Global Health, Sept 2012.
Conditions That Predispose to Pulmonary Hypertension and Right Heart Failure in Persons Exposed to Household Air Pollution in LMIC
G Bloomfield, et al.
Emerging evidence and research based on ambient air pollution also implicates HAP in the development of cardiovascular diseases such as myocardial ischemia, high blood pressure, and congestive heart failure, as well as with elevated right heart pressures 7, 8, 9. Cardiopulmonary diseases such as pulmonary hypertension (PH) and right heart failure (RHF) are common in LMIC and are often associated with human immunodeficiency virus (HIV), schistosomiasis, parenchymal destruction from tuberculosis, COPD, and other conditions common in LMIC 5, 10. Little is known, however, about the interplay between HAP, right heart function, and these common comorbidities in LMIC. Understanding these relationships is important so that the magnitude of the effect of HAP on PH and right heart function is understood and appropriate measures are taken to reduce the associated morbidity.
This review begins by highlighting what is known about the common causes of PH in LMIC using the international PH classification framework and highlighting conditions specific to LMIC. We then discuss HAP and its relationship to PH and RHF. Based on the disproportionate distribution of PH and RHF worldwide, we propose that the presence of certain comorbidities specific to LMIC may predispose individuals exposed to HAP to developing PH and RHF (Fig. 1). Where data are available, we review the literature regarding the effects of pre-existing comorbidities on the impact of exposure to HAP on PH and subsequent RHF in LMIC. Where data are lacking, we present a conceptual framework of the unique comorbid factors in LMIC that may predispose people to developing PH and RHF when exposed to HAP. Lastly, we suggest that a small proportion of patients exposed to HAP who develop isolated RHF may have no other predisposing factors and this group of patients deserves further study. By offering this conceptual framework on conditions specific to LMIC, HAP, PH, and RHF, our ultimate aim is to highlight the multifactorial nature of these complex relationships and suggest ripe avenues for further investigation.
