Role of Echocardiography in the Detection and Management of Air Pollution-Induced Cardiovascular Events in Urban Settings

Dear Editor,

Air pollution has been acknowledged as one of the major public health concerns, especially in urban areas globally.[1] In terms of cardiovascular consequences, air pollutants trigger chronic inflammation (leading to endothelial dysfunction and atherosclerosis).[1] At the same time, they also generate reactive oxygen species, which can damage blood vessels and augment the risk of hypertension because of persistent vasoconstriction and arterial stiffness.[2] Air pollution can alter heart rate variability (increasing the risk of arrhythmia and sudden cardiac deaths) and expedite the development of arterial plaques, leading to atherosclerosis and rise in the probability of thrombotic events.[1] In addition, air pollution can also contribute to left ventricular hypertrophy, heart failure, pulmonary hypertension, and the exacerbation of preexisting cardiovascular diseases.[1]

Echocardiography is an effective tool for detecting early cardiovascular changes resulting from air pollution.[3,4] To begin with, echocardiography aids in the detection of structural changes, such as left ventricular thickening and hypertrophy because of the increasing afterload.[3] Air pollution-induced inflammation and hypertension contribute to left atrial enlargement, which in itself is a predisposing factor for atrial fibrillation.[3] Similarly, pollutant-induced pulmonary hypertension enhances the workload on the right ventricle, causing hypertrophy.[4] Echocardiography can also detect functional changes, such as reduction in left ventricular ejection fraction resulting because of myocardial dysfunction.[3,4] As air pollution affects myocardial relaxation, patients can present with heart failure with preserved ejection fraction.[5] Finally, echocardiography can also evaluate vascular burden and hemodynamic changes, such as elevated pulmonary artery pressure.[2] Further, the presence of reduced coronary flow reserve is suggestive of early microvascular dysfunction, which makes the heart more prone to ischemia from air pollution-related oxidative stress.[2]

Regardless of the immense utility of echocardiography, the presence of some challenges has limited the optimization of the same.[3,4,5,6] The primary concern is that the limited access to echocardiography facilities and trained personnel, especially in low- and middle-income nations, makes the process of population screening difficult.[6] This can effectively be dealt with through expansion of public–private partnerships, deployment of mobile echocardiography units, and training of technicians to perform echocardiography in low-resource settings.[6] One of the practical concerns has been the variability in echocardiographic protocols, expertise of operators, and interpretation of markers. This will need the formulation of standardized protocols to detect these markers to promote consistency across different settings. In addition, regular workshops can be conducted for operators to sustain high-quality imaging and interpretation standards. Further, remote reading of echocardiograms by expert cardiologists (tele-echocardiography) can significantly improve diagnostic accuracy in underserved regions.[6]

In conclusion, echocardiography is an effective tool to detect early cardiovascular changes in urban populations exposed to high levels of air pollution. The presence of different echocardiographic markers in individuals exposed to air pollution provides significant insights into the cardiovascular consequences of air pollution, thereby aiding in early diagnosis, risk assessment, and timely implementation of public health interventions.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.