BACKGROUND: Left ventricular (LV) remodeling and its transitions from compensatory adaptations to LV dysfunction have not been examined in adolescents with perinatally acquired HIV infection (PHIV). We used cardiovascular magnetic resonance (CMR) in a cross-sectional study to characterize PHIV-related progressive LV remodeling in adolescents in South Africa. METHODS: Adolescents with PHIV on antiretroviral treatment and their HIV uninfected peers completed 3 T CMR examination. We defined LV remodeling by LV mass/volume (M/V) ratio, modelling progressive LV remodeling as increasing M/V ratio. Linear regression models were applied to estimate the correlates of progressive LV remodeling. RESULTS: Overall, 71 adolescents with PHIV [mean age: 15.2 years; 54% male] and 36 HIV uninfected [15.1 years; 42% male] peers were enrolled. Adolescents with PHIV had lower mean LV M/V ratio (0.68 vs. 0.75 g/mL; p = 0.004) than HIV uninfected peers, without LV hypertrophy in either group. Among adolescents with PHIV, increasing M/V ratio was accompanied by increasing interstitial volume [adjusted mean change (AMC) per 0.1 g/mL M/V ratio: 1.75 mL, p < 0.001] with no change in global circumferential strain (GCS) [AMC per 0.1 g/mL M/V ratio: -0.21%, p = 0.48]. However, in HIV uninfected individuals, increasing M/V ratio was accompanied by increasing peak GCS [AMC per 0.1 g/mL M/V ratio: -1.25%, p = 0.039] with no change in interstitial volume (AMC per 0.1 g/mL M/V ratio: 1.16 mL, p = 0.32]. CONCLUSIONS: Successfully treated PHIV is associated with less severe LV remodeling in adolescence when compared to HIV uninfected controls. LV remodeling in PHIV is associated with disproportionate expansion of the non-contractile interstitium not accompanied by improved GCS.

Cardiovascular imaging modalities in the diagnosis and management of rheumatic heart disease.

Rheumatic heart disease (RHD) is prevalent in sub-Saharan Africa, where the capacity for diagnosis and evaluation of disease severity and complications is not always optimal. While the medical history and physical examination are important in the assessment of patients suspected to have RHD, cardiovascular imaging techniques are useful for confirmation of the diagnosis. Echocardiography is the workhorse modality for initial evaluation and diagnosis of RHD. Cardiovascular magnetic resonance is complementary and may provide additive information, including tissue characteristics, where echocardiography is inadequate or non-diagnostic. There is emerging evidence on the role of computed tomography, particularly following valve replacement surgery, in the monitoring and management of RHD. This article summarises the techniques used in imaging RHD patients, considers the evidence base for their utility, discusses their limitations and recognises the clinical contexts in which indications and imaging with various modalities are expanding.

Diagnosing cardiac disease during pregnancy: imaging modalities.

Pregnant women with known or suspected cardiovascular disease (CVD) often require cardiovascular imaging during pregnancy. The accepted maximum limit of ionising radiation exposure to the foetus during pregnancy is a cumulative dose of 5 rad. Concerns related to imaging modalities that involve ionising radiation include teratogenesis, mutagenesis and childhood malignancy. Importantly, no single imaging study approaches this cautionary dose of 5 rad (50 mSv or 50 mGy). Diagnostic imaging procedures that may be used in pregnancy include chest radiography, fluoroscopy, echocardiography, invasive angiography, cardiovascular computed tomography, computed tomographic pulmonary angiography, cardiovascular magnetic resonance (CMR) and nuclear techniques. Echocardiography and CMR appear to be completely safe in pregnancy and are not associated with any adverse foetal effects, provided there are no general contra-indications to MR imaging. Concerns related to safety of imaging tests must be balanced against the importance of accurate diagnosis and thorough assessment of the pathological condition. Decisions about imaging in pregnancy are premised on understanding the physiology of pregnancy, understanding basic concepts of ionising radiation, the clinical manifestations of existent CVD in pregnancy and features of new CVD. The cardiologist/physician must understand the indications for and limitations of, and the potential harmful effects of each test during pregnancy. Current evidence suggests that a single cardiovascular radiological study during pregnancy is safe and should be undertaken at all times when clinically justified. In this article, the different imaging modalities are reviewed in terms of how they work, how safe they are and what their clinical utility in pregnancy is. Furthermore, the safety of contrast agents in pregnancy is also reviewed.